GT2871 USERS. SR motor - Page 122 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Tom N · 05-29-2015, 08:32 PM

Quote:

Originally Posted by Geezy

Has anyone tried the new hks ss-cams?

According to their website. The specs for their new revised step 1 cams are 256 with a 11.5mm lift. More aggressive than the old step ones. Now i know ramp rates play a huge part on performance. That being said. How do you think the new ss-cam would perform in comparison to jwt s3 or s4? Seeing as the specs on paper come close to the s3, would the ss-cam be able to bounce at 8000 rpm with stock srings like jwt cams? Or would you suggest uprated springs? Could 350hp be easily netted with the ss-cam on a .64ar 2871 stock intake manifold and "codyace special" exhaust manifold on a heart breaker dyno dynamics?

Before anyone asks: what boost level, ecu, supporting mods, etc. Lets be within reason here.

The Tomei poncams are also 256 with 11.5mm lift. I used them on a 20g set up, which is just a little bigger than a 2871, and they work very well.
They idle perfectly even with a/c on and hold power till 8k rpms.

Geezy · 05-30-2015, 11:27 AM

Quote:

Originally Posted by Tom N

The Tomei poncams are also 256 with 11.5mm lift. I used them on a 20g set up, which is just a little bigger than a 2871, and they work very well.
They idle perfectly even with a/c on and hold power till 8k rpms.

Did you get uprated springs to rev to 8k? Reliably? Or the stock springs ok for that abuse? I know the next week link are the lifters.

Tom N · 05-30-2015, 11:34 AM

Quote:

Originally Posted by Geezy

Did you get uprated springs to rev to 8k? Reliably? Or the stock springs ok for that abuse? I know the next week link are the lifters.

Upgrades springs and duel guide rockers.

Options13 · 05-30-2015, 01:42 PM

I'm running

S13 SR20DET Black top
Greddy intake manidold
550cc Sti injectors
Megan exhaust manifold
260 12mm lift Tomei pon cams
Gt2871r or s15 ball bearing turbo?
Power fc d jetro

Dynoed at 330whp, 270 tq at 1 bar

Injectors were maxed out so I have id1000s on order and going back in for a re tune. Any ideas what I may get with bigger injectors and 20psi?

S13alldayyo · 05-30-2015, 02:05 PM

Is it a s15 turbo or gt2871r you can't really push a s15 t28 to 20 psi

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S13alldayyo · 05-30-2015, 02:06 PM

You most likely have a gt2871r because at 14/15 psi I got the same exact numbers as you buddy

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Geezy · 05-31-2015, 09:20 PM

Quote:

Originally Posted by Tom N

Upgrades springs and duel guide rockers.

Good to hear that these cams can hold power to 8k with the 2871r. But do they require uprated valve springs to do so?

Tom N · 05-31-2015, 09:25 PM

Quote:

Originally Posted by Geezy

Good to hear that these cams can hold power to 8k with the 2871r. But do they require uprated valve springs to do so?

I personally experienced valve float on the stock springs at around 400hp.
I would use upgraded springs. This was on a 20g not a 2871 but the 20g is just slightly bigger.

cotbu · 06-01-2015, 07:06 AM

You can float the valves at any horse power level, it was probably the rpm that cause the float or an over rev from a missed shift. I make 400hp well within the power band of the stock valve train limits. All without high lift cams and revving to 8krpm that alone reduces the chances of floating valves. At least that's the practice I've been following.

If you're looking at upgrading cams, you should follow the recommendation of the manufacturer, period!

Sent from a Highly Tuned Note 4.5!!!

Tom N · 06-01-2015, 08:15 AM

Quote:

Originally Posted by cotbu

You can float the valves at any horse power level, it was probably the rpm that cause the float or an over rev from a missed shift. I make 400hp well within the power band of the stock valve train limits. All without high lift cams and revving to 8krpm that alone reduces the chances of floating valves. At least that's the practice I've been following.

If you're looking at upgrading cams, you should follow the recommendation of the manufacturer, period!

Sent from a Highly Tuned Note 4.5!!!

It was a hp/boost cause. If I tried to go over 22psi they would start to float. If I stayed at 22psi or less it would run clean to 8k Rpms.
Above that boost, which was a little over 400hp, they would start to float around 7k Rpms.
Tomei says springs aren't needed for the 256 poncams which is probably true on a stock turbo.

cotbu · 06-01-2015, 09:16 AM

Well I can honestly say, with 25psi from a gtx2867r, 415hp and a gt2871r, 448hp my valve train didn't float. So I'll look into it a bit more. I ran greddy easy cams, and jw s3 cams for that test. There's got to be people floating valves left and right, if it's boost related in anyway.

