arghx

iTrader: (3)

Ok so my 88 T2 with s5 turbo is getting pretty bad boost creep especially now that it's colder outside. The previous owner said he ported the wastegate, but I guess it wasn't enough, because I have my turbo XS MBC set to wastegate pressure and it will still hit like 15 pounts at like 1/4 throttle.

Now I could pull the turbo and try to port it some more... but I'm thinking what's the point? It's already got like 80k on it. Why not just go ahead and get the BNR stage 3 I had been planning on, and run it at like wastegate pressure for now? The BNR comes with a 35mm wastegate. I have a 550/720's, Warlboro 255, Rtek 1.7, and SAFC.

What do you guys think about running a bigger turbo on low boost for a while until I get the time and money to do everything else? I have a wideband. A BNR stage 3 probably makes as much power at 6-8 psi as my stock turbo is doing at 12-15.

rx7 FC TII

iTrader: (3)

i say go for it im about to switch from my stock s4 to a stage 2 and BNR is 20 min drive from me

classicauto

iTrader: (3)

well, with those injectors at roughly 80% duty will give you enough fuel for about 280 at the flywheel. Depending on what hp numbers they are saying for that turbo you'll get a good idea about wether or not thats enough fuel.

StarScreaM2k1

The BNR would probably be set @ 10psi to make roughly the same power as what you have right now. Also going with 550/720 WILL NOT be enough to sustain a stage 3 at higher boost levels. The wastegate on the BNR is larger, which will help with boost creep yes, however if your thinking to get the BNR and lower boost levels, why dont you do that right now off of stock? or is it still boosting hard with it set real low? Also if your going with the BNR and plan to run higher boost later on, a Rtek 1.7 and SAFC wont be the best way to go about things. The Rtek is good for a baseline ecu, however i would either get a emanage (thats what i personally have, on a 88t2 rebuilt motor, hybrid turbo and 550/720), get a haltech, or a Rtek 2.0, point is your gonna need some better tuning capibility to be more reliable. Also, you dont want to run injectors anything higher the 80% as classic said, anything more and your likely to hammer the injectors open 100% or closed and that makes engine flood to shitz, or go boom!

Personally what i recommend, is set your current turbo to factory Wastegate (decrease boost) watch your boost gauge (get a aftermarket one if you have one) and be careful on the throttle to prevent boost spiking. Its gonna be a pain for a bit, but you'll get used to it, i did when i was breaking in my motor and had to have it so there was no boost. Get the BNR, if your planning on going for 300ish HP get 720 primaries and 1000 secondaries, upgrade the rtek 1.7 to 1.8 (its like 25 bucks) and that way theres native support for 720 primaries. Get yourself a better ECU/Piggyback unit (emanage w/ retk) OR screw the rtek and go fullblown management like a haltech or something. Also make sure you have the other supporting mods for that much HP which i assume you may already have. You may have to wait it out save cash get everything and then do it all. Do it right, or dont do it at all. I have tried to cut corners on my build and well, in the end i ended up spending more, first for cutting the corner, and then having to buy the proper stuff, so i learned, buy the proper stuff right from the get go, and make sure you have everything you need to have those ponies reliable.

rx7 FC TII

iTrader: (3)

^^^ i agree with him im also building up on my mods so i can do it all at once......just need more cash

FCKing1995

iTrader: (3)

same here... too bad i wont have enough to do all i have planned for another 2 years probably ill probably do it in stages. bnr, exhaust and rtek chip first, then other mods second

bacek

do it right ONCE... why dont people see things that way?

FCKing1995

iTrader: (3)

? Not everyone has $5,000 at their disposal at one time. Whats wrong with modding in stages. its actually better to do it in stages so you dont throw an assload od mods at it and then have issues and have to track it down. Do 1 mod at a time and that way you can keep track of any bugs in the system.

JeffForSale!

how safe will a stage3 be on 720/720s?
streetport/stock tmic/rtek1.8/walbro255

arghx

iTrader: (3)

To clarify, the boost will NOT go lower. It hit 15 last night and I was barely getting on it. My boost controller is set to the lowest boost possible. I need a bigger wastegate, and my friend whom I purchased the car from already ported it some.

