Went out to Sacramento raceway last night. Heres a quick rundown of my car's setup.

06 Evo IX GSR 5-speed
stock IX turbo, E85 fuel
17" BBS MR rims with 245/45/17 Hoosier drag radials (23psi)
Megan coilovers 7k front, 5k rear

I did 2 runs and the 60fts were my personal bests. But both runs had very low trap speeds considering I'm on E85 fuel and made 400whp/388wtq at GST Motorsports.

first run...
I1 - 1.600
I2 - 4.949
I3 - 7.882
MPH (I3) - 83.451
I4 - 10.425

E.T. - 12.566
MPH - 107.964

second run...
I1 - 1.573
I2 - 4.823
I3 - 7.730
MPH (I3) - 84.855
I4 - 10.269

E.T. - 12.406
MPH - 108.174

What could be the problem? This was my second time on E85 and both trips yielded just about the same results.

 

Wow that is low.... maybe try a boost leak test, you might have a boost leak somewhere

 

Clutch still good?
You are down on mph even by the 1/8 mile.

 

Wow, that thing is trapping really low. What altitude? Any logs? A log of any run should help tell the story, whether the clutch is slipping or if their are other problems.

 

Thats odd, I agree with the boost leak test. Probably have a nasty one.


And yes, aside from your mph being low at half track too, when you cross the traps, do you have to shift into 5th?

 

You might be pulling timing, I would log it. There icould be a chance the track is off, did you get a chance to compare your times with other vehilces?

 

Temp of your dyno vs temp while at the track? Def do a boost leak test.

 

Forget about your dyno numbers also. they dont mean jack. Its all about what you do at the track. those numbers dont sound so bad.