Turbocharged Single 450cc

[claas900]

Hello, I've been searching the forms for the last few days, tho I have found a lot of answers, the posts that really had the info I was looking for were older post and I wanted to know if there was anything more current?
Heres what I've got. Its a 432cc Cannondale ATV. I do have it turbo'd and just got It running. Right now where in the early stages of tuning. The turbo is a vz21 I believe? Its smaller then a GT12.
Of course I'm looking for max drag race power, my rev limiter now is set at 10,500rpm tho I can take it to 11,800rpm I'm just being safe with it now.
The motor as it sits w/out the turbo makes 50hp to 52hp at the wheels, on a Dynojet Dyno.
So I have some random questions to ask?
#1 I know you guys have to run a restrictor. Do you guys ever get to just run it wide open just to see what you can get out of it?
#2 I've read on a single you have to have a intake plenum space at least twice the size of the motor, I'm around 3x the volume. This does make scents to me but I would think the same thing would apply to the exhaust side as well?
#3 I see you guys run the GT12 and some the GT15. A lot of ATV guys run the GT20 or GT22, I think its for the big exhaust pulses. I'd think with a larger exhaust volume you could run a smaller turbo?

[Kirk Feldkamp]

The questions aren't that random, but they'd be a lot easier to answer with some context. Do you have any real problems with what you're running now, or are you wondering if you're actually having problems? In FSAE, turbochargers aren't necessarily used to increase power in the same ways that they are in "normal" applications. The turbos that are commonly used (GT12, GT15V, etc) actually have the same flow capability as the unmodified engines, so removing the restrictor won't really show you anything. In other words, a turbo in FSAE is more about power recovery than it is about making power beyond stock.

Don't get too out in the weeds thinking about exhaust "plenum" volumes. While you may have some benefit to doing an exhaust plenum, it would be helpful to hear what issues you're actually having now. People tend to mistake fuel and/or ignition tuning issues with design problems with the turbo hardware... which is less often the case. In fact, if things are sized right with an exhaust plenum, I would bet you'd get into boost earlier in the RPM band than with an exhaust plenum.

The question of turbo selection is fairly simple. Do you have a power goal and budget in mind? If you have measured the actual output of your engine, then you're already further along than most people are when they start the matching process.

-Kirk

[claas900]

At this point, I cant say I really have a known problem. I'm just not %100 sure I'm on the right track and wanted to know other people's thought. It hasn't been running very long, but we are just data logging, tps,boost,rpms and AFR. Once we get it tuned in better I'm going to do a pressure test on the exhaust side and compare it to the boost side. I've read if its 1 to 1 ratio then I'm ok?
My power goal would be between 80hp to 90hp at the wheels. I have another Cannondale ATV built to 495cc with 62hp at the wheels. If my turbo 432cc will out run my 495cc bike then I know I've made more power and at the point will dyno it again. If not then I know I've got to do something with the turbo. One of the reasons I'm here to see what people will say and or what I can do to improve my setup.
When I had read about intake plenum volumes it had got me thinking about the exhaust side as well. If with a single cylinder you should have 2 to 4x plenum volume, is there a rule of thumb for the exhaust side as well? Thanks

[Kirk Feldkamp]

Is this being tuned with a carb or fuel injection? You're logging most of the right stuff. EGT is the only other thing I'd keep and eye on, but that's more of a turbo safety thing than anything (to make sure you don't melt the turbine). 90 hp would be a pressure ratio of about 1.8... or maybe 2.0 after realistic losses in the intake tract. This would mean you'd need about 15psi at the compressor to meet your goals. The map of the RHF3 that I found should do that with reasonable margins.

If I were you, I would do my tuning on the dyno rather than by the seat of my pants. Load variations that occur because of changes in traction/hills/bumps/etc in the real world can cause non-linearities to get built into the tuning, and potentially cause problems. Also, you really have very little way of standardizing the loading between runs, so comparing (and optimizing) results on the level will be difficult at best.

Finally, the reason we use intake plenums in FSAE is somewhat different than the reason you'd use one for a non-drawthrough application. The sizing of the intake plenum in your case will have no effect in relation to why we talk about it. The only reason exhaust plenums are usually ever discussed is in relation to odd-firing interval or V-twin engines (such as on a Harley). In your case, you have strong and even pulses, so an exhaust plenum probably isn't necessary or recommended.

-Kirk

[claas900]

It's EFI. I'm using a Zeitronix Zt-2 data logger. My waste gate is set at 8psi. Thats funny you said I'd need about 15psi my engine builder said he thought I'd need about 15psi as well.
I do agree with you on the dyno. But my dyno guy wants $350 to tune it. And with me being so unsure of my set up I didn't want to spend the money on it just yet. This is the first known Cdale turbo build and where not sure how the motor is going to hold up. I'm not %100 sure my turbo is right. When I do data log I get everything warmed up then make a long run. Most times ill just stick it in 4th or 5th gear plus its geared very tall so i get a nice long pull. I think it will get me close enough to know if I'm on the right track or not.
If it will out run my 62hp bike I'll know I've made more power and just go from there.
Some people do use the RHF3, but I've heard its limited to 10psi, after that the shafts break.
My engine builder just got a Dyno, and I know he'll dyno it for next to nothing just to have the info. But I'm in Ca. he's in Pa.
From what I've read guys will run the GT12,RHF3,GT20,GT22 or GT28. So that's quite a range on what everyone says "works." I've really thought about just getting some used turbos and getting them all to enter change on the bike and just sending everything to my builder in Pa. and let him go for it.
When you say pressure ratio of 1.8 to 2.0 I'm not sure I know what that means? Thanks again I do appreciate the conversion.

