here's the intro:

last winter, i ran my car at the speedway and my best time was 15.2. i had the rrm non i/c t28 (7psi)with their crank pulley and intake manifold, a 2.5 in exhaust and stock rims with some neogens.

the problem:

i ran last night with a mishimito intercooler/ custom i/c piping, greddy ebc (7.5psi), test pipe, stage 4 clutch with a 12lb fidanza flywheel, custom 2.5 in down pipe, heat wrap from J-pipe to exhaust pipe and 17 in motegi rims that apparently weighs around 6lbs heavier than my stocks (each) but had tires that were wider for grip . why was i running mid 15s all night? my old setup ran consistent low 15s..

its was also hot last night, the weather was probably around 90 degrees compared to las winter's 45 degrees.. any advice or ideas would be greatly appreciated.

 

well the weather plays a big factor but I want to ask you did you perform any checks on your car before running ie boost leak, tire pressure so on and so on.

 

no leaks, i ran my car with the tires set on 30psi just like how i ran my car before.. i was honestly expecting a 14 sec run since im packing a little more power.

kinda sucks when you run slower than before. lmao

 

Its slightly obvious that cold air is denser then hot air , meaning the turbo can pack more useful air into a tighter space and make more power .....

it is the weather 100% , anyone that runs will tell you this and its correct

 

What are you tuning with? The weather will also play a big roll considering the two very different temperature swings you were experiencing.

 

not tuned yet, im waiting for a harness to tune the car with an emanage. would the weather affect my times this drastically?

 

how big of factor are his 17" wheels? They are heavier so that will slow you down as well. Try running a 16" or even 15" rims.

 

Umm.. at low boost, im sure smaller rims will not change much. slicks or drag radials might make up a difference in a few tenths, but nothing crazy. Temp, track temp, and the cars tune would all play a big roll in the car not going as fast as you were hoping to see

 

You're running 7-8 psi on stock timing?

 

basically. why?

 

Cooler weather is always better