It just seems like if I pull the turbo, I might as well put the BNR on there b/c what's the point of going through that kind of trouble on a 80k mile jspec? I want somebody else to port it because I'll probably screw it up or something. With the amount of time I have, just pulling the turbo and getting it ported may take multiple weekends.

And if I'm going to pull the ECU, I might as well do Rtek 2.0, and while I'm at it I might as well put an EBC in b/c I have to cut wires and stuff anyway. And I guess if I'm going to put a new turbo in I might as well do injectors so I don't pop the thing. And if I put new injectors in I might as well install this fuel pressure regulator that I have lying around, and if I'm going to do that I might as well change the pulsation dampener... ugh. I guess to do it right I should do everything at once.

Maybe I should just pull the stock turbo and try to port the wastegate further to fix the boost creep. I'll think about it. I guess one mod just leads to another otherwise...

FCKing1995

iTrader: (3)

lol that sounds like me lately. I was just gonna get mine running better with injectors and an rtek... but then while i have that appart i might as wel do this, then might as well do that... next thing i know my list is like 1500 bucks

AlexG13B

iTrader: (7)

Bryan from BNR said run 4x 720s

BLUE TII

iTrader: (9)

For now it sounds like you should try to limit boost on your stock turbo until you decide what your next option will be.

You must add some intake and/or exhaust restrictions to limit boost creep.

My favorite method is to put in an exhaust restriction as far from the turbo as possible so you still have good spool, but limit boost on the top end.

The easiest way to do this is make some gaskets for the Y-pipe to mufflers connection that have a smaller diameter hole.



15psi at 1/4 throttle sounds like another problem to me.

Is your dual scroll actuator stuck shut putting all the exhaust through the primary scroll?

Is your WG opening at all?

StarScreaM2k1

From what it looks like here is what i suggest:

1) your turbo boosting @ 15psi @ 1/4 throttle is not right for a stock unit. Are you sure your boost gauge is setup correctly? i would recommend taking your boost controller completely out and running it stock. I think your boost controller is giving the issue.

2) you might want to do things in stages rather then tons of things at once and not being able to debug your problems, if you have any. Install things 1 at a time (if you can, some things you cannot) and keep adding so that way you dont get jumbled up with problems.

3) you brought up Pulsation Dampner, theres a good thread in the 2nd gen archives, but if you want my quick 2 cents, get a FPR and add a Marren FPD. Those 2 with some large injectors setup properly with some SS Braided Fuel Lines and your gonna be completely set in that department.

Like i live in Canada, and last 2 - 3 weeks its been pretty cold... anywhere from 10 to 0 degrees celcius. And i have seen other people with T2 that dont have such a big increase with boost just with the temp change. Thats why i think your boost controller maybe causing something with your Wastegate, as Blue TII said, do you know your WG is working? are you sure its not the Boost Controller? Also what specs to you have for Intake and Exhaust? Do you also have a streetport or stock ports?

arghx

iTrader: (3)

I'm pretty sure it's not my boost controller. I've tried two different ones and had the same problem, and this is with the boost set to wastegate pressure.

I haven't verified that the wastegate is opening. When I get some time (hopefully this weekend) I am going to hook up a hand pump to the wastegate to see if it opens up from like 10psi or so of air.. If it doesn't (and I suspect it won't now that I think about it), the actuator may be screwed up or the whole wastegate is seized shut. I know you can pull the little rod thing off with the turbo on the car, so I'll do that and see if the flapper will open or not.


I have a 3 inch downpipe to Greddy SP2 exhaust. Motor has aggressive street port and Greddy front mount intercooler. I'm not up for adding in restrictions to the exhaust. That seems desperate... I'd rather put the car down and pull the turbo.

I already have an aeromotive adjustable FPR that I havent' installed yet, but I was just saying that if I'm going to do the fuel system I'm tempted to do it all at once.

StarScreaM2k1

hrm... now knowing more about your car and your mods, i would say its most likely the wastgate actuator, i still wouldnt rule out the BC just as yet tho, i would say disconnect it go to stock just to see what happens. But thats your call!

arghx

iTrader: (3)

that's going to be enough for a stage 3?

My5ABaby

iTrader: (7)

If the guy that does the Turbo's says so...