GT2871 USERS. SR motor

[TFD]

Ok, now we're talking cams:
Im in the market for a nice set to match mu 2871 .86 56 trim turbo.

Thinking about the 11.5 mm 264/264 step 2's but uprated springs are needed.
I putted S4's (11.7mm 266) without uprated spring in my fwd DET and worked fine (even tough the lift is a tad higher).

1. Are uprated springs realy neasesery for the step2's and why on the S4's not? (Said on the sr20 forum).
2. Is the 264/264 or 264/272 combo better suited for the .86 turbo?

Its been talked a lot in 57 pages but the .86 turbo not that much, so hence my question.

Grtz,
Daniel

[slider2828]

I have the same turbo GTRS style, which is the 3 inch opening one. HKS 264/264 step 1 cams..... Stock intake and exhaust manifolds for road racing...

From my experience depends what driving you do. 264 step 2's are like 272 step 1, the power delivery is later really not that much big difference... If you run track or highway pulls or what not, 264 step 2 or 272's all the same, spool later.

If you want something streetable off the line mid torque fun 264 step 1s...

So it depends what type of drive you want... and what mods.... Obviously intake and exhaust manifolds will help top end horsepower, but I like cast stuff cause shit doesn't break... hahahah...

[TFD]

Well, I have a VCT S14 sr20det so to maintain the VCT I can only use the step 1 256 intake cam. Since my mid-high rpm turbo, the 256 duration is not in the optimum working area and therefor not the best match for the turbo imo. So thats why I came to the step 2's with 264 intake cam.

[slider2828]

Unless you are the man, its super hard to tune vct with those cams.... just get S13 cam gears on those cams and call it a day.

[u_contempt]

i run a 52trim gt2871r .86 with 264's and retained vtc. i love it.

[Luvs2slide]

For those whose cars been tuned, do ya'll know if they touched ignition timing much? Reason I ask is b/c my tuner is mainly adjusting the fuel map. Of course, he adjusted for a/f ratio, and knock so far. My car is being tuned for drift, and we actually tuned while I was drifting. Just curious if there is lots of HP to be gained by adjusting the ignition timing. Right now at a constant 7500 RPM the car feels great with lots of reponse and knock kept below 15. This is about 4 hours worth of beating on the car.

[jspaeth]

Originally Posted by Luvs2slide

For those whose cars been tuned, do ya'll know if they touched ignition timing much? Reason I ask is b/c my tuner is mainly adjusting the fuel map. Of course, he adjusted for a/f ratio, and knock so far. My car is being tuned for drift, and we actually tuned while I was drifting. Just curious if there is lots of HP to be gained by adjusting the ignition timing. Right now at a constant 7500 RPM the car feels great with lots of reponse and knock kept below 15. This is about 4 hours worth of beating on the car.

Of course there is power to be gained with timing, but you need to know what you are doing.

Some of the better setups out there (safe as well) are running GT2871R with cams (260-264ish)

....and running, say 17-18* of timing at 4000 RPM at 20 psi, tapering up to as high as 20* by redline.


Be careful....too much timing will easily blow your motor at these power levels....

[nothix]

My setup:
Z32 Maf
GT2871r .64 3" inlet
550cc Deatschwerk
Freddy Intake Manifold
Meagan Exhaust Manifold
Tomei Turbo Elbow
Enthalpy Tune
Walbro 255lph
Stock Fuel Rail and FPR

I was shooting for 350whp, but from what I've read here this setup may only be good for 300-325 which would be good =)

motor isnt in the car yet, should I do anything else before I drop it in?
Head Gasket?
Cams?

[jspaeth]

Originally Posted by nothix

My setup:
Z32 Maf
GT2871r .64 3" inlet
550cc Deatschwerk
Freddy Intake Manifold
Meagan Exhaust Manifold
Tomei Turbo Elbow
Enthalpy Tune
Walbro 255lph
Stock Fuel Rail and FPR

I was shooting for 350whp, but from what I've read here this setup may only be good for 300-325 which would be good =)

motor isnt in the car yet, should I do anything else before I drop it in?
Head Gasket?
Cams?

