Ball Bearning Turbos (GT28)

[TurbZ]

Which one is a better unit for a street car with standard internals, 550cc injectors and a GTR fuel pump + all the other bolt on bits?

Ball Bearing Turbos

Option 1 -----------------------------------
Garrett GT28 Ball Bearing Turbo
Drop In replacement on Nissan SR20DET
Part Number #GSB8001
Rated 320hp

Spec's:-
0.64a/r Turbine Housing (5 bolt outlet)
0.60a/r Compressor Housing (TB03)
Watercooler Centre
60 Trim Compressor Wheel
31 lbs/min Comp Flow Max.
62 Trim Turbine Wheel
Integral Wastegate 7psi

$2188.00


Option 2 -----------------------------------
Garrett GT28 Ball Bearing Turbo
Bolt On replacement on Nissan SR20DET
Part Number #GSB8004
Rated 380hp

Spec's:-
0.64a/r Turbine Housing (5 bolt outlet)
0.70a/r Compressor Housing
Watercooler Centre
48 Trim Compressor Wheel (T04S)
48 lbs/min Comp Flow Max.
76 Trim Turbine Wheel
Integral Wastegate

$2750.00


Option 3 -----------------------------------
Garrett GT28 Ball Bearing Turbo
Bolt On replacement on Nissan SR20DET
Part Number #GSB8005
Rated 440hp

Spec's:-
0.86a/r Turbine Housing (5 bolt outlet)
0.70a/r Compressor Housing
Watercooler Centre
48 Trim Compressor Wheel (T04S)
48 lbs/min Comp Flow Max.
76 Trim Turbine Wheel
Integral Wastegate

$2855.00

[sfifteen]

I'd go for option 2 for best a round performance. Option 3 might be a bit too laggy.

[Drifter]

Looks like you've been to GCG Turbz :)

I actually got Option 1 from them a little while back and I now wish I researched a little more and went bigger. He showed me the Option 2 turbo and it looked a little too big.

If I did it all again I'd go for none of the above and get the 'Ray Hall Special' 350Hp turbo. I think it's a Garrett GT2535 and would be a perfect compromise for street and track.

Greg from the mailing list has one so he might be good enough to offer his opinions :)

Of course, it all depends on how much power you want and wha tyou want to use it for.

[Drifter]

Oh yeah, and a GT28 with the same specs as option 1 is also on Ray Halls website (>>HERE<< (http://www.turbofast.com.au/)) but it's only rated at 280 Hp so go figure as to wha tthe difference is.

[IMOA]

Actually none of the turbos you've listed there are GT28's, they're GT25's.

Option 1 is a good little turbo, quick spooling, not bad top end and very driveable.

Option 2 is also fine for the street and will give you a bit better top end with a more progressive application of power

Option 3 is a dog IMO. Badly mismatched, very laggy and really only good for dragging. You can do much better.

IMO the one to get isn't the rayhall special but use the cartridge 446179-0032 in the same housings as the "ray hall special". The only difference is the trim of the compressor wheel (56 vs 48) and should give you the power you're after and still be very streetable. Just be sensible with the tune as you will be getting into risky territory with a standard internalled SR.

[NIZ180]

I was actually thinking option 2 with the 0032 cartridge.

[Jnr_Zilla]

I have just picked up a Garrett Turbo very similar to the option 2 but with the 0.60AR housing still with the T04s 48 trim blades....

I was told by the guy that sold it my mechanic that from his experience with fitting Garrett turbos to SR20's that this is the best all round performer....

In his opinon the 4 inch inlet of the 0.70AR turbo makes it too laggy but with heaps of top end.... with the 0.60AR ie. stock inlet you get all the benefits of the T04s but with very little lag and obviously a little less top end power due to the smaller AR restricting the air slightly....

I am fitting this to my GTi-R this week... I paid over $1000 less for the turbo than what gcg have quoted and the bloke that we bought it off called the turbo a GT28 BB turbo not a GT25 BB

Also check out www.horsepowerinabox.com as they seem to be very quick at answering emails and have prices that are much cheaper than GCG....

[Drifter]

Originally posted by IMOA
IMO the one to get isn't the rayhall special but use the cartridge 446179-0032 in the same housings as the "ray hall special". The only difference is the trim of the compressor wheel (56 vs 48) and should give you the power you're after and still be very streetable. Just be sensible with the tune as you will be getting into risky territory with a standard internalled SR.

Ahh i forgot you had the 0032 core. I stand (slightly) corrected. I'll have to remember that when time comes for a proper upgrade. That sounds like a nice turbo.

[180sx]

It's a very nice turbo, they might be priced a little out of some people's range though.

If you go the extra and get the 0032 CHRA, the best match would be to get the 0.86 AR exhaust housing, not the 0.64 as it is better matched to the compressor trim. A little bit more lag, but much much better for top end flow, and generally a better match.

[Ustasa]

180sx It's a very nice turbo, they might be priced a little out of some people's range though. If you go the extra and get the 0032 CHRA, the best match would be to get the 0.86 AR exhaust housing, not the 0.64 as it is better matched to the compressor trim. A little bit more lag, but much much better for top end flow, and generally a better match.

When you say matched what do you mean by that and why is it better?

