adamlewis

Youre an absolute tool. Why do you have to even say **** like that?
Its not the wastegate you asshat. Its the fact that the stock turbo falls off in the upper RPM's. Known problem. Search for it. Only way to "fix" it is to upgrade.

adamlewis

Jacob, why dont you just use my old turbo? I still have it in the garage somewhere...
I dont know how good of shape the turbo has to be in, but I know the turbine is good. The compressor is still good ( though it did grind against the housing a little so the edges are a litttle ground back ), but the seals are whats blown. You can have it if BNR will take it.

snub disphenoid

I admitted to deliberately feeding misinformation into the thread, dunno if you can read. Asshat? Oh jeez, my brain, oh it hurts my feelings. You hurt me over the internet, my self-esteem is at an all-time low. There, feel better about yourself now?

jacobcartmill

iTrader: (6)

s4 turbos hold boost my 87 TII held 8psi to redline as well.

its something they did differently with the s5 turbo.

adamlewis

8psi.


Try holding 12 or 14 to redline.

PilotSi

How much boost do you want to hold to redline? As far as I understand it, the stock S4/S5 turbos become terribly inefficent at around 11-12psi. Personally, my S4 w/ S5 turbo can hold a rock-solid 10psi all the way to redline, with no problems. If you're running over 12psi on a stock turbo, you're foolish anyways. You'll kill that turbo very quickly and you're only introducing more heat, since it is outside it's effiency range.

I think in Jacob's case, a cheap TO4B/TO4E wheel or hybrid upgrade is the way to go. Of course, you will add the needed fuel as well I think the hybrids are great for the majority of us who desire alittle more power without overdoing it.

David

jacobcartmill

iTrader: (6)

thanks for your input.

you can run as much boost as you want (under 15 or so) on a stock s5 turbo and it will be at 6psi by redline unless there is something different about the turbo.

Turblown

iTrader: (12)

Matt, if you want to come by and use my wideband for a small fee you're more than welcome.

Zbrown, sure sounds great.

Adam, I know I have seen several rx-7 not hold boost in person. I am trying to figure it out.
One thing I did not mention is my intake ports are just touched up, and my exhaust ports are bigger than the sleeve ( pretty large ). A friend with an identical setup, but with very large intake ports, and sleeve matched exhaust ports, cannot hold boost to redline. It actually bleeds off past 4950 rpms. I cannot confirm for sure if its either the porting, but I'm working on figuring it out. I'll tell you this though, being able to make power where it counts makes my car a lot faster than everyone's who's bleeds off.

RX-7vinny

Can anyone tell me what BNR stands for and their website.

RylAssassin

Jacob im in the same boat as you. I need to upgrade my turbo soon and i wanted to spend around 500 bucks. Ive read on here that you can hybrid s5 turbos for 500 bucks and make them good for 400hp. They were also selling To4B brand new on ebay a while back that was listed for Rx7's. They were going for 400 bucks i think. They also got those stainless tuebo manifold on ebay for our cars that can be used with aftermarket turbos.

PilotSi

Odd. My turbo can hold 10psi all the way to redline. It's a stock turbo other then the ported wastegate... I have tried 12psi before, and it does bleed 1psi by redline, but that's not much. Sounds like a backpressure problem to me -- what kind of exhaust do you have? Do you have a DP? Any cats?

David

Madrx7racer

BNR http://www.rx7store.net/index.asp?Pa...S&Category=364

Turblown

iTrader: (12)

I doubt that. On my current setup I have the RB 2.5" dp and from there back its 2.25" to the RP 2.25" Catback. Soon to be replaced ofcourse.
My friends FC that does bleed has apex n1 catback and 2.5" dp.

PilotSi

Go ahead and doubt, I don't care. Many factors come into play on why a turbo could bleed boost. At the very least, restriction in the exhaust or intake can play a role in this. The condition of your turbo is another. I have the same exhaust setup as yours except I also have a Bonez cat & 3" TID, and mine only bleeds boost at 12psi. At 10psi, it is rock steady all the way to redline.

So instead of doubting me, maybe you should help the original poster on what his options are. Or maybe we have come across something bigger, and we should find out a reason why you guys are bleeding boost...

David

dr.jones63

All you have too do is put a turbo back "race" exhaust and a intake on without porting your wastegate and that puppy will boost way past 1 bar. Trust me. Boost creep is not good. As a matter of fact anyone who has actually done it will tell you that building boost aint the problem, it's too much boost. If you don't believe me call Mazdatrix or any other knowledgeable shop and ask them. A hybrid (alot cheaper) or a full T04 (Manifold, Turbo, wastegate, custom downpipe = $2500) flows more air at the same boost level and can boost to a higher psi with out losing efficiency. Now you can throw in a standalone which is cheaper than blowing your motor.

91 NA coupe. w/ Series5 13BT /TII drivetrain
3" turbo-back N1 exhaust / 3" TID
Starion FMIC w/custom piping

You have issues if your not making boost with that setup. What size is your custom piping? Mandrel bends?

Rex4Life

He's right, I have no problem holding 10 psi til redline. Carefully try running without the wastegate hooked up and you'll see what I mean. Hell I even have the single GSL-SE muffler on and have no problem getting boost.

As far as upgrade turbos, I'd go with one of the BNR turbos at the rx7store. They seem to be reasonably priced for what you get and you know it will work well on your car.