550s too small go with 740s or bigger if you can.
Having the upgraded manifold is pointless without cams.

If you are gonna have that manifold, which hurts spoolup a little bit, mights as well get some cams to take advantage of the 6000+ RPM range, where the stock cams just don't cut it.

Suggest Jim Wolf S3, HKS Step 2, or Tomei 260s


Yes HKS/Cosworth metal headgasket is good.


Without the cams, you could make like 340 or so probably, but with the cams, it could be closer to high 300s

[nothix]

Originally Posted by jspaeth

550s too small go with 740s or bigger if you can.
Having the upgraded manifold is pointless without cams.

If you are gonna have that manifold, which hurts spoolup a little bit, mights as well get some cams to take advantage of the 6000+ RPM range, where the stock cams just don't cut it.

Suggest Jim Wolf S3, HKS Step 2, or Tomei 260s


Yes HKS/Cosworth metal headgasket is good.


Without the cams, you could make like 340 or so probably, but with the cams, it could be closer to high 300s

Well I might go back to stock Intake Manifold then, cause I want quick spooling over top end power.

I'm thinking same setup but with stock Intake Manifold.
550cc, gt2871r .64, stock cam

when/why do I need to upgrade to a metal headgasket

I'm trying not to tear into the motor at all. The idea was to slap on the turbo and injectors thats it. Somewhere along the way I picked up the cheap ebay intake mani

[jspaeth]

Originally Posted by nothix

Well I might go back to stock Intake Manifold then, cause I want quick spooling over top end power.

I'm thinking same setup but with stock Intake Manifold.
550cc, gt2871r .64, stock cam

when/why do I need to upgrade to a metal headgasket

I'm trying not to tear into the motor at all. The idea was to slap on the turbo and injectors thats it. Somewhere along the way I picked up the cheap ebay intake mani

If you want better midrange, keep the stock intake manifold and stock cams......and you will have a nice, peepy car.

It will make around 300 ft-lbs or so by 3900-4000 RPM, but the torque is going to start dropping off extremely early (around 5500-6000 RPM or so) and as a result, your "max hp" will probably be around 320-330 hp.


Still a very fun, OEM-like setup...

[S13 curtis]

Originally Posted by nothix

Well I might go back to stock Intake Manifold then, cause I want quick spooling over top end power.

I'm thinking same setup but with stock Intake Manifold.
550cc, gt2871r .64, stock cam

I'm trying not to tear into the motor at all. The idea was to slap on the turbo and injectors thats it.

Looks like you picked the wrong turbo man.

for what your looking for you will be more effecient with an S15 T28 or GT28RS .86.

I had a 56trim 2871r .64 with stock cams and greddy intake manifold and it felt kinda sluggish on 93 octane. I switch to E85 but it still wasnt that impressive to ME.

[codyace]

Originally Posted by S13 curtis

I had a 56trim 2871r .64 with stock cams and greddy intake manifold and it felt kinda sluggish on 93 octane. I switch to E85 but it still wasnt that impressive to ME.

Slow spool to me, is a 30r...certainly nothing will touch the stock stuff, but I'll gladly take the greatly better average power than the marginally (and by marginally we're looking at 400-500 rpm of 'spool up') any day of the week.


There's always a point of diminishing returns...you want that spool monster as much as the rest of us, but thre is zero advantage of it spooling super fast, only to have it fall on it's face.


Here is a great comparison of a 28RS car (FWD car) versuss mine. Same setup (S3 cams, extruded GTiR manifold, o2 pipe, 3" exhaust etc etc...I mean the Sentra car I based my stuff off forever ago.

