GT2871 USERS. SR motor

[Seraphim38]

Originally Posted by codyace

24psi would probably blow spark out on the stock ignition too.

Even with Splitfire coil parks we started to quench the spark on the plugs at 430rwhp, but the gap was at 034. We trimmed them down to 022 and had no more problems pushing on.

I can't imagine running stock coil packs. When I swapped my splitfires back to stock coil packs while waiting for a replacement coil, my AFRs lost a full point because they couldn't burn the excess fuel--even at idle.

[derass]

I'm having trouble setting the boost level on my setup. I'm using an HKS actuator which has a specified opening pressure of 0.8-0.9 kgf/cm2 (11.4-12.8 psi) However, everything I try still has the turbo creeping past 15 psi.

With no preload, it will hit 10 psi at 4000 rpm then steadily creep past 15psi until redline. With more preload it would build more boost initially but still creep. With this increased amount of preload, the boost pressure would spike hard when coming back on throttle, causing my Haltech to hit its overboost protection. What is going on?

Also, I unknowingly had the wastegate pressure signal completely blocked by my boost control solenoid. Why did the boost not shoot up over 20 psi?

[cotbu]

Originally Posted by derass

Also, I unknowingly had the wastegate pressure signal completely blocked by my boost control solenoid. Why did the boost not shoot up over 20 psi?

Turn the boost controller off or disconnect / remove the boost solenoid, if you're running waste gate pressure.
You also have to adjust the hks actuator if you haven't already.

Your boost controller isn't able too regulate boost
With no boost signal, the internal waste gate had to use back pressure to open the waste gate and it take a lot of pressure to open a 7psi waste gate. Something like 17-20psi on the boost gauge. So an 11.3-12.8psi internal waste gate might take anywhere from 25 -30psi to pop open with out a signal.

Probably not true, but it sounded good in my head.

[180sxqc]

hey guys,

After a few years of reading/following threads on here religiously (especially this one), I just installed a few parts yesterday: nismo 740ccs, Z32 maf w/ Apexi suction intake and a JWT tuned ecu.... holy shit... I was running my gt2871r on stock map and stock injectors for a few hundreds miles (afr reading were ok, I have a windeband installed) and on 7 psi, I can tell the car feels alot faster, on boost afr is very stable between 11.4-11.6...

I can't wait to crank the boost today to 12 psi probably (for a start)... I'll keep you guys posted, I do not have a dyno reading but by butt dyno tells me IT'S FUNNNNNNNNN!!!

I am not racing or anything, just a few pulls... Let me tell you it's been a while I haven't enjoyed my car like this

P.S. Everything else is stock (cams, bottom end, head, etc.)

[180sxqc]

12 psi in insane compared to stock.. I know most of you guys been there a long time ago.. but you know what it feels like... damn it's fast compared to stock

Believe I chose the right parts, everything went smooth and the JWT tune brings so much power and feels just like stock

cheers!

[derass]

would a lean condition (>20 afr) prevent the turbo from building more than 15 psi? due to lack of combustion force?

cannot understand why the turbo did not build more than 15 psi at redline without the wastegate hooked up.

[801nismo104]

If your running that lean dont drive the car!

[801nismo104]

Originally Posted by 180sxqc

12 psi in insane compared to stock.. I know most of you guys been there a long time ago.. but you know what it feels like... damn it's fast compared to stock

Believe I chose the right parts, everything went smooth and the JWT tune brings so much power and feels just like stock

cheers!

Sweet! Throw some jwt s3 or S4 cams and it will be a lot more funner

[derass]

Originally Posted by 801nismo104

If your running that lean dont drive the car!

I haven't been since noticing the issue. The car idles and drives fine but above 9 psi, the AFRs spike to >20. I know this from data logging. The car was dyno tuned a few weeks ago and made 320whp. I dont know what happened since then. I don't think the tuner would have tuned without monitoring the AFRs up top, that is basic tuning 101.

I'm just trying to figure out why the turbo was not building boost uncontrollably with the wastegate disconnected. I don't think the turbo is damaged, as is responds very well, has no play and spins freely.