[Kirk Feldkamp]

Where in CA are you? $350 for a complete dyno session is actually fairly cheap. What do you get for the money? The other way to look at paying for dyno time is you can either pay the money and be somewhat gentler to the motor... or accept a higher risk of popping the thing by not tuning it properly. For most of these singles, a failure of most any component has the potential of wiping out most of the expensive parts of the motor... which is going to cost you a LOT more than $350 to fix.

Areas to look out for on these sorts of engines are going to be rods and pistons. The rods are usually fairly lightened up for efficiency reasons, but that tends to mean you don't have a heck of a lot of head room to go above the stock power level. If you can get a high quality after market part like a Carillo or something in there, that's probably a better bet. The pistons for the thumpers tend to be pretty non-optimal for turbos too. I would think the thinner skirts and smaller rings can limit the heat transfer out of the piston. If there's any way to add an oil squirter jet to cool the bottom of the piston, that could help tremendously too. Furthermore, the pistons tend to be pretty damn large in diameter and have higher crowns, which both tend to limit the homogeneity of the charge near the edges of chamber. You may have to end up running richer lambdas (AFR's) to compensate for potential lean pockets at the edges of the chamber. Hopefully you've done your due diligence and lowered the compression of the engine already to deal with what you're about to do to it. If not, it's not rocket surgery to cut the dome down to lower the CR, and you can get 'er dun on a mill with some careful measuring/cutting. Alternatively, a cylinder spacer might be the hot ticket, but you'll have to keep an eye out on the cam chain setup to make sure that's still going to work with everything spaced out.

8psi should get you in the 75hp ballpark with proper tuning.

Whoever told you about the 10psi limit on a RHF3 is probably a goon. The shaft breaks?! Yeah right... they probably just didn't feed it enough oil or oversped the thing. So you know, the pressure ratio (PR) is simply the absolute pressure at the compressor outlet divided by the absolute pressure at the compressor inlet. The RHF3 compressor map shows it can go to a maximum pressure ratio of about 2.7(~25psi boost at sea level), but has a useable range of about 2.5 (~22psi boost at sea level). If you really cranked the boost and intercooled the hell out of it and everything held together, you could probably get 115 to 125hp out of that turbo on that motor. This is all based on pretty low fidelity compressor maps I've found online, so take those numbers with a grain of salt.

At any boost level, just be very aware of your ignition timing and the onset of any detonation. Keep diligently reading the plugs to make sure you're not seeing any signs of detonation. My guess is your main failures if you get into detonation will be breaking delicate piston parts... be it rings, ring lands, skirts, or valve pockets.

[claas900]

I'm in Hanford, about 45 min south of Fresno. The $350 if for fuel tune only no ignition. That was also a none turbo motor, so I'd guess it'd only be more with a turbo?
The motor has a stock rod, tho its not a Carillo rod it is a H-beam style, very strong rod for a factory rod. We are using a stock piston that has been dished out a little. Stock CR is 11.5 I think it was? Not sure what the new compression is. Theses motors stock have a piston squirter. But I did increase the oil pressure from 2.0 psi at idle to about 4 psi and from 4.5 psi at rev to 7 psi at rev.
The stock cam timing is 106 intake and 106 exhaust. Tho we have learned over the years that if we keep cam timing separation of 2 to 3 degrees with the intake always being higher yields the best peak and most usable power curve. Its been a wile but I think my turbo motor has 118 intake and 115 exhaust. Witch is some unheard of numbers for our motors but the builder thought it would work good with a turbo.
I am able to talk to the stock ECU and did take out 6 degrees of timing starting at 3,500 rpms across the broad to be safe.
I also wanted to add I found this wile doing some research The motor he is using is a Honda 400ex ""The turbo is a TD04-9b off a dodge colt turbo, I tried a IHI-rhf3 ballbearing turbo but it was way too small, it would make 1psi of boost at idle and 15psi just revving it up, there was some great off idle torque, but that was it. The exhaust side of the turbo just didn't flow enough to make any top end horsepower. The 9b is still almost a bit small as it builds 5psi just driving up the road at any speed in any gear. At 45mph it is boosting all the time and really want to go""
It's kinda funny the way he talks about the IHIrhf3 is almost the way mine is responding, tho mine is so pig rich right now,10.2 afr I dont want to say to much. Its hard for me to find the time to really spend tuning it.

