GT12 turbo

[powered by wattard]

We ran the Garrett GT12 turbo with the special carbon face seals and are still experiencing some oil in the inlet manifold due to compressor side seeing vaccum. Have other teams with carbon seals experienced this (eg. Ghost who walks)

We have restricted the oil flow to the turbo with a 1.6mm diam orifice. Has anyone gone smaller.

Have teams tried scavenging the oil out line of the turbo with there dry sump scav pumps. if so, haw much vacuum was generated in the casing to eliminate this problem.

Were running 1.2Bar boost at 6000RPM with a prototype 434cc inline twin.


William Attard
Melb Uni FSAE 2000-2004

[powered by wattard]

We ran the Garrett GT12 turbo with the special carbon face seals and are still experiencing some oil in the inlet manifold due to compressor side seeing vaccum. Have other teams with carbon seals experienced this (eg. Ghost who walks)

We have restricted the oil flow to the turbo with a 1.6mm diam orifice. Has anyone gone smaller.

Have teams tried scavenging the oil out line of the turbo with there dry sump scav pumps. if so, haw much vacuum was generated in the casing to eliminate this problem.

Were running 1.2Bar boost at 6000RPM with a prototype 434cc inline twin.


William Attard
Melb Uni FSAE 2000-2004

[The guru of guru's]

We didnt restrict the oil flow at all. Is the small amount of oil really a problem for your engine? We noticed the plenum had a thin oily film inside when we went to rebuild the engine after the race. What type of map readings are you getting? Hows the engine comming along?
Cheers
Dave.

[Robert]

Hey William

Where did you get carbon seals for your turbo I talked to Jeff at Garrett and he said that they didn't offer any. Did you make your own or use a seal from another turbo? Do you have a part number?

We are having similar problem with out turbo and oil consumption. I talked to the rep at Garrett (Jeff S.) and he said that the oil pressure needs to be at about 12psi at idle and no more then 30psi. To keep the pressure from going over 30 we used a guage inline to the turbo and a small valve that we could adjust. Now the oil pressure stays below 30 but we still have oil problems on the dyno.

However I am going to begin testing the system with our dry sump system that is on our car, hopefully this will solve the oil problems.

If not I am going to start working on a way to collect the oil in the intake before it reaches the engine.

The rules really need to change so we can mount the throttle and restricter after the turbo. This would solve all oil consumption issues.

[Robert]

Hey Dave

I don't know how you are not sucking oil like crazy with the stock oil pressure. What does your system look like? Can you send me a picture?

Our did you get a turbo with magic seals in it?

[BeaverGuy]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Robert:
The rules really need to change so we can mount the throttle and restricter after the turbo. This would solve all oil consumption issues. <HR></BLOCKQUOTE>

Yeah, and then the point of the restictor would be what? If it comes after the turbo then they might as well say no restrictor at all.

[RagingGrandpa]

what would be wrong with restrictor, turbo, throttle, in that order? I don't really understand the 'intent' of the rules regarding that (I agree turbo before restrictor is unfair, obviously)

[Jarrod]

restrictor first would allow a big tank of air after the restrictor, before the throttle, so that the engine could effectively run unrestricted for a short period of time when coming back on to the throttle.

[Ryan Schoffer]

i have done alot of research into turbocharging these vehicles, and from all my experience with 'normal' setups i have concluded that it is mostly a waste of time

one could easily get 70+ hp out of a stock F4i, even 75 is easily achievable (trust me on this, or see our car this year =D ), and i dont think that 5-10 more hp really makes up for the extra weight, complexity, cost and reliability issues of a turbocharged setup

i know what you are going to say about there being a more useful powerband down low with a turbo, but IMHO, with a 6 speed gearbox and the low speed courses we run, it is very easy to gear the car properly so that the N/A powerband is more than adequate (~6000 - 12000 RPM on our car is 30+ ft-lbs)

the way i see it is, until rules regarding the intake track are modified for forced induction cars, a turbocharger, while a curiosity in this kind of setup, does not warrant even slight consideration

your opinion may vary, but that is my 2 cents

[The guru of guru's]

I think the throttle should be after the restrictor....makes a little more sense if you ask me

[PatClarke]

Originally posted by Robert:
"The rules really need to change so we can mount the throttle and restricter after the turbo. This would solve all oil consumption issues".

Originally posted by The ghost who walks:
"I think the throttle should be after the restrictor....makes a little more sense if you ask me"

I have some bad news for you guys. The rules committee has very recently discussed this very issue, and I can promise you that the next version of the rules for 2005 and thereafter will remain as is.
The Rules committee is very aware of the oil consumption problems with the current setup but are also aware of the impact of placing the throttle after the restrictor.

By the way, I am NOT speaking on behalf of the rules committee. Any official statement on the rules committee will be made through the normal communication channels.

