race fuel tuning

[disturbed1]

hey guys, i know people wont be too forth coming sharing tuning techniques etc but australia sucks when it comes to big hp tuning and the americans seem to be well above the rest when it comes to supras.

bacically im about to go for a tune, 7mgte (stock internals) mhg, trust t78 etc etc

this is a new turbo setup compared to the old gt3040r which made 400 rwhp on pump fuel (ultimate 98 its called over here but basically the most expensive unleaded fuel at ever servo station)

that power was on 18 psi and 18 degrees timing up top on full load (12:1 afr). the motor has a hks 3mm hg so compression is very low hense the low power for relatively high boost.

anyway, with the t78, i plan to tune to 1 bar on pump at approx 18 degrees and 12:1 afr also (in australia - it seems norm that most cars get tuned to 18-20 degrees timing at full load) and hopefully make about 350-400 hp

i will then be draining my fuel cell and then topping up with top shelf leaded racefuel such as c16, sunoco max nos etc etc

now ive heard plenty of stories of people throwing in another 6 or 7 psi boost and an extra 10 degrees timing etc but im in no position to foolishly risk my motor.

so this is where im stuck,

is there some basic priciples to stick to? for those that dont mind sharing, please do - or atleast give me the basics.

how much extra boost is considered reasonablly safe on race fuel?
approximately what do you limit your boost to on pump fuel (for comparisson sake)
how much extra timing to do put in over pump tune
and lastly what kinda afr do u aim for.

i know there is a hell of alot more to it then just that but just curious as a rough guide how u guys tackle race fuel tuning.

im interested in all motors, (fully built 1jz/2jz/7ms etc), not just stock 7ms

feel free to send me a pm if u rather not post such details.


cheers

 

[IJ.]

I'd just tune the same way I do for any fuel Chris.

Electric ears and a Knock Sensor on the dyno adding boost/timing till gentle rattle then back it down a couple of degrees for safety.

 

[disturbed1]

I'd just tune the same way I do for any fuel Chris.

Electric ears and a Knock Sensor on the dyno adding boost/timing till gentle rattle then back it down a couple of degrees for safety.

theres not 1 tuner over here that uses knock detectors.

mate bout a gizzmo knock detect for like 1k or something, is actually pretty hard to use and setup when your not used to them. i will be strapping that to my motor for tuning purposes but not sure how much help it will be

 

[Mr. Y]

Just add timing while torque increases and check for det. carefully. At least how I do road tuning: 11.5 AFR, safe ign advance... Adding 1-2 degrees at WOT, making 1/4 pass, listening to engine, watching trap speed, reading spark plugs. When more timing doesn't add significally horsepower anymore (trap speed) I just stop at that boost level. Then more boost and same fun with ign. advance. Yes, that requires a lot of time and fuel but It looks safe enough to me...

As for listening to engine, at high RPMs (4K+) there is a lot of noise and I'm not sure that light det. can be heard.

 

[IJ.]

That's why we use a combination of both on the Dyno.

Haven't broken an engine since we started doing it this way <fingers crossed holding a 4 leaf clover and a rabbits foot while touching wood>

 

[grimreaper]

and knocking on glass to save your ass.

 

[hottscennessey]

Electric ears and a Knock Sensor on the dyno adding boost/timing till gentle rattle then back it down a couple of degrees for safety.

I use det cans, I was using an electric stethoscope but it didn't take well to the vibrations.

For my motor, I've noticed a decent threshold before detonation, where the motor isn't making any more power... I stop adding timing where it stops making power.

 

[IJ.]

Scott: It hasn't actually stopped making power it's drowning