Same dyno, similar conditions. I wish I was able to get this on a load bearing dyno, but I have easy access to a dynojet. Oh well. On street both cars spool 20 psi in the 3600/3700 range.



Sure spool up is the same, sure torque is similar (in regard to peak) but look at the total difference in average HP....even if you scale back my boost level 2 or 3 psi, it's not going to fall off like that, nor reduce so much...THAT is the advantage of the 2871r .64....it has all of the quick spool charectersitics (namely due to similar turbine housing) yet has that top end power due to the different compressor.

It's a win win. If you only want to make 300 whp peak, then for sure the s15 turbo would be your best bet (as the Disco potato is damn near the same thing)...but if you want to make anything over that, the 2871r is the only way to fly.

[inopsey]

my 3071r t2 is not laggy (full boost 17 psi by 3300 rpm, building 10 psi by 3k) this is no more laggy than a 2871r and makes more torque too. i dont understand how all these internet bandwagon jumpers put down this turbo when none of them have any experience with it.

[codyace]

Originally Posted by inopsey

my 3071r t2 is not laggy (full boost 17 psi by 3300 rpm, building 10 psi by 3k) this is no more laggy than a 2871r and makes more torque too. i dont understand how all these internet bandwagon jumpers put down this turbo when none of them have any experience with it.

17 psi by 3300 rpm?

Do you have any logs or graphs?


Heck even a 28R would barely be spooling 17 psi by 3300 rpm.


Trust me when I say brother, if the 3071r could really spool where you claim, it would be on my car.

[steve shadows]

We just tuned a car this past weekend,

350 WHP, 305 FT LBS or torque,

2871R .86 Housing, Full boost by 4000 RPMS at 1 BAR

This run was ....yes at 1 bar,

This number is from a dyno dynamics, about 900 ft above sea level

91 octane, conservative timing map settings.

Car has stock bottom end, bringing it back in a bit to try to hit 450 WHP at 22-24 PSI....

[codyace]

Originally Posted by steve shadows

We just tuned a car this past weekend,

350 WHP, 305 FT LBS or torque,

2871R .86 Housing, Full boost by 4000 RPMS at 1 BAR

This run was ....yes at 1 bar,

This number is from a dyno dynamics, about 900 ft above sea level

91 octane, conservative timing map settings.

Car has stock bottom end, bringing it back in a bit to try to hit 450 WHP at 22-24 PSI....

Pump gas right

[jspaeth]

Originally Posted by inopsey

my 3071r t2 is not laggy (full boost 17 psi by 3300 rpm, building 10 psi by 3k) this is no more laggy than a 2871r and makes more torque too. i dont understand how all these internet bandwagon jumpers put down this turbo when none of them have any experience with it.

Hmmm I wanna see this.. My buddy has a 3071R on his S2K and it doesn't hit 17 psi till well over 4000 RPM.

[drag113]

Originally Posted by steve shadows

We just tuned a car this past weekend,

350 WHP, 305 FT LBS or torque,

2871R .86 Housing, Full boost by 4000 RPMS at 1 BAR

This run was ....yes at 1 bar,

This number is from a dyno dynamics, about 900 ft above sea level

91 octane, conservative timing map settings.

Car has stock bottom end, bringing it back in a bit to try to hit 450 WHP at 22-24 PSI....

cams? (f)greddy manifold? more details!

[Def]

Originally Posted by codyace

17 psi by 3300 rpm?

Do you have any logs or graphs?


Heck even a 28R would barely be spooling 17 psi by 3300 rpm.


Trust me when I say brother, if the 3071r could really spool where you claim, it would be on my car.

Yep, my GT2560R hit 17 psi at ~3400-3500 RPM. No way a 3071R is outspooling that unless you're talking in 5th gear uphill.

[inopsey]

Originally Posted by codyace

17 psi by 3300 rpm?

Do you have any logs or graphs?


Heck even a 28R would barely be spooling 17 psi by 3300 rpm.