[180sxqc]

Originally Posted by 801nismo104

Sweet! Throw some jwt s3 or S4 cams and it will be a lot more funner

I still have a few psi left before adding some cams!! I might consider to buy a pair next winter when my car is in storage

[Mesarina]

Originally Posted by guitaraholic

At what RPM do you feel it starts to catch up to the stockers? I know the top end on those is pretty good, but how much of a hit do you take on the bottom? Do you ever feel like the car is falling on it's face on the bottom end?

BTW with the BC's how much vacuum are you pulling now at idle?

feels pretty laggy on the bottom end, but makes up on the top end, i pull 15mmhg of vacuum, but I do live at about 5500feet..

[cotbu]

so your pulling .59inhg even at 5500feet which atmosphere is like 12psig i doubt you are pulling less than an inch of vacuum. Could be wrong, but maybe my plane needs a tune up.

[cbh148]

On a recently rebuilt s13 SR (new stock pistons, ARP head studs, Cometic headgasket, rocker arm stoppers, Megan tubular manifold), how much pressure should one limit their boost too with a 52 trim "HKS GT-RS style" 2871R?

HKS adjustable wastegate actuator (also have a Hallman manual boost controller)
stock 370cc injectors
stock MAF
stock tune

i know with my s15 ball bearing t28 and stock t25g, they say the limit is about 12psi. is it any different on the GT-RS style 2871r?

[801nismo104]

the stock injectors and maf are really limiting you from making some good power. if i were in your position i would atleast get a tune and crank it up to 10psi max. upgrade your injectors and get a z32 maf and you have the potential to make alot more power

[zombiewolf513]

Originally Posted by cotbu

so your pulling .59inhg even at 5500feet which atmosphere is like 12psig i doubt you are pulling less than an inch of vacuum. Could be wrong, but maybe my plane needs a tune up.

uh wut? haha

[cotbu]

It says what it says if it's over your head let it go!

Sent from my Overclocked Debloated SIII

[EsChassisLove]

If anyone wants a 2871 set up mines for sale.

[cotbu]

Originally Posted by EsChassisLove

If anyone wants a 2871 set up mines for sale.

See you completely cutout the baby steps that time, 14psi to 24psi then to I'm selling my shit!

Sent from my Overclocked Debloated SIII

[EsChassisLove]

Originally Posted by cotbu

See you completely cutout the baby steps that time, 14psi to 24psi then to I'm selling my shit!

Sent from my Overclocked Debloated SIII

I can't pass up this deal for a top mount .64 GT3071! It's time to make some real power.

[Seraphim38]

do it. Did the top mount .64 gtx3076. as posted above, and it is a monster. I wouldn't ever go back.

[EsChassisLove]

Exactly bro.

Looking at this guys SR20 that is very similar to mine. He has 264/264 11.5mm lift cams and stock valves compared to my 260/260 11.2mm and +1mmvalves. Also he is on enthalpy and I am on AEM V2.

He made 418whp 330wtq at 17psi. 250wtq at 4300rpm. And his HP never fell it only kept climbing, tq stayed flat.

I'm positive my tuner can bring that 250wtq to around 3800, with around 340-350wtq. And hp around the same at 8500rpm.

I'm sacrificing a few hundred rpm at the low end but my redline will go from 7000 to 8-8500.

I'm very excited.

[Seraphim38]

best wishes. My 64 AR 3076 did 460rwhp at 21 psi on pump gas at 7500 and we didn't spin it up to what the solid lifter valvetrain, ATI damper and balanced internals would let us. We had a couple degrees of timing that could still have been added, and a half point to full point of AFR to optimize yet. I am still tempted to go back and work on getting 500rwhp on pump. As tuned, we saw 342 pounds of torque at 3400 or so and flat until redline. Currently redline is at 7850 but given the amount of power it makes from 4500rpm, there isn't much need to ring it out.

Anyway, we probably shouldn't add a bunch of GT30 frame turbo pomp and circumstance to the 2871 thread. If you want to talk about builds, tuning or anything else, PM me your phone number and we can talk SRs.

