GTX2971R questions

[Revmatch]

Hello, I'm hoping someone can share some knowledge and/or experience to help me decide on how to proceed with my plan for my MS3 (gen 1).

I'm weighing some possible turbo options (reconsidered every three days ) and one of these is the GTX2971R. I'm looking at the IWG and a EWG set ups with their inherent accompanying decisions and thus their holistic outcomes.

So, as you may already know, there is an ATP 2971R IWG kit available of the MS3 (90 trim and 84 trim options).

And the 2971R (just the turbo) is also offered in the two turbine trims.

90 trim:

PRODUCT SPECIFICATIONS:
* Compressor Wheel Inducer: 54.1mm
* Compressor Wheel Exducer: 71.4mm
* Compressor Wheel Trim: 58
* Turbine Wheel Inducer: 56.5mm
* Turbine Wheel Exducer: 53.6mm
* Turbine Wheel Trim: 90
* Standard compressor housing is T04E Frame with 4" inlet, 2" outlet, and built-in & machined anti-surge.


84 trim:

PRODUCT SPECIFICATIONS:
* Compressor Wheel Inducer: 54.1mm
* Compressor Wheel Exducer: 71.4mm
* Compressor Wheel Trim: 58
* Turbine Wheel Inducer: 56.5mm
* Turbine Wheel Exducer: 51.8mm
* Turbine Wheel Trim: 84
* Standard compressor housing is T04E Frame with 4" inlet, 2" outlet, and built-in & machined anti-surge.


COMPRESSOR HOUSING OPTIONS:
* T04E Frame with 4" inlet, 2" outlet, and built-in & machined anti-surge. Default / Standard Option
T04B Frame with 3" Inlet and 2" Outlet (same compressor housing as GT2871R or GT28RS)

I don't know what turbine trim is offered in the ATP kit (waiting on their response).

IWG set up:

I have heard that the GTX 2867R and GTX3071R have been successfully run without creep issues unless significant exhaust flow mods have been made like head porting. But since the 2971R seems like an unproven set up for the MS3 thus far, the possibility of boost creep issues has me questioning IWG and porting may be necessary--which is fine, I guess. Furthermore, if going IWG, there is an ATP kit available (which would make things simpler). And interestingly, this kit uses a .72 A/R. I'm not sure what compressor housing is offered in the ATP kit (Edit: ATP says 4"compressor inlet and 2" compressor outlet is standard)

EWG set up:

If running in EWG configuration which is more appealing to me at the moment, I am considering an EWG manifold, 2971R "super core" and an ATP turbine housing (not ATP EWG housing) with a V band down pipe connection. Meanwhile, the optional turbine housings to be run in EWG are offered in .63 and .82 A/R (the housing offered in the ATP 2971R turbo kit is a .72 A/R).
So, might you have any suggestions on what trim (90 or 84) and what A/R (.63 or .82) to run with this turbo? This is for a fun street car set up with good response (2867R like but with more top end--flatter torque curve to redline).

As far as I understand things, there are four possibilities with varying degrees of quick spool vs. top end here (90 trim with .63 or .82 A/R and 84 trim with .63 or .82A/R). But I don't truly know how to decide on what to do. If I was to run this setup, I naturally don't want to make a bad decision here that would not fit my MS3 stockish parameters (not intending to raise RPM, wish to stay on stock or stockfish clutch, do not intend to change gear ratios). For example, what might the difference be between the 84 trim in the .82 A/R housing vs. the 90 trim in the .63? My instinct tells me that the 90 trim wheel and .63 A/R is the way to go. As stated earlier, I am waiting to find out what the ATP kit trim is so that I have something to compare to, at least theoretically (for example, the EWG 84 trim with .63 A/R may be comparable to the IWG 90 trim .63 or even .82 A/R?; might one set up be optimized if running pump gas vs. meth?).

I hope I was able to clearly pose the possible scenarios. There seems to be many influencing factors and I am trying to pick up what I can.

If any has any real world experience or can offer some advice to shed some light, it is much appreciated!

[Revmatch]

I sent an email over to ATP,
The response was:

"The difference in spool between the 84 and 90 trim is negligible (100 to 150RPM). The 90 trim will support slightly greater top end flow. If you plan to max out the turbo, we suggest the 90 trim GTX2971R version.

If you prefer improved low end response and top end power is not not a certain, we suggest a GTX28 series model.

If you plan to utilize the standard T25 frame turbine housing for the GTX29 series, we suggest the .86 A/R version" (I think he meant .82)...... "The .63 A/R will spool very quick. However, the .63 A/R will choke the GTX2971R in the top end."

