GT2871 USERS. SR motor

[flamebag16]

Originally Posted by slider2828

Funny thing, my car also blew on cylinder 2. I actually had a cracked piston but rings were fine and I ran also 16 psi. Anyways, in my case, I think there must have been some defect on the bottom, so I rebuilt with forged everything. Sometimes these things happen and a 2871R pushed considerably more air into the cylinder... I say there just isn't much you can do. I tuned my own car and ALWAYS kept AFRs under check with innovative wideband with data logging... Not much you can do sometimes, doesn't mean the tune is bad....

Yea wideband is somehting i will be investing in before i start car up again i guess shit happens not blaming it on the tune just making sure i dont make the same mistake twice anyways i will also be going forged bottom end also looking into some springs and retainers and cams

[smelly240]

in the midrange i always find myself pulling timing - 3800-5000ish. and then ease it back up 6000-7400 to about 18-20 (however much it takes before it starts to knock then back it off a bit) i've done a few cars previously enthalpy - its not that they're bad - just you cant just throw a map on it and have it be perfect. Every car will not be the same - regardless of the mods being the same. Thats why a lot of people with enthalpy ecu's use a afc with it - but that fucks with ur timing. get that wideband for xmas and make sure its right.


obee breaky my cah! no good cowboy! you not numba one!

english translation - the obeejuice has cracked intercooler making car run like doodoo.

P.S. stock metal front s13 fenders are whack, obee. im staying with frp forever so piss off sandwich eater man!

[BiG MiKE86]

So I took my car back to the dyno yesterday after changing a few things that gave me problems last time - BOV, couplers, fans, boost cont., actuator, etc..

Heres the thing which baffled the fawk outta me and everyone there - I am running a GT2871r .64a/r with Tomei 256/256, 740cc, etc.. all the nessessary mods for 350ish rwhp

@ 10psi (ATP's "Special" Actuator) I made 296rwhp/256rwtq
@15psi I made 328rwhp/283rwtq - everything seemed spot on - for those 2 runs

So we Tried for 18-19psi - Car would completely fall flat on its face @ 6500rpm and 330rwhp as if it had some sort of rev limitter (PowerFC was set to 7400rpm) AFR's were perfect, timing was good, hp and tq curve looked great.. it Just Stopped @ 6500 rpm even holding the pedal down - it sounded like someone had turned on the dyno brake (if that makes any sense)

Under no Load or lower psi the car would rev out perfect in/out of gear

The PowerFC was reading the MAFS max voltage? @ 4400mv
The TPS graph showed it was reading fine
AFR's were perfect
Timing was dead on

WTF?

Sidenote: The shop owner said the turbo may be failing @ higher psi or Locking up (which should/would restrict air flow causing the symptoms) He mentioned that he'd seen this before - idk guys wtf?! help

[ni5mo240]

Originally Posted by BiG MiKE86

So I took my car back to the dyno yesterday after changing a few things that gave me problems last time - BOV, couplers, fans, boost cont., actuator, etc..

Heres the thing which baffled the fawk outta me and everyone there - I am running a GT2871r .64a/r with Tomei 256/256, 740cc, etc.. all the nessessary mods for 350ish rwhp

@ 10psi (ATP's "Special" Actuator) I made 296rwhp/256rwtq
@15psi I made 328rwhp/283rwtq - everything seemed spot on - for those 2 runs

So we Tried for 18-19psi - Car would completely fall flat on its face @ 6500rpm and 330rwhp as if it had some sort of rev limitter (PowerFC was set to 7400rpm) AFR's were perfect, timing was good, hp and tq curve looked great.. it Just Stopped @ 6500 rpm even holding the pedal down - it sounded like someone had turned on the dyno brake (if that makes any sense)

Under no Load or lower psi the car would rev out perfect in/out of gear

The PowerFC was reading the MAFS max voltage? @ 4400mv
The TPS graph showed it was reading fine
AFR's were perfect
Timing was dead on

WTF?

