BLOWN8

Today i went to two different places to dyno my car. Both places had dynojet, the second was an AWD Dyno, and the first was not.

Previously, i went to the dyno at Mustang Magic, with the mods: RE intake, SR motorsports High flow cat/ midpipe with resonator, Mazdaspeed exhaust, and CZ stage 2 (modified) ECU.
My best run was:
194.6hp and 139.1 torque

With the CZ off was:
178.8hp and 134.3 torque

Today I decided to go to a different place to get the dyno done because it was for a much better price and it was an AWD dynojet, which doen't mean much but they say it is better, with DIFFERENT mods: RE intake, Rotary performance midpipe (no cat), mazdaspeed exhaust, UR Pullies, and CZ stage 2 (modified) ECU.
My best run was:
181.02hp and 139.45 torque

This number was the best out of 6 runs, with some runs using different maps on the CZ. (some less agressive and some more agressive)
So i decided to go back to the original place were i first started at mustang magic.

At Mustang Magic, with the mods: RE intake, ROTARY perforance Midpipe (no cat), Mazdaspeed exhuast, UR PULLIES, and CZ stage 2 (modified) ECU.
My best run out of 2 was:
188.4hp and 142.1 torque

which doesn't make sense becasue i would think that with the pullies and bigger and less restrictive midpipe, i would put down alot more horse.
Unless the bigger midpipe is to big, and doesn't give enough backpressure, as the SR midpipe? I don't know
Any input would be great.

Icemastr

Wish you could have dynoed with the SR midpipe and rotary performance midpipe on the same day but sounds like the SR motorsports midpipe is better.

dmp

Back pressure is 'never' a good thing; but it could be the larger mid pipe reduces exhaust gas velocity. :-/

still, 195whp is pretty darn good - were those the corrected or measured numbers? Corrected numbers mean diddly when comparing runs on the same day/conditions...

It could be the Correction factor was different at the locations, thus, 'measured' hp could tell a truer tale.

davefzr

Also.. those runs seem pretty accurate.. What was the process that you went through to prepare your car? Did you simply disable DSC/TCS or did you also remove the ABS sensor as well?

Thankx!

dmp

...is that 'the key' to getting numbers w/ the car?

davefzr

It's what I have read countless times on this forum. We are trying to set up a dyno day here in so cali so we'll see what methods they use to dyno the car.

epitrochoid

not even then...after awhile the ECU thinks you're stopped at a red light with your foot on the gas, and it jumps in to protect the cat.

BLOWN8

The DSC/TCS were disengaged, as well as the ABS.
Both of the days that i went to the dyno it was a clear sky, and today was colder than the original day by 15 degrees. So if anything i should have had better pulls today.

BLOWN8

I might swap the midpipes again putting the SR midpipe in and return back to the dyno to try and back track everything.

zoom44

how far was the drive? did you let it cool off after arriving and before the dyno runs? did you do the runs back to back or was there time in between the 2 runs today? thats why you should stick to one dyno and make sure they are or arent using the correction factors and always do it the same way. there are so many variables that can make a 10hp difference that you can never be sure why the difference is there. was the first a Mustang dyno? or was Mustang just the name of the place? from my reading they seem to always show less hp than dynajets do. so there is something strange there if so. but realistically the numbers on the mustang place dyno seem to show a loss of a couple of horses when you switched mods. so it would appear that your original mods made more power the 7 hp difference between that one mustang run and the similarly equipped dynojet run couls simply be a difference between the 2 different dynos.

rotarygod

You can dyno a car on 5 different dyno's and you'll always end up with 5 different numbers. Hell, you can dyno your own car 5 times on 1 dyno and get 5 different numbers. They theoretically should be closer together though. What you are seeing is a prime example of how dyno numbers aren't as important as people think they are. Every dyno is different. The hard part is accepting this since you would think that they should be the same. It's kind of like bathroom weight scales. I have 2 different ones in the house and I get 2 different readings. Either that or I weigh more downstairs than I do upstairs.

When you are using dyno runs to determine how much power you got, first of all, stick to 1 dyno on 1 day. Also, do not ever base performance gains or losses on a number that you got on a different day or at a different location. When you mod the car and redyno it on the same day, base your gains on percentages rather than how much horsepower you gained. This will tell you far more. Which really tells you more, "I gained 5 hp" or "I gained 1/2% more power"?

BLOWN8

I let the car cool off before the dyno runs, and also in between runs for about 5-7 minutes with the dyno fan running.

AlexCisneros

the torque numbers increased... That's always good :D

Also, did you try turning off the cz mod like you did the first time?

Gord96BRG

How did you disengage the ABS? If just pulled a fuse, then the sensors are still providing input to the PCM (bad for power). If you unbolted the rear wheel ABS sensors and tied them back from the rear wheels, then good for getting a more accurate reading from the dyno.

Regards,
Gordon

zoom44

Hymee, i think it was, has shown with his testing that this car seems to produce more power when its a little warmer then when allowed to cool between runs. next time do the runs closer together.

REXNdBst

Well besides the dyno result showing different numbers. Does your car feel faster after you installed the Rotary performance midpipe and the UR Pullies?

BLOWN8

The power felt is kind of the same, plus the power from pullies you don't feel.