chris1994rx7

Hi everyone,

I just went through a decent overhaul on my 94 RX7
the upgrades that are in place are
new vacuum lines, new High flow cat, new aluminum pulleys, racing beat dual tip exhaust, new fuel filter, and new turbos these are the new turbos

It also has a turbo timer installed by previous owner.
I was reading on turborx7.com and it says " it is commonly replaced with a mid pipe or a high flow cat. As soon as this catalytic converter is replaced, the exhaust back pressure is radically different and a tuned or aftermarket ECU is needed to compensate for the sudden increase in flow. If left untreated, the turbo will have less restriction and in turn, without the proper upgrades, will spool uncontrollably faster. This results in boost spikes, uncontrolled increases in the amount of air pressure given from the turbos." Link to site


I found out my turbos where leaking oil bad down the exhaust and broke the cat. That is why I replace the cat and the turbos. At this point I just want to be able to drive the car safely, I plan to put the FC commander in the future, but need to know if this is an absolute necessity before I start driving it?

Thank you

lduley

iTrader: (1)

You can drive it, just don't have any fun with it because you could get a bad boost spike and pop goes the rotary

If you drive it calmly and not make it boost until you get the commander, you should be aight

Sgtblue

iTrader: (16)

The information in that link is wrong. There is boost SPIKE and there is boost CREEP. While both can result in a lean condition, they have very different causes.
*Boost SPIKE is caused from opening the INTAKE side. As the name implies, it's on-set is sudden, often first seen on cool mornings or evenings when air is denser. It is controlled with a boost controller.
*Boost CREEP is from opening the EXHAUST side. Too little back-pressure causes the relatively small wastegate of the stock twin turbos to be overwhelmed which results in a more gradual but equally dangerous lean condition in the engine. The only way to avoid creep is to port the wastegate (not an easy job since you have to remove the turbos) or keep some back-pressure in the system. A cat, even a high-flow cat, should be enough.
And adding a PFC won't help with spike or creep since you can't really tune for an abnormally high level of boost.

All that said....the addition of a hi-flow cat alone, along with your other modifications, won't result in creep. You are maintaining a cat. That along with your cat-back will provide enough back-pressure for you to avoid creep and keep it at 10 psi. You would risk it if you installed a mid-pipe which provides virtually no restriction.
And I'm speaking from experience. I have a downpipe, a BONEZ hi-flow cat and arguably even freer flowing cat-back than your's...and have never had creep. Still, if you don't believe me, feel free to search the 3rd Gen. section.