TurboTagTeam

This isnt related to a honda but you guys are some of the most knowledgeable(Sp?) people with forced induction.

My brother has recently bought a after market supercharged bmw. An M5 to be exact. After recieving the car there were some minor issues to be figured out. The biggest is a tunning issue. When the car was originally tuned it was only tuned untill 6000rpm since the motor was brand new. The builders didnt want to rev it any higher. So after 6k they set the fuel curve real ritch to be on the safe side. So....

The car now has 6000 miles on it since the rebuild and its about time to set this thing straight. We bought a AEM uego gauge and did some pulls. Everything is gravy untill 6k (duh!) and then the A/F goes of the scale on the ritch side. My brothers biggest concern is reliability. Should we lean it out or just let it be? I am telling him to lean it out a little but I want to see some replies of what you guys think.

Some specs.

Cryoed block
arias 9.5 pistons
corillo rods
darton sleves
vortech t1 blower pushing 1bar as of now
Fully ported and flow matched cylinder heads
New over sized Stainless valves (1mm greater diameter)
schrick stage 2 cams
idividual throtle bodies with secondary injector bosses
supersprint headers
aquamist water injection
custom fuel management system (builder assures me the fuel tables are easy if I can tune a honda)

So far the car is putting down about 800whp. So we could leave it running ritch and deal with the power loss.

This is the whole build. We would tkae it back there to get tuned but we are in michigan and the shop that built it is in cali.

http://www.discovery-automotiv...&id=4

KeyserSoze

Ok, first of all nice numbers, secondly why not just find a tuner near you and have him tune the car?? There are deffinately target numbers for AFR depending on your app, but if you don't feel comfortable making the changes, perhaps some more research, find someone willing to teach you, or have a pro do it. Maybe I'm not understanding what you are asking though. It's just that if you don't know how to tune your car (or your brother doesn't) I'm not so sure that you want to learn how to tune on an m5. Don't take it the wrong way. Just my $.02

TurboTagTeam

Its not that I cant tune. I can. I am no pro but I am sure I can take out some fuel up. I have had several conversations with the builder and he is telling me that any monkey with a computer can do this. I know what you are saying. If i had ANY doubts that i could tune this I wouldnt toutch it.

My question is not if i can tune it, my question is should i tune it. Kinda like a better safer than sorry mentality. Am I making any sense?

Bailhatch

If you know how to tune then you should know that the AFR under boost should be pretty smooth and not drop 3 or 4 points after any particular RPM.

If they didn't tune, or apparently even guess, at the fuel up top I wonder what the timing looks like

SOHC_MShue

whats the afr like in boost and what does it go to after 6000 rpms?

TurboTagTeam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">whats the afr like in boost and what does it go to after 6000 rpms? </TD></TR></TABLE>

It imediatly drops to 10.8 and stays around there 10.5-11

SOHC_MShue

that really isn't bad at all for an 800whp car. You might be able to lean it out slightly, but i would think that high 10's to mid 11's would be fine.

0mtber

iTrader: (2)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bailhatch &raquo;</TD></TR><TR><TD CLASS="quote">I wonder what the timing looks like </TD></TR></TABLE>

Me too