[B Lewis @ PE Engine Management]

Hi claas900,

What are you able to change in the stock ECU? If you are interested in moving to a complete stand alone engine control system (fuel, ignition, data logging, etc) we have one that we have been using a lot on quads with a lot of success (YFZ450R, LTR450, KFX450, Raptor 700, etc).

Contact me offline if you are interested in talking about this further (513-300-6768).

Good luck with your project.

[claas900]

Its uses the GP Control SAGEM MC1000 ECU. I can change everything with it, fuel, ignition,reset TPS, and more things then a person should be able to mess with the only thing I cant do with it is Live tuning and data logging. So for fuel control I use the PCV and Zeitronix Zt-2 data logger. I have ran across your sight in the past, sounds like a good cool product. Thanks

[B Lewis @ PE Engine Management]

Sounds like a cool project. We have been working on a 500cc land speed bike for a customer that makes about 25 psi of boost on alcohol running staged injection with the EDGE system. Turbos on small motors can be a lot of fun.

If you need any help let us know. Good luck with your build.

[claas900]

Thanks. As with most projects they always take way to long. In one hand I hate a 6 day work week, but in the other it lets me afford the project. Thanks Again I will keep you guys posted.

[claas900]

I wanted to give you guys an update. The turbo I had on there turned out to be way to small, the bike just wouldn't rev past 8,600 rpm. The exhaust side was just way to small, in the end I lost a piston from it swelling to large in the bore.
So I did drop in a new piston, and picked up a Td04 turbo from a 04 Subaru wrx. At first it wouldn't build more then 5 lbs of boost, then I learned the WG was just bouncing off its seat, from the large exhaust pluses so as a test I tied it shut. Now I see 9 lbs at 10,000 rpm. I have the rev limiter set at 10k to be safe but can take it up to 12k. Right now I have about 3 lbs at 6k and 5 lbs at 8k.
So the boost comes on a little late, tho with a 12k rev limiter I'm sure I'd have even better boost. But my problem is with the WG tied shut I'm not able to control boost, with that being said I'd like to see 15 lbs of boost. So I'm sure my exhaust side of the turbo is a little to large.

[claas900]

I just wanted to give this an update. I've sent the motor and turbo to my builder in Pa. I was able to talk to a Yamaha turbo builder in person witch was very nice beings I"ve never seen or talked to anyone in person about a turbo single. He said I did need an air box plenum 6 times the size of motor, so a box of 160cu in. So I added a box but have never ran it with it.
The engine builder said he should have it in a frame this weekend, he will dyno it with the air box and with out, I also sent him a few different turbo combos to try out. So I'm pretty excited and cant wait for his call.

[JWard]

Any more updates?

[claas900]

Hello, right now its putting down 75hp, and 41ft-lbs at around 13lbs of boost. We ran it w/out the air box and it still put down 75hp but torque was down to 38 ft-lbs and the power curve w/out the box was very steep and short, with the box nice and fat along with a nice and flat curve plus it took off half a sec. on the pull. With out the box we'd say we avg. 64hp threw the gears, with the box about 70hp threw the gears.
From what I have read, you need an air plenum of 4x to 6x times the size of motor 8x max. So I'd need a box 160 cubic inch. We had a stock box handy so thats what we ran just to test it. The stock box is 231 cubic inch,8.75 bigger then my motor. So now I need to fab a real box.
I think right now where running VP C14 race fuel, we have C16 on hand but we lost 2hp with it. So all that means is theres still more to be had and where with in the range of the C14 fuel.
We have another turbo where going to try, its just a little bit larger. Where really wanting 85hp but we'll see. If the larger turbo helps then we might go even larger.

[claas900]

I'm sorry its 11.5 lbs of boost not 13lbs.

[Kirk Feldkamp]

Which turbo did you end up using to generate these results? Have you used it in a vehicle yet, or is this all just on the dyno? If you used the TD04, the boost response in the vehicle may not be as awesome as your dyno numbers might suggest.

[claas900]

The one with 75hp is a Td04-9b from a 3000gt, We would like it to spool sooner.
The 2nd one we have is a Td04L-13t from a WRX,at this time its a bust. Wont spool soon enough.
I'm not a master on turbos by anymeans. But the TD04 doesnt seem to far off from spec vs the Gt20, I cant figure for the life of me how the Honda 450r guys get them to spool.
The only thing that comes to mind is we have different cam timing.
The guys that run the gt12 use them for play bikes and not drag bikes.

[Mbirt]

I think your cylinder head is holding you back at this point. Notice how much power the Racer's Edge AZ turbo 450r is making "off-boost" in this video:
http://www.youtube.com/watch?v...eVgU&feature=related (http://www.youtube.com/watch?v=yuXdmvreVgU&feature=related)

[claas900]

I've seen that video. That bike is a 575cc I'd guess he's around 75-80hp N/A.
Mine's a 432cc with a ported head,puts out about 50-52hp N/A I know my head will support 65hp on a 505cc N/A. A few guys have NOS with around 73hp.
I really dont think the head is my problem, it's either the cam timing or my turbo just isnt right?
Would you guys think my turbo is really that far off?

