GT2871 USERS. SR motor

[S13alldayyo]

Honestly it seems like the gtx and gt is the same exact thing, according to the people I have seen dynos from..... Havnt seen one for better then an old school gt series


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[Bleakley]

I've only seen direct comparisons of the gt2871r and the gtx2867r. I do not understand why people wouldn't go with the gtx2871r. Seems hardly anyone is using it even though it seems like the biggest/best you can do for a t2 bottom mount off the shelf.
Please shed some light...

[derass]

This article has some great information regarding GT vs GTX: http://blog.perrinperformance.com/ga...omparo-part-2/

It seems to me that a GTX makes more HP at the same boost pressure when compared to its GT counterpart. It also seems that the gains are greater as you compare higher boost pressures.

[cotbu]

Originally Posted by s13drob

S13 Sr20det
91 pump
18psi boost
Power FC Djetro
Gtx2867r .64 external gate
VQ coilpacks
Stock ex mani w/Tial WG
Tial bov vta
Tomei 256 poncams
Supertech valve springs/retainers
Apexi HG with ARP studs
CP pistons 86.5 w/ 8.5 comp
Stock rods w/ ARP bolts
Nismo fuel pressure regulator
Walbro 255
3" exhaust

Tuned by Koji as well. I've been wanting some advice on my setup and since Koji is being mentioned. Given that it's a GTX turbo. People aren't mentioning much on their fuel choice but it seems like everyone is using higher than 91 for the numbers their getting. It seems like I need e85 to get more boost.

Steve shadows, works with cali piss, I mean 91oct so maybe he could help you out,
I know he pulled bigger power out of a super 60 on 91oct iirc.

Originally Posted by Bleakley

I've only seen direct comparisons of the gt2871r and the gtx2867r. I do not understand why people wouldn't go with the gtx2871r. Seems hardly anyone is using it even though it seems like the biggest/best you can do for a t2 bottom mount off the shelf.
Please shed some light...

The gtx2871r came after much scrutiny about the marketing of the gtx2863/67.
So it wasn't available when this debate was in its prime.

Originally Posted by derass

This article has some great information regarding GT vs GTX: http://blog.perrinperformance.com/ga...omparo-part-2/

It seems to me that a GTX makes more HP at the same boost pressure when compared to its GT counterpart. It also seems that the gains are greater as you compare higher boost pressures.

All known facts and selling points are true about the gtx! The only misconception is that the 63 and 67 are upgrades from a gt2871r, sure you get an increase in spool, and should be able to run more boost but they don't out perform the gt2871r.

If you look at some of the comparison graphs most people reach full boost with the gt2871 around 4000rpm. Those graphs in the links are bigger turbos and still spool faster than the average gt2871 dynos that are posted in this thread.
Those people are the target demographic for the gtx 63/67/71 series turbos.
After you dump a stack on a turbo or any part for your car you'll probably say it's better too!

Any who, just be happy with what you build, who cares if that girl/guy, makes more power and torque than you!


Sent from a Highly Tuned Note 4.5!!!

[slider2828]

I think all evidence points to that the GTX with a twin scroll manifold definitely helps, but I think right now all the turbo chargers are getting really expensive. Cost per performance i think GT2871r has a lot of value vs gtx

[s13drob]

Originally Posted by cotbu

Steve shadows, works with cali piss, I mean 91oct so maybe he could help you out,
I know he pulled bigger power out of a super 60 on 91oct iirc.

Ultimately I'm going to run e85. I think there's so many benefits for the fuel and the nearest station is only a mile away.

Originally Posted by slider2828

I think all evidence points to that the GTX with a twin scroll manifold definitely helps, but I think right now all the turbo chargers are getting really expensive. Cost per performance i think GT2871r has a lot of value vs gtx

I agree. Like others have said it wouldn't be cost effective to swap from the 2871 to a gtx version. I ended up with my gtx because I got it from another member 2 years ago new for the price of a 2871r new.

[slider2828]

go devil robot from Futurama!!! MUAHAHAHA OT lol

[Bleakley]

Wish they made twin scroll T2/T25 housings... I think it's absolutely fucking stupid that they do not...
I for one would flippin' dig that gtx2871r or even the gtx2971r in a TS set up. Probably boost similar to an S15 turbo. Damn..

[bshotts]

Some have said that the "return on investment" of a twin scroll T2 turbine housing would be minimal at best especially at our displacement (2.X L), however I can't overlook the fact that the factory cast iron SR20 manifold was mostly divided and was designed that way for a reason. Any time you can divide and group exhaust pulses if beneficial IMO and is just going to aid in transient response. I believe this to be true especially considering all the OEMs are putting twin scroll setups into production cars from displacements as low as 1.XL on up.

I thought at one point I had seen a twin scroll T2 option from someone?

[Bleakley]

I read the first part and was annoyed with the ignorance of some, then it was redeemed with the mentioning of the newer lower displacements having TS setups. It's more efficient, period..

[cotbu]

The fact of the matter is, if you have trouble spooling a small/medium frame ball bearing turbo you have other issues. Regardless if a twin scroll housing is beneficial or not, your shit will always suck, worse than the next guy. Just fix your shit!
Or you'll be like maybe I need to extrude hone my twin scroll manifold and housing!

