R33 Turbo rebuild question

[RedEclipze]

So everyone knows that stock turbos with ceramic don't last long after 100 plus kms. My question is, is it safe to do a stock turbo rebuild with steel, instead of ceramic and not have to worry about the computer needing a tune.

My attempt is to keep the car as stock as possible, but get the broken down crap out, and generally upgrade the car to it's greatest capacity at stock level.
I've seen "n1 Turbo Rebuild Kits" all over the place and i have to wonder if the computer will need a tune. Normal N1 Turbos required a re-tune of the car did they not? Can i use those steel wheel build kits and be fine?
What other suggestions do people have to modify? "twin turbo" plate weld perhaps? Anyone ever stay stock after that pipe was done and have issues? I had it done on my 1990 but i had the car re-tuned so i didn't notice a difference.

any info is greatly appreciated.

[Skym]

Rebuilt turbo's are called hybrid turbo's, as they use parts from different turbo's like GTi-R or Silvia turbo T28? Garrett CHRA inside machined stock compressor, exhaust housings (to suit the bigger diameter wheels). They then become similar in spec to N1 turbo's. Probably could buy a Garrett GT28 CHRA x2, wheels to match, machine stock compressor, exhaust housings (makes it bolt on with stock intakepipes, etc).

The Dodsons R32GTR in link below runs hybrids -

http://www.youtube.com/watch?v=9IRjpZdIYE0

You would need to retune stock ECU, upgrade fuelsystem (injectors, fuelpump, Z32 AFM x2 + Z32 plugs x2), boost controller (or use factory boost control) to match.

[dsmart]

If you buy the steel wheel rebuild kit and have your turbo's rebuilt and balanced it is were unlikely you would need to retune anything. If you are planning on running 14psi or even slightly more your stock fuel/air/tune will handle it just fine. The steel wheeled factory turbo's wont push any more air at the same boost level as the stock cermamic ones so there is no reason for a retune. People who run garrett -7 or -9 can get away with 280awkw without changing anything and those turbos push a larger volume of air at the same pressure. That being said the engine will always benefit from a tune but its not neccessary to start changing parts with stock turbo's.

[Skym]

A hybrid RB20 turbo helps a RB20DET produce 20hp more (peak hp) at same boost level due to leaning out A/F ratio (factory ECU tune). RB26DETT shouldn't be any different, except it would produce more hp due to 2x turbo's forcing more air into engine.

It can have a safe A/F ratio at peak hp, but at peak boost at lower rpm it can go lean. Factory fuel map was made lean enough for factory turbo's at peak boost at lower rpm, but once you start adding a bigger turbo or turbo's it leans out too much at peak boost at lower rpm. You would need a ECU retune to correct this.

Common thing to do when upgrading turbo's is fitting an upgraded fuel system, ECU tune to match. Even R33 N1 turbo's can produce around 455hp at 1bar. Without boost restrictor, basic breathing mods, should be able to produce around 0.9-1bar (boost level depends on if you upgrade dumppipes to fully derestrict engine, turbo's or use factory dumppipes). Can lean on factory fuelsystem with ECU retune, boost controller, adjustable FPR, 255lph or so fuelpump. Stock GTR injectors are said to be 440cc, but when tested are more like around 480cc. Roughly 1cc = 1hp.

If it's a R33GTR, can use R32GTR stock ECU (need to change to R32GTR o2 sensors), retune ECU with Nistune. PowerFC, Link ECU, Vipec ECU, etc are some of the other options.

[RedEclipze]

Right on. I was under the impression, that yes i will be keeping the stock turbo, but replacing interior parts that i would be safe. i wanted to confirm that. i'm not neccesarily getting a bigger turbo, just replacing the stock ceramic. Can steel really produce 20 hp more? With stock turbo housing?

[xcye]

If you only change the exhaust wheels on those turbos, you won't see any hp increase if they are running at the same boost pressure. The only benefit the steel wheel bring is that you can run them at a much higher pressure level for a lot longer.

[Skym]

You supposedly can't change the exhaust wheel due to ceramic exhaust wheel is glued to shaft. A new CHRA (Centre Housing Rotating Assembly or centre part of turbo) usually has to be fitted and that has slightly bigger compressor, exhaust wheels hence you have to machine housings to suit. Although some claim to have replaced exhaust wheel, but might have changed shaft, wheel as one. Stock turbo was made by Garrett Japan for Nissan.

On RB20DET at 12psi, there's a 20hp gain at peak hp with hybrid turbo. That's with stock SMIC (Side Mount Intercooler), podfilter, 3" exhaust (from factory dumppipe), modified stock BOV, stock ECU tune. With those mods it's usually around 250hp, but get 270hp with hybrid turbo.

On GTR with boost restictor still in place, should be around 12psi and get similar hp gains as on RB20DET (or more hp due to being twin turbo and has a bigger intercooler).

[nickisonfire]

I already do it on mine pretty simple, juste unscrew the compressor wheel and remove the ceramic crap shaft and put the new one, you don't need a bigger housing just bolt on lolll but you will loose a bit on the lag section because of the steel is heavier for sure but it worth the price if your planning like 1.4 bar of boost but if you just stay at stock boost keep the ceramic one they wont blow i rune mine at 0.9 bar for about 3 years when i had it and no shaft play nothing ho and i almost forgot if you put the steel one make sure to go to a chop and calibrate it , or you wont past 100km lolll they always write wheel fully balance but you have to build the turbo to balance it lolll good luck buddy

[RedEclipze]

Understood. I'm still undecided. I know the ceramic will eventually go, and i figured replacing the interior parts with newer more durable parts that it would give me longivity. What i DO NOT want to do is re-tune the computer. If i can run steel parts in a "hybrid" turbo, which most chances are will give me more HP, even with a boost restrictor, will i have to re-tune?

