like 2days ago...here in nyc was very hot outside.
my boost tapers down from 21psi-17psi thru redline...
it happens only on a hot day,,,
its holding fine on a cool day...
anyone know what the problem is? thanks

 

try the auto setting on your intercooler sprayer

 

Turbo cars are greatly effected by the weather. I really wouldn't worry about it.

 

The problem is air density. Temperature and altitude play the largest roles in density. A google search will teach you everything you need to know.

 

haha funny you posted this. mine was doing the same thing, I was going to spend the money and get a new bypass valve because I thouht it was leaking, until today was a little cooler and less humid it was holding boost fine.

 

what bypass valve? is it bov?
i got hallman mbc, aps bov, and it happend to me!
i dont think its affected by hot air... mine used to hold boost 21psi-20psi perfectly fine thru 7k rpm on a cool day.
maybe the rubber hose came loose due to hotter engine bay temp & hotter outside temp???

 

My car feels like **** right now in this hot weather in FL!!

 

I thought it was my stock bypass valve that took a crap on me. Noticed it on friday that it wasnt holding boost to redline( 21 dropping to 18/19). Didnt drive it yesterday, took it out today and it was fine. Im thinking it has something to do with the humidity, and moisure that it rained all week.

 

Thats why I only drive mine at night

 

Mine does the SAME exact thing...pisses me off. Need some good booze for the car to lower the intake charge!

 

bump

 

Make sure you are measuring in the same gear. 4th is best (on the 5 speed)

Heat will greatly effect performance of cars, as it's all about air density. Hot air is less dense than cold air, hence the reason your car works differently in the different temps.

 

yep this is very true....when it was winter up here i had to turn the boost down because i was spiking straight to boost cut at like 25psi.....now i;m struggling to get it to hold around 20-21. DAMN HOT WEATHER! I still want to test from boost leaks and stuff....but i think the hose i bought to build one is going to be too small. Nothing is ever easy.

 

but 21psi to 17psi ?

 

MBC.

Everyone says EBCs are useless and not worth the money but a MBC is a metered pressure to the wastegate. Regardless of air temperature, humidity, etc. A good EBC attempts to keep the set boost level throughout the RPM range. So where a MBC will drop from 21 to 17 an EBC will not. Of course I speak only of the HKS EVC V because it is the best one on the market currently. I can assure you a EBC will hold more boost in this situation.