Sent from a Highly Tuned Note 4.5!!!

derass · 06-01-2015, 09:25 AM

I know a guy who lost his motor because of valve float. He was using JWT S3. I think what it comes down to is fatigue of the stock valve springs. If they still maintain their original seat pressure then all is well, but If they are tired, then you can experience valve float. For this reason, I would choose Procams with upgraded springs over JWT S-Series without.

Tom N · 06-01-2015, 09:26 AM

Quote:

Originally Posted by cotbu

Well I can honestly say, with 25psi from a gtx2867r, 415hp and a gt2871r, 448hp my valve train didn't float. So I'll look into it a bit more. I ran greddy easy cams, and jw s3 cams for that test. There's got to be people floating valves left and right, if it's boost related in anyway.

Sent from a Highly Tuned Note 4.5!!!

All I can say is my experience on the dyno. We backed off the boost and then upped it again twice and the result was the same. Put it on the street and still would get valve float around 22-23psi. Now my 22-23psi is a different airflow than others at that same boost level but the float would start at that point for me and happen around 7k Rpms.
We Put springs in the car and have run it to 28psi with out issues.

S13alldayyo · 06-01-2015, 09:26 AM

How did you get 448 off a gt2871 how much boost?

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derass · 06-01-2015, 09:33 AM

And what cams were you using to break 400 with the 2871?

cotbu · 06-01-2015, 10:03 AM

How I would say tuning.
25psi and greddy easy cams 256/264.
That's what it took to break 400hp with the 2867r, but after I put the 2871r back on I forgot to change the boost, and that's what we got!

That set in motion, the block sleeving and wiseco piston upgrade. I have now, if the block is capable of 450/500 stock well it only made sense. Next is the transmission!

Sent from a Highly Tuned Note 4.5!!!

cotbu · 06-01-2015, 10:45 AM

Quote:

Originally Posted by Tom N

All I can say is my experience on the dyno. We backed off the boost and then upped it again twice and the result was the same. Put it on the street and still would get valve float around 22-23psi. Now my 22-23psi is a different airflow than others at that same boost level but the float would start at that point for me and happen around 7k Rpms.
We Put springs in the car and have run it to 28psi with out issues.

What were the symptoms, besides loss of power. Did you use an clear acrylic valve cover to watch the valve springs float? Then play the video back in slow motion.? In your case it may well be boost related. But... N/A engine float valves too!

Sent from a Highly Tuned Note 4.5!!!

S13alldayyo · 06-01-2015, 10:47 AM

Damn dude I'm at 20 psi/405whp with tomei poncams

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cotbu · 06-01-2015, 10:52 AM

Quote:

Originally Posted by S13alldayyo

Damn dude I'm at 20 psi/405whp with tomei poncams

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Cams don't make huge power by themselves, but they do shift the power to the right.
Knowing that your tuner should be able to take advantage of that rpm shift.

Sent from a Highly Tuned Note 4.5!!!

Tom N · 06-01-2015, 11:28 AM

Quote:

Originally Posted by cotbu

What were the symptoms, besides loss of power. Did you use an clear acrylic valve cover to watch the valve springs float? Then play the video back in slow motion.? In your case it may well be boost related. But... N/A engine float valves too!

Sent from a Highly Tuned Note 4.5!!!

Its defintely valve float. Myself, Martin ( enthalpy ) and my good friend Jerry known as Lancerman in the dsm world all agreed it was valve float. And it went away with upgraded springs.
I'm not saying it's simply boost related I'm saying it would happen at 22/23psi and 425hp every time.
Turn the boost down to 20 and it would pull to 8k clean and be at 400hp

Cams alter your VE and when you retune for that they allow for more power by allowing for more air to make it into the motor vs being trapped in the intake.

cotbu · 06-01-2015, 12:22 PM

K, that's reasonable. Yes, they alter volumetric efficency for a certain rpm range. That's why it's not a huge gain, without tuning. And if you pick the wrong cams you can loose power. I've seen a lot of people slap in some 272 cams and wonder why, they don't make power revving to 8500rpm.
Horsepower curve looking like an excitebike jump.

Sent from a Highly Tuned Note 4.5!!!

Tom N · 06-01-2015, 01:21 PM

Quote:

Originally Posted by cotbu

K, that's reasonable. Yes, they alter volumetric efficency for a certain rpm range. That's why it's not a huge gain, without tuning. And if you pick the wrong cams you can loose power. I've seen a lot of people slap in some 272 cams and wonder why, they don't make power revving to 8500rpm.
Horsepower curve looking like an excitebike jump.

