supercharging a single.....the wr450f in particular

[jonny8]

Was thinking of putting a rotrex c15 on the wr450f. Reckon could get torque up over NA by 20% across rpm range and 30% up low down. Only prob is the thing might blow up........hmm
What are peoples views on fitting the rotrex on this or any other single?

[Duarte]

seems like a very interesting idea!!

[drivetrainUW-Platt]

sure give it a try, you wont have to worry about exhaust pulses from the single like with a turbo, and heck, video tape it runnin so if it does blow up we can all see a cool video!!!

[BryanP]

Very interesting project. We have been considering something similar but don't have information on appropriate superchargers. I would appreciate if anyone would post links to some manufacturers web sites.
thanks
Bryan

[threehondas]

Restricted singles LOVE intake volume... even forced induction singles seem to benefit aswell.

I'm not sure how you'd set it up with the supercharger...

It would be nice not having to worry about turbo oil pressure from the low oil pressure of roller bearing crank singles.

[drivetrainUW-Platt]

I have no clue where to even look for that small of a supercharger, turbos for our application are easier to come by since they put turbos on diesels as small as 25hp, never heard of anything that small with a superchager, good luck!

[Mustang Mac]

Eaton was working on a small supercharger for up to 650cc's I believe. Supposedly it was to be launched a few years back, but then nothing. You could always make your own, but rotor tolerences need to be very very tight. You could also take a turbo, remove the turbine housing and make a new shaft and bearing supprts for a pulley and you'd have a centrifugal blower. Instant Vortech.

[John Bucknell]

The cool thing about blowers is you can spin them as slow as you need to get the proper pressure ratio (albiet at a somewhat lower efficiency if too slow). The problem is usually getting them big enough. I think the Eaton M45 off a MINI you could probably run at 1:1 on a 600cc. It's probably physically the same size as the engine though...

[Jeff The Pyro]

eaton m45?

if you happen to be near pontiac for fsae 2005 look around for UCSD...

it is a pretty gnarly beast of an air pump though, weighing in at ~20lbs. i guess it doesnt hurt for the intimidation factor...

[jonno]

we've found a swiss manufacturer (possibly Rotrex - sorry can't remember off the top of my head. if it is rotrex though, i'd imagine it's this as it's their smallest model... link (http://www.rotrex.eu.com/files/sheet_C15-16_.pdf)) that would supply us with a supercharger suitable for our wr450 but we didn't get it this year for a number of reasons.

1) we couldn't warrant the extra £500 to buy it this year - our budget was pretty streched

2) we are terrified of cranking the power too much on the WR450 - don't know if you've seen it but these engines are on the edge of what they are capable of.

3) Look at Formula Student 2004 sprint lap times for proof that the single is fast enough anyway (the 3 singles all placed in the top 5) none of these had any forced induction, why complicate an engine that is fast enough already.

4) there is no easily accesible shaft, you'd have to cut through to the flywheel / alternator winding and run the 'charger off that.

An electric may be an option as you can presumably run them at any speed you want from your ECU? We tried to get one out of Visteon (http://www.visteon.com/products/automotive/vtes.shtml), but they couldn't get one for us. I believe one of the California teams used one a few years ago... how did that run?

[Kirk Feldkamp]

It's about time somebody noticed these things. All the performance maps and dimensions are on the website. It's a Danish company, which is fun for technical questions. (http://rotrex.com) The C15-16 is PERFECT at 1:1 for the 600s. My buddy and I recently started a company based on selling the TTS-Performance kits (http://tts-performance.com) for the GSXR1000's and such. The bracket is the same... the only tricky part is the seal out of the side cover... but they've got it well thought out. It works without any leaks. Any FSAE kid worth his weight in beans can figure it out. I think both 2 Wheel Tuners and Superbike just did articles this month on the TTS kits. From what my buddy says while riding it, it's unbelieveable how much power it makes. TTS says they're making 200 at the wheel on the dyno, but the first one we did was making 230ish on a Dynojet. I'm pretty sure the kit Richard (TTS) runs has some boost leaks, which we sorted out, and I think he has subsequently fixed. My buddy is a BIG guy, and has ridden his share of uber-fast bikes (turbo busa @ 320 hp, N2O busa, N2O TLR1000) and he can't stop talking about how easy this one is to ride. It makes power VERY linearly just like stock, but the thing just keeps pulling harder and harder. The boost doesn't just HIT at 4000 like is usual for 'turbusas'. If you've never hopped on a new GSXR1000, you can't even begin to realize how rediculous that is. Long story short, you can get the Rotrex units though California Superbikes (http://calisuperbikes.com). That's my skragely self standing behind the bike on the homepage. I'm really not sure on pricing, just give him a call (mention me, aka Kirk http://fsae.com/groupee_common/emoticons/icon_biggrin.gif). I think there are also kits available for the other various sportbikes.

