[pearl62]

I am really torn about which turbo to go with... I am putting together a D18 (D16 with Darton sleeves and D17 crank) with either 77 or 78mm bore (another question). I am building this for autox use, so super quick spooling is the highest priority, that why I ma also going for as big cc's as I can get. I am also planning on a fully ported head with +1mm valves. I suppose 250- 300whp is the goal.

I am currently torn between getting a GT28RS (Like this one or a SR20DET upgrade), or a T3/T4 46 trim like this one.

I guess I am having a hard time finding out what the spool RPM is for each. I have searched and it's hard to find actual RPM's instead of just "it's quick". I know it's hard to get good answers since everyone's setup is different. Has anyone had any experience with the GT28RS to say how much better the GT28RS might be compared to a T3/T4 hybrid?

For manifold, I am leaning towards the LoveFab AC-mini me, with 3" DP. RLD-Fab also has a nice setup.

 

[pearl62]

If it's being built for autocross, and you're looking at spending that much here's some advice... DON'T DO IT!
If you are doing autox and want to race in SM, get a B18C5 or a K20 and increase the compression...
Turbo lag is terrible for autox and with that much power you'll just spin the wheels in the turns.
I speak from experience, I have a 10:1 77MM, 272hp, 240tq Turbo D16 - with a Quaife, and Chris Travis's stock block ITR with custom geared trans is a lot better... Check out my dyno plot in my VBpic gallery for more info.

If you're absolutely dead set on a turbo D for AUTOCROSS, get a gt28R or RS keep it as small as fast spooling as possible...

Thanks gpny for the great info! Your setup is similiar to mine, though I am in a 96 DX hatch with Y8 trans + Quaife LSD.

I'm just checking out your setup... Better gearing might help you out. I'm wondering if comparing a DX trans with a custom geared ITR is really apple-to-apples. Do you think his ITR engine or the gearing is what makes his car more competitive?

I agree that the ITR setup is a killer. I am hoping that the combination of a long stroke SOHC 1.8l, combined with a quick spooling turbo will be competitive. It's lighter weight, and theoretically should provide better low RPM torque and driveability.

There's a couple guys that run SM here that I have B18's, and one with a K20. I agree that the K is the best way to go, but I just can't justify the additional cost right now. Maybe when prices come down in a few years... a stroked K24 with K20 head would be awesome!

 

[pearl62]

Check out some of bones gear ratio combo in the trans forum. You could mix and match a good setup...

Sounds like Chris has a good combination of an optimal trans, lots of grip, and exceptional driving skill... What we all aspire to!

 

[pearl62]

Another question... Should I go for a non-Garrett GT28RS? I see lots of turbos for sale out there that are labelled as 'GT28RS', and are spec'd with dual ball bearings and all the the similiar specs to a Garrett GT2860RS, but they are not made by Garrett. Is it worth getting, or is Garrett still the way to go?

Usually these are sold as Nissan SR20DET or CA18DET upgrades on eBay and elsewhere...

 

[pearl62]

Do you think it's worth getting a cheap one new, then have it rebuilt with new good quality bearings? It seems like such a huge price difference for the the Garrett name...

 

[pearl62]

I got this response from BlaastPerformance with regard to rebuilding a cheap eBay 'GT28R' to Garret specs...

Ball bearing turbos are not rebuildable. garrett of chinese.

The chinese BB turbos are as bad as the journal bearing ones. They fail in no time. If you do a month, you're lucky.
People send them to me all week long for repair. It's funny to see all these blown turbos that still look sparking clean just like they're out of the box!​

Oh, and a new CHRA costs $770!

I'll just have to start saving for a real Garrett GT28RS...

 

[pearl62]

Will do!

 

[pearl62]

Hi Craig,

I'm in SM already anyway, since I've got a ported head and regrind cam. I figure I have no other choice than to turbo or swap.

BTW, I just bought some 550cc injectors off eBay from you. Just searching for injector clips now...

Also, I ended up goin with a T3/T04E 0.48/0.60 46 trim with ported turbine housing and stage 1 1/2 turbine wheel upgrade (59->65mm wheel). Much cheaper than a GT28RS, but should provide similar spool. I can always upgrade to the GT28RS later...

Thanks,
Stephen