I have just recently installed an apex'i n1 dual exhaust and about a week after installing it I began seeing some weird problem. I like to street race it and when I'm racing when the tac hits about 4k the engine starts to like not get enough power to accelerate and then it begins to pick up again, after it starts going again it's increases revs really fast like normal, but then when I **** it will do it all over again. I talked to a few people, someone suggested that since I have a 88 rx-7 non-turbo that because it's a 6 port rotary there may not be enough back pressure to open the secondary intake ports. the first steps I took to try to figure out the problem is I changed the fuel filter, spark plugs, ignition wires, and I added 3 bottles of STP fuel injector cleaner and ran it on high octane fuel. the ignition wire were the last thing I replaced and after I did the car immediately ran at 100% efficiency! that was last week and now today I was whipping it around and it started to do it again. I would greatly appreciate any help anyone can give me on this problem. I hope someone has experenced it or knows whats wrong, the exhuast is designed for a non-turbo so I don't think it's a back pressure problem. It's really starting to **** me off cause i lost to an intergra the other day! If you want you can e-mail me at USNALAX1@RCN.COM.

 

I think that they call this the 3800 rpm hesitation. Use the search button up above and search for 3800 hesitation.......

This might help.
http://www.atlantarx7.com/secondgenfaqs.html
http://www.geocities.com/motorcity/d...299/ground.htm
http://www.johnr.com/rx7faq/faq3.html
http://home.rmci.net/panther/faq.htm

 

is it only while its driving?? why dont u rev the engine manually and see if they're opening in time and completely... if anything sounds like clogged injectors or bad grounding.... and stp fuel injector cleaner wont do a damn thing if they're clogged to a point where it hesitates...

 

when i rev it in neutral it's fine. but once it's in gear the damn thing won't move at 3800 rpms with alot of throttle.

 

Like DeadRX7Conv said, its the 3800RPM hesitation. Also if you are running a midpipe (no cats), it may be be lack of backpressure causing the 6th ports to not open, but usually with that problem, they dont open at all, but you are saying it picks up again, so its probably the hesitaion. There have been countless posts about it and how to fix it, use the "search" button on the top righthand corner of the page, and type in "3800 stumble" or 3800rpm hesitaion", or something similar, you will find tons of info.

By the way, where is Easton PA?

 

it's in PA by right near philiburg NJ...it's about a 80 miles from NYC