Trust me when I say brother, if the 3071r could really spool where you claim, it would be on my car.

this isnt my car but the same turbo and stock cams boosting 24psi. check out the full car here POWERTUNE Red Dragon - Hardtuned.net dragon&st=0&fcat=

my boost controller logs boost vs rpm

lastscan1.jpg

[jspaeth]

Originally Posted by inopsey

this isnt my car but the same turbo and stock cams boosting 24psi. check out the full car here POWERTUNE Red Dragon - Hardtuned.net dragon&st=0&fcat=

my boost controller logs boost vs rpm

Attachment 20153

I see 10 psi at 3300 RPM onm a load-bearing dyno.

[codyace]

Originally Posted by inopsey

this isnt my car but the same turbo and stock cams boosting 24psi. check out the full car here POWERTUNE Red Dragon - Hardtuned.net dragon&st=0&fcat=

my boost controller logs boost vs rpm

Attachment 20153

Those are pathetic numbers for 24 psi on a 30r.

[shibbyRPS13]

The car Steve is talking about is mine, I just posted a review in the shadowerks review thread with all of my mods as well as the dyno sheet if you guys want to check it out.
http://zilvia.net/f/businesses/16350...shadows-2.html

[steve shadows]

Originally Posted by codyace

Pump gas right

Pump gas with a car with dyning fuel pressure because we were running of gas the last few pulls...

and 91 not to really bring it down total shit gas

cus in Cali we have all kinds of additives on top of the octane already sucking ass...

[S13 curtis]

Originally Posted by Def

Yep, my GT2560R hit 17 psi at ~3400-3500 RPM. No way a 3071R is outspooling that unless you're talking in 5th gear uphill.

no offense but for an s15 T28 that is kinda slow spoolyou prolbly had an exhaust leak.

On E-85 20psi it had full boost by about 3000-3200 it actully spooled faster than my T25. The torque was definately there with E85, spinning the tires from a 2gear roll from around 3500 on up to about 6000rpm or so.

Originally Posted by inopsey

my 3071r t2 is not laggy (full boost 17 psi by 3300 rpm, building 10 psi by 3k) this is no more laggy than a 2871r and makes more torque too. i dont understand how all these internet bandwagon jumpers put down this turbo when none of them have any experience with it.

Also that gt3071 graph is atrocious for 24psi. 250+whp@24psi then get walked by an S14SR with a boost controller.

no way your pulling 17psi@3300rpm with a GT3071.86 unless you have a 2.5+Liter motor. sorry man it dosent add up.

[G240]

Originally Posted by S13 curtis

Also that gt3071 graph is atrocious for 24psi. 250+whp@24psi then get walked by an S14SR with a boost controller.

257.6 Kw = ~345 hp Would have expected more from that turbo especially with 98 Ron fuel which I think is being pointed out.

[Luvs2slide]

by using 256 tomei poncams, would i be seeing any benefit by running a greddy intake mani and SS ex mani?

my mod list is:
Sard 850s
2871 .64 (3" inlet)
Tomei elbow
3" downpipe/catback, etc
Running 1 Bar on stock HG

[slider2828]

Originally Posted by Luvs2slide

by using 256 tomei poncams, would i be seeing any benefit by running a greddy intake mani and SS ex mani?

Anything you do to the intake and exhaust manifolds on larger frame turbos would help... But "help" is defined as slower spooling more top end power higher peak torque, vs. quicker spooling...

Exh and intake manifolds give you benefits of higher peak but power comes later.

[jspaeth]

Originally Posted by slider2828

Anything you do to the intake and exhaust manifolds on larger frame turbos would help... But "help" is defined as slower spooling more top end power higher peak torque, vs. quicker spooling...

Exh and intake manifolds give you benefits of higher peak but power comes later.

I've gotta think that having the powerband shifted up to the higher RPMs a bit has to help out a lot........allows you to stay in lower gears longer, and thus better overall acceleration as you pass through the gears.