Sidenote: The shop owner said the turbo may be failing @ higher psi or Locking up (which should/would restrict air flow causing the symptoms) He mentioned that he'd seen this before - idk guys wtf?! help

Your power fc has a boost warning/limiter feature built in to it. When you try to dyno at 18-19 psi it cuts out, mine was doing the same thing until I turned the boost warn off

[BiG MiKE86]

Originally Posted by ni5mo240

Your power fc has a boost warning/limiter feature built in to it. When you try to dyno at 18-19 psi it cuts out, mine was doing the same thing until I turned the boost warn off

I do not have the boost cont. for the power fc - im using a Greddy Profec-B Spec II so the Power FC Has no way to tell how much boost im puttin out

[blkkouki]

[quote=ni5mo240;2471881]Your power fc has a boost warning/limiter feature built in to it. When you try to dyno at 18-19 psi it cuts out, mine was doing the same thing until I turned the boost warn off[/quote

[s15specR]

Mines run to 25-26psi easily, if its falling dead on its face like you said it maybe something in the ecu, idk

[slider2828]

He's bsing you.... What MAFS are you running? That is so weird.... on my N62 I run 18 PSI and I still don't max the MAFS out....

[smelly240]

it isnt maxing out a z maf - thats for sure.

is there a "fuelcut" setting or a load limit on a powerFC?

[BiG MiKE86]

Originally Posted by SoguRacing

bro, it's your cams. here's my dyno with boost control problems and step 1 hks 256/256 cams. you need more duration. mine at 10 psi with boost conrtoller problems as you can see.

otherwise same setup. i'm getting a retune with bigger cams and smaller injectors and now i have a boost controller installed for my next tune.

Hey @ those rpms could you describe what happened? Because we kept it WOT and it didnt respond or do anything just fell off

[cotbu]

The old 330hp lock out. Happened to me, but it was my cams they were stockers

[BiG MiKE86]

Originally Posted by cotbu

The old 330hp lock out. Happened to me, but it was my cams they were stockers

oh rly? ur car didnt completely die @ 6500rpm did it? im running Tomei 256 poncams in/ex

Originally Posted by smelly240

it isnt maxing out a z maf - thats for sure.

is there a "fuelcut" setting or a load limit on a powerFC?

I couldnt tell ya - ill ask my tuner

[SoguRacing]

bro, it's your cams. here's my dyno with boost control problems and step 1 hks 256/256 cams. you need more duration. mine at 10 psi with boost conrtoller problems as you can see.

otherwise same setup. i'm getting a retune with bigger cams and smaller injectors and now i have a boost controller installed for my next tune.

[SoguRacing]

honestly I wasn't in the car while it was being tuned. "steve" from "shadowerks" was. you'd have to pm him about that.

[cotbu]

oh rly? ur car didnt completely die @ 6500rpm did it? im running Tomei 256 poncams in/ex

No, it didn't the run went to 7250rpm, and I don't even have a gt2871r... go figure! I was just trying to help you find a solution!

[smelly240]

if shadows is doing your car - he would know -

i never used a PFC - and i know he's a haltech master (maybe pm brianw or shawn (RT)

[SilEightyKid]

Would it be bad to use JWT S3 with JWT springs and retainers?

[garagelu]

Why would that be bad? Its good that you are using all high end, reputable components.

[codyace]

Originally Posted by slider2828

I mean codyace has an awesome setup, but we are talking about port polishing this and swain and hone that and I am sure it makes a huge difference with great response, but this is for people knowing what they are doing. Ima just a bolt on and make it reliable guy and for 95% of people out there, its the same philosophy which is kind of what Obeewon's philosophy.

I have no port and polish. I have nothing fancy on the cars.

Extrude Hone, External Gate, and Swain Coat are still LESS than getting a worthwhile tubular manifold. Even then, you can't be promised that it won't crack and won't make the same power.

I'm not sure what you read, but my car is full of real world parts, assembled by a real world guy. Trust me when I say, if I was building a race motor with this turbo, that it would make much more power and spin much higher...but alas, this is a street car.

So comparing tuning philosophies, really oranges to oranges, a .86 has more lag, but not that much difference to a .64 and in the top end, the .86 will out pull the .64. You just can't get away from design....

I would be willing to say thta a 380 whp .64 car will be quicker than a 380 whp .86 car. That low end grunt and boost resopnse (you can't always look at a dyno chart, you need to look at power production over time). is what makes the car gravy. Peak numbers are for super street readers. Average TRQ are for fast car owners.

Originally Posted by steve shadows

Do you need help locating one?