PDR

[The guru of guru's]

Hi Pat
Are all of these rules in place for our safety and that alone? If so how can having the throttle before the restrictor be a breach of that? I understand your postition but can you clarify for us, the reason for the throttle being before the restrictor? From an emissions point of view i think the throttle should be an acurate governing device to reduce unburnt gasses and the like.
Sorry to be a pain.
Cheers
Dave.
Dave.

[Big Bird]

I'll hazard a guess as to why the restrictor is after the throttle, although I'm sure Pat will respond before I finish this. Imagine if throttle then downstream restrictor was allowed. As Jarrod has said, you could put this enormous air tank after the restrictor, effectively enabling unlimited air supply. Add in a turbo and we have 150hp CBR600's powering our cars. Fun, yes - too dangerous, definitely. The legal implications of novice students driving around in home-made 150hp, 220kg cars are too horrendous to consider.

The purpose of this comp is to learn, not just to build some rubber burning rocketship at our uni's expense. By deliberately restricting horsepower, it makes us consider all the other aspects of building a fast car - chassis dynamics, suspension and drivetrain design, blah blah blah. So we have to think stuff through and we learn.

I reckon the rulemakers have the formula pretty well spot on. we have a great comp where many different types of vehicles (both forced induction and normally aspirated) can be competitive, and at reasonable budget. The rules are the same for all of us, so if you insist on going forced induction then so be it. There is no need to cry foul when you hit upon the problems that many of us foresaw in the first place.

Cheers all,

[PatClarke]

Dave,
You have to take your racers hat off and remember this is a design competition. You have a formula to contend with, and part of that formula is the size and location of the restrictor.
This has been discussed at length, and it is fair to say that the consensus is that FSAE has available quite enough power at this stage, thank you.
So my suggestion would be to just accept the rule as it is and get on with life. Discussing it here serves no purpose now except to waste your breath.
If you have a legitimate argument why the restrictor should be before the throttle, then you should make a submission to the Rules Committee via the normal means.
Let me warn you though "More Power" or "Easier to control oil leaks into the turbo" are certainly not going to be acceptable arguments.
PDR

PS, Thanks for your comments Geoff. You have about the right idea!
Pat

[The guru of guru's]

Yes i can see the reasoning for it being the way it is. Otherwise theres no point in having the restrictor if it were placed the other way round. Sorry to waste your time Pat.
Cheers.
Dave.

[Frank]

i think they should abolish forced induction, that would solve the turbo oiling problem.

e85 while we're at it (how much sponsors dollars do they get for that anyhow?)

[PatClarke]

Dave,
You are not wasting my time http://fsae.com/groupee_common/emoticons/icon_wink.gif I was just suggesting you shouldn't waste yours! Anyway, we can talk about it soon.

And Frank, Gawd you are getting cranky in your old age http://fsae.com/groupee_common/emoticons/icon_smile.gif http://fsae.com/groupee_common/emoticons/icon_smile.gif http://fsae.com/groupee_common/emoticons/icon_smile.gif. But I guess if someone makes it worthwhile to use 'corn gas' then E85 will continue.
Take a look at the very latest RaceTech. Some lunatic has written 4 pages, with pictures, about the UQ car http://fsae.com/groupee_common/emoticons/icon_wink.gif I'll be in Brisbane all next week, so I will bring up my airmail edition for you to read/scan/copy as it won't be on the newsstands for a month or so. It might help you raise an additional dollar or two to spend in Blighty.
I'll give you a call when I am up there.
PDR

[Frank]

gees thx pat,

its not old age making me cranky, it's this lunatic plan of building a car in 6 months that is driving me mad http://fsae.com/groupee_common/emoticons/icon_smile.gif

http://mechcam2.mech.uq.edu.au/ViewerFrame?Mode=Motion&Language=0

[PatClarke]

Hi All,
Getting close to the comp and I am sure all are working rather than sleeping. Actually, I am looking forward to the whole thing. I think this years competition will be the best ever from the Technical/Design point of view.

Reason for this post is to remind people of one reason why the Rules Committee are leery of changing the turbo/restrictor arrangement.
We are all old enough to remember this
http://freespace.virgin.net/shalco.com/tte_ban.htm
It has taken me a while to track down the link. It makes an interesting read and gives an insight to a motorsports culture that has no place in FSAE
PDR

[jack]

i wouldn't be too suprised if crappy welds on intake plenums, n/a or turbo, lead to "restrictor bypass"...

[PatClarke]

Jack, the Tech judges apply the "Formula 3" test for that http://fsae.com/groupee_common/emoticons/icon_wink.gif
PDR

[Kirk Feldkamp]

Jack,

If you've ever had intake leaks you know that it's not an advantage!!! There is no way of throttling the motor once you starting drawing all that air through the hole(s), so it revs up... and then keeps revving uncontrolled even after you close the throttle. It's definitely not what you're looking for!

-Kirk
UC Berkeley

[Asmith7]

Has anyone had success scavenging oil form the rubo with their dry sump oil system? If so how did you manage not to starve the turbo? Dis this allow you to avoid having to restrict the oil pressure from the engine?
Thanks
-AJ