GB: Garrett GT2860's

[NismoS-tune]

Good stuff, -5 it will be. Now about the Optional turbine housing, how does that change things up? There's 2 options .64 and .86. The smaller AR would spool quicker and the larger one would have more peak power?

[tokes]

You got it. The .64 will spool quicker but won't make power at as high of RPM's as the larger housing, and will make less peak power at a given boost level. The .86 will spool later and hold power stronger, but will obviously have weaker midrange.

[NismoS-tune]

hmm.. big laggy power is no fun on the street. I guess it's the .64 for me then. Well, maybe I could do the laggy boost. Anyone run the larger Turbine? I'm curious when does useable boost comes in. 4500rpm for .86 vs 3500rpm with the .64?

[DougTaylor]

Perfect Doug! How is the response of the 2860's with the poncams? Doing the exact same setup on a car we are doing right now. Hense myself getting in on the gb.

It's looking great so far, but I've been keeping it under 4000 rpm because of the new clutch and very low load. Turbos are kicking in easily around 32-3500 even at half pedal. 4000 comes way too quick after that. The fconv is in learn mode right now, and we'll hopefully have it on the dyno may 25 if reg has time. Remind me and I'll send you the sheet if you like, or maybe even let you take it for a spin!

[DougTaylor]

Sorry I forgot to add that I did go with the .64 AR so I could enjoy it on the street.

[NismoS-tune]

In case the group buy goes like most group buys and doesn't go through, I'd like some quotes for these turbos. Twin 2860-5 .64.

When comparing the .64 and .86, lets say at 1.5 bar, I would make much more power with the larger turbine then while sacrificing response I guess? Anyone running the .86? Let's say I get the .64 and I'm not happy with the little ones, the turbines are interchangeable without sending them in or replacing them I hope.

[tokes]

hmm.. big laggy power is no fun on the street. I guess it's the .64 for me then. Well, maybe I could do the laggy boost. Anyone run the larger Turbine? I'm curious when does useable boost comes in. 4500rpm for .86 vs 3500rpm with the .64?

The small diference in A/R ratio is not going to make a 1000 RPM difference in spool. I'd say 2-300 RPM's at most.

If you get the .86's and don't like them, it would be realtively easy to swap them for a set of .64's. I don't believe the turbo geometry changes at all when changing A/R's on a T25, so it would just be a matter of getting a set of .64's, pulling off the turbos, putting on the different housings, and reinstalling the turbos.

[Terrh]

I have the 0.64's and I'd trade for the .86's.

They'll be ported too unless I got a PM about them like, tonight or tomorrow.

[NismoS-tune]

So you've maxed out the smaller ones and you'd like to try the others?

[NismoS-tune]

Bump, group buy!!!

[bronigs]

I'd be in for GT2860-5. Braden you seem like a hard person to contact can you provide a telephone number. I want those Apex'i Filters also. Please contact me and provide a telephone number, but count me in for gt2860-5.

The -5 seem to be the best since they are direct bolt on to the original exhaust manifold and dump pipes.

[tokes]

All of the GT's that have a 707160-X part number are bolt on. That includes the -5, -7, -9, and -10 turbos.

[Danno]

I might be interested in getting a few, but I'll give you details on how many later. June 5th is the deadline for ordering?

Your math seems off from my understanding: $1670 for a pair + $85 shipping + $40 customs = $1795USD. Did you calculate the shipping and customs duties per turbo?


A bit of info on these Garrett Turbos:

-5 are HKS 2530 equivalents
-7 are R34 N1 (ball bearing) equivalents
-9 are HKS GT-SS equivalents
-10 are HKS GT-RS equivalents

They are called "equivalents" but they are not identical. There are some very minor differences in specs between the HKS and Garrett turbochargers, but most will not be able to tell the difference.

Dash 5's are the most common of this series turbo for the RB26 on street cars from my experience. Choosing the right turbo does take a lot of research and depends on what other mods the car has and what it's purpose will be. Garrett has a Turbo Application Search Engine on their website to see what others have used on specific vehicles.

[NismoS-tune]

The HKS versions of these turbos have shown to be better. Maybe that's part of the reason why they're almost twice the price, other than being HKS. Once the group buy deadline is past I will be looking at some prices on HKS GT2530s (US dealer preffered due to economy).

[DougTaylor]

FYI - got the car on the dyno today finally with the new 2860-5s - 300 whp at 5 psi !!! Why no more you ask? Blew the connections off the intercooler.. More on Monday.