Seriously, hook at brother up I'm not scurrrred hehe. Although I may lose my fan club (oh sarcastic me) haha.

Originally Posted by slider2828

Yah in AUTOX low end loss is unacceptable.... and I prefer a little more linear gain then bigger mid and top end gain.

.64 2871r + 4.63 rear geras = smiles all the way to the bank.

Originally Posted by BiG MiKE86

it Just Stopped @ 6500 rpm even holding the pedal down - it sounded like someone had turned on the dyno brake (if that makes any sense)

Like, you couldn't rev above it? Or it's just not making power?

Check to see if you're blowing out spark? Gap them puppies down to .022

Originally Posted by SilEightyKid

Would it be bad to use JWT S3 with JWT springs and retainers?

Not bad at all! S3's love stock springs, but love upgraded jwt springs as well (JWT no longer sells retainers, they use OEM ones)

[BiG MiKE86]

Originally Posted by codyace

Like, you couldn't rev above it? Or it's just not making power?

Check to see if you're blowing out spark? Gap them puppies down to .022

Didnt want to REV past 6500 - and it wasnt like bouncing off a rev limitter - it like hit a wall and died slowly even with the pedal to the floor

I will try gapping the plugs down some more this weekend thank you for the help

[jakerps13]

Originally Posted by BiG MiKE86

Didnt want to REV past 6500 - and it wasnt like bouncing off a rev limitter - it like hit a wall and died slowly even with the pedal to the floor

I will try gapping the plugs down some more this weekend thank you for the help

What intake do you have? Small filter can be a restriction and I've personally seen the stock rubber intake collapse when warm/higher boost.

[BiG MiKE86]

Originally Posted by jakerps13

What intake do you have? Small filter can be a restriction and I've personally seen the stock rubber intake collapse when warm/higher boost.

3" Piping Pro Aluminum Intake + Apexi Filter

[SilEightyKid]

I don't know but would the stiffer springs affect the way the engine rev?

[SilEightyKid]

Thanks for clearing that up. Btw cody, I see that you're running a Greddy elbow what's your input on that? Does it really help separate the gases and help spool? Do you think it would fit with the GT2871R GTS version since it has a S15 compressor housing.

[slider2828]

It does work because it is divided all the way down past the flange, so yes it does work. Yes it would fit because the turbine side is the same as all other T25s...

[SilEightyKid]

Originally Posted by slider2828

It does work because it is divided all the way down past the flange, so yes it does work. Yes it would fit because the turbine side is the same as all other T25s...

It looks like it would hit the stock wastegate diverter. Maybe you're referring to the GT2871R with the 3 inch inlet not the GTRS version.

[S13 curtis]

Jus wanted to know what you guys think i will be putting down on stock 8 psi
this is my set up:


SR20det Red top
GT2871r .64 3' inch inlet on stock boost
Greddy intake manifold
Megan exhaust manifold
Megan elbow
Stock Cams
370cc injectors
megan down pipe & test pipe
HKS HI power exhaust
Exedy stage 2
Stock 62 ECU
ARP Head Stids
Apex 1.1mm Metal Head Gasket
FMIC

[codyace]

Originally Posted by S13 curtis

Jus wanted to know what you guys think i will be putting down on stock 8 psi
this is my set up:


SR20det Red top
GT2871r .64 on stock boost
Greddy intake manifold
Megan exhaust manifold
Megan elbow
Stock Cams
370cc injectors
megan down pipe & test pipe
HKS HI power exhaust
Exedy stage 2
Stock 62 ECU
ARP Head Stids
Apex 1.1mm Metal Head Gasket
FMIC

Unsure, but i bet you max the injectors/maf

[slider2828]

^^LOL that is so sad! Spend some money on other stuff instead of I have stuff... OMG... Lol.... I don't think you CAN run 8PSI on a GT2871R...

Sad....

[S13 curtis]

i also have no a/c or ps i think it should be around 250whp give or take but i dono. im getting cams,740cc,and a Power FC.
well the car isnt running yet and i herd stock boost is 8 psi on the 2871r. I dont think the stock maf will be maxed. i have a N62 but its jus sitting in my garage until i get it tuned. I jus need to daily drive it for now, jus wondering though what it would make at what ever the stock boost is.