[Kirk Feldkamp]

In my experience, it's pretty rare for a head to truly limit a turbocharged setup. Sure, it can hold things back to some degree, but you can more often than not just turn up the wick ("moar boooost!") to find more power. In general, your limits for a turbo setup will be the choke and surge limits of the compressor, and the turbine power generation and choke flow.

Ok, some simple calculations... If you're making 75hp at 11.5psi boost, that's a pressure ratio (PR) of ~1.78. If you were able to have 100% efficiency and zero losses through your intake system, that would suggest that you could get 1.78 * (50 to 52hp) = 89 to 92.5 hp. Obviously this isn't the case. The real indicator of your new power output is not your PR, however, it's the density ratio. What your power ratio (new/old power... in this case 75/50 = 1.5) indicates is that you're probably losing a fair amount of density simply by heating the intake air unnecessarily. With enough intercooling and attention to the intake geometry, it's actually possible to make the density ratio meet or exceed the pressure ratio (mre on that later). In this case, my guess is that the way oversized turbo is operating *far* from it's peak efficiency region. Assuming the TD04 is close to the GT20 (which I think is false... i think it's even bigger than the GT20), take a look at where this plots on the compressor map from the Garrett site ( PERFORMANCE MAP (http://turbobygarrett.com/turbobygarrett/turbocharger) - click on the red "performance map" tab in the middle of the GT2052(1) page) A common, reasonable assumption is that for every 100hp you have roughly 10lb/min of airflow on gasoline. You can do the math, it's fairly straightforward, but in most cases this is reasonably close for most estimates. In other words, in this case, you're looking at ~7.5lb/min at a pressure ratio of ~1.8. Yes, that puts you smack dab on the surge line for all three of the GT2052 variants. This indicates even with that (smaller) GT20 turbo, you're already too big! How have you determined the TD04 is analogous to the GT20? Have you found legitimate compressor and turbine maps for that turbo? That's really going to be the only way to make that call confidently.

Honestly, for this setup, I would absolutely recommend the GT12. Do the same thing I just did above on the GT12 (follow the same link as above, but look at the GT1241). See? Both the compressor and the turbine will operate in much more efficient regions of the maps for where you're at. In other words, you will make more power at the same boost level you're at now with the GT12. If the boost cannot be controlled with that turbine housing and internal wastegate (which I highly doubt), there are plenty of ways to increase the wastegate flow and get you back into a controllable region. The GT12 is absolutely capable of 100+ hp on that engine with proper intercooling, intake, and exhaust design. Why do you say that guys using the GT12 only use them on play bikes (and why does that matter at all?)

What are you guys using for launch procedures when drag racing? It's very common on high hp turbo drag cars to run HUGE turbos relative to the displacement of the engine... but they also have very high PR capabilities... and none of the smaller products have high enough PR ranges that would also work well with the mass flow's you're looking at. If you want to get that thing to spool when you're staging and you insist on running too large a turbo for the power you're making, then you probably want to look into some sort of "two-step" antilag to make boost off the line. There are TONS of ways to go about this. With the right size turbo, this wouldn't even be a problem! If you absolutely beat the snot out of the GT2052(3), you might be able to eek out 150hp with some major antilag and intercooling. Honestly, and with no other motive than trying to help you make better power, I'd highly recommend getting the turbo in the right ballpark instead.

Are you limited by the rules for intercooling type or anything like that? If this is a drag-only machine and the rules allow it, I would very seriously consider a liquid to air intercooler that uses dry ice to cool the circulating liquid. You'll have to use a high % ethylene glycol or alcohol based fluid (so it doesn't freeze), but this is a relatively inexpensive way to send your density ratio through the roof! If the rules allow it and you're not doing it, you're leaving a lot of inexpensive performance on the table! When you're doing your dyno power runs, how are you dealing with the intercooling?

-Kirk

[claas900]

Thanks a TON!! When I see the math using my numbers it all clicks. I have only seen compressor maps for the Td04's. I've been told/read on a single its about getting rid of the big exhaust pluses which is why they run GT20's on the 450's. I think the Honda in that video is running a GT22? They say getting enough air to the motor isn't the problem again its the big exhaust pluses so some run a GT2252 turbine with a GT2052 Comp.
The way I compared the turbine side of the Td04 and gt20 is wheel size and A/R. The Td04 is a 71 trim with .41 A/R.
It's also my understanding that the maps don't take into account the motor spinning 11,500 rpms which is why they say the gt12 is better for play as it runs out of steam on top end, again going back to the gt20 for more top end?
As for launching we haven't got that far but its an ATV with a wet clutch, its easy/common to slip them to get what you want from the motor. But where open to suggestions?
What advice would you give for intake geometry? I know adding a Air Plenum made a huge deferents. I've read 4 to 8 times the size of motor, and the shape doesn't matter as long as it "open".
I was looking at Bell inner coolers web sight, how does this all translate into CFM so I get the properer size cooler?
Thanks Again you've helped put a lot of things into prospective. Patrick

