steinvb12

iTrader: (4)

Just wondering if there can be much of a difference from one Dynojet dyno to another? I recently had my car on a dynojet dyno and produced 302 whp with a 3rd gear pull. Then this past weekend I took it to another shop with a Dynojet and it produced 282 whp with a 4th gear pull. Right after we did a 3rd gear pull and it was about 290 whp. But that would indicate it is still reading 10 whp low. Why would this happen??

The only difference between the two times is that instead of stright 93 octane, I used a 93 and 100 octane mix (half and half) and turned the boost up from 22 psi to 23 psi. And it seems the 2nd time was still lower than my original dyno reading. I would think if anything it would be higher, especially since they are both Dynojets.

My mods are:
Utec Piggyback ECU
HKS Cat-back Exhaust
HKS 264 cams
HKS Cam Gears
Greddy EBC
Walbro Fuel Pump

1st time: 302 whp
3rd gear
93 octane
22 psi

2nd time: 282 whp
4th gear
93 and 100 octane mix
23 psi

Anyone have any thoughts? Or is it typical for all dynos to read differently even if they are the same type?


steinvb12

GTVEVO

iTrader: (22)

Basically no dyno reads the same, since you were at two difference shops they probably had the dyno software setup alittle different compaired to the other. There are factors day to day that impact the reading even if they are adjusted the same also. Honestly no dyno will read exactly the same, this is why you usually find one and try to stick with it and do testing before the mod then directly after so you can see a true difference in gain.

Dynos are fun but on the other hand if you switch around they can be frustrating. I wouldn't worry about it to much.

steinvb12

iTrader: (4)

Thanks for the input. I wasn't too worried, but I'd just thought I would get another opinion. They had a stock SIT come too, and it put down 240 whp, which I would think it fairly accurate. However, the 4th gear for a 6 speed is difference than 4th for a 5 speed...

Also, what is the difference between doing a pull in 3rd vs 4th. Shouldn't the dyno also have to adjust for that?

GTVEVO

iTrader: (22)

When you test on a dyno to get the best accurate results I believe you want to be as close as a 1/1 ratio as possible in the drivetrain. I believe 3rd is a little low and 4th is alittle tall so opinions vary with different dyno operators. I don't know the exact pieces of it but this is what I was explained so others might be able to answer that question alittle more indepth for you.

Evo348

For every car before it gets on the dyno it has to be at full working temperature( water temp gauge has to be in the middle) and since the evo VIII gsr is a 5 speed, then the most accurate gear would be third. Unlike the MR version that's a 6 speed then the most accurate would be fourth, just like in skylines and supras. A dynojet would be the most accurate to really measure you WHP, try to stick away from mustang dynos since they dont read awd. Its a dissapointment to just guess your whp than just dyno it right? well take care bro i hope this helped you.

BadazzCR

iTrader: (5)

There is no way to manipulate the Dynojet software to get higher readings. So as long as you dyno'd with the SAE correction both times on both dynojets there should be less than a 2% difference.

steinvb12

iTrader: (4)

What should the SAE correction be? I believe one dyno map had .99 and the other "1.00 uncorrected". This can't be much of a difference, can it?