[NIZ180]

180sx which turbo you reffering to. the ray hall special or the GCG option 2

[180sx]

Ustasa: I mean the flow rates of the exhaust housing matched with the flow rates of the compressor housing. With the 0.64 housing, and the larger compressor housing, when the exhaust housing runs out of puff, the compressor housing still isn't in it's peak efficiency.

NIZ180: I'm referring to the Ray Hall special that uses the 0032 housing, not the 0031. Same goes with any of the Garrett BB turbos that are designed to a straight bolt on to the standard exhaust manifold. Anything with the T04S compressor or the larger trim GT35 wheel would benefit with the better matched 0.86 exhaust housing.

Don't get me wrong, I'm not saying the 0.64 is worse, it depends on the application, but if you want the compressor and exhaust efficiency to match better, then careful consideration should be given to both ends of the turbo.

Cheers

[IMOA]

Originally posted by Drifter


Ahh i forgot you had the 0032 core. I stand (slightly) corrected. I'll have to remember that when time comes for a proper upgrade. That sounds like a nice turbo.

You don't stand corrected at all (well not until that post anyway :)) I have the -0031 core and if truth be told I prefer the -0032. I'm going to see if there really is someone in aus with the rebalancing machine (heard rumours, doubt it though) otherwise I may pick up the 32 cart and swap them over.

Interesting comments from 180 regarding the matching. Do garrett have a .7x A/R exhaust housing for retail sale? They're certainly out there but I wonder if this would be a nice fit with the 32 cart.

[TVC]

Originally posted by 180sx
It's a very nice turbo, they might be priced a little out of some people's range though.

If you go the extra and get the 0032 CHRA, the best match would be to get the 0.86 AR exhaust housing, not the 0.64 as it is better matched to the compressor trim. A little bit more lag, but much much better for top end flow, and generally a better match.

Sorry, but i'd have to disagree with you on that.
Friend of mine had the .86 housing on the T04s model and it was an absolute dog. Didn't come on full boost until it was time to change gears, and then once in the next gear, you were off boost again. I think i was just as disappointed as he was.
Then he swapped this for the .64 housing and the car came alive.

[Drifter]

Sorry to deviate a little but it's all good to know..

Is it true that a compressor housing of A/r 0.70 and greater on these GT turbos will foul the standard exhaust manifold on a 200sx and require a new manifold or adaptor plate? Or is it the turbine housing..or both..or neither? :)

[180sx]

TVC: True, I haven't done it myself, or know anyone who has done it, so until I do, I stand corrected. I was merely working off flow figures and compressor sizing. The T04s is pretty much mismatched with any of the "bolt on" exhaust housings, as they are all bloody small to bolt up to the standard manifold.

Drifter: Yes, apparently it's true, the T04s compressor housings (commonly the ones with 0.70ar) foul the manifold. Not sure is this is the same with the S13 though, as I "trial" fitted a friends GT35 700hp BB turbo up to my manifold, and it has a slightly larger compressor housing than the T04s, and it didn't have any clearance issues at all. *shrugs*

I'll let you know soon though :) (hopefully, turbo was meant to be here last week!)

[TVC]

Yeah, well i plan on getting this turbo.........

taken straight from Ray Hall page.

CHRA (Core Assembley)
Model GT25
Turbocharger part No n/a
CHRA Part No 446179-0032
Compressor Stage
Hsg. A/R n/a
Wheel Trim 56
Model GT35
Wheel Dia 2.09/2.80
Horse Power 400
Comp Flow lbs 44
Turbine Stage
Hsg. A/R n/a
Wheel Trim 76
Wheel Dia 1.85/2.12

Should be fun...!


...i hope :P

[180sx]

What compressor and exhaust housings are you going to use with that?

[TVC]

Not sure yet on the compressor.
The Ray hall special uses the .60 but i was thinking .70
I have to sort that out.

but the exhaust housing will be .64

What do you guys think ?

[Ustasa]

This is a street combo so keep to the smallest turbine housing you can..remember exhaust gas is a diff density and temperature to inlet air and so has completely different flow properties..like lott said..your turbine will outflow the compressor in nearly every application…no point in some 1.06 a/r whopper if it means boost comes in at 5k rpm..stick to a 0.64 a/r or smaller and make sure your turbine wheel size is smallest possible that will bolt onto the centre housing/cartridge. No need to worry for surge in this application since it’s a new garrett design and its not possible to bolt on some old t04 comp to a baby t3 exhaust section

Basically keep the turbine smallish and compressor middish…2.25 inch inducer on the compressor is more then big enough especially on a sr20

[180sx]

Thanks USTASA... I'm running purely off theory here, and welcome any suggestions/comments from people who have played around with them.

I'll be using the 0.64 housing as well I think, but I'm using a GT30 CHRA with T04s compressor

[Drifter]

Originally posted by IMOA
I have the -0031 core and if truth be told I prefer the -0032.

What are the boost characteristics of the one you have?

Say, 4th gear on a level road..
At what rpm does boost start to build?
At what rpm does it reach full boost (how much psi)?

[AKA180]

Originally posted by TVC
Not sure yet on the compressor.
The Ray hall special uses the .60 but i was thinking .70
I have to sort that out.

but the exhaust housing will be .64

What do you guys think ?

go for the .60 front as the .70 will not fit unless u get a new exhust manifold i just put a GT2540 on my 180sx sr20 now all i have to do is get a microtech tuneit and she will be smoken
:D :D :D :D