[Kirk Feldkamp]

So I found a TD04-9B compressor map here: http://www.stealth316.com/images/td04-09b-cfm.gif. Standard air density at 70F @ 14.7psi (ambient) is about 0.075 lb/ft^3. Since the chart is in ft^3/min, multiply the X-axis by 0.075 and you have lb/min. So for the 7.5 lb/min (100CFM) @ PR ~1.8 you're seeing for 75hp, that puts you at about 65% compressor efficiency. Compare this to roughly 75% compressor efficiency at the same operating point on the GT12. In the words of Paris Hilton, "that's HUUUUUGE." You can do the math on what this is doing to your density ratio! Straight up, this is a poor match for what you're trying to do with this turbo/engine combo.

Can you post some pictures (or links to pictures) of what you've got? There may be some simple fixes, there may not. Both the intake and exhaust would be nice. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Kirk Feldkamp]

So in your video (http://www.youtube.com/watch?v=Gw4vsCpfMDA&feature=plcp&context=C38dfb46UDOEgsToPDskJwwc3euwy-sZsCgfLFkXrr) you say it's a TD04-13T. I found that compressor map here: http://forums.nasioc.com/forum...thread.php?t=1846868 (http://forums.nasioc.com/forums/showthread.php?t=1846868). If you multiply lb/min (7.5 as we determined before) by .0006291, you'll get it in m^3/s (aren't units fun? http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif) . In this case, you're looking at roughly .047 m^3/s. Plot where that point lies on the compressor map link above. It's SOLIDLY on the surge line at 60% efficiency. Keep in mind that this is at absolutely max power, and you aren't ever going to the right of this point . This turbo is WAY TOO BIG for this application! Hopefully you can see this, and feel free to ask more questions about this if you need help understanding the problem. If you're in Fresno, you probably go up in the mountains or high desert to ride. Unfortunately because you're already ON the surge line, you are more than likely beating the snot out of the air and the turbo any time you go to higher altitudes. Altitude compensation is part of what a wastegate is doing for you! As the ambient pressure decreases, it will automatically increase the pressure ratio (putting you even deeper into surge). Surge does *gnarly* things to your thrust bearing (severe wear), and your charge temps will also suffer greatly. Furthermore, the boost may be unpredictable and fluctuate rapidly if you get deep enough into surge.

In the video you also mention something particularly disturbing. You talk about how much oil overflow you're getting under boost. This is a *strong* indication that your compression ring(s) is shot or your valve seals are shot (more likely rings). The oil doesn't push itself out magically because there's boost in the cylinder. The boost is supposed to STAY in the cylinder. If you're getting high crankcase flows, that usually means your combustion gasses are leaking out (which also decreases power and also causes a number of other problems). This could also mean that you're getting detonation in the cylinder, which tends to unseat the rings and allow gasses to leak out into the crankcase. In fact, crankcase flow is what a lot of tuners will use to determine if an engine is detonating on the dyno. You'll usually see the crankcase flow spike before you actually hear anything. Frankly, with your quoted charge temps, I wouldn't be any sort of a stretch to imagine this is what the problem is. I mentioned in a previous post how most of these high performance singles basically have pistons with tiny skirts and usually only one compression ring and an oil control ring to reduce friction. If you can, I would look into (A) checking the cylinder for wear per the manual, and (B) checking the ring gap and/or ring tension. Don't ignore this one, it's serious if you want the engine to last. If I were doing this and running the 15psi boost you claim in the video, I would definitely look at adding a second compression ring to a custom lower compression piston!

Also, I was confused by your description of your turbo oil feed. If the oil is already pressurized after going through the pump, you damn well better not have air in it! If it did, the rest of your bearings would probably already be shot, and you probably wouldn't have much oil pressure at all anyway. In other words, your gravity feed tube shouldn't be necessary. The way these sorts of oil systems usually work is the pump will scavenge from the sump... go through the pump (which is governed by a pressure relief valve) and filter... all before it gets fed out to the lubricated components. In other words, you're not going to be able to increase/decrease the oil pressure within the system unless you modify the pressure relief valve or do some air-over-hydraulic intensifier or something.

NO INTERCOOLER!? You're killin' me, Smalls! This would help make a dramatic difference for the charge temps when you're driving. Your charge temps (quoted at upwards of 190F) are WAYYYY too high. There's an interesting calculation at the beginning of Supercharged (http://www.amazon.com/Supercharged-Testing-Installation-Supercharger-Systems/dp/0837601681) that outlines what an acceptable charge temperature is given the compression ratio you're running. Basically, you know what temp you've got going into the cylinder, you can add on the heat due to the compression within the cylinder, and you need to keep that below the autoignition temperature of the fuel you're using (with some margin). 190F is blazin' hot.

Generally it's recommended that you buy an intercooler that's as large as your installation will reasonably allow. There are also lots of tips in the FAQ and tech sections on the TurbobyGarrett.com (http://turbobygarrett.com/turbobygarrett/turbo_tech_basic) website.