Sent from a Highly Tuned Note 4.5!!!

That's why this car has 256/260 cams in the car vs just bigger is better mentality.
Key to going fast is paying attention to the power under the curve not just a peak number.

Options13 · 06-06-2015, 12:12 AM

Car hits the dyno next week, i'm hoping for 380-400 at 18psi.

S13.4 Hybrid Valve Cover
S13 sr on stock rebuild.
Full 3" exhaust
Greddy FMIC
GT2871r w/ .64 housing w/ greddy profec II boost controller
Greddy Intake Manifold
Megan Exhaust Manifold
Tomei 260 cams w/ 12mm lift
Tomei RAS
BC springs & titanium retainers
Radium Fuel rail on ID1000's along with an aeromotive FPR.
all managed on power fc d jetro.

contemplating on if a q45 throttle body is even necessary?

anyways i hope i can hit the numbers i want!!

soundboy · 06-09-2015, 06:43 PM

Very quick question. Is a gt 2871 a stock s15 turbo?

bshotts · 06-09-2015, 06:49 PM

Quote:

Originally Posted by soundboy

Very quick question. Is a gt 2871 a stock s15 turbo?

Negatory...stock S15 turbo is T28 ball bearing center cartridge sir. Garrrett GT2860 to be exact. Someone can chime in if that's incorrect tho

cotbu · 06-09-2015, 08:18 PM

Quote:

Originally Posted by bshotts

Negatory...stock S15 turbo is T28 ball bearing center cartridge sir. Garrrett GT2860 to be exact. Someone can chime in if that's incorrect tho

The first part is right, no its not a stock s15 turbo. The s15 turbo is actually a gt2560r, the gt2860rs is the disco potato.

So you have the s15 turbo, aka gt28r, and the gt2560r.
Then we mentioned the, gt2860rs which is the disco potato aka gt28rs.

Sent from a Highly Tuned Note 4.5!!!

Silvi · 06-10-2015, 06:25 AM

S15 stock camshafts
Gt2871.64
External wastegate
Tubular exhaust manifold
Greddy intake manifold
VR6 throttle body
780 cc injectors

1.2 bar boost - 400whp (gearbox limit)

cotbu · 06-10-2015, 07:55 AM

Quote:

Originally Posted by Silvi

S15 stock camshafts
Gt2871.64
External wastegate
Tubular exhaust manifold
Greddy intake manifold
VR6 throttle body
780 cc injectors

1.2 bar boost - 400whp (gearbox limit)

What does this mean?

Sent from a Highly Tuned Note 4.5!!!

fullthrottle · 06-10-2015, 08:56 AM

Quote:

Originally Posted by Silvi

S15 stock camshafts
Gt2871.64
External wastegate
Tubular exhaust manifold
Greddy intake manifold
VR6 throttle body
780 cc injectors

1.2 bar boost - 400whp (gearbox limit)

I dont think thats enough boost to make 400whp with stock cams. Atleast Ive never seen it done before. Its very very difficult to hit 400whp with the .64

fullthrottle · 06-10-2015, 08:58 AM

Quote:

Originally Posted by cotbu

What does this mean?

Sent from a Highly Tuned Note 4.5!!!

He has a 6 speed so he doesnt want to push more power.

05-30-2015, 01:42 PM	#3634
Options13 Nissanaholic! Join Date: May 2007 Location: OR Posts: 1,825 Trader Rating: (43) Feedback Score: 43 reviews	I'm running S13 SR20DET Black top Greddy intake manidold 550cc Sti injectors Megan exhaust manifold 260 12mm lift Tomei pon cams Gt2871r or s15 ball bearing turbo? Power fc d jetro Dynoed at 330whp, 270 tq at 1 bar Injectors were maxed out so I have id1000s on order and going back in for a re tune. Any ideas what I may get with bigger injectors and 20psi? __________________ Drift team page www.facebook.com/savageimpression

06-01-2015, 07:06 AM	#3639
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 47 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	You can float the valves at any horse power level, it was probably the rpm that cause the float or an over rev from a missed shift. I make 400hp well within the power band of the stock valve train limits. All without high lift cams and revving to 8krpm that alone reduces the chances of floating valves. At least that's the practice I've been following. If you're looking at upgrading cams, you should follow the recommendation of the manufacturer, period! Sent from a Highly Tuned Note 4.5!!! __________________ LoverTechnologies "Half Broken Things!"

