RX7413

iTrader: (1)

Hi, everyone
I have a 1994 RX7 and I know the stock PSI of boost is 10lbs. I recently purchase this car so I really don't know if this car is tuned or not. I stepped on it yesturday and my saw my boost went to 14PSI! It gave me a really good pull and I have a feeling this car has been tune. I checked under the hood and looks like he did a engine rebuilt and all the reliable mods were done. I have a 3inch from turbo back. Now the question is how can you be sure if this car is tuned or not? Is it safe to leave the boost where it is at? I have never drivin another RX7 so I don't know how stock is felt like. Everyone opinion is appreciated. thank you

baggedoutmazda

does it have a stk ecu? need a list of mods. stk ecu at 14lbs = boom

RotorRyan

iTrader: (3)

ya if its the stock ecu 14 psi is scary.

dgeesaman

iTrader: (7)

Take it to a tuner or a rotary shop. Don't assume it's set up for 14psi. Don't assume anything.

bajaman

You should be hitting fuel cut if you are truly boosting that much psi.
It really doesn't take much over boost to flummox the stock ECU, lean out, and then...bad things.
My stock engine died this way, I'd done the airbox mods, and put a Racing Beat dual tip cat-back on and one (not so) fine 40 degree day I went out for a drive, got all over it, and blew the hell out of the front rotor's seals, which ruined the turbos and ended up with me letting the car sit for 2 1/2 years while I saved money up to rebuild it.

BonesZ33

iTrader: (5)

yea .. when you overboost your going to feel like your fuel just cut off.. i can't believe you bought a car and didn't know if it was stock or not what kind of conversation went on when you were talking to the previous owner ?!.. you should call him and ask him whats done to that car

RX7413

iTrader: (1)

well, i test the car and at first it hit 14 psi and then drop real quick to 10 psi all the way so i don't know if that's something going on? or it is normal? this is the modds of my car. Full 3 inch turbo back exhaust, vacum line been done, all I know is this engine has been rebuilt already, AST coolant, koyo alluminum radiator and I don't know if it has a stock ecu but I think so. The last owner told me what he did and he bought it like that so I really don't know.

does anyone know if there's a good tuner around MA or CT?

djseven

iTrader: (56)

BOOM If it is on stock ecu that is in your future. I assume it is still on the sequential setup and the 14 psi spike happens after transition?

dgeesaman

iTrader: (7)

You need a boost controller to tune down to 10psi. It will also eliminate the spike. I'm a fan of spending $90 for a pair of manual boost controllers. The electronic ones work equally well except you get more blinky stuff to look at and more ***** to play with.

Hopefully you have a catalytic converter in there somewhere. If it's straight through you might have other boost control problems.

RX7413

iTrader: (1)

Yes after the second turbo kick in then it start the spike

RX7413

iTrader: (1)

I do not have a catalytic converter. I have full 3" turbo back and also the airpump is eliminated.

hurleysurf24

iTrader: (3)

ditto. boost controller solved my issue of late boost and spikes.

superjet3

iTrader: (38)

How does the car idle? Check to see what ECU you have it is in the passenger foot well on the right side.

DaveW

Then you need to have a ported wastegate, or you will have boost creep, and overboost no matter what boost controller you use. If you have creep, no boost controller can control the boost, since it is a case of the exhaust flow overpowering the wastegate.

hurleysurf24

iTrader: (3)

no over boost with my e01 special cutback setting when it reads anything above preset limit.

Alec

Is it recommended to port the wastegate if you run a 3 inch exhaust WITH race kat?? (I have not yet experienced boost creep with my mods, open air, 3` exhaust, pettit ecu, running 13 psi)

DaveW

If you have a catalytic converter in the exhaust, then, probably not. As long as your boost is controlled to the level of your tune, you should be OK.

Dave

Alec

Ok, thanks!

Monsterbox

iTrader: (6)

When I installed intakes, my stock system went crazy and it would spike to 14psi then drop down to 10 and settle itself.

When I installed my midpipe, game over....14psi fuel cutting like a M-F.

I installed aftermarket boost controller and this solved the issue of 14psi and spike completely....the car would only boost 7psi and creep up to 10 near redline.

Bottom line is - stock solenoids can't react fast enough which will cause the spiking/instability, and stock wg will creep 3psi from baseline.

I then ported my W-G pretty wide whole and even with a 3inch exhaust it STILL creeps like a bitch in cold weather.


You need to get this car on a wideband to see if its tuned correctly.

BonesZ33

iTrader: (5)

i would also like to add that the previous owner of my car did the same thing... he ran a couple of mods such as intake and downpipe which made the car have boost spikes.. which ultimately led to detonation and destruction of the engine

so until you get a boost controller i stronly advise you to be very easy with you car and not to make any WOT runs

RX7413

iTrader: (1)

ok well, i will buya boost controller to see if it works thanks guys for the advice.

red_dragon

iTrader: (10)

Dual boost controller setup worked wonders on my car. Some people say it's better since you can also tune the transition. I swear the transition is so smooth it's almost like having 10-10-10, or maybe 10-9.5-10. I had a friend watching my gauge and he couldn't really tell if it dropped, he just felt it kick hard at 4500. I got the expensive *** hallmans ($85 each!!). Mostly because they looked cool i guess, but any manual controller should do the same job.