Btw, your charge pipes are also a lot bigger than they need to be. We figured out yesterday that you're at about 100CFM at full power. Assuming that pipe you're using has a 2" inner diameter, that means your average flow velocity is roughly 76 feet/sec. The speed of sound is roughly 1100 feet/sec. Generally, you're fine if you shoot for 0.3 mach you'll still have reasonably negligible losses due to the speed of the flow. Yes, this number is a "rule of thumb" pulled out of one's butt, but it seems to work just fine for estimates. This would equate to roughly a 1" *inner* diameter tube for the current flow rate you're seeing. If you end up eventually making more power, it'll still be just fine as the numbers won't change dramatically for the setup you're running. Ever wonder why the outlet on a small turbo is as small as it is? Because there's no point in making it bigger! This should free up a TON of space for your packaging and goal of keeping things "stealthy" (which I like, btw). Don't listen to anyone that tells you that you're charge tubes would be too small at a 1"ID... it's just not true.

Only last comment I had was the sensor you're planning on using for reading fuel pressure will probably not be happy with being forced to be in contact with gasoline. Unless I'm mistaken, that one looks like an air-only style sensor, but I could be wrong. If the sensor dies quickly, you'll know what happened. If it doesn't, oh well, run it!

-Kirk

[claas900]

Let me try to make sure I answer everything.
I have 2 Td04's I've played with. Lets stick with the 9b for the current set up.
I ride in Pismo most times.
We dished out a stock piston, there very strong for a stock piston and very cheap prefect for testing. Getting some made isn't out of the question, we just wanted to keep it cheap until we get it set up right.
Your right about piston rings we have gap-less rings in it now. Tho oil pucking is kinda of a Cdale thing. They kinda have a bad ventilation. I added a 3/4npt to the case and that helped a ton, now we get just a slight spit right around 10,000. But this isn't to say the piston isn't on its way out.
The Cdale is a dry sump, and the upper frame rails is the oil tank. The scavenger pump,pumps a lot of oil and air. I think it was part of Cdale's crank case venting.
I wanted to make sure I got pure oil to the turbo, so the oil goes into the top of the pipe I made and that gives the air time to separate/ the turbo feed comes out the bottom. The restrictors are at the top bleeding back into the frame. Its hard to explain. It has worked well. But I really think in the end I'm going to modify the stock oil pump and use it to feed the turbo.
I didn't use an inner cool because this is the first known turbo Cdale, if it was going to be a bust I didn't want to lose a lot if I tossed it. It is in the plans tho.
I have learned scents the video the charge pipe is to large, and that a 1.5" would be more then enough.
The sensor is an AEM I believe? I think it is fuel safe? But I really didn't care it was for data longer anyways and is not going to stay on the bike.
If I missed anything please let me know. Again Thanks for the help. I've told the dyno guy stop the testing lets get a gt12 http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Kirk Feldkamp]

If you're just running around at Pismo, stick to an air to air intercooler. The liquid won't really benefit you in that case, especially since you're already limited on packaging. Make sure the intercooler is out front where it will get clean, cool air. When dynoing, you're going to want to make sure the intercooler is also being fed cool air from a strong dyno fan.

If the gapless ring solved most of the problem you might be ok. Still be very aware of any detonation on the dyno, and read the plug for added safety. How do you guys make your pulls on the dyno? 5th (or 6th?) gear, I hope. You want the rate of change in roller RPM to be as slow as possible. This is an ATV/kart dyno, not a car dyno, right? I've been privy to a few turbo dyno sessions where the engine was dyno'd in too low a gear, thus allowing the engine to rev too fast to really be loaded heavily. The indicated power numbers will suck if that's the case. One guy went up a couple HUNDRED hp when he switched from pulls in 3rd gear to pulls in 6th!!! Granted, that was an unrestricted 600 with a big turbo.

Not 1.5"... 1". http://fsae.com/groupee_common/emoticons/icon_wink.gif Even 1" is conservative in this case.

On the topic of the plenum, you shouldn't have too many problems as long as the airbox isn't tiny. Just make sure your entry/exit aren't just sharp edges (taper and radius things) and you won't have any problems. Since you're set up to measure pressures, you should measure at the turbo outlet and up in the airbox (the base is usually a good spot). By subtracting the two, you'll see what the pressure loss is through the system. Log and analyze this for your power pulls. That's how you can tell (A) if your intake geometry is ok and (B) if your airbox is a proper size. If the airbox pressure doesn't "draw down" as the RPM's and power increase, then you're fine. You could actually continue to reduce the airbox size to the point where this starts to happen. Assuming air of the same temperature, if the pressure in the airbox drops, so too will the power output.