Sent from a Highly Tuned Note 4.5!!!

[RurouniMidnight]

Got my car retuned today by Martin of enthalpy ;^)
He tuned it a year ago and has been running excellent. I recently installed some tomei poncams and the car now fells better than ever, way more power and pull up top.

Here is last years dyno (red line) with recent tune (blue line) with the cams overlayed. I made about 68hp more at 6500 rpm haha.

Setup is :
S15 sr20det
Gt2871r .52 trim 64 ar
660cc injectors
Cody ace manifold with 38mm external tial mvs
Z32 maf
Tomei headhasket and studs
Tomei poncams 256 dur 11.5 lift
Also wanted to note i have 4.6 ring and pinion which could cause numbers read lower by 8% or so. Ita everything i aways wanted tho, great balance of power reliability and spool. ♡ Martin he's the man.

[UG-T]

@ what boost level? ^

[RurouniMidnight]

this was 20psi

[Dboyizmlg]

Looks like you need a Freddy intake manifold to keep top end from falling off.

[Tom N]

I would go with a extrude honed stock intake myself.

[Bleakley]

Originally Posted by Tom N

I would go with a extrude honed stock intake myself.

I'd definitely like to see back to back dynos of that at least..

[RurouniMidnight]

More than happy with results, car feels awesome and has great balance. I might run switch to E85 and top feed injectors in the near future mainly for better cooling in this Texas heat and drifting. Its a S15 motor so no freddy intake manifold and i care more about the mid-range power anyway.

[Tom N]

Originally Posted by RurouniMidnight

More than happy with results, car feels awesome and has great balance. I might run switch to E85 and top feed injectors in the near future mainly for better cooling in this Texas heat and drifting. Its a S15 motor so no freddy intake manifold and i care more about the mid-range power anyway.

I have a S15 motor also. The extrude hone factory intake does not kill midrange like a aftermarket manifold does. it simply helps carry the top end.
Here's a dyno graph of a stock location T2 20g on 15/16 psi
We were letting out at 8k rpms and as you can see the power doesn't have a big drop off.

[cotbu]

Originally Posted by RurouniMidnight

this was 20psi

even with the 52trim, 17psi should provide 350hp.

At first glance.
It doesn't look like he did much retuning to me, the graph stayed the same and it utilized the extra fuel that was present from the old tune.



Sent from a Highly Tuned Note 4.5!!!

[spools420a]

Is the twisted motion v1 gt2871r a good start I'm looking for 280-300whp and I'm looking at the twisted motion one since there $350 shipped.what a/r would be best for this.there's 3 gt2871 types correct? So I take it the smallest one should be what I need you think?I would rather go disco potato or s15 turbo for these lower HP numbers but there just too expensive compared to that twisted motion gt2871r please let me know,thanks.

[Bleakley]

@Tom N, did you like the results? and everything from the extrude honed intake mani? I'd like to send off my exhaust manifold and was debating on sending the intake in too, just to help open it up a little bit because it seems (out of AAALLLL the dyno graphs I've looked at) it's a little restricting.. But do not want to jump to a greddy, because my god do you lose a good bit at the bottom end..
Extruded intake
JWT S3's
Extruded Exhaust manifold
And an S15 turbo
Was gonna rock that setup for a little while til I saved up for whatever's next.

[Tom N]

Originally Posted by Bleakley

@Tom N, did you like the results? and everything from the extrude honed intake mani? I'd like to send off my exhaust manifold and was debating on sending the intake in too, just to help open it up a little bit because it seems (out of AAALLLL the dyno graphs I've looked at) it's a little restricting.. But do not want to jump to a greddy, because my god do you lose a good bit at the bottom end..
Extruded intake
JWT S3's
Extruded Exhaust manifold
And an S15 turbo
Was gonna rock that setup for a little while til I saved up for whatever's next.

I am a big fan of extrude hone intakes. I have used them on my DSM also.
They make a noticeable difference but don't kill the bottom end.

[Bleakley]

Thank you for that feedback. Excellent.

[spools420a]

When you guys get let's say enthalpy tune and you want too fine tune the setup,when you go get it tuned must you provide your own piggy back or standalone or can the shop tune the enthalpy ecu with there own standalone so I wouldn't need to buy one?

[Bleakley]

Talk to Martin and see if you can datalog and he can fine tune for you.
You would probably be much better off. Martin has literally done at least a thousand tunes for SR's. Only a handful of people can make that claim.

[aga]

here's my dyno sheet. the dyno operator did some mistake, its not 360hp , it's 346, and 42kgm

my setup:
gt2871 .64
nismo 740cc
apexi power fc
1 bar boost
100 octane gas but low ignition advance
sr20det zenki s14

[cotbu]

Are we still critiquing dyno graphs?

[derass]

Is that 346 number WHP or BHP?

Because 346 WHP would be very impressive for 1 bar and stock cams (it seems). BHP would be more reasonable.

[aga]

Originally Posted by derass

Is that 346 number WHP or BHP?

Because 346 WHP would be very impressive for 1 bar and stock cams (it seems). BHP would be more reasonable.

flywheel. wheel was around 310something. yes stock cams, i wanna get tomei poncams 256 and a 60mm throttle body soon. also exhaust manifold & external