i have a 93 rx7 and it has a dp, mp, and intake(although the filters are almost black with dirt).

before anyone says anything, no i dont have an ecu...yet.

i think i have boost problems that i will be working on for the next two days, but because of the midpipe i still get a fairly good boost pattern, 9-8-8.

no creep, nothing. not even a spike at transition.

im not boosting much, as i just got the car, and the midpipe but i slowly eased into the throttle a few times and found out about the boost.


has anyone else had this happen?

 

ha....just proves the stock cat-back is so horribly restrictive (and heavy) that no amount of uncorking will overcome that thing

 

I wouldn't think just the stock muffler would restrict boost creep that much with a mid pipe. The only thing that holds down the boost to those levels with a MP and no boost controler has got to be a boost problem. Maybe you have your turbo control solenoid connectors just behind the vaccum chamber hooked up the wrong way, or you don't have restrictor pills. What was your boost pattern before the MP?

 

Yes, the stock cat back DOES have enough restriction to keep stock boost with a midpipe, I ran that setup for a while and it kept rock solid 10 psi.

But now I have a ported wastegate and dp/mp/cb and it holds 7 psi till redline

 

dont know, i just bought it. like i said, i will be working on it for a couple hours tomorrow at school and then i have all afternoon/evening friday to track down the problem.

the intake in an a'pexi twin filter(not sure if there are different ones) could the air filters being REALLY dirty affect boost? i wouldnt think so but this is my first turbo car.

thanks

 

Ya when i had DP MB and power fc it would hold the boost just fine, once i got my catback on it spiked like no other!

 

what tf are you guys smoking??

the stock cat back does not restrict the exhaust enought to eliminate boost creep and spike.

Swolbynos - you're not making normal boost b/c you got a problem. with nothing more than a downpipe using the stock cat and cat back you will likely make a little more boost. with a midpipe, you should be in boost spike city! what you probably got is a boost leak and some fucked up vac hoses or a bad solenoid saving your *** right now

 

that is what i was expecting when i bought the car <---- this is me now. i would rather leave it like this for a bit to get used to driving it then get it fixed after i get used to the car.

i always used to think these cars looked cool and were pretty fast, but it also just feels so *right* driving this car. and i dont even really fit into it lol. (im 6'4")

 

WTF are u smokeing? did you add a midpipe befor your catback?

I have 3 other people that are on this forum that can vouch for what my car DID

I had a manual boost controler, and a boost gauge, i set it for 10psi, worked fine, i had a DP on when i did this, once i put the midpipe on, i notice NO SPIKING WHAT SO EVER!

as Soon as i put the racingbeat cat back on i spiked to 1 full bar the first time i got on it!!!!!!

the stock catback is that restictive!

 

i hope you arent talking to me....









if so, refer to post #5 in this thread please

 

i agree with alberto... I had intake, DP, MP, stock catback, but also an ecu. I was hitting over 14psi without a boost controller. The stock exhaust (IMO) is not restrctive enough to keep boost down. Maybe you have some other problem that is keeping the boost lower. Get an ECU quick if you want my opinion.

 

PS is it really worth it to risk an engine? I guess if you are not having any boost problems and you are feeding it enought fuel, then fine. But you are going to need an ECU eventually.

 

I had a dp, mp, and stock catback and the boost creep was crazy. Only way to avoid it was not go so hard on the throttle.

 

Swolbynos

it wasn't directed to you

it was to alberto_mg

 

Yes, actually I did. That was how my car was when I got it. Made a quick 13psi of boost at part throttle if I wasn't careful with my right foot. I quickly replaced the midpipe with a stock cat and got an RB exhaust on there at the same time.

Swolbynos - i guess there can be an upside to having a boost problem after all
This car does feel great driving it. Take care of it and it will keep you smiling...

 

I'm going with a full 3" exhaust setup as soon as I finish my trans work but I'm going to stick a restrictor plate between the DP and MP to prevent spike/creep... I am thinking 2.25" will be just enough restriction without costing me performance.

The stock exhaust system is heavy as well so loosing it will gain some performance just in the less weight. I'm with everyone else, unless you have a stand-alone or an ECU tuned specifically for usage with a MP than dont run one -- or run a restrictor. I have an ECU meant for a midpipe that is tuned for 1BAR... but I'm not using it since my car is a daily driver and I dont plan to run more than 12PSI.

~Kris

 

well I guess that goes to show us every RX7 is unique, even when using the same mods everyone gets different boost readings.

 

But hopefully, nobody walks away thinking they can run such a setup safely. I'd get an ECU, fuel mods, and tuned safely before I took my chances.

 

i will be getting a fuel pump and a power fc for christmas (i will be contributing to getting them too )

 

no offense, but it seems like a complete waste of time to upgrade your piping if you're going to restrict it. if the creep is that bad, port your wastegate..