If the oil reservoir is in the frame, that oil is probably *not pressurized*. The reservoir is fed by the scavenge pump(s) with bubbles and all and feeds the pressure stage(s) of the dry sump. The point of the reservoir is to let the bubbles shake out before feeding the pressure pump. If you're pulling turbo oil from in between the oil reservoir and the feed to the pump on the engine, then you're not actually pressurizing the oil going to the turbo! A common trick for FSAE turbo setups is to pull pressurized oil out of the pressure switch/sensor hole. I know the singles don't usually have anything like that, so you might be stuck finding another place to tap into the block. Alternatively, you could find a small electric turbo oil pump on ebay. There were some slick little inexpensive ones the last time I looked.

Good choice on the GT12. http://fsae.com/groupee_common/emoticons/icon_wink.gif

-Kirk

[claas900]

Its an ATV Dyno, we do 5th gear/top gear with tall gearing,something like 90mph.
I'll go with 1" charge pipe http://fsae.com/groupee_common/emoticons/icon_wink.gif
The Cdale has a air horn from the factory, but also the motor guy also builds a real nice one worth about 2 hp on a N/A motor.
The frame is just like an oil tank on a normal bike no pressure, I did data log the oil pressure to the turbo,22 to 26psi. My motor has 4psi at idle and 9 at rev. I know the Yamaha 700r have 9 to I think 12psi also the Honda 450r guys do the same thing tap right into the oil filter cover with good success. The Cdale main oil pump is tiny tiny. I'm going to talk with the builder and see about making a larger one or trying to "stack" two pumps. So we can tap right into the oil filer cover like normal ppl do. I do have one of those small pumps your talking about, but what a PITA plus the extra weight on an ATV I had to think of every way not to go that route.
So whats your take for the 450r guys running such a large turbo gt20? I'm not trying to step on your toes, but they run it and it works i guess? Tho to be honest I've never seen one in person. They say the gt20 gives them about 105hp and the gt22 is worth about 120hp. I spent a few hours talking with a guy that builds turbo kits for the Yamaha 700r, he does gt22 turbine with a gt20 comp. Tho he doesn't build anything for the 450cc class he said if I where to drop my bike off and have him build me one he'd use that same turbo, to be honest he was a very nice guy and I thought very knowable. He had said 1" to 1.25" charge pipe.
I do keep going back and forth on your math for selecting the gt12 to learn/understand it best I can. I'd like to see an honest 15lbs maybe even 17lbs, the gt12 will do that with in its range?
I had something else I wanted to ask I was thinking about at work, what was it???

[claas900]

I noticed the gt12 has a 1-1/8" turbine inlet, thats so small its hard to believe a motor a breath threw that? The Cdale motor has two 1-1/8" pipes that join into a 1-3/4" pipe. Should I run the two pipe separate until/to the turbo, or join them sooner?
The dyno guy told me his bro has a K03 turbo off a 2004 1.8L Audi we could try if we wanted. I told him I'm still learing to read maps and I thought it was still to large?
Why does it seem that ppl talk more about the comp side then the turbine side. They always want a bigger comp, and dont seem to worry as much about the turbine side?

[Kirk Feldkamp]

The pressure ratio (PR) the compressor operates at is simple to calculate. It's the absolute pressure at the oulet divided by the absolute pressure at its inlet. At sea level, standard ambient pressure is ~14.7psi. So the PR = (boost [psi] +14.7)/14.7. So you can check your math, this would mean 17psi of boost equates to a PR of 2.15. Play around with some more numbers to get the hang of it. For the quick and dirty answer on how much power that *could* make, you multiply the original NA power amount by the PR. As I explained before, this doesn't account for the compressor efficiency and any losses in the intake tract. This also assumes you have enough intercooling to remove a fair amount of heat from the intake charge.

If you've spent any time reading threads on the rest of the forum, you surely know it's never smart to blindly look at what anyone else is doing and simply copy them. If you've been around racing long enough, you also know that *everyone* lies to their competitors. Plus, you'll find more bullshit (technical and otherwise) surrounding dyno results than almost anything else. The other thing to keep in mind is that just because some other guy does it, doesn't mean his is actually working properly. When this thing is dialed in, I wouldn't be surprised if it made between 105 and 115hp with the GT12... and be WAY more responsive at the same time. If you really need more power after that, you would probably want to think about adding nitrous or something like that. Maybe going to methanol, ethanol or a high mix % of either with gasoline. Unfortunately, there's not a lot of good choices of turbos that will allow you to push the boost higher at the mass flows you're at. The larger end of the Garrett lineup has a lot more options than the small end.

Looking at the GT12, you're sort of limited by the compressor outlet anyway. 36mm for the hose is a weird size. 1 3/8" OD tube with a hose bead would be about right. Keep the wall thickness at 1/16" or so and you're golden. Finding 1 3/8" silicone hose is possible, but you might have to Google around for a while to find it.

[claas900]

Well again Thanks for all the help, I'm keeping an ear out for a used gt12. I agree with all the dyno bs posting. It makes it hard to know whats what.
Well I need to head out to work.

[Kirk Feldkamp]

Any updates?

[claas900]

I do, I've been meaning to give an update just just busy at work. Give me a few days to get back on here.

