A little bacground on the car. efiny turbos with about 7k, motor with about 20k, down pipe, m2 medium intercooler, apexi pfc. the car has also been tuned without any further mods about 2 months ago by Steve Kan.

I dynoed at 277 whp but only at 6500 rpm because the injectors are maxed out passed that.

the probablem is sometimes recently when i get on it from a stop, after the 1-2 shift i hardly have any boost in second gear. its normaly around 5-6 psi and slowly drops untill i shift into third gear. after that the boost is fine. also this doesnt always happen. sort of at randome times but it does seem that when i shift faster between 1 and 2 it hppens more frequently.

Ive checked all the vacume lines that i can easily get to and all seem to be secured.

I'm wondering if this problem is occuring because when i shift at 6500 from 1 to 2 the ratioes put me right into the rpm range that the the turbos are switching over and they have already lower boost than normal.

Any idea? Any help is appreaciated.

 

Start with new check valves - replace the ones that are green/black in this diagram:
http://www.davidgeesaman.com/rx7/93v...lor.edited.jpg

Dave

 

Thanks alot! Where can i get new check valves from? I checked rx7store.net and rx7.com with no luck...

 

PM DaleClark, or buy them from the dealer. You might even find something suitable at the local auto parts store.

Dave

 

Had the exact same problem, end up being a missing check valve right after I bought my car. There kind of expensive from the dealer for a little peice of plastic but well worth it. Try this, instead of gunning it in first gear, try doing it in second gear with a quick shift to third and see how fast third gear builds boost. If the same outcome then Id say check valve.

 

daleclark has a bunch of viton check valves. I got some from him real cheap, and they are working great!