GT2871 USERS. SR motor

[EsChassisLove]

Originally Posted by codyace

Stock head here as well, aside from JWT S3 Cams. No headwork no nothing.

Oh wow that's awesome. Pump gas also? No water/meth?

I'm expecting 350whp on 18psi. Going to be on a dyno dynamics also so it will read pretty low. I think.

[Kingtal0n]

Originally Posted by codyace

Stock head here as well, aside from JWT S3 Cams. No headwork no nothing.

Ah, the beauty of a high performance head from the factory. I think it took chevy about 20 years to catch up?

[LuckyX2]

First off I'd like to say hi as this is my first post here (started on nico a while back )

I have a s15 turbo redtop sr20det setup with poncams that just put out 293whp and 299tq; tuned by myself on my Haltech Platinum 1000. But after witnessing my little s15 turbo's inability to hold boost in the upper rpm's (spiked to 18psi, tailed to 12psi...) I've decided to move to the 2871/s3 combo.

Unfortunately, due to some some poor machine work on my head, my sr is in pieces now. The valve stems were machined down too far and the shims were pressing on the retainer before the valve stem because of that, thus loosening the keepers and eventually leading to one failing. I'm in the process of fixing it but the plan is to bring it back better than ever with a 2871 and some s3 cams.

I was wondering, Cody, that since I'm about 5 minutes from the Diehl's Paving you dyno at; would you be interested in meeting up when I go to re-tune? It's probably not going to be for a bit since I have to order valves, wait, replace them, measure clearances, order the shims, wait and then put them in but I thought I'd give a heads up.

My setup will be as follows:
Gt2871rs
S3 cams with adj. gears
Solid lifters and dual springs
Mild port/polish
LS2 Coils
Tubular exhaust manifold
Greddy FMIC
550cc (650cc @ 4bar) injectors with adjustable fpr
Walbro 255lph
3" exhaust
Haltech Platinum 1000 ecu

There's a few things I'm interested in seeing:
1.) 2871rs vs 2871r
2.) How much difference will cam timing produce in the powerband?
3.) What advantages will my extra head work bring? Solid lifters should produce more usable cam lobe area and thus more area under my power curve and also, I hope my handy work with a dremel payed off...
4.) Stock ignition vs. LS2's; any real benefit at this power level?
5.) Tubular vs. honed stock
6.) Standalone vs. Jim Wolf/Enthalpy

I feel like my car has a pretty unique set of supporting mods and could make for some interesting comparisons to yours, Cody. It's just a shame that there are too many variables to pinpoint what would be making the differences.

[codyf44]

best cams for 2871r .86?

[codyace]

Originally Posted by BlackZenkiS14

So the Extrude Honing process on an OEM manifold...what does that do for power/response? Im a fan of the OEM manifold myself, but would like to make it as efficient and powerful as possible. Considering doing this in the future.

Extude hone stock manifold is the *only* way to fly. Cheaper than a tubular crack a fold, more efficient, and real deal boss. Plus if you go external you can't beat it.

Originally Posted by EsChassisLove

Have to admit that torque curve is absolutely beautiful. Peaks at 4200 and holds strong till redline. I love it.

Can't wait to post what i make on Saturday. Stock head though.

If it was a load bearing dyno you'd see it in the 3500-3800 rpm range where I hit full spool. With the 4.6 Final Drive the car is a rocket.

I went 11.65 @ 120 first time ever on slicks. A good driver would have that in the 11.0-11.2 range at the same power level/with my new boost control.

FWIW: My newest chip makes 12 psi at 5500 rpm. Thank you JWT.

Originally Posted by EsChassisLove

Oh wow that's awesome. Pump gas also? No water/meth?

I'm expecting 350whp on 18psi. Going to be on a dyno dynamics also so it will read pretty low. I think.

That's a pump gas number, my water injection is not setup to make more power, just detonation resistance. I don't trust a produce aisle sprayer pump.

Originally Posted by Kingtal0n

Ah, the beauty of a high performance head from the factory. I think it took chevy about 20 years to catch up?

