SR20 Tune

[Zeph331]

Hi guys i have a question, is this the limit of S15 turbo?

I was on

-Redtop SR
-Apexi Djectro
-550CC
-S15 BB Turbo
-Intercooler
-Exhaust
-WalBro 255

All my tuner could get out of it was 215WHP on 10psi. And said there was Fuel Shortage
This is the kind of power i think u can make on Stock ECU 370? I dont have a Boost Controller yet, but i just needed to tune the car to run.

I was kinda underwhelmed. I think i was expecting atleast 220 - 230. Is this the limit of 10psi? or do i need to go to a different tuner

[cotbu]

that's about right for 10psi.try 11psi for that extra 10hp. that turbo starts to wake up about 14psi, and should be fully awake by 17.
the fuel part is bullshit, unless you're on a dd, and are really pushing 350hp from a gt28r

[Zeph331]

Hmmm alright thanks for the quick response cotbu. Do these tuners usually have leeways incase of accidental overboosting issue? What im trying to get at is if i raise one or to pound do i need to go back in for tune again?

[Kingtal0n]

If your fuel pump is bad, it could be running out of fuel.

550cc injectors will normally net you at least 340rwhp.

If you are on a stock camshaft your limit on a dynojet is 320rwhp at 18psi through that turbo, with 96% confidence.

Your ignition timing at 10psi, WOT, should start out around 10-11* at peak torque (3500rpm-4000rpm) then by 5000rpm 12*, and by 6500 rpm 13*

So, example: 11-12-13-14 as you move from 3500-7000 at 10PSI, THEN check your knock counts, should be < 12

For 18psi you would want,
9-10-11-12


I'd be willing to bet you have about 15* there, which is too much and will result with your pistons getting beat up over the next