I hope to get mid 300's or so on 93 gas and over 400 with meth efficiently. I wonder how far the .63 will go on the MS3 and what power will the turbo be choked.

[broda]

Out of the combos you listed I would personally go with the 2971 84 trim .82 A/R w/ EWG. Going with a .63 A/R maybe be a little too small if you want over 400whp in its efficiency range.

[Revmatch]

Thanks broda. And what are your thoughts on the 90 with .82? Spool penalty? So the 82 trim and .82 is a good balance?

[broda]

I would say the 84 trim with the .82 A/R would be the best "happy medium" spot. I can't imagine the 90 trim being too much slower in spool since the difference between them is pretty minor. There isn't a whole lot of information I've seen out about the GTX29 turbos and I don't think I've seen anyone use one with our platform yet so it's hard to give any sort of concrete advice on it.

Edit:
http://www.atpturbo.com/mm5/merchant...ory_Code=GTX29

The turbine housing is a .86 A/R after all. And the only option for the DP flange is a 5 bolt so you couldn't do a V Band anyway unless if you found a different turbine housing from elsewhere.

[Revmatch]

Yeah broda, I can't find any village knowledge of running this turbo. On the ATP site, the 90 trim is the default trim on their turbo kit BTW.

The focus ST guys seem to be preferring the smaller A/R (.64) over the (.86). I imagine this is because of their 2.0 displacement. But I'm foggy on how this relates to the MS3. It seems that the two are very similar though. The turbo is capable of 465hp according to guys at Stratified Tuning.

[Revmatch]

This is what I was looking at:

ATP housing for 90 trim turbine wheel available in either .62 or .82 with 3" V band flange:

T25 Plus, T25 Inlet, T31-V Band Outlet Turbine Housing FOR GT28/GTX28, GTX29, GT30/GTX30, GT35/GTX35 : atpturbo.com

Also broda, those housing options are IWG.

[broda]

Oh, you're right. I didn't see that there was an optional 3" V Band on that. My mistake.

There's a COBB IWG Bracket which deletes the IWG if you still want to do EWG as well.

[Revmatch]

Yes but I feel that is not an elegant solution if I were to run EWG. I'd prefer a manifold for EWG and a simple turbine housing. I looked at tial stainless housings as well but I don't think they will fit the 2971 well. They do offer housings for the 28x, 30x and up, however.

[SpeedRebirth]

You definitely want a 80+ AR! 63 is very small/restrictive. It's already a "small" turbo so you don't want to choke it.

Talking about efficiency, you need to consider exhaust backpressure. The smaller turbine/housing the greater the backpressure will be, which results in less efficiency because the exhaust gases has a harder time to evacuate the cylinders.

This is also where a better exhaust manifold comes in. And I recommend you stay clear of the OEM flange, it's pretty restrictive compared to v-band/T25 ect. And EWG is always nice and improves flow quite a bit. Same with boost control. Especially if it's mounted on the manifold instead of the turbine housing.

For 400whp I really suggest you get a 3,5" intake to keep it efficient

[Revmatch]

Thanks for your input, SpeedRebirth.

Yes, I understand that the engine will breathe easier with the larger A/R and I am also seeing the appeal in going EWG and finding a non stock flange solution. Hopefully the EWG solution will be cost effective as well.


My car is nearly stock at the moment (kinda late to the party--everyone and their step sister is running big turbo it seems) but I do already have the 3.5" intake. Other parts are waiting to be installed (Carillo Super-A rods, gauges, IM spacer, catch can with PCV plate, etc.). Naturally, I'm trying to devise a solid plan taking into account all the factors I can get my head around. It seems this turbo may be a nice match for the MS3 and I'm interested in seeing what this turbo can do efficiently with good flow mods.

[broda]

Is there any particular reason that you're looking at those Carrillo rods? You can get forged rods + pistons for the same price as those cost themselves.

[Revmatch]

Got them because they can be had with stock piston 22.5 wrist pin, lighter than stock, and can more than handle what I plan to put them through. I was originally planning to just use gen 2 pistons but am now thinking of going with the 4032/Mahle pistons from SP. Anyways, I have to use them! they're sitting right here next to me.

[broda]

If you have the means to do so, I'd recommend seeing what your cylinder walls look like and checking the bore as well to see if you'd need to get .020 over pistons before ordering any. It's just one less hassle if you find that you need to bore out your cylinders.

[Revmatch]

Thanks broda.

Pablo at SP63 said all looks good though cylinder 3 has lower compression than the rest. The plan is for SP63 to do the engine work--the engine will get a refresh, VVT, new rods and likely will use SP pistons that will be sized accordingly.

[Hammology]

If your doing all this work why not a bigger turbo? Lol you'll be surprised how fast you max that thing out, and then you'll be stuck wanting more. But .82 hotside is the way to go.