[claas900]

Sorry its been so long. First Kirk I do wanna say Thanks for all your help and I'm not trying to step on your toes with where I went with this build. Again I really appreciate your help.
Just a little recap with the Tdo4-9b turbo we made 75hp at about 10-11 lbs at 11,500 rpm redline. We thought the turbo was to big because it was hard to spool. We did add an "air box" or "air chamber" to the TB about 8 times the size of the motor so about 200ci-in. That helped a ton with the power band but did nothing for spooling. I do have that chart but cant figure out how to post it here?
So for a long wile there I was on the look out for a used gt12 never found anything, but then one day I ran across a gt15 for a song so I thought why not. I fabed it up "My fab time is free". This turbo sucked to be honest, 56hp at the same 10-11 lbs redline and the motor just didn't want to rev there. When the bike was first fired up it was pig rich, bad sign. It would barley run. Had to take out fuel everywhere. The gt15 didn't really spool any sooner and was prety much lbs for lbs with the td04 threw the rpm range.
The motor/dyno guy says he's 99% sure the exhaust side is just to small. Keep in mind he's not a turbo junky, just speaking from the motors he's built. He's very open minded. So this puts me back at with what little info I have found and ppl I have talked with that maybe I do need to go with a gt20 or gt22. They say the "singles" just put out one big pules and theses small turbo turbines just can't flow it? So maybe even the td04-9b is still to small on the exhaust side?
Kirk after reading this you still think the gt12 is the way to go?
On a side note my wife and I are expecting our 2nd child. Crossed fingers for a girl http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Kirk Feldkamp]

Cool man, congrats!

Yeah, without digging into about 30 more questions, I don't know how to help you troubleshoot the system. It's possible that you need a larger turbine side... and that's ok. If you're set on the bigger turbo, there are other ways to mitigate the spool issue. Are you already using a wastegate controller? Have you considered a small shot of nitrous to get the turbo up to speed faster on the bottom end? Ignition retard as a form of anti-lag could help too.

-Kirk

[claas900]

Thanks
To be honest I'm really not set on a larger turbo, everything you have said about the gt12 makes scents to me. But the only change made was the turbo, so if I knew nothing about nothing I'd say the turbo is to small. I mean is it possible that the exhaust side is to small and just cant flow it? Doesn't/isn't one big large exhaust pulse from 432cc require a larger flow/turbo then say a 4 cylinder 432cc motor? I dunno maybe I've done something wrong and its staring us in the face?
At this time where just using the stock WG sometimes we add a helper spring,most times its worth about 2psi so no wastegate controller. Nitrous isn't something I really care to mess with. Right now we haven't done anything with the Ignition, all stock settings we can tho.

[Ike Bruckmann]

Hey guys I am in the middle of building my cannondale 450 and have a VZ21 turbo kit I have built.I have some questions on how to tune this the best and what map sensor to use . I have A GP CONTROL TO MAKE THE CHANGES ,AND HAVE 2 725CC INJECTORS FOR IT AND WILL BE RUNNING E85 ETHANOL. I would like to talk to someone that has done this with a cannondale. please call me 619 607-7333 thanks Ike the bajaracer

[claas900]

It was nice talking with you Ike.

[Homemade WRX]

Just my $0.02 after reading this and now reviving it from the dead is that the single large exhaust pulse is creating a turbine flow/WG control issue from the 'small' turbine. The compressor is spot on by the numbers but the turbine's small size, I think is the issue. It's a case like this where I wonder how an exhause 'plenum' would help to reduce the exhaust pulse strength and make exhaust flow rate through the turbine more linear...of course if you could keep the flow only going toward the turbine http://fsae.com/groupee_common/emoticons/icon_wink.gif

I'd love to see data of exhaust pressure, turbo speed and pre-intercooler boost pressure for this setup.

I think a larger turbine A/R, if only it were available, would help a great deal on that GT15 or a for a GT12.

P.S. You're indication of being fat on the GT15 can be a indicative sign of exhaust restriction. If you can't get it out of the engine, you can't get it in. Bet it was a pretty large shift in manifold pressure ratio.

[claas900]

Your right, there is something to do with the large exhaust pulse. When we went to the gt15 from the TD04 we had to lean it way out just to get it to run half way right, right then we knew the exhaust side was way to small.
At this time I don't have any record of the exhaust psi. We never did measure it with the gt15 only TD04. Looking back at everything and learning more yeah we even had to much with the TD04.
I'm %90 sure even with the TD04-9b that the 9b comp wheel is enough air for the motor, I'd bet even the gt15 comp wheel is enough. But the WRX TD04-13T exhaust side isn't large/flow enough.
I think the advice I got from the guy that turbos the Yamaha 700's is right. Gt2252 exhaust side with gt2052 comp side. But I'm not going to throw $1,400 at turbo just to lose it. I've been on the hunt for used ones with no luck.
A for the exhaust "plenum" Idea I'm not sure where to stand tho take a look at this video,http://www.youtube.com/watch?v=FoYHrYgNlak&feature=related they made the exhaust way longer then it has to be, and no other turbo mfg. does it this way, they always make it short as possible.