ProjectD

iTrader: (15)

Is it possible to convert a journal bearing turbo like my Garrett T04r to a Ball bearing turbo? I am just wanting tobuild boost sooner without sacraficing too much top end. I have a 1.0 Exhaust A/R on it now And I plan on going with a .84 And I'm sure that will help with spool time. But I'de still like the responce of ball bearings.

Can anyone give me some guidance on the subject. I love the T04r And Don't really wanna give it up just wanna improve on it i guess. I'd love a T04Z but the price for a new one is a bit steep. I'm open to suggestions. BTW i have a decent sized street port (will post pix later if needed.)

Thanx in advance

dubulup

https://www.rx7club.com/single-turbo-rx-7s-23/t4-guys-bb-chra-602761/

RacerXtreme7

iTrader: (2)

Yes and No. You can't simply take your CHRA and stuff ball bearings into it. You might be able to get Turbonetics to take your comp and turbine wheels, backplate, and housings and use their ball bearing CHRA but they only use a single angular thrust type bearing with rear journal, so any spool up gains would be minimal or even not noticable seat of pants. You can try and get Innovative Turbo Systems (ITS) to re-use the afformentioned parts from your turbo, but its unlikely they would mess with any used stuff to build you a ball bearing unit and will probly just try to sell you a CHRA with wheels assembled on it so all you'd re-use is your comp and turbine housings. Garrett on the other hand will only sell you a completely assembled BB CHRA with wheels assembled. Again, you'd essentually only use your comp and turbine housings again. Try out the .84 before you blow your wad on BB units if your turbo's still in good shape. BTW, your top end loss going from 1.00 to .84 probly will not be felt at all, as the T04R has pleanty of compressor left in it.

~Mike............

Zero R

iTrader: (1)

Sick Mike..... sick.



-S-

ProjectD

iTrader: (15)

Thanx for the help guys! A few more questions

1. If I understand what I've read, The option that Dubulup posted would be a direct swap only requiring me to change housings? Are those wheel gonna have the same specs as my current wheels? Essentially the same EXACT turbo with ball bearings instead of the origional journal (thrust) bearing?

2. If yes then would that make my turbo a T04Z? From what I read the only difference is that the Z is ball bearing.

3. I am currently running the t04R kit from rx7store.net And I was told that manifold has a tendency to creep, which i have experience. And i think I know why, The tubing coming off the main exhaust runners for the wastegate seems to be very restrictive. I'll go take some pic to better explain. And also my idea to remedy this. But the point is I am experiencing this creep with a tial 46mm WG. but if nothing else in my setup changed except the exhaust housing from 1.0 to .84 would that cause the creep to get worse?

ProjectD

iTrader: (15)

well I wasn't able to get any good pictures but to further explain my idea.....the tubing for the WG that comes off the runners SEEMS large enough in diameter BUT, The whole cut out of the runner seems too small. So my guess ( and that's all it is) Is that is the bottleneck in the system. It's not at a very easily reachable location but I may be able to gring away some of the resricting material without affecting the welds. Any thoughts on this? I know it's hard to understand without pics but hopefully you get the idea.

dubulup

1. yes, you understand correctly...

2. T04Z, and yes that price just got steeper if you consider what you've invested already.

3. I can't say for sure, a .84 should produce more back pressure on the motor...but I don't know how this could/would effect boost creep.

how much boost are you running now? at some point there should be a happy medium of exhaust flowing thru the WG runners and manifold pressure...

ProjectD

iTrader: (15)

Depending on the outside air temp I could run about 13-14 psi on the spring (11-12 psi spring i think) That is not bad i guess but I would like a more stable, consistant base boost reading.

I'm just not sure what to do now, Like you've said considering what i've already invested I'm gonna loose either way. Right now I'm even considering a GT35R t4 flange. I'm sure i won't be dissapointed with way it spools, and it seems people are making decent power.

decisions decisions...

dubulup

maybe tune it up to 15psi (which is plenty safe) then you should have plenty of flow thru the turbine housing and not need to rely on the WG so much.

check sig. and PM Zero R @ a-spec this is a win-win