I took my car today with new mods and I'm depressed. For some reason it just doesn't make the power everyone else seems to make on this forum.

Here are some before and after dyno's. The mods are as follows ( My car is a 2003 G35 5AT ):

Before:

Vortech w/ 3.12" pulley with idler pulley mod
600cc injectors
walbro
Skunk2 Plenum Spacer
Testpipes with oem exhaust
1 step colder plugs

After:

Vortech w/ 2.87" pulley with idler pulley mod
600cc injectors
walbro
Skunk2 Plenum Spacer
Megan Racing long tube headers
"Nismo" replica 3" exhaust
cooling fan on the intercooler
1 step colder plugs


Here is the dyno:


The exhaust, headers and pulley only gave me 11whp?

A/F was in the mid 11s and timing was in the 18's. I could go higher but it would start to knock and lower would lose a decent amount of power. Boost would top out at 12psi.

 

assuming the tune is good. do a compression check to see how healthy the motor is.

 

sorry to hear this.. i feel you.

you seems to have boost building up, so, no boost leak. and since you have this much boost, then there isn't any slip.

how's your AFR?

try to compensate this with race fuel.. see how much you get.

 

one more thing came to my mind... how's your tranny?

 

you got 290ish whp with the 3,12 pulley?

 

I'm getting the same numbers as you, however i have the hks kit, tomei headers, different exhaust and the kinetix manifold on stock pulley.

How much extra is the smaller pulley supposed to give you?

 

May be a good idea. My car has 80K miles and before the Vortech it put down 240whp which isn't too bad. I DO have 20" wheels which I know don't help but getting only 11whp more from these mods is ridiculous.

A/F is mid 11's.

Seems fine, it'll even chirp 3rd gear. I do however wonder how well it maintains 3rd gear clamped down though...it does have 80K miles after all and is stock ( just has the trans-go shift kit ).

No, I put 349whp with the 3.12.

 

349whp on 3.12 and 360whp on 2.87 isn't really bad tbh. i know you should probably be seeing 380-390whp, but look at other factors that might be affecting your setup.

3" exhaust isn't always the best move to do when FI, this might contribute to your power loss.

 

240whp on an auto? Same dyno? I (and most i believe) achieve 230-240 whp stock with a manual trans.

 

Does seem a bit low for 12psi IMO. I hit 414whp at 10psi on my custom Vortech system. The only thing I would say is that the replica NISMO exhaust could be hurting you. I believe boosted performance just found out how restrictive the exhaust they were using was.

 

240whp was with the testpipes and plenum spacer on the same dyno.

I can't think of anything else...I feel like dynoing again and unbolting the muffler to see what happens.

 

I'm pushing 410 whp with a 3.12, manual transmission. Your exhaust could be the problem. Also if your Auto in a G that number is correct.

 

That is what I would do. I bet the muffler is where you are loosing a substantial amount of power. Good luck.

 

you're missing a lot of power. most folks (including the 5ATs) with the 2.87 and similar mods are at or above 400whp.

 

somethings not right there....the graph shouldn't double back on itself.

Also that line is pretty squiggly. I'd probably look into a different tuner.

 

^ the circled area is where his torque converter locked up.

 

i would have to say it's a auto trans thing. I have header back exhaust 3.12 pulley 10psi different intake though and some other things and i'm at 397whp without water/meth injection. I have a manual. Thats what I have to say about it.

 

Yup, that's the torque converter locking up. Even bone stock it would do it.

As for the squiggly line, it's always done it. I'm also my own tuner...lol.

Today I installed a 3"cutout.

 

That is why it's low...


J/K..

You're an auto so that didnt help. good luck..

 

Are you running really conservative timing?