[SpeedRebirth]

Now that we know the whole story it's easier to give appropriate advice

On a built block the 29 turbo is pretty small if you look at what the block can handle. But you wanted quick spool so it might be a good compromise Definitely go with the big AR housing

[broda]

In before he goes high compression pistons and a 6266 instead.

[Revmatch]

My turbo selection is not set in stone and I'm actually feeling a little vulnerable to your peer pressures!.....
I'm trying my best to achieve a balance on as simple a setup as I can and not throw down a whole lot more $$. I want it to be simple so there's less to go wrong and find a balance. The 2971R which seems to have a nice range of power and spool that would match the mods I have planned. Alternatively, I am entertaining all options within the engine work I have planned and the FJP S360 kit taps on my shoulder every once in a while but a more tame version if that's even possible (with a cat, extra resonator, and not maxed out). I'm thinking that I likely will not be able to provide the time, space, or experience to maintain it. I'm not sure i would enjoy it either on a daily basis even. But I don't know, I'm in new territory here. But it is exciting!


Actually, my front runner plan right now if it is feasible, is to run the FJP kit with a smallish turbo like the GTX2971R. Am I crazy?

[broda]

*cough* http://www.mazdaspeedforum.org/forum/foru...kozmic-195048/ *cough*

[Revmatch]

Originally Posted by broda *cough* http://www.mazdaspeedforum.org/forum/foru...kozmic-195048/ *cough*

Thanks for the heads up. I loved godzilla as a kid. But that's going from one extreme to the other for me. I never entertained going that big. Needs to have a get out of jail free card with that. The 5858 was an option for a little while especially after seeing some of the results with it but the non water cooled scared me a little as well as some of the dissatisfaction I came across with precision. But I understand that they must run well for a lot of people.

[cshunter]

My 5858 with ball bearing, ceramic coated hotside, manifold and ported head head was hitting 20 psi around 3600/3700 rpm.

If I were to do it again, I'd either go efr or hta/x/y/z (whatever letter they use for their awesome ones)

[MSP611]

Id go efr 7163 if u want power and spool ask @Alpha; he has one and sees full boost at 2800-2900rpm. Tht is on a 3071r sized turbo with 2867 or 2871 spool characteristics... They are IWG as well and have an attached EBCS as well... They are slightly pricey but are proven to hold boost, not creep, no need for aftermarket EBCS, no need for EWG and plumbing, they come In t4 twinscroll (small AR tho) too.

Sent from my Nexus 7 using Tapatalk

[Alpha]

Originally Posted by MSP611 Id go efr 7163 if u want power and spool ask @Alpha; he has one and sees full boost at 2800-2900rpm. Tht is on a 3071r sized turbo with 2867 or 2871 spool characteristics... They are IWG as well and have an attached EBCS as well... They are slightly pricey but are proven to hold boost, not creep, no need for aftermarket EBCS, no need for EWG and plumbing, they come In t4 twinscroll (small AR tho) too. Sent from my Nexus 7 using Tapatalk

I couldn't have said it better myself man, but the flow is slightly greater than a GTX3076R IIRC.

I love my prototype 7163 and the production version that's available now flows even 15% more than mine.

[Code Monkey]

Someone dynoed 450 to the wheels on a GTX2971 on their Gayata.

[Revmatch]

Thanks for the input everyone, I have already decided on something similar to the 7163 without the IWG and the built in ebcs--kinda like the EFR lite....
It's the updated Borg Warner SX-E s200 7670 aka s257 with the FJP turbo kit. Going to run a .82 a/r and see how that goes.

I'm excited!

[Alpha]

Originally Posted by Revmatch Thanks for the input everyone, I have already decided on something similar to the 7163 without the IWG and the built in ebcs--kinda like the EFR lite.... It's the updated Borg Warner SX-E s200 7670 aka s257 with the FJP turbo kit. Going to run a .82 a/r and see how that goes. I'm excited!

Nice dude!

[WetzMS3]

Originally Posted by Alpha Nice dude!

Where have you been boss?

Did you ever get fueling sorted out? We need to get together this spring, I haven't seen your car in like a year and a half and my car has changed quite a bit.

[Alpha]

Originally Posted by WetzMS3 Where have you been boss? Did you ever get fueling sorted out? We need to get together this spring, I haven't seen your car in like a year and a half and my car has changed quite a bit.

Hey man! I focused on selling my street car (99 Z) and have really just been enjoying the 6 as is until I see what happens with the new CP-E IM and their AUX system.


I'm DEFINITELY down for some good NATOR meets this Spring. Nice! I'll have to check your ride out