I have had my Stillen stage 2 installed for about 2 weeks now, dyno'd it yesterday on a mustang dyno and only got 262rwhp at best, af ratio was 9.9 right across the board, needless to say I am totally stumped.

Possible important info :-

g35 6mt coupe
2800 miles (not had first service yet)
boost pressure was showing a max of 5.2 psi
plugs looked fairly good, not over sooty

Does anyone have any clues as to why it is running so rich and why I am getting so little power.

I have booked another dyno session on a dynojet for this coming saturday and a service for tomorrow, could it be some kind of pre first service ecu thing ?

Help ....

Colin

 

Only thing I can say is that Mustang Dynos are usually about 20 HP off from a Dynojet. Thats still too low though..

 

The Mustangs are usually HIGHER than the Dynojets which makes it even worse. I have never seen AF ratios that bad and as far as I know the Stillen is not tunable. Maybe the problem is with the 7th injector being too large or stuck open? Something is really wrong here. Sorry, I am not familiar with the Stillen setup.

 

You should send it back and go Vortech....

 

Ok, talked to Stillen, apparently on some 04's there is something with the valve timing that results in less than expected boost, hence the 5.2 psi that I'm getting.

The result is that Stillen are going to send me a new pulley to bring my boost back upto 6lbs which will fix the af ratio and bring back the power to an expected 284rwhp on a mustang which it turns out shows 12% less than a dynojet. (this 12% also means that I had 246rwhp before install)

So, mystery explained hopefully, I will update y'all with post dynojet sheets on saturday ...

Colin

 

Colin,

This is a little off topic but, where are you going to dyno? A friend and I want to dyno but, don't know where to go...Would more guys lower the cost? Let me know. Thanks.

Nilo

 

[QUOTE]Originally posted by cersoft
Ok, talked to Stillen, apparently on some 04's there is something with the valve timing that results in less than expected boost, hence the 5.2 psi that I'm getting.

The result is that Stillen are going to send me a new pulley to bring my boost back upto 6lbs which will fix the af ratio and bring back the power to an expected 284rwhp on a mustang which it turns out shows 12% less than a dynojet. (this 12% also means that I had 246rwhp before install)

So, mystery explained hopefully, I will update y'all with post dynojet sheets on saturday ...

Colin [/QUOT
Stillen needs to explain how raising the boost .8 psi will reduce the leaness? Seems like you need to tune the a/f to around 11/12 range. What does Stillen recommend for their S/C in your car? The valve timing is an overlap of several degrees with the exhaust valves relative to the intakes. What T and Hp #'s has Stillen advertised with this S/C?

 

350dgrz:

I have been using FAME (mustang dyno) 425-869-8324 but I will be using Carb Connections (dynojet) 425 820 1871 from now on if things go well on saturday.

jpc350z:

Because there is not enough boost the engine is actually running rich, hence more boost will return the af ratio to about 11.5

Stillen are quoting 384 crank hp, not sure about the torque values ...

Colin

P.s Got the 6 rib pulley in my grubby little hands, goes on tomorrow.

 

Mustang dyno's DO NOT RUN HIGHER...they run 10% to15% LOWER that dynojets . The reason you are not making any power is your A/F is way to rich to even drive the car . It may be that your not getting any boost at all and getting fuel for the boost your missing . It also may just be your tune is that far off. Take it back to the installer ASAP Your more than likely gonna need new plugs .They will foul with that much fuel going in

 

I didnt read the whole thread before I replied .I just get worked up when people think the mustang dyno is a bad dyno. Dynojets are liked so much because of the high hp you get off them . Mustangs are used to get real world hp and to tune the car right. Glad you got it worked out .Check your plugs

 

Got the new pulley on today and will be dynoing tomorrow, feels a lot stronger ..... gonna need new tires soon :-)

Colin

 

you might also be best off finding out what other cars with various mods dyno there, so you have some sort of yardstick to go off

 

"booger" is correct! The Mustang usually shows about 15% less than the Dynojet but to me the Mustang is the better dyno! Correcting the A/F will get you to where you should be.

 

dyno'd the car, 308rwhp and about 272lbtq, pretty happy for a really drivable 6lb system ...

I'll post dyno sheets monday ...

I'm off driving ...

Colin

 

I WISH THIS WOULDA BEEN A STICKY!! as it explains the DJ versus Mustang measuring philosphies fairly well...

i saw about 7% difference in the two, when running a loaded (full weight and control) mustang dyno, and then 'unloaded", to have DJ numbers, sae correction only...

 

Scott...I told the operator of the dyno I use about that artical, and he said he has done tests over the years with a dynojet operator 50 miles away. on the same cars .And his run on average of 12% lower .