I would like for my turbo to respond a bit quicker on my car when running 8psi or less (ie: less lag). I think the t3/t04e .57 trim is a bit too big for my application, now and in the future (b18c1 in an Integra). My question is, can I change out my compressor parts on the turbo to make it a .50 trim? I am pretty sure I would need a new compressor housing (different a/r?) and of course the .50 trim compressor wheel. Are these parts easily swappable and can I order them online or call Garrett directly? Do I have the right idea or am I completely off? Thanks for any help.

Justin

 

Yes you sure can. You need the new wheel and yes a new housing machined for that wheel. The .50 and Super-.50 are very nice. Excellent choices.

But the factor that influences spool-up the most is turbine side A/R. And it's the easiest to change! .63 is normal. .48 is super-spool but top-end suffers. .82 is too big.

You can prolly live with .48 for a while (and like it) if you intend to change it in the future. They are like $125 or so and easily interchangable yourself.

 

My turbine is a .63, I think I want to leave that the way it is. Going to the .50 trim should still spool a bit quicker though too right? What is the difference between the .50 and the Super-.50? I'm just looking for a bit quicker spool, not a huge gain, which is why I don't want to downsize the turbine a/r. I'm also going with 3" exhaust and an EBC soon so that should help too. I just think I'll be able to make better use of a .50 trim turbo at 8psi than I would with a .57 trim.

Do you know where I can find the parts I need to do the change? Your help is much appreciated, thanks!

Justin

 

i think i would focus on the exhaust and not touch the turbo. i would be concerned about having to balance the rotating assembly of the turbo. but markc is the expert there. but exhaust is a win win mod. more spool more power etc. boost controller is gonna help even more.

 

Oh you cannot change the compressor wheel yourself (unless you have a VSV balancer machine). You have to send it out to do that, but fortunately the compressor wheel is much less epensive to change than the turbine wheel.

The difference between a .50 and a super-50 is the major diam. of the wheel. .50 is 3.00". super-50 is 3.20". Now it doesn't make sense to me, but the super-50 is said to spool faster. They (Majestic Turbo/Turbonetics) say the larger bottom diam. allows it to move move air per rev for better spool. I say the greater mass slows down the spool. But what do I know.

I have a Stage3/.63 turbine with a super-.50 compressor.

 

Do your exhaust first. You'll always be able to change your compressor after if you still want to. I upped m exhaust from 2.25" to 3", and I noticed the spool was much quicker than before. If your getting the exhaust anyways get it first so you know where your spool up is going to stand when you go to swap your housing on the compressor side. Otherwise you might swap it and find out later you really didn't need to.

 

Falcon, tzsir: Yea the exhaust and EBC is already a definite near future mod, it's been the next thing on my list since the turbo went on . The turbo change is something I just have been thinking of recently.

MarkC: Cool, so I have the same turbo as yours but the .57 trim wheel. Would I have to send it directly to Garrett for the change or can somebody else rebuild it and have it balanced?

Thanks again.

Justin




[Modified by justinCO, 3:11 PM 12/31/2002]

 

if you'd like to change out to a 50 trim wheel and compressor housing, here is some pricing.
garrett 50 trim compressor wheel $120
garrett .60 a/r compressor housing $139
labor including balance $40
4-5 business day turnaround

i would suggest that the .48 a/r turbine housing on only 8lbs would suit your needs just fine though. $159

 

Thanks a lot for that info. I'm gonna finish up my exhaust and ebc and see how she runs then. If I feel the need for quicker spoolup at that point I'll look further into changing up the turbo. Maybe I'll do the .48 a/r turbine until I build the motor for more boost, then I could slap the .63 back on. We'll see. Thanks again!

Justin

 

I think that would be the best path to take.

 

MarkC - what psi are you running and what rpm do you get full boost on your set up? Are you running a stock engine?

 

Hey MarkC,
Does that super-50 compressor housing (is it A/R .60?) have a 4" inlet? If so, did you have any clearance problems once you switched? Any pix?
Thanks fella!

 

I must accentuate the fact that the nature of the hot side of the turbo determins 90% of what the spool and boost threshold characteristics of the turbo are. The energy to create rotation of the turbo comes from the hot exhaust gases, and as such it is the manner in which the energy from these gasses is harnessed the determines the aforementioned characteristics.

I do agree with what they said above, to a point. Exhaust is ALWAYS a good idea on a turbo car, there is not reason not to start there unless you already have a VERY good setup.

Changing exhaust housing sizes is a simple tradeoff....a higher A/R will give you a higher boost threshold, but will increase the flow of the turbine housing and allow for more top-end power. A smaller A/R will increase the velocity of the exhaust gasses at lower RPM's where there is less being combusted over a period of time, but at higher RPM where that volume gets larger, it will be restrictive.

HTH!