Well I am about to enter the world of RX7 ownership within a few days. I have been lurking here for quite some time , and thought I would ask about midpipes. I have read almost all of the FAQs , articles and archived posts , but I can't seem to come to a solid conclision about running a midpipe.

I am purchacing my RX7 from a local member , the listing can be found here...

https://www.rx7club.com/showthread.php?t=568973

The car currently has a midpipe and has been modded with the poor mans non sequential mod as well. After doing some research I am having a manual boost controler and a 2in restrictor plate installed before the drive home ( 1150 Miles) . From what I understand this is good preventive maintenance for boost creep , but it most likely will not eliminate it. From information from the FAQs and the forums I have read this can still be an issue with the stock ECU and under high stress it could cause detonation , any advice on this?

I plan on driving the car conservitavly on the ride back and keeping a good eyes on the Boost guage so I can keep it on the safe side. This car is a really big deal to me , and I just want to do everything right. Sould I look into a PowerFC + Commander and or a high flow cat for the sake of ultimate reliability?

I'm sure this question has been asked a million times before , but I just got a lot of contridicting information about the whole midpipe setup , and thought I would see what the general consensus was. Thanks in andvance for your help!

 

If you are going to run a midpipe on the STOCK ECU and STOCK Turbo's with a non ported wastegate then YES GET A RESTRICTOR PLATE IN YOUR EXHAUST ASAP. I run a 21/4 restrictor plate between my midpipe and catback with no bad effects and no boost creep due to the stock sized wastegate being overwhelmed. If you do not on your first, second or third WideOpenThrottle run you have the potential of blowing your motor due to boost creep if your stock ECU doesn't hit fuel cut first.

Get a PFC or any EMS that can compensate for the midpipe.

Other than that welcome to the Forums and the FD RX-7 and happy rotoring.

 

If the owner has been running the car in that condition (boost creep, stock ecu), the motor may already be damaged or on its last legs.

EDIT: Nevermind. Lane Change is a long term member here and it looks like he was running a Pettit ecu with the car. I would ask him about the creep issue. Installing a restrictor plate is perhaps a good idea. You don't have to mess with the boost controller, though, you can just unplug the wastegate actuator solenoid (in front of intake manifold).

 

You don't necessarily have to install the plate for the drive home. Just keep your foot out of it and drive it home nice and easy, then you can turn wrenches back in your driveway.

Dale

 

Like the others said, boost creep is clearly observed on a boost gauge. Ask the seller what boost it's tuned for. Then on the test drive, see if the boost hits it's limit and stays there. If it continues to rise, it's creeping. If it's going to creep, it will generally only happen at full throttle - use less throttle and the problem is solved.

The one place where you might need to be careful is making a highway pass in 5th. The boost reaches max pretty readily in 4th and 5th.

Dave

 

My worry exactly. I hit 15 psi in 5th above 80 mph without even trying.

 

Wow with mine use to be automatic It would come up to about 7-8PSI if I passed in OD. The Boost spiking is horrible with the automatic. I am glad I converted to Manual. When the tranny switched gears the boost would spike +3 PSI and come back to 10PSI after the gear switched.... VERY DANGEROUS.

( Manual > Automatic )

But yeah just watch the boost level and you should be OK just no WOT runs until the plate gets installed betweent he MP and CB.