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Discussion Starter · #1 ·
I went back to TurboXS today for another dyno run. This time I had my ATP racepipe in. When I first arrived I had about 1/8 tank of 94 octane. After several runs we put 1/2 tank of 100 octane unleaded race fuel (CAM2 GT 100).

I was a little dissapointed with the results. The racepipe didn't seem to make much difference at full boost. There is a little more HP from 3000 to 4400 rpm, but not at peak power. (Hector, you were right man.) The power curve is a little smoother tho'. The torque is hard to compare, since the HP is SAE corrected but the TQ isn't. The weather today was warmer and more humid than the first time I dyno'd it, so the results are probably a little lower today because of that.

Interestingly, we ran the car at stock boost (12 lbs) for one run, and it measured 240 HP, so it's possible the exhaust mods are accounting for that extra power, but it doesn't seem to make a difference at full boost. The speculation is that most of the resistance in the exhaust system is catback, but time will tell.

The 100 octane fuel allowed me to run a little more boost and gave me about 8 more HP, but it seems that the ECU is not able to take advantage of the better fuel. Perhaps the timing advancement is already max'd out.

Anyway, it was worthwhile for the learning experience alone. It's going to take us awhile to figure out what makes this car tick.

Later,
Dan

Bottom line, today's measurements: 265.3 WHP (SAE Corrected), 293.4 WTQ.

Legend:

Dashed red line: My baseline run on 4-18.
Dashed blue line: My run today with no cat + 94 octane + 16.6 psi boost.
Solid red line: My run today with no cat + 100 octane + 18.1 psi boost.


http://import.h8rs.com/drolander/2003-04-26-TXS-HP.PNG
 

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well time to get the catback replaced and see if thats really it! im betting it is a little that, and the rest is ecu. if turboXS would get off their ass :p and make a utec for this thing, the hp would be amazing with a custom map.

dammit i cant wait. any of you rich guys wanna give me a loan? :lol:
 

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Yeah Dan,

A 3" highflow cat is pretty big for our setup. I sell those for the TT supras and those put out 400 + to the wheels so Its definatly has alot of flow capability. It will be some time before you would need a race pipe.


Its good becaue you guys can stay legal and run with a highflow cat and not loose any real power. The only differenve you might notice is in the sound.


Dan, go dyno your car again, this time disconnect the catback rught after the cat. :)
 

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How long does it take the ECU to adjust to a different grade of fuel? I was under the impression it took a while, it has always been a habit of mine to fill the tank with octane boost/race gas before I go to the track, so the ECU could adjust on the way there.
 

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Dynapack I see. I had my R/T done on a Dynapack, corrected. Here is a good example of its accuracy. The day I dynoed my car a stock E36 M3 dynoed 207hp to the wheels, being it's 240hp flywheel rating this comes in at 14% drivetrain loss, I would consider that very accurate. Here's my run.

http://webpages.charter.net/dragomni/mydynoscan.jpg

My car would have been making approx 250hp at the flywheel with 217hp to the wheels, 25hp more than stock, K&N drop in and 3" cat back which is a major upgrade on the R/Ts, pretty accurate.

I like the Dynapack, "supposed" to be more accurate, and best of all it's easily portable.
 

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Discussion Starter · #11 ·
DODGETWEAKER said:
P.S. - Looks like the dyno at TurboXS is running alittle high. Do you have a run with the car in total stock configuration? Maybe you should visit another dyno to see if the car puts out the same numbers. When is the last time the dyno was calibrated? The only thing I trust chassis dynos for is A - B comparisons. Focus on the delta in output not the abosolute value until you can back the numbers up with runs on a different dyno. My rule of thumb is +Delta=Good & -Delta=Bad. :lol:
I didn't dyno my car stock, but the TurboXS project car dyno'd at 230 stock, 265 with MBC. I agree that the delta is the important number. The June issue of Turbo Mag has an interesting article where they took a car to 5 different dyno's in one day and got very different results at each. Interestingly, the Dynapack they tested was right in the middle of the bunch.
 

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Discussion Starter · #12 ·
el_jefe said:
How long does it take the ECU to adjust to a different grade of fuel? I was under the impression it took a while, it has always been a habit of mine to fill the tank with octane boost/race gas before I go to the track, so the ECU could adjust on the way there.
We reset the ECU to let it "learn" with the new fuel and made quite a few runs on it. I don't know exactly how long that process takes, but after the first 3 runs we weren't seeing anymore changes.
 

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Discussion Starter · #13 ·
DODGETWEAKER said:
Most all OEM engine management systems with a knock sensor do not advance spark when higher octane fuel is used. The engine is calibrated on the recommended fuel and the knock sensor is used to protect the engine if lower octane is mistakenly put into the car. If knock is detected, spark is retarded until knock is no longer detected. Over time, spark advance will increased back to the original level as long as there is no knock present. Until a octane sensor is invented for a vehicle, a car with stock hardware and stock calibration will not see any power gains using fuel with an octane higher than the recommended level.

If you are seeing a gain with race gas, it is because the increased boost was causing a leanout condition and your engine was retarding spark due to knock with pump gas.
I'm sure you're right with regards to domestic cars. But what they were telling me was that Japanese cars often have their JDM maps still in them because they are tuned for higher octane gas in that market. So they can take advantage of higher octane fuel by advancing timing until the knock threshold is reached. We wanted to see if maybe PVO slipped something into the ECU. ;-)

I'm looking forward to that UTEC.
 

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so what do you guy's think my car would produce hp wise with the mods i have and the 100 octane sunoco gt running 20 # of boost
52 mm tb
holley 255 ltr hr pump
+20%inj
grainger and wastegate bleed set to 20#
adj fuel reg
K&N cone filter
91 an up coil
8mm wires
aftermarket fan
aluminum vacum block
talon bov moded for 30#

:twisted:
 
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