Install Advice - Full Exhaust and ECU
 

Looking for any last-minute advice on a full exhaust replacement coupled with an Apexi ECU install. A little info upfront...

I recently acquired a non-running 93 R1 manual that is bone stock. 51k miles. I've spent the last two months running down and fixing about 25 different things on the car that were needed to get it up and running properly, safely, and more reliably as it sat for 3+ years. It's now running great.

I'm wanting to mainly keep the car stock as it's a weekend driver/project car. Not looking to do anything crazy with it, but would like to see if I could get a few more horses out of it while improving the look, sound, and reliability. While going through the car issue by issue, I picked up a 3" HKS downpipe, a Racing Beat dual tip catback, and a 2nd gen Apexi ECU. Today, I ordered a resonated midpipe from Banzai Racing. Currently, the intake is stock.

I have read through Dale's instructions on the Apexi install so I'm good there. Before tearing out the existing exhaust, I'd like a little advice.

1. Recommendation on whether to wrap the downpipe, or leave it as-is. It's not coated.
2. Should I wait to do the exhaust until I can swap out the stock intake for something like the Apexi Power Intake, or go ahead and do the exhaust now and intake later?
3. Should I install the new ECU with the stock intake/exhaust setup to make sure there's no issues there, and then replace the exhaust, or do them both at the same time?

Down the road, the only other modification under the hood that I'm planning is a radiator swap. Once this is all done, I'll probably spring for a pro tune.

Thoughts?

Wrapping the down pipe will bring down engine bay temps a bit. Some say wrapping will trap moisture btwn the wrap and metal causing dmg long term.

exhaust can be installed before intake. Wont have any negative effects.

when working on any part ive found installing one thing at a time and go for a quick spin is a good idea so if anything goes wrong you know where to start looking. It doesn't matter what you do first but i usually do the easier, quicker one first.

I saw a drastic drop in cabin temps after wraping my downpipe. I have a RHD though, which means the dp runs directly under my feet.

Aftermarket intakes don't do much. They make more induction noises but most suck in hot air from the engine bay. I had the Apexi intakes and sold them. Look up the cheap bastard mod for the stock air box. It's costs close to nothing and has proven to reduce intake air temps and increase hp.

I wouldinstall the new ecu first and check it, like you suggest. You said that it is a used ecu so it's better to check and be safe.

What part of Nashville are you from? Lots of us floating around. Especially on the southern side.

No advice, sry.

Another thing to consider that has been mentioned many times - running without a catalytic converter will make your exhaust smell really bad, to the point of being annoying even inside the car. If you don't want to use the OE cat, there are many threads on here with opinions on which aftermarket cat might be best.

Welcome. I'm in Antioch and work in West Nashville.

I would wrap the down pipe.

I would keep the OEM airbox.

I would install a wideband, then install exhaust and monitor AFRs. If it gets too lean, reinstall OEM exhaust until you can get a tune.

This is a good thread if you haven't checked it out already.
https://www.rx7club.com/3rd-generati...added-1104322/

Thanks everyone for the advice. The downpipe is wrapped, coated, and ready to go.

I've decided to hold off on the install until I can secure a Datalogit for my Apexi. I bought the Apexi FC used, and it may have a tune on it that matches my setup. Instead of just wiping what is on there and starting over with a default tune, I want to check it first.

I'm surprised no one had mentioned this, but if you run a full exhaust with no cat, the is a good chance you'll have an over boost condition.

This would be really bad. Having the cat or some type of restrictor will prevent boost creep. Having a cat would be the best option, because our cars stink without one. Also, think of the polar bears....

Vince