no. turbine wheels are different and so is the way the housing attaches to the CHRA. Borg Warner does make a v-band only, external wastegate housing for EFR 6758 (for Indy). They were rumored to release it publically but never did.

it's like circumcision

Thanks for clarifying. :bigtu:

you know what i have been doing a bit of thinking today and is the efr 6758 really worth it for me over a gt2871r? spool has never been an issue with the 2871 on the race car and it was making 355bhp at 1.2 bar. owen developments who built the last turbo recommended we could easily run 1.6 bar without problem!

would the benefits outweigh the cost/work? i can get a gt2871r for £650 with uprated bearing cages and internal heat shielding. an efr 6758 is going to cost £1000+ and need either a new manifold or major surgery to fit. also the efr is hard to get your hands on where as i can get a Garrett next day!

could someone please convince me what i should do!!

are there any other good options that will bit my fm manifold just to make the decision harder?

GTX2863 or 67. I have seen them both do 400+ and spool better than the 2871r.

the gtx series look very good! according to their website the GTX2867 is good for 480bhp... next option is .64 or .86 a/r. the old GT2871r was .64 a/r and the lag was easily acceptable. wonder how bad .86 would be?? i would imagine it would be ok on a race car...

going to call my supplier tomorrow and see what i can get one for at trade.

http://www.turbobygarrett.com/turbob...366-1_comp.jpg

would probably be around the top right of the map if i estimate at 400bhp air flow will be around 45 lbs/min and a pressure ratio of around 3... would mean it should be very efficient rite through the rev range though.

found this... thoughts?

GTX2867 .86 A/R vs .64 A/R Turbine Dyno

Skip the GTX. By the time you get the GTX chra, a turbine housing (GTX is an upgrade, not a complete turbo), wastegate and a blow off valve, you'll be well over the price of an EFR with less performance.

except that he already has everything to run the gtx without modifying anything

Fucking reading. I'd still sell the accessories and get the EFR. Even the journal bearing S series from Borg Warner are outperforming the GTX in every category.

OP, good luck. You'll be second guessing yourself until the moment you click the buy button. We've all been there.

called my supplier and i can get a gtx2867r with exhaust housing, uprated steel bearing cages, internal heat shielding and a built in egt boss for £890 ($1400) plus tax (which i can claim back).

seems like a good deal to me. we are never going to know how good it is if nobody tries it. be good to see a real comparison between this and the BW.

Well i bit the bullet and went for the GTX2867r..... Hope i don't regret it!

https://www.miataturbo.net/attachmen...ine=1359401996

Nice, in for results.

Don't fael out on us now, get that thing to a dyno (you know once you put it back in the car and all).

That's the plan... just been in contact with the mapper to see when he can get me in. Question is, how much boost???

ALLOFIT:firedevil

haha would love to run all of it but last time i did that ended in an engine rebuild and this new turbo.....

now got egt probe so think i will just keep upping it until inlet or egt starts to get crazy. really want the race car to be reliable this year as well as fast.

can't wait to see the plots

Motec M4 plug still there. :)

What turbine AR did you go for?

yea with the engine rebuild and the new turbo the winter budget is all used up. the m4 is not ideal i know but think its going to have to battle on for another season.

Decided to try the .64 housing and see how that goes first. hot the end of the world if i have to get the .86 at a later date. The gt2871r that was on before was pretty good on a .64 housing. Shame the housing was damaged after the bearings exploded!

Good call, I did the same thing. Turbine housing swap is easy anyways.

just an update on this. never got around to posting results but here they are.

https://www.miataturbo.net/attachmen...ine=1390767033

my mapper suggests that the crazy amount it needed to be strapped down and tyre pressures lowered would be worth around another 30hp. this was at 1.6bar. didnt really want to run any more as it is now killing gearboxes. once the new box is sorted we will turn it up to 1.8 and see where we are. i am happy with the results though. what u think? did i make the rite decision on the GTX2867R?