Car has a dump-back exhaust running 91oct winter CA gas. First six consecutive dyno pulls shown. Running the Stage 0+ 91oct baseline XEDE map.

WHP and torque:

 

AFR and Boost:

 

Shiv how come you say Winter gas? Is there a difference?

 

There is a difference almost all over the country when it comes to winter fuels. There's a whole lot of things going on with this and will take extensive reading to understand the whole thing.

http://www.epa.gov/otaq/rfgecon.htm
http://www.epa.gov/region02/faq/refgas.htm
http://www.npradc.org/issues/fuels/s..._fuels_map.pdf
http://carbon.cudenver.edu/~landerso/98wa61a01.htm

 

what was the base line on the stock car before the Xede ???

 

Mayhem thanks for the links. I didn't realize there was a difference.

 

Never dyno'd this particular car in completely stock form. It showed up to our shop with a dump back exhaust already installed. This represents the lowest two dyno pulls (208-210whp).

Regards,
shiv

 

thanks , either way nice gains !!! I wonder how much more can you get with a custom tune out of it ...You think 255whp can be achieve ???

 

Unlikely. Usually Stage Zero+ top out at around 245-250 on non-winter gas. On winter gas, this one topped out at 241 (but with a slightly smoother curve) after custom tuning. It's usually not until you get into the Stage 1 level (add cam gears) does power output go above 255whp on 91 oct.

Shiv

 

Shiv,

Any estimate on how 93 octane gas would favorably affect whp??

 

Should add another 10-15whp. Kinda hard to say exactly since all of my out-of-state maps were tuned/tested on a Dynojet which is calibrated differently than our DD dyno. FWIW, identically modified cars, on 93 octane, on the Dynojets at Pruven and BM Tranny usually make over 300whp.

shiv

 

Hey Shiv, when I was in there you told me that I should be using Union 76 fuel because it doesn't contain MTBE... I was told last night that since the first of the year all stations have to be MTBE free. Is this true? Are there any other reasons you recommend 76? It's not the official fuel of Nascar anymore!

-CJ

 

i mainly use Chevron , Shiv how much can you benefit from cam gears .
an can more be achieve out of the cams gears once you get cams for them 264/272combo ??

 

I was wondering why cjbecks car with a dump back made only +10 peak power over the average stock evo's that you test (stk~196 to cjbecks~208)? I had read a post by you that a magazine article got +30 whp by just adding the same exhaust! I can understand car to car differences, but is cjbecks car on the weak side? Can you give some insight? Due to low boost? Otherwise, with the xede it looks pretty strong.

 

Different dynos, different cars, different days. Although I suspect the 1st variable is the biggest contributor. I just don't trust some dynos. I'm much more confortable with the numbers we get from out dyno that was is reported by a magazine tester on some 3rd party dyno that I've never used.

shiv