it very well could be excessively cold temps... my friend's GSX has an overboost prob when temps are down......

 

for the last time..check for boost leaks.

 

what's up guys.
I have a question, I do not have the money to take my evo to a dyno but I have these mods:

I have hks s-sbov, s-afc, ground cables, mbc, intake, exhaust, no cat, downpipe, and running 21psi, and when the bov blows in spikes to 26psi.

How many horses do you think I have?

My evo also backfires on hard and quik shifting, not too loud. what could it be?
Is it dangerous?

 

Your BOV should not be spiking that hard with a MBC. You need to check for leaks. With your mods you should be around 300whp/280tq would be my guess. Give or take.

 

Turn your boost down and get tuned. 26 psi is pretty dangerous without any form of engine management.

If you want an accurate gauge of your hp go to the track and post your trap speeds.