You mean 40 years right? I wouldn't call LT1 heads anything special, nor Vortec.

Originally Posted by codyf44

best cams for 2871r .86?

If you insist on the .86 housing,

JWT S4 if you wanna run 20-24 psi. JWT S3 if you wanna run 18-20 psi.

[EsChassisLove]

Haha yea so my HKS actuator turned out to be a bit faulty. Very rare but hey it is possible.

I got tuned on 10psi. Don't remember what power I made.

I'm changing my set up now. External wastegate, 850cc top feeds, Blitz SBC, and water injection before I go back to the dyno.

[codyace]

Originally Posted by EsChassisLove

Haha yea so my HKS actuator turned out to be a bit faulty. Very rare but hey it is possible.

I got tuned on 10psi. Don't remember what power I made.

I'm changing my set up now. External wastegate, 850cc top feeds, Blitz SBC, and water injection before I go back to the dyno.

All internal gate suck. My HKS unit was no better than my Garrett unit...in fact the same junk.

External is boss

[SLiDe_WaYz]

Originally Posted by EsChassisLove

Haha yea so my HKS actuator turned out to be a bit faulty. Very rare but hey it is possible.

I got tuned on 10psi. Don't remember what power I made.

I'm changing my set up now. External wastegate, 850cc top feeds, Blitz SBC, and water injection before I go back to the dyno.

I'm using a HKS actuator, haven't installed it yet hopefully it isn't faulty.

[codyace]

Originally Posted by SLiDe_WaYz

I'm using a HKS actuator, haven't installed it yet hopefully it isn't faulty.

Originally Posted by HIGHFIVEBETA

You meant all internal gates suck? Lol

Junk maybe harsch, but th eend result is all the same; crap


If you want to run reliable 15+ psi of boost, external is the way to go/PM me on how to make it all work.,

[240ss]

Reviving this thread because i just finished my set up and think this thread is awesome and very informative! Im running the .64 a/r Made 368 whp and 295 f/lb @ 16 psi on a dynojet.

My setup is as follows:
s13 blacktop sr
stock bottom end
bc 264/264 cams w/ springs and retainers
metal hg w/ arp head studs
freddy intake mani
tubular exhaust mani
3" full exhaust
front mount
Apex'i Power FC

Just got it tuned today and would like to share my results. Tell me what you guys think.

[codyace]

Seems to spool a little later, and the torque cuve is a little funky, may be due to boost control though.

Good power though regardless!

[240ss]

yeah its probably due to the internal gate. after reading all about using the stock mani w/ external gate im really considering doing it. would that give me a quicker spool?

[codyace]

Originally Posted by 240ss

yeah its probably due to the internal gate. after reading all about using the stock mani w/ external gate im really considering doing it. would that give me a quicker spool?

No doubt the internal gate can cause some wacky wacky curves, as boost controllers are working overtime trying to make em work.

I've gone external now for 3 years, and love it. Holds boost, enables me to run low boost without any creep worry, and just in general seems to help build boost smoothly as it enables the boost controller to work regularly.

If you're interested, shoot me a PM as I have a local fab guy that does them for people.

[Luvs2slide]

^ I'm having done up by Cody as well. So easy to deal with!

On another note, it was previously mentioned that the wastegate hole needs to be dremeled out larger for boost spike/creep issues. I did this before i installed mine and never had any issues. Might want to look at dremeling out the hole as a temp solution.

[BlackZenkiS14]

Anyone using one of these Precision Turbos yet? They make one to directly replace the 2871R

http://www.precisionturbo.net/turboc...rger---5128/75

They claim to have better response and power output than Garret stuff...?

[180sxqc]

Anyone tried porting the stock manifold? Any good results? It's gonna cost me alot to send to manifold to the US from Canada, get it extruded-honed and sent back and I figured out I try only porting

Anyone?

[codyace]

Originally Posted by 180sxqc

Anyone tried porting the stock manifold? Any good results? It's gonna cost me alot to send to manifold to the US from Canada, get it extruded-honed and sent back and I figured out I try only porting
Anyone?

