gt2871r vs TS-GT3071R for Response

[guitaraholic]

Ok, I've got the flame suit on, but even with searching, I am finding conflicting data. But here it is

I would like at least 350-400 whp (but more is welcome). I've been looking at the dyno graphs. The Twin Scroll GT3071R looks as responsive, if not more responsive than a GT2871R. I'm not looking to be a dyno queen, nor have any wish to do stupid Highway top end races. What I am looking for is lots of response that is good enough for road racing and some auto-cross, but the occasional 1/4 would be fun to.

Both the Twin Scroll and the GT2871R look like they can do ~20lbs of boost by 3800 or so. Hell my T28 isn't that much better than that.

[juggernaut1]

For your reference I make 24 psi by 4000 rpm with my twinscroll 3071 with Tomei 260/260 cams and Hypertune intake on s15 black motor with VCT. Boost was dropping to 22 psi at the redline - I made 388rwhp on a dyno dynamics dyno - that was an initial tune on a 37C degree day.

I went from a stock s15 turbo to this setup and in all honesty I don't feel like I've lost any bottom end based on the way it drives - it just feels like a much ballsier s15 turbo. I've never been in a 2871R equipped SR so I can't comment on how they compare.

The beauty of the twin scroll 3071 setup is that if you want a power up grade you just slot in a 3076 into the exhaust housing, retune and your good to go.

[s15specR]

Well this is a great comparison.

On the same S15 motor, VCT compatible 260/260 Tomei cams, Tomei Expreme Mani and Elbow, 740CC Inj. GT2871r 56Trim, on a dyno dynamic dyno as well.

http://i267.photobucket.com/albums/ii319/tripleJs15/Car/dyno_psi.jpg

[guitaraholic]

For your reference I make 24 psi by 4000 rpm with my twinscroll 3071 with Tomei 260/260 cams and Hypertune intake on s15 black motor with VCT. Boost was dropping to 22 psi at the redline - I made 388rwhp on a dyno dynamics dyno - that was an initial tune on a 37C degree day.

I went from a stock s15 turbo to this setup and in all honesty I don't feel like I've lost any bottom end based on the way it drives - it just feels like a much ballsier s15 turbo. I've never been in a 2871R equipped SR so I can't comment on how they compare.

The beauty of the twin scroll 3071 setup is that if you want a power up grade you just slot in a 3076 into the exhaust housing, retune and your good to go.

If that's the case, I would be more than happy with a twin scroll setup. My S14's T28 has good enough response to make it fun. Yes, if I am caught off guard, it's a dog at first. But as long as I monitor the RPMs and stay above 3500 or so, then its a pretty all around turbo (ie autocross, straights, ect ect), it just falls completely on its face on *UMPH*...lol.

Were you able to keep your A/C with your setup?

[MrChow]

I believe it how good of a tune matter in the end. Idk.

Look up steve_shadows S13 sr20 w/twin scroll up. He makes good power and it full boost at 3.8 to 4k.

[Z33dori]

my buddy was running the GT3071RTS w/ Full race manifold

can't remember all the parts... but on 15psi it made 375, was at full boost by about 3800-4000 maybe a lil lower... been a few years since i rode in it... but it felt pretty nice... not hella laggy

[MadScientist]

I am considering the GT2876R for the same reasons you mentioned above (OP)... I also wish to keep the A/C because New Orleans is hot as F%^*.

I see alot of confusion in the HP #s also.

Only real question I have is why 260 cams... and why keep the VTC??
Most of the SR guys are keeping the cams low... I rarely see 270+ or a staggered IN/EX cam set-up!

-Drew

[driftage240]

twin scroll full race gt3071r ftw...im making 403wp at only 20psi on pump gas...gt2871r is a good turbo but the gt3071r kicks alot harder..My old setup was a s15 turbo..i haven't felt any real loss in response..

