Race Preparation of 1999 R6 Engines

Hey Crazies,

I am involved in a racing team competing in the Australasian Formula
SAE event. Each year we build a racecar from scratch and compete in a
very professional field for the championship.
Starting next year I will be heavily responsible for the
engine/drivetrain aspect of the car.

some specs from our 2003 car:
Weight: ~225kg wet
Torque: 57Nm
Power: 83hp (flywheel) peak (all inlets sucking through a single 20mm
restrictor
Accelleration: 0-100 in 3.5-4 seconds
Lateral Acceleration: ~ 1.5g
We run a MoTec M4 fuel injected 1999 model R6 engine.

We have used the same race engine for four years running now, and I
was wondering if anyone with race/psycho R6 riding experience could
tell me what the suss engine components are under high stresses. We
cannot afford to have an engine failure in the event, and considering
the engines run restricted, we should not bust an engine so long as
precautions are taken by replacing sketchy components.

Ie are the rods prone to failure? if so are there aftermarket titanium
etc replacements for race applications??

Also i would like to radically alter the final ratios of the
drivetrain. In the autocross event we currently don't get out of
second. Our rear sprocket is as large as we can currently make it at
55 teeth. (any larger and it will start impacting our control arms).

Can the final drive be modified by changing 2 cogs somewhere in the
transmission or does the whole set of dogs need to be replaced??

If anyone knows of ANY common failures of this engine please tell me!


Thanks for any help!

Chris

 

ahh...uni nsw goes sae racing...so are we next year...or the year
after...or...
this is 650cc powered open wheeler racing...to give the students something
to do

 

We have run a car every year since the comp began.
We won outright in 2000.
What uni are you from ?? La trobe??
I look forward to seeing whatever it is you plan to wheel out. Don't
get your hopes up with that kind of attitude.

So do you know the last thing about R6 engines?

 

maybe i do, maybe i dont...i know many things
maybe i'm a yamaha factory race team engineer...not gonna tell you with that
attitude

'hey crazies', not really a relevant greeting
no explanation of what SAE is
no, hi i'm a student at ... and we are...
reasonably well worded request for information


go talk to drag racers about transmission mods

 

So how's this work? You get a motorbike engine, you restrict it to perform at
only 70% of what the manufacturer has tuned it for street use, then worry that
you're going to break it.. so... what other stuff have you learned at uni?

Nev..
'03 ZX12R
'02 CBR1100XX

 

So how's this work? You get a motorbike engine, you restrict it to
perform at

uni?

Getting 83hp after running it through a 20mm restrictor is pretty bloody
good. Given that stock they put out maybe 110hp with 4 x 34mm inlet
trumpets.

 

Hey Chris,
Love the SAE project - I'm an ex-Monash boy and my housemate is working
on the 2004 car.

Re: the R6 engine, in my time trawling the forums when I used to own one,
the only common failure I heard of was gearboxes. Generally 2nd gear, which
I suppose since you're a) using that gear almost exclusively and b) possibly
putting heavy stresses on it; could well be something to pre-empt with a
rebuild.

I got the impression that the failures were generally caused by excessive
wheelies (ie rough treatment) and improper gearshift usage - i.e. people who
weren't able to ride smoothly and kept crunching it in from neutral.

Check out some of the sub forums on here:
http://pub114.ezboard.com/byamahar6messagenet

Jules

 

what about the front sprocket ??

 

Titanium rods? For an undergrad engineer project? Who the hell's funding
this?

For an actual answer, no 600 supersport race series I ever heard of allows
that level of modification (and I'll be surprised to hear SAE does, for that
matter), meaning it's unlikely anyone at Carillo's bothered to sit down and
knock up the CNC code to chew an R6 conrod out of a chunk of Ti... anyone on
your team feel like blazing a trail?

Again, youse are all fuggen engineers... forgo a subsidised piss-up session
down at the Uni bar one evening and pull the gearbox clusters out instead,
find out for yourselves.

That said, I don't think there'd be much scope for fitting significantly
smaller gears. It's all a pretty snug fit in there...

