billyghog

Member
Jan 31, 2004
12
0
Does anyone have any dyno graphs for the following engines or similar?

KTM 525SX
Yamaha WR450
CRF 450

I am on the UCSD Formula SAE team (we build scaled down formula one cars) and we are playing with the idea of using a single cylinder to save some weight, but wonder what the power trade off would be. The rules say we can run anything under 610cc and it has to be a 4 stroke. Also all air going into the engine has to pass through a 20mm diameter hole (restrictor). An electric start would be nice - we have to have one and don't really want to build one. Whatever it is it needs to be fuel injected, but that won't be too hard. Does anyone have any ideas?

Here's our website if anyone is interested:
http://sae.ucsd.edu
(it really needs an update, but all our info is still there.)

Thanks-
Billy
 

marcusgunby

LIFETIME SPONSOR
Jan 9, 2000
6,450
2
I posted some graphs up a while back-the thread was called dyno requests, it had a Cr450f -peak hp was about 55-57rwhp, but that was tuned to be ridable, over 60hp is ok but much more will be hard to get iMO as most tuning parts are for mx not high revs,also not sure about the restictor and how that will alter power.
Hope that helps.BTW you can bore out the CRF to just over 500cc but thats as large as i have seen.
 

bclapham

LIFETIME SPONSOR
Nov 5, 2001
4,340
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Billy-

i recon the KTM would be the best bet, you can buy the big bore kit to make it 540 and a guy on here stroked one to make it something daft like 600ccs and i think he dynoed it- i think you can even buy the crank ready to go- MXA did a review on that bike. I think the KTMs can be hooked up to electric start also and has plenty of gearbox options.

Its never gonna bee as fast as an engine from an R6 though- there was a thread ages ago where some dudes put a GSXR engine in a go cart man that thing was wild!!!!!
 

YZ165

YZabian
May 4, 2004
2,431
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That's one sick "go-kart"!
 

ScottS

Member
Dec 29, 1999
478
0
as an SAE memebr I find this fascinating

onr thing to consider is that the transmissions on the bike engines may not be robust enough for asphalt use with two sticky tires and a heavy ( by comparison to the bike) load-some kinf of cushoined drive may be needed-

The most bulletproof engines would be the XR650 or the LC4, both are over the 610cc limit but could made to fit


The KTM 525 engine would be awesome , and it is very light-

BUT- since you mentioned fuel injected- go over to Cannondaler.com and you can pick up a fuel injected 450cc engine pretty cheap. Could be made larger displacement too. Also lots of tech support
 

ScottS

Member
Dec 29, 1999
478
0
I guess a nbce touch on the Cannondale engine is that it is made in USA. E -start also.

Just an idea.
 

billyghog

Member
Jan 31, 2004
12
0
Thanks Rich! Scott - it's chain driven to a differential. We haven't had any transmission problems with our current engine, but we haven't driven it a whole lot yet either. There were other teams at the competition that were runnung CRF450's and they didn't have any problems there. (I'm not sure how well they held up afterwards.)
 

Rich Rohrich

Moderator / BioHazard
LIFETIME SPONSOR
Jul 27, 1999
22,839
16,904
Chicago
Billy - Something to keep in mind is Optimum Power has a complete working fuel injection system for the YZF engines based. They have been very friendly to FSAE teams in the past and may be willing to lend some assistance. At the very least take them up on the offer to buy their G.P. Blair designed Virtual Four-Stroke software package for a ridicuously low price.
 

cujet

Member
Aug 13, 2000
826
5
The early CR5 makes around 55RWHP. A few of the late model "easy to ride" versions were down to about 53RWHP. Of course power junkies like me find it will make up to about 70RWHP with a good pipe and simple porting mods. The 70RWHP flavor is not too bad either as far as reliability and ease of control. It still can be trail ridden, for instance. In full drag race mod status, it will make up to and over 90RWHP. Then the engine becomes quite a handful to ride. It also takes a toll on crankshaft life, as 9800 RPM is really placing too much load on the crankshaft and rod bearings.

Chris
 

500_boy

Member
Jan 3, 2004
85
1
How much HP would be acheived with just a brand new stock cylinder with an FMF Knarly Pipe, Reed Block and Proper Jetting. Also what are these porting mods you so speak of, sorry if Im a bother , but the HP bug bit me a long time ago so when I get something I try and get as much HP out of it while still keeping its reliability.

You should see the plan I have for the Cummins in my truck :) 400hp/950ft/lb :)
 
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