06-01-2015, 09:16 AM	#3641
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 47 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Well I can honestly say, with 25psi from a gtx2867r, 415hp and a gt2871r, 448hp my valve train didn't float. So I'll look into it a bit more. I ran greddy easy cams, and jw s3 cams for that test. There's got to be people floating valves left and right, if it's boost related in anyway. Sent from a Highly Tuned Note 4.5!!! __________________ LoverTechnologies "Half Broken Things!"

06-01-2015, 10:03 AM	#3646
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 47 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	How I would say tuning. 25psi and greddy easy cams 256/264. That's what it took to break 400hp with the 2867r, but after I put the 2871r back on I forgot to change the boost, and that's what we got! That set in motion, the block sleeving and wiseco piston upgrade. I have now, if the block is capable of 450/500 stock well it only made sense. Next is the transmission! Sent from a Highly Tuned Note 4.5!!! __________________ LoverTechnologies "Half Broken Things!"

06-01-2015, 12:22 PM	#3651
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 47 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	K, that's reasonable. Yes, they alter volumetric efficency for a certain rpm range. That's why it's not a huge gain, without tuning. And if you pick the wrong cams you can loose power. I've seen a lot of people slap in some 272 cams and wonder why, they don't make power revving to 8500rpm. Horsepower curve looking like an excitebike jump. Sent from a Highly Tuned Note 4.5!!! __________________ LoverTechnologies "Half Broken Things!"

05-30-2015, 02:05 PM	#3635
S13alldayyo Zilvia Addict Join Date: Mar 2012 Location: Florida Posts: 653 Trader Rating: (3) Feedback Score: 3 reviews	Is it a s15 turbo or gt2871r you can't really push a s15 t28 to 20 psi Sent from my iPhone using Tapatalk

05-30-2015, 02:06 PM	#3636
S13alldayyo Zilvia Addict Join Date: Mar 2012 Location: Florida Posts: 653 Trader Rating: (3) Feedback Score: 3 reviews	You most likely have a gt2871r because at 14/15 psi I got the same exact numbers as you buddy Sent from my iPhone using Tapatalk

06-01-2015, 09:25 AM	#3642
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 33 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	I know a guy who lost his motor because of valve float. He was using JWT S3. I think what it comes down to is fatigue of the stock valve springs. If they still maintain their original seat pressure then all is well, but If they are tired, then you can experience valve float. For this reason, I would choose Procams with upgraded springs over JWT S-Series without.

06-01-2015, 09:26 AM	#3644
S13alldayyo Zilvia Addict Join Date: Mar 2012 Location: Florida Posts: 653 Trader Rating: (3) Feedback Score: 3 reviews	How did you get 448 off a gt2871 how much boost? Sent from my iPhone using Tapatalk

06-01-2015, 09:33 AM	#3645
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 33 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	And what cams were you using to break 400 with the 2871?

06-01-2015, 10:47 AM	#3648
S13alldayyo Zilvia Addict Join Date: Mar 2012 Location: Florida Posts: 653 Trader Rating: (3) Feedback Score: 3 reviews	Damn dude I'm at 20 psi/405whp with tomei poncams Sent from my iPhone using Tapatalk

06-06-2015, 12:12 AM	#3653
Options13 Nissanaholic! Join Date: May 2007 Location: OR Posts: 1,825 Trader Rating: (43) Feedback Score: 43 reviews	Car hits the dyno next week, i'm hoping for 380-400 at 18psi. S13.4 Hybrid Valve Cover S13 sr on stock rebuild. Full 3" exhaust Greddy FMIC GT2871r w/ .64 housing w/ greddy profec II boost controller Greddy Intake Manifold Megan Exhaust Manifold Tomei 260 cams w/ 12mm lift Tomei RAS BC springs & titanium retainers Radium Fuel rail on ID1000's along with an aeromotive FPR. all managed on power fc d jetro. contemplating on if a q45 throttle body is even necessary? anyways i hope i can hit the numbers i want!! __________________ Drift team page www.facebook.com/savageimpression

06-09-2015, 06:43 PM	#3654
soundboy Zilvia Junkie Join Date: Aug 2013 Location: trinidad Age: 41 Posts: 320 Trader Rating: (0) Feedback Score: 0 reviews	Very quick question. Is a gt 2871 a stock s15 turbo?

06-10-2015, 06:25 AM	#3657
Silvi Leaky Injector Join Date: Nov 2011 Location: IL Posts: 131 Trader Rating: (0) Feedback Score: 0 reviews	S15 stock camshafts Gt2871.64 External wastegate Tubular exhaust manifold Greddy intake manifold VR6 throttle body 780 cc injectors 1.2 bar boost - 400whp (gearbox limit)

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