[guitaraholic]

Originally Posted by Seraphim38

best wishes. My 64 AR 3076 did 460rwhp at 21 psi on pump gas at 7500 and we didn't spin it up to what the solid lifter valvetrain, ATI damper and balanced internals would let us. We had a couple degrees of timing that could still have been added, and a half point to full point of AFR to optimize yet. I am still tempted to go back and work on getting 500rwhp on pump. As tuned, we saw 342 pounds of torque at 3400 or so and flat until redline. Currently redline is at 7850 but given the amount of power it makes from 4500rpm, there isn't much need to ring it out.s.

That is very impressive, to get 342 ft-lbs at 3400 RPM, that isn't much more rpm than a 2860, and is very comparable, and even better than a lot of 2871r's.

I don't even see 3071s hitting that low, and you have a larger compressor wheel to spin. Good job,, do you happen to have a dyno graph?

[EsChassisLove]

Yea give us a dyno graph. People's jaws drop at my 2871 making 250wtq at 3500. Let alone a 3076 making 342wtq at 3400.

That's V8 territory from a 2.0.

[sr20det_510]

hello guys im pretty new to the sr's but here it goes i need your guys info and advise please, so im building a 510 2door with an s13 redtop and what i have planed for this is starting from bottom up, greddy oil pan, stock micro polished crank, .5 bore on block to make it 86.5, arp main studs, eagle rods, cp 86.5 9.0:1 pistons, dont know what size apexi head gasket please advise,???? with arp head studs, personal ported head, dont know what spring, retainers, seats, rockers, lifters, to use please advise?? thinking of step 2 264 hks cams, tomei or hks stoppers, 800cc injectors, greddy intake mani, i have a megan top mount exht mani, gt2871r, dont know what tb to use please advise?? map or maf?????? hks ssqv 4 bov, frp??? dont know what ecu setup to use??? am i missing anything??? please guys any input is greatly appreciated, sorry for the long post, my goal is to reach atleast mid 300's in hp, but altimate goal is a dialy, reliable, efficient, lil fun setup that i can romp on all day any day thanks again fellow zilvians..

[jamg]

Originally Posted by EsChassisLove

If anyone wants a 2871 set up mines for sale.

how much are you asking for it.

lol 24 psi...

[zombiewolf513]

Originally Posted by sr20det_510

hello guys im pretty new to the sr's but here it goes i need your guys info and advise please, so im building a 510 2door with an s13 redtop and what i have planed for this is starting from bottom up, greddy oil pan, stock micro polished crank, .5 bore on block to make it 86.5, arp main studs, eagle rods, cp 86.5 9.0:1 pistons, dont know what size apexi head gasket please advise,????

APEXi 87mmx1.5mm itll be labeled 8815

Also, youll have to grind down 2 of the arp main studs to the bottom of the hex to clear the upper oil pan and install them using the 2 locknut method. Research it youll see what i mean



Im running a similar setup with a haltech platinum sport 1000 with no maf and full speed density setup.

Im running stock springs, no need for me to with JWT S3 cams.

You should be able to excede your goal with a solid tune

Get a FPR. I use a tomei type L, the sard is highly rated, but i hear theyre the same product

Theres a multitude of tb's to choose from, just google it

You need a better flowing fuel pump, dont forget some way to wire all this crap and turbo lines, nice gauges, rod and main bearings, id get all new timing guides and chain thermostat, water pump, oil pump (deck it flat with the block), new rear main seal, so on and so forth

[EsChassisLove]

Originally Posted by jamg

how much are you asking for it.

lol 24 psi...

It sold already.

Sold for pretty cheap!

[sr20det_510]

But what do you guys think about the 9:1 compression pistons? Run that 1.5 apexi gasket? What do u guys think about my setup? Ecu? Bore? Thanks for your input zombie

[KoukiMonsta]

Originally Posted by sr20det_510

But what do you guys think about the 9:1 compression pistons? Run that 1.5 apexi gasket? What do u guys think about my setup? Ecu? Bore? Thanks for your input zombie

has the block/head been decked?

that effects compression ratio, i have been researching it myself lately as im running the same setup...

apexi 1.5 seems to be my plan, tho i think this head has been surfaced twice..not entirely sure.