You could, and it's not going to hurt, but the extrude hone process is really the way to go.

[Pantaloons]

im running the precision 5557 ball bearing turbo and 11:1 compression pistons now

it spools 21psi at 3200 rpm


who needs v8s

[WhiteS12+1]

Mine finally went under the knife last night, after about 2 years of part collecting. Installing a freshly built head, JWT S3 cams, .64 turbo, and PFC. I can't wait to get all the bugs worked out and get some power numbers.

[codyace]

11:1 compression yowza!

[Silverbullet]

Any reason why BC 264 cams were never mentioned in this thread? Is the lift too high for the BC cams? They are 0.475" (12.06mm) which is significantly higher than the JWT, HKS and Tomei at comparable levels.

[codyace]

Originally Posted by Silverbullet

Any reason why BC 264 cams were never mentioned in this thread? Is the lift too high for the BC cams? They are 0.475" (12.06mm) which is significantly higher than the JWT, HKS and Tomei at comparable levels.

It's becuase they are fuckin junk.

Really.
They've been mentioned a ton of times. Sure they'll make more power that stock, but they are no where near the league of a quality cam.

Cam 'potential' goes way beyond simple duration numbers...it's easier to google cam info than it is for me to type it up

[Pantaloons]

sr's should come 11:1 factory is all im saying haha

[tabasco122]

i have the bc 264's, dont have my 2871r yet though. they seem to perform pretty well, i ran a 13.7 at 103 at 9psi on the stock turbo, which i was on its way out because i think it shit the bed now. I am contemplating getting the jwt s3's though, because cody speaks so highly of them. ill probably see how the bc's perform with the 2871 before i decide to replace them.

[2forty]

I've never really heard anything good about bc cams.

[tabasco122]

well the previous owner put bc rods, retainers, valves, and springs, so he went with the cams too. i got the whole car fully built for 2k, so im not complaining about any of the part choices.

[S14DB]

The main issue I had with BC cams is that their base center was off when I dialed them in. I have to get cam gears to get them straight, I have heard other people having the same issue with them.

[tabasco122]

from what i was told that was only an issue with the bc 272's, is that what you had?

[Silverbullet]

Originally Posted by S14DB

The main issue I had with BC cams is that their base center was off when I dialed them in. I have to get cam gears to get them straight, I have heard other people having the same issue with them.

Was it a manufacturing defect or did they design that angle? Did it give more or less intake/ex overlap?

[codyace]

The big thing is, that the BC cams have little to no research and design time. They are copy cat cams, cut on generic lobes, on generic sticks. Sure they will make power, sure it will be better than sock, but they will never drive, make as much power, or make as much torque (both peak and average) than a quality cam. Sure there stuff is cheaper, but they require you to get springs....so now the costs are the same as a nice cam, and you're forced to use generic springs/retainers with who knows what development behind them.

I prefer JWT cams as they have the most design and research IMO of them all. They still actively make the cams, and change them as research indicates. Some of the other popular cams have been on the same setup now since day one...not that is bad, but it's no furthering of their product.

HKS makes nice cams, are affordable, but only the StepII's are worth anything (to me)...which now requires a spring change. Not a biggy, but the cost is there, and the time.

Tomei also makes quality pieces...I personally would run Tomei's before HKS, but that is me. It seems they however are a little soft if you directly compare duration (which is 100% wrong way to do it, as there is so much more, but for forum sake I guess it flies). Is it maybe on softer lobes? Who knows. Again though, the Poncams work, but it seems that the Procams (which require springs again, more money) make the better power.

And again, that's where the JWT to me works best....the S3 and S4 are welld esigned, and work perfectly fine on the OEM springs and valvetrain...so ultimatly they are 'cheaper' as you don't need to install springs(or buy them)....but give the best results.


I may be bias, but JWT has been designing SR cams forever for sure.


Anywho, if you want more information, read here: http://www.jimwolftechnology.com//wo...ft_secrets.pdf

I just stumbled across that today looking up the C series cams, kinda nice that they wrote it.