Strange loss in boost at 5K RPM

[Krmnnghia]

Need your help guys....So I was hopping on the onramp to hit the freeway and I was in 3rd at about 2.5K RPM's. As I hit it hard it boosted as normal and when I hit right around 5K RPM I lost all boost and the car lunged back as if I lost all power. I let the rpm's drop and thewn I had boost again. Any ideas? I haven't had the problem again in the past 24 hours. My buddy was in his H2 behind me and didn't see anything out of the ordinary coming from my muffler...just the normal small puff of smoke.

Mods are as follows: all Greddy and Dejon IC piping, Greddy S BOV, injen intake, 2.5" exhaust and hi flow cat, stock turbo and downpipe.

Any Ideas? Thanks

 

[CanadianTSi]

You probably hit fuel cut.

 

[Groomz]

You should NOT be venting to the atmosphere.

95-99 DSM's came with the T25 turbo which is maybe the smallest turbo in existence. It starts to lose boost at around 5500rpm's. You are hitting fuel cut, which is most likely from boost spike/creep from the free flowing exhaust. Get a boost gauge and go from there. Also check for boost leaks.

-Groomz

 

[nanokpsi]

I NEVER had fuel cut on the t25. 3" trubo back with o2 eliminator, no cat-bcs restictor removed. I doubt that is the problem with just ic pipes and catback.

Boost leaks would be a good place to start.......

 

[Krmnnghia]

Who said I was venting to atmosphere? I have the injen intake and the greddy is using the stock dump tube. I have pulled the car to about 6K RPM before and never got fuel cut....I guess tomorrow I will tighten all lines andhoses and just keep an eye out. Thanks Guys

 

[WhipmastaFlex]

you're definatly not hitting fuel cut. not with just those mods. i have a 14b, intake pipes, HKS SSQV, 3" turboback, no fuel cut (and i'm venting ). once i turned it up to 16psi, then i hit fuel cut. and fuel cut doesn't just make the car kinda slow down and lose power. it shuts the damn car off and it bucks your ass forward. you'll know when you hit fuel cut. the T25 blows hot air after 5k rpm. you're probably getting a good amount of knock and your car is pulling timing up top. happened with me before i switched to the 14b. when i was at WOT after 5000rpm, my car felt like it was decelerating.