[Zerolift Autolab]

Built SR - HKS Step 2's, supertech valvetrain, Peak Boost Turbo Manifold - GT3071R + AEM 20psi Pump Gas
- made 459 whp 388 tq
Full boost happens at 4000 - holds to 8000 falls off a bit to 8500 ( drop is about 25 whp )

Please feel free to contact me with any questions or setup inquiries.
Thanks,
Robert

Other Recent Setups:
S13 SR - Stock Motor
550 Injectors + GT28R + Power FC
Made 288 whp & 275 tq

S14 SR - Stock bottom end
HKS Step 1 Cams
Supertech Valvetrain
550 injectors
GT2871R
AEM EMS
Made 343 whp & 318 tq

[juggernaut1]

If that's the case, I would be more than happy with a twin scroll setup. My S14's T28 has good enough response to make it fun. Yes, if I am caught off guard, it's a dog at first. But as long as I monitor the RPMs and stay above 3500 or so, then its a pretty all around turbo (ie autocross, straights, ect ect), it just falls completely on its face on *UMPH*...lol.

Were you able to keep your A/C with your setup?

Yes I was able to keep the aircon - Australia is a hot place in summer. To do so I had to drop the compressor by 30mm (although 35mm would have been perfect) to clear one of the manifold runners. All this required was 6061 Alli plate bolted to the original aircon engine mounting point with countersunk mushroom bolts and the compressor just bolted to the helicoiled alli plate but 30mm lower. Also needed a slightly longer belt IIRC. Didn't need to touch the aircon lines at all. Just slipped a heat resistant sleeve over them.

[juggernaut1]

I am considering the GT2876R for the same reasons you mentioned above (OP)... I also wish to keep the A/C because New Orleans is hot as F%^*.

I see alot of confusion in the HP #s also.

Only real question I have is why 260 cams... and why keep the VTC??
Most of the SR guys are keeping the cams low... I rarely see 270+ or a staggered IN/EX cam set-up!

-Drew

Actually I woudn't use the 2876 turbo - its a bit of a mismatch - to much compressor for the turbine. If you refer to the Garrett website on this turbo they also hint at this by suggesting that it is not for performance applications.

VCT gives better bottom end and therfore a broader power band - back to back dyno's also clearly show this. My VCT has been adjusted to come in at 1500 and switch off at 7000 rpm.

Unfortunately bigger cams and stiffer springs ultimately lead to the death rattle so common with the VCT. Luckily mine is still holding out at this stage.

Tomei 260/260 cams are probably holding back the turbo a little at this stage however I wanted to see how the twin scroll setup would initially fair. Now that I can get 24 psi by 4000 I might swap to some HKS Step 2 264/264 or similar as I have some spool to play with.

[johngriff]

I would like at least 350-400 whp (but more is welcome).

TLDR

3071r

[juggernaut1]

Anyway, here's a couple of pics of my setup.

http://i241.photobucket.com/albums/ff132/juggernaut000/SR20Build020.jpg

http://i241.photobucket.com/albums/ff132/juggernaut000/SR20Build019.jpg

[guitaraholic]

Wow, that is a very clean setup Jug.

Ok, I know everyone is going to ask "WHY?" but here it goes. Is it possible to do a bottom-mount EQUAL Length setup w/ external W/G's? I know for a T3 you have to trim the mounts. If possible I would like to keep it stealthy, and also, a top mount brings the center of gravity up a bit. Not a huge deal, but if its possible, that's the route I would like to go.

[efrain240sx]

well as far as equal length runners I have not seen one yet, but NEUKIN does have a nice bottom mount T3 manifold with a external WG.

http://i147.photobucket.com/albums/r316/efrain240sx/neukinkabm2.jpg

http://i147.photobucket.com/albums/r316/efrain240sx/neukinsrbm2.jpg

[OBEEWON]

I've been thinking about the 3071. I think keeping Air Con should be fairly easy with an extended line right? Has anyone tried it?

[ArmadaJspec]

For your reference I make 24 psi by 4000 rpm with my twinscroll 3071 with Tomei 260/260 cams and Hypertune intake on s15 black motor with VCT. Boost was dropping to 22 psi at the redline - I made 388rwhp on a dyno dynamics dyno - that was an initial tune on a 37C degree day.

I went from a stock s15 turbo to this setup and in all honesty I don't feel like I've lost any bottom end based on the way it drives - it just feels like a much ballsier s15 turbo. I've never been in a 2871R equipped SR so I can't comment on how they compare.

The beauty of the twin scroll 3071 setup is that if you want a power up grade you just slot in a 3076 into the exhaust housing, retune and your good to go.