I've now heard of four cases of them having top-end problems; the most
recent one involved a cracked valve bucket, the others were a while ago so
I'm a bit hazy on remembering, but I think another was a snapped spring
which led to a valve jamming open and being twatted by the piston.

All of this was on bikes owned by quick people who'd clocked up a lot of
hard-ridden km's by the time the failures happened. If you guys are doing
this properly and are pulling the top-end apart every so often, you should
be safe. Stronger valve springs are available from everyone from Yamaha
Factory Racing to Stevo's Speed Shop in Lurnea, so, I dunno, maybe go a set
of them?

 

Why ? I think it's a perfectly apt description of the denizens of
aus.moto

Does it need to be explained ?

Did you want a formal request via registered mail ? The thing is those
who have been here a while know who Chris is and the fact that his
team builds one of these toys - he even shared a website about it last
year. Secondly he specified quite clearly what he was looking for -
someone who races an R6 or at the very least flogs the hell out of it,
and then wanted to know what breaks. He also asked about options re
gearing - perfectly reasonable request to me. Not one I know the
answers to unfortunately. But I can't see that he deserved the
response - there's harsh week and there's unreasonable....

Reasonable advice, but maybe he was hoping someone here might have
done it ?

JL

 

ah ok

seems the only people willing to give this a thought are boring,
sarcastic old f***s with nothing better to do than have a poke with a
very inadequate stick.
Then again i suppose with a subject that includes 'race preparation'
and 'r6 engines' one can expect a throng of wanksters pounding at the
gate.

I introduced the car adequately.

I was asking for ADVICE from people with TRACK EXPERIENCE riding the
first series of R6's. Why did you even post?

Anyone got anything RELEVANT to say??

 

My cat's breath smells like cat food.


BTH

 

so... what other

how to approach people who dont know you and convince them that it is in
their best interests to help you

 

ahhh...

thanks for the advice.
I had been thinking about doing the valve springs, still unsure cos we
generally run a ~14k limiter. Might be the right plan to change them
anyway.

Jules: Re: gearbox...
yup I've already rebuilt it once, and after the pounding it got this
year when we kind of lost a clutch and a shift linkage and we had to
do a few accelleration runs urban warrior impro style, I think we'll
be having a close look at it again.

Re: Ti rods, that was a stupid example. However if we were to replace
them we'd be writing the CNC code ourselves and machining them in
house (we have a number of 3X and one 5X mill at our disposal). I am
just looking for common component failures to look at. Our 4 engines
have served us well so far.

Thanks again,

Chris

 

Yeah we're running the smallest we can at the moment.

 

Which is pretty much what it is on the street R6, anyway. Tachos lie just as
much as speedos...

In that case, it might be an idea to do it just for the hell of it... after
all, isn't that what SAE is supposed to be about? While you're at it, some
Ti valves and a heavier crank, which'll better match the greater drivetrain
inertia of a four-wheeled vehicle, might also be in order.

How high's your compression ratio? Upping it is supposed to be the go for
getting around inlet restrictors.

 

Thank you jules.
I've yet to hear any Australian team claim a better value

 

'hey crazies', not really a relevant greeting

would you walk up to people you dont neccessarily know, whos help you seek
to further your own ends and say 'g'day ya mad bastard'?

what about the half of the world who does not know what it is
hell, i'd never heard of it untill 6 months ago or so
guess i'm a bit ignorant then

well i thought a bit more formality in his pitch would be representative of
the position he holds

well sorree...he is only interested in those people he already knows...thats
a good way to go about it

my reply to his first post is;
which i do not think contains any 'ATTITUDE' and is faintly disperaging of
my own faculty for dragging its feet somewhat re getting into the series and
describes the idea of sae to them who dont know



which tells me his attitude is...we are the best, you dont have a hope...are
you capable of helping me anyway, if not piss off

no doubt he was...i have a mate who drags such a thing with a trick box he
built to prevent second gear blowing up and make it shift under full load
but why didnt i just say that in the first place
then he would have been 'friend, pal, buddy, maaaate, come in have a beer'

but now he appears to have gone off his naa naa

 

You do realise this isn't a bar, don't you?

 

<CLAIM>

my SAE team is running 3 billion horsepower out of an R6 engine.