Boost problem
 

I have a 10-8-8 boost pattern. It has been this way since I purchased the car. It was totally stock at that time. I have since added a catback, downpipe, new o2 sensor and a K&N air filter. My boost pattern is still 10-8-8. My car is a 94 if it matters. Any ideas? I was thinking maybe a smaller pill on the secondary. Any other thoughts?
Thanks for any help.
Tracy

Forgot to mention, my downpipe glows quite a bit after boosting. I searched and it seems this is fairly normal, but could be a sign of a clogged cat. Could a clogged cat cause the boost to be low only on the secondary?

Sounds like a clogged cat to me unless there is already a boost control system on your car you are not aware of.

I don't think there is a boost control system. I'm almost positve the car was totally stock when I bought it.

I think with the mods you have listed, you would be seeing higher boost levels than that and even possible boost spikes, not 10-8-8. How many miles on the cat?

My car only has 60k miles. I don't have any problems with boost spikes. Every once in awhile it goes to 11 on the primary, then settles back to ten. There has to be something restricting my boost. It just seems like a clogged cat wouldn't give such consistent numbers.

Also, any ideas what a good search topic would be? I've tried boost, which was kind of overwhelming, and clogged cat. Any suggestions?

Try this thread: https://www.rx7club.com/forum/showth...ht=clogged+cat

or this one:
https://www.rx7club.com/forum/showth...ht=clogged+cat

or this one:
https://www.rx7club.com/forum/showth...ht=clogged+cat

I still think it is a clogged cat, but a quick way to tell is to do the Home Depot manual boost control install. If you can't increase your boost that way, it is either a clogged cat or a boost leak somewhere. Check your collector pipe after the Y-pipe for cracks or cracks in any of the couplings after the turbo.

The fact that your boost didn't go up when you added the dp and cb makes me think that the cat could be clogged. It could be a problem with some of the valves that control the turbos. If it is then this place should help:

http://www.autosportracetech.com/RX-7/rx7stuff.htm

You could check for anything obvious like popped off vacuum hoses, but I'd rule out the cat before getting too deep into the turbos. It wouldn't hurt to check the y-pipe coupling too. You need to take it off and inspect it for cracks. In fact, check all intake hose couplings. Make sure they're tight and there's no leaking.

Good luck

I have a 94 and i have the same problem. I also have hi flo cat. When i first put it on, i got 10-8-9. That's as far as it will go. I also installed manual boost controller and all i get is high primary same secondary. I don't know if some of the 94's have that problem or what.

I've got a solid 10.5psi til redline...oh nevermind I have less 1/3 the vac lines you guys do.

sorry :p

Thanks guys. I'll check over everything you suggested. Hopefully I'll be able to isolate the problem. I'll let you know if I figure out what it is. It sounds like I'm going to be buying a cat, but I'll check everything else you mentioned first so that I don't waste my money. The thing that confuses me is, if it is the cat, then why would it only affect one turbo? Anyway, I'll mess with it more and hopefully it will be something obvious that I missed.
Thanks again for the links.

It's not that the cat is only affecting one turbo, it's that there is much more air going through your engine at higher RPM (aka when the secondary is going nuts). More air demand means that a clogged cat will have more of an effect on the problem.

That makes sense. Thanks for explaining, I'm still pretty new at this.

i doubt it's your cat man. As i said I had this problem forever. I put in hi-flo cat and i only get 1psi up. Still same shit. It's probably a leak somewhere, but god knows where.

According to http://www.autosportracetech.com/RX-...aryExplanation (thanks LAracer), if I disconnect the electrical connectors for the wastegate and turbo pre-control solenoids and get 7psi of boost, then my ecu is what is restricting boost or I guess it could be the solenoids themselves. Hopefully, I'm understanding that correctly. If that is the case, I have a 93 ecu in my garage that I can hook up and see if that corrects the problem. If I don't get 7 psi, then it could be a boost leak, exhaust leak, the clogged cat or any number of other possibilities. So far the only 94's I know of with this problem are BoostinFD's and mine. I'd have to hear of a few others before I would be convinced that it is a 94 specific problem. I guess swapping out the ecu's would answer that question.
By the way, I'm not a man; man ;)

I have a 94 and have no boost issues. In fact, until I put in the Greddy boost controller, I was getting 13-14-12 patterns with cat back and intake.

so have you located your problem man? I'm Still stuck with 10-8-8