I currently am running a AMS GT35r kit on my car and made 407 awhp. When I was running, my idle was very bad due to my weird injectors. Suddenly the car feels 10x slower then it use to be. I am still hitting full boost, actually even more boost as both my gauges show more then 21 psi, which my MBC is set for. My list of mods are: AMS GT35, AMS DP/TP, 910cc Injectors, Stock UICP, LICP, Greddy FMIC, Head studs, Fuel Pump. At boost, I am running perfectly fine, but the car is very sluggish. I really can't find the problem, as I have really checked everything from the piping to the oil. Does anyone have any suggestions? Thanks alot.

 

Check your compresion on the motor.
Check your cam timing
Do a boost leak test, and no looking at everything does not count.
What engine managment are you running?
Do you have a wideband?

 

x2 let us know when you find out what it was

 

I would take out the compression, and do a leak down test

 

keep us posted i am in the same boat 370whp at 23psi on my 35r mine is less so dont feel bad lol

 

My guesses:
1. Summer is arriving in SoCal. With the big turbo (35R) and hot weather, you will have more turbo lag.
2. With the hot weather, you make less power due to less dense air.
3. With the weather and the big turbo, a 1 psi difference in boost due to warmer weather can make an easily noticible difference in power.
4. As you get more and more used to your power, your car feels slower.

Do the other checks as others have mentioned above for piece of mind: boost leak, compression, etc. Then, do a log of a couple of WOT pulls to double check that you are getting no knock.

Good luck...