I need some serious opinions from experienced FD owners. What would happen if I opened the exhaust and intake completetly on a 93 base model?

The engine is stock and has good compression and relatively low miles. I plan on cutting the exhaust right after the pre-cat and running it to the side. Later I will gut the pre-cat or install a downpipe but for now I will just run the pre-cat and wide open turbos (removing the airbox and air-pump.

I am aware of the obvious issues :

1. Make sure the car doesn't catch on fire.

2. Make sure nothing gets in the turbos.

3. Make sure the car doesn't overboost.

This may sound crazy but I want to hear the REW with open intake and exhaust. I have done this to other RX7s and they sounded great but I know the third gen is not to be messed around with like this. I don't care if something breaks I will upgrade it.

I plan on installing gauges later and if the car is leaning out or overboosting I will have to intall a restrictor pill in the hose to control it to near stock boost and I may run race gas. For now I will just start it up with open intake & exhaust and rev it a few times. I may add octane booster later.

What do you all think it will sound like? Any potential problems I am not taking into consideration? How many psi do you all think I can get? What psi is fuel cut?

Thanks for your advice in advance.

 

wouldnt do it if i were you........it will sound obnoxiously loud....and you will be punished by the rotor gods......

 

Holy shiet!!! It's loud as hell but man it sounds cool. I will start it in the morning it is way too loud. I haven't revved it yet. Wow it sounds badass. Will keep ya'll posted.

 

Without proper engine mangagement I do believe that you are inviting disaster. Open header style noise is fine, detonation is not. Get engine management, guages, etc, then open things up.

 

I don't think it will detonate dude. Detonation happens under load (boost) and I am boosting like 3-5 psi when I rev to 9 grand. So I just have to warm up and keep the intake air clean and new plugs and synthetic oil and I think I can rev the shiet out of it every morning on my way to work. I shift at 5000 rpm in second and up I only redline in first gear. In my previous experience in turbo rx7s I think I found that overboosting mostly happens in the higher gears and detonatiom in high rpm. Thanks for the comments though.

 

I wonder how many psi I would get in first. When I said 3-5 psi at redline I meant in neutral I expect at least 9 in first with this crazy setup. I should be ok up to 12 psi at least for a while no? I promise I won't redline second gear.

 

Totally trollin'.

 

Most people I have spoken to don't go over the stock boost pattern (10-8-10 on the twins) without engine management, especially with modded exhaust. I just noticed in your profile that you are talking about a TII, so forget what I said about twins. But I still would be very careful and stay out of the boost. I believe what you are doing will lean out your A/F to a point that I know I wouldn't want to even screw with. Good luck and I hope you don't pop it. You have added plenty of air and no extra fuel (no hiflo fuel pump, no computer, no injectors), just my opinion here.

 

I agree about the fuel. But really what do you think will it blow up just by idleing or revving in neutral? I don't think so. Do you think it will make it around the block? By the way I am talking about an fd

 

If you have an open intake and exhaust, it will be building boost so quickly and running so lean while doing so that you're serioulsy risking detonation. Even putting a downpipe and midpipe on the car is deadly to most engines without some sort of engine management/boost control. Don't do it unless you really wanna rebuild the engine.

 

911 I know thanks but do you think the car will blow if I just rev it in neutral? What about flooring it in first? Do you think I will get away with it. The car is insanely loud. Can't wait till my neighbors wake up so I can start it again.

 

ok, just running the car in nutral? WTF is the POINT? so you can sit in your yard and **** everyone else off? wow. why don't you go do a couple WOT runs and tell us what happens. my money is on a blown engine, but i want you to try it anyway.

 

I know it sounds like a waste of time but I am waiting to save up some money for aftermarket intake andexhaust so I removed the stock ones since I am not driving the car right now. I know it would blow up at wot thanks I was just wondering what would happen if I redline first in front of my house. I do not want to blow up a good third gen motor out of stupidity but I love the sound and I want to video tape it it sounds like a racecar.

 

yeh, ok, don't do it, running open down pipe on the stock ECU in any gear is asking for trouble. even without boosting you are still flowing WAY more air through the engine with open I/E. don't.

 

ok...dont....leave it alone till you can mod it properly.....

 

Yer an idjit

 

wow it's so loud kewl

 

If you're saving up money until you can get a proper intake and exhaust on it, then why didn't you wait until you can get a proper intake and exhaust to take off the old ones? Were you just bored and felt like fighting rusty nuts and bolts?

 

yes. it hurt but pain is love and yes i was bored. merry christmas

 

If you are going to rev the engine in neutral, make sure you only rev it slowly. A quick rev (even in neutral) will cause some boost build-up(5 psi on a stock car). Also I wouldn't recommend flooring it(even in 1st gear). Even though 1st gear doesn't put much load on the engine, with open exhaust and intake you can still overboost the engine. If you really want to drive it around like that, I would suggest you pop the c-clip holding the waistgate accuator arm to the turbo manifold door. Now you can drive the car around NA(hopefully) without any problems. My clip popped loose on me a while back and I had no boost on the primary turbo. Just be carefull!

 

Buy racecar soundbites or download some 787B sounds off the forum dude.

With that kind of fucked up configuration, you're looking at a potential $3000.00 experiment... that'll buy alot of DVDs.

 

'nuff said...

 

Back from the dead........
Thanks for the advice and the constructive criticism.
The car is still using this setup with no problems although I wouldn't recomment it at all. I am saving money for intake and exhaust until then I'm not driving it. I just start it every once in a while. It runs healthy, idles well sounds incredible, backfires loud. It does not overheat or knock although I haven't revved it over 5k because the sound is unbearable. Do you guys think that it will overboost if I redline in neutral? I added two cans of octane booster to a 1/4 tank of premium. Also, do you think it will build up carbon if I never rev it past 5k? Thanks

 

Without engine load (actually driving the car), max boost is about 4 PSI.

 

did it blow sky high yet ?