GT3071R T25/28 Flange > GT2876R

Very Impressed with this turbo set up on m sr20det (red top). I agree it's basically a GT28 on steroids.
http://i283.photobucket.com/albums/kk287/armadajspec/sdf.jpg
http://i283.photobucket.com/albums/kk287/armadajspec/l_ac233fe8149e40c699c89cf995460382.jpg
http://i283.photobucket.com/albums/kk287/armadajspec/l_391e186e6d6541c9936676a5ebfb0a69.jpg
http://i283.photobucket.com/albums/kk287/armadajspec/l_d70d04196f184124a2deba5dd7bcbaa2.jpg

[guitaraholic]

Armada, is that an equal length manifold, if so, how hard do you think it would be to use a T3 flange instead of the T2?

[nismo tuned s14]

I've been thinking about the 3071. I think keeping Air Con should be fairly easy with an extended line right? Has anyone tried it?

I'm also considering the GT30R and want to keep the a/c. I have a KA24DE(T). Are there any issues keeping the a/c with the KA?

[MadScientist]

Wow, that is a very clean setup Jug.

Ok, I know everyone is going to ask "WHY?" but here it goes. Is it possible to do a bottom-mount EQUAL Length setup w/ external W/G's? I know for a T3 you have to trim the mounts. If possible I would like to keep it stealthy, and also, a top mount brings the center of gravity up a bit. Not a huge deal, but if its possible, that's the route I would like to go.

^^^^ This is where I am also. I want to keep the A/C and keep it bottom mounted... I dont care if its Internal or External waste... I am considering welding a T3 flang (or V-band) on my Tomei Mani and a v-band for ex-waste.
The 3071-WG fits bottom with minor trim to the engine mount (IIRC)... with that concept I hope a non-WG will fit!!!

-drew

[deukalionS14]

I have the 2871r .64 but haven't been able to really see it's true potential due to bad piston rings and other minor engine problems...buuuut the rebuild is almost done!! back on topic...i liked the response and the little power that i did see but i also want to do a GT3076r set up. I rode in Steve's car and holy shit i cant wait to find an excuse for an upgrade!

[juggernaut1]

I've been thinking about the 3071. I think keeping Air Con should be fairly easy with an extended line right? Has anyone tried it?

I have aircon in my setup - no lines need to be extended, but I had to have a plate bracket made up to drop the aircon compressor 30mm. You can just see my aircon compressor in the above pics.

[steve shadows]

I believe it how good of a tune matter in the end. Idk.

Look up steve_shadows S13 sr20 w/twin scroll up. He makes good power and it full boost at 3.8 to 4k.

I use a single scroll GT3076R and it outspools 90% of the GT3071R single and twin scroll setups I have seen and even the 2871R ones (because no one actually tunes them properly with a dyno that is capable of steady state tuning).

My car is single scroll, I get 18 PSI of boost on a GT3076R with the oversized T04S Housing at 4100 RPMS...!!!! That's right....

Throttle is soo touchy boost feels instant.

This is why steady state is soo valuable, your create the optimum cylinder pressure in every single cell in the map by using the dyno to lock you in and tune cell by cell, making insanely better response than any single scroll car tuned on a straight roller dyno.

Just ask all the Aussies how they make such wicked fast cars.

If you want to have the best response get 264 Step 2 HKS Cams, get your valves de-shrouded, use a small IM like a stock SR IM (is the best) then use a lighter Flywheel and a oversized throttle body like a Q45, then use a GT3071R Single Scroll ( or twin scroll if you desire a little more transient response).

In my experience though the TS and SS turbos are not night and day difference when BOTH tuned on Dyno Dynamics dyno.

Nailing the EXACT Timing in each cell by tuning cell by cell is what will really give you that light switch response and insane top end power as well..

Gotta go Dyno Dynamics.

[ArmadaJspec]

Armada, is that an equal length manifold, if so, how hard do you think it would be to use a T3 flange instead of the T2?

Honestly not hard at all if you know how to weld (preferably TIG). Cut T2 flange off and buy a T3/4 Flange weld to Exh. manifold to your spec. make sure you mock up couple of times due to clearance issues (motor mounts). then add a external waste gate tube/pipe onto exh. manifold with v-band flange and Tial Ext. Waste gate
OR
With T2 flange Gt3071r weld the internal waste gate Flap on exhaust housing closed. then add a external waste gate tube/pipe onto exh. manifold with v-band flange and Tial Ext. Waste gate. Same concept as T3/4 manifold.