I just got a new evo with a 2.4 37r, meth, etc... I turned the boost up to 25psi and everything was good.. tried turning it up to 29-30psi. The car began backfiring during boost. What could be the cause. I know that usually it means that you are pushing too much boost, but there is no way that 29psi should be too much for a 37r. Could the meth not be completely on or something?? Anyone have any ideas. P.s. car only revs til 7000rpm.. I'm guessing that can be fixed with tuning right??

 

Of course you need tuning! Don't tell me you were raising the boost without simultaneously tuning the ecu to compensate for the changes in air/fuel. That's just dumb.

 

I agree completely. The backfiring is probably too much fuel/meth running through the cylinders and igniting in the exhaust.

 

i would leave it at low boost untill you get professionally tuned

 

You probably ( in addition to a tune), need to gap your spark plugs. Do yourself a favor and get a wideband o2, monitor your a/f ratio. Your back firing is probably caused by unburned fuel from a misfire(boost blowing spark out) and the heat of the turbo/exhaust igniting the unburned fuel. Hope that helps

 

you can't just assume the car can run at 29 psi

you need to have the car tuned before you start playing around

 

Yes! Get it tuned ASAP!

 

AHHHHH everyone..I didn't just drop the parts in. I bought the car previously built..etc. It has been tuned by shawn ivey (i believe) I know it was built somewhere over there. I was told by the previous owner that it could possibly be the sparkplugs. He said they may be going bad because the tune is either lean or rich (i forget) and they burn out quick. He also left me a jug of windshield washer fluid to keep the meth tank full. (He didn't know i was going to turn up the boost) I know that windshield washer fluid has properties of methanol in it, but isn't it like half water too. I was told the car was tuned for full meth only, maybe this could be the problem...but i plan on getting a retune very soon. I have turned the boost down to 18psi, and it still does it in first gear. I will turn it down more in the morning.

 

Dont bother, just stop beating on it until you get tuned, and get the Denso IK24's spark plugs and gap them accordingly.

 

yah? WHt's the name of the previous owner? I am sure I can tell you more about the car.

Sean

 

Bill .. he has a bunch of tattoos on his arm.. sorry if you're not the one who tuned i am almost sure he said you are though... here is a link to the car
https://www.evolutionm.net/forums/sh...d.php?t=358216
look familiar??

 

Well, the thread says Shawn Ivey. No clue who that is as the tuner I know is SEAN..

 

If its tuned...then why it only revs til 7K?

 

Car IS tuned..i talked to shawn ivey.. he said that he did indeed tune it a while ago. He doesn't know why it only revs to 7000rpm. He didn't set it up that way.

 

get that thing tuned asap before that nice mod list is poured out on the street.