Anyway, back to FSAE, Rotrex also claims that it is preffereable to place the throttle BEFORE the supercharger. Unlike the problems we all have with the oil leakage without carbon face seals, the Rotrex actually WANTS to have it there. They claim they don't leak, and I'd tend to believe them. Oh yeah, the other cool part is that the oil system is completely self contained. There is a separate "traction fluid" (side note: this stuff smells like crap) crossflow cooler that acts as the cooler/reservoir. The drive rollers inside the supercharger act as a little pump to move the fluid around. No coking to deal with, no turbo oil lines to hook up/position/restrict. As for light, the thing only weighs a few (maybe 6) pounds. On top of that, there is no lag. Nada. No kidding. Ask Keats at CaliSuperbikes. Oh yeah, you can run a "normal" exhaust setup too. This should make this a VERY attractive option to teams that already have a good NA setup!!! The bracket and pulley setup is really simple, check out the pictures on the CaliSuperbikes website!

The main drawback I see is the inability to run up the boost at lower RPMs. That's the beauty of the turbos... you can easily use a boost controller to spool the little turbo hard at lower RPM, and then taper it as you hit the restrictor. That gives you a car that's pretty simple to drive, but then again it takes a lot of development to get there. I guess with a reliability outlook in mind, the Rotrex could be alomst as burly, as you can use the drive ratio to make the restrictor choke at say, 8000 RPM. For that matter, any 450 could be boosted quite easily, and you wouldn't have to worry about getting it to spool. If I could go back and do it all again, I might just try one of these instead of the turbo. Then again, I wouldn't have the job I have right now if I hadn't gone the turbo route!

Can you tell I've put a lot of thought into this? http://fsae.com/groupee_common/emoticons/icon_smile.gif

-Kirk

[Dan B]

Originally posted by jonno:
An electric may be an option as you can presumably run them at any speed you want from your ECU? We tried to get one out of Visteon, but they couldn't get one for us. I believe one of the California teams used one a few years ago... how did that run?

That was Cal Poly Pomona in 2000. The Formula Student judges liked it. I am now running the spare 135A GM alternator on my 6000lb chevy truck after buying it off the team http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Marshall Grice]

am now running the spare 135A GM alternator on my 6000lb chevy truck after buying it off the team

Yeah, and his truck only weighed 5000 lbs before he put that alernator on!!!

[jonno]

The Visteon one I linked didn't look too heavy... there's an interesting SAE paper available here (http://www.visteon.com/utils/whitepapers/2004_01_0523.pdf). If you set your ECU to control it so you only get boost at WOT, I think the system would be powerful.
Still don't think singles need to be 'charged though (well not until several teams have them running well and are looking for aditional performance gains)

[Nero]

would not a Lysholm blower ala' autorotor do the job better?

[Big Bird]

The big question that keep coming to my mind when I read this thread is.... But why?

If something works because it is light and simple, do you make it better by adding weight and complexity? Colin Chapman, I don't know if you've got internet access up there but if you are reading this, we are all really really sorry.

I'd question the need for an extra 20% torque, power whatever - but if that is what floats your boat then you can get there with decent intake design and time setting up the fuel injection. But supercharging? You would be hard pressed to convince me that the extra weight, time, complexity and risk is justified.

Cheers all

[Z]

Geoff,

I put a post on the "Single cylinder engines" thread proposing a 600cc single with low compression ratio and supercharging. The main advantage of this was simplicity! Specifically, you could do away with the gearbox, and all the hassle and performance loss that amateur drivers have when changing gears. This engine would be a lightweight 80hp electric motor.

Later posts (on "Single" thread) suggested that a bespoke engine of this type could be made as a very simple side-valve "Briggs & Stratton", with compact overall dimensions, light weight, and good overall reliability (see the "GT12 Turbo Single" thread for problems when boosting a small capacity stock engine).

Yes, "simplicity" sure is a curly concept...

Z

PS. Jonny8 did ask "or any other single?". I wouldn't do it on the wr450f, for reasons given in "GT12 Turbo Single"...