One more question. When i took my "twin turbo" pipe out on my r32 i re-tuned the car, but i also installed an apexi computer and z32 maf set-up. It had to be re-tuned. IF I STAY STOCK everything, but am just looking to get more air into both turbos (the divided twin turbo pipe deal), will i have to re-tune? Anyone stay stock? Is it too much of an air difference into the engine? Re-tune due to the air/compression ratio?

[dsmart]

You supposedly can't change the exhaust wheel due to ceramic exhaust wheel is glued to shaft. A new CHRA (Centre Housing Rotating Assembly or centre part of turbo) usually has to be fitted and that has slightly bigger compressor, exhaust wheels hence you have to machine housings to suit. Although some claim to have replaced exhaust wheel, but might have changed shaft, wheel as one. Stock turbo was made by Garrett Japan for Nissan.

On RB20DET at 12psi, there's a 20hp gain at peak hp with hybrid turbo. That's with stock SMIC (Side Mount Intercooler), podfilter, 3" exhaust (from factory dumppipe), modified stock BOV, stock ECU tune. With those mods it's usually around 250hp, but get 270hp with hybrid turbo.

On GTR with boost restictor still in place, should be around 12psi and get similar hp gains as on RB20DET (or more hp due to being twin turbo and has a bigger intercooler).

No offence but almost all the info you've given, relating to rebuilding r33 gtr turbo's with steel turbines, has been incorrect. I dont want to call you out or anything but maybe do alittle more research on the subject

Dave

[dsmart]

To the OP, although rebuilding your stockers with steel components seems like a cheap way to go I think after its all said and done you will be dissapointed with the results. Originally I was going to go this route but after pricing out a proper rebuild it was almost the same cost as buying a set of garrett 2860 -9 or -7 turbos. It picked up a basically new set for $1400, the rebuild price was going to be $1200. The OEM turbos with steel wheels will handle more boost safely but they will spool alot slower and not have as much hp potential...basically they are just an older design journal bearing turbo. if you want to run around 15-16 psi you likely wont need to buy bigger injectors or mafs. That being said it would be wise to go to a dyno and see how well your motor will handle to new turbo's. If you start running out of fuel or maxing out airflow then deal with it.

I have a nistune setup for mine and will install it before I go to the dyno, my plan is to have it tuned with the stock fuel/air setup and see how far I can go. If i need more fuel i'll buy injectors and retune. If you research topics on steel wheel kit rebuilds you will see that most people who have done this either regret it or end up selling them and getting different turbos. Everything ive said is of course just my thoughts on this but because im went through the same decisions as you, I figured it might be helpful for you to know. Goodluck

Dave

[RedEclipze]

No, thanks very much, that helped alot. Basically if my turbo's go to **** i'll replace them with stock or equivalent.
Thanks

[Skym]

Dsmart, no offence taken. There's alot of conflicting info out there, even when talking to turbo rebuilders about can stock turbo be changed to steel exhaust wheel.

From what I understand, stock GTR turbo CHRA is a 270 degree non ballbearing. Upgrading CHRA makes it a 360 non ballbearing and more reliable. So it's not just the ceramic exhaust wheel. I had a list from Japan showing the differences in spec between stock GTR, N1, Group-A turbo's, etc on R32, R33, etc. Also there are other things to take into account which are fixed at same time inside CHRA (even new turbo's have these faults that are fixed / upgraded by turbo rebuilder).

I knew someone with R32GTR that rebuilt stock turbo's to hybrid spec. You are correct about that it reaches peak boost higher in rpm than stock turbo's, as he did mention that. Similar result on RB20DET, where peak boost is around 700-1000rpm later than stock, but pulls to 7500rpm where it creates peak hp and boost level doesn't drop off until 7500rpm, which is the revlimiter. But he got them to spool up to full boost earlier via ECU tune, etc. From what I can remember, produced over 400awhp with them on stock engine. But had a big Apexi FMIC, etc, which can affect when turbo's reach peak boost at lower rpm.

Also I've been in Skylines before, after hybrid turbo upgrade and with ECU retune, hybrid turbo. ECU retune solves alot of the problems. Even my cars engine has a hybrid turbo.

With turbo or turbo's reaching full boost later in rpm, engine can be offboost most of the time on street, so get better fuel economy. At least that's what I have noticed on my car.

[RedEclipze]

Skym, thanks for the reply. Your points make alot of sense based on your experience, but Dsmart was giving me suggestions based on mE NOT WANTING to re-tune. I'm essentially looking to do a re-fit of the stock turbo so i don't have to worry about the ceramic. I don't want the hassle of having to re-tune the car, be it stock ECU or an aftermarket. I just don't trust any of the tuners i've met around me. I ran into a serious issue with my r32 when i started upgrading and the potential out there to tune the car wasn't in my opinion good. In fact i sold the car because of how badly they tuned it, which essentially messed the engine up. Suffice to say, i don't want to have to take the car t anyone here in NB. If i was in Ontario, maybe. At least they have quality tuners. Or elsewhere, besides NB.

Any suggestions? Skym?

[Skym]

You can drive around without it being tuned with hybrids (up the fuelpressure at idle, throughout powerband with adjustable FPR, 255lph or so fuelpump to stop engine going lean and do this on dyno with wideband plumbed into exhaust to check A/F ratio). But it won't drive as good as with a tuned ECU.

Or pay tuner outside area to tune car (have to pay for tuner airfare or travel cost's) + arrange to rent a local dyno (some dyno places rent their dyno, but owner of dyno operates it). Sometimes people pay for tuners airfare between countries or from another part of world. But best to get a few cars together and share the cost's, so it's affordable.