boost spikes with a test pipe
 

has anyone experienced any bad boost spikes by changing their main cat? is this really bad? I just bought an fd with a test pipe and a catback along wiht reliablity mods but should i change the testippe back to the main cat? i just wanta keep things on the safe side...also, im running stock boost right now...

We don't use the term "test pipe" here..:)

I thought you posted you had a downpipe before? Is your main cat removed as well?

The stock FD exhaust is pre-cat, main cat, and cat-back. The pre-cat is replaced with a "downpipe". The main cat is replaced with a hi-flow cat or a "midpipe". The cat-back is replaced with a...cat-back!

If you are on the stock ecu, you definitely do not want to be running a midpipe, but a downpipe is just fine.

You don't want it spiking over stock boost. The cat-back is probably the main thing that's really opening it up for that, so I'd just stay out of high boost and save for an upgraded ECU.

sorry, new to the roptary lingo but yeah i have a dp, midpipe and catback...im gonna take your advice and put on a cat asap...so since i changed my catback i should upgrade my ecu?? sorry guys for all the threads but im new to this.

Well, when you typically do more than two mods to the intake and exhaust you're going to experience boost creep. The wastegates on the stock turbos can't bleed off the boost quick enough so this is what causes the spike when the airflow is opened up. The spike usually isn't much, but it's sometimes enough to cause a lean condition and blow the motor. By upgrading the ECU you run less of a chance of this as the fuel maps are beefed up and you're supplied more fuel to prevent a lean condition.

also, since im running the stock ecu, should i change the midpipe to a main the main cat or a highflow cat? whichever is safer ill go....

You should be able to just get a boost controller to keep your boost levels down. Use that as a temporary fix until you can get an ECU upgrade.

Same conversation once again...

https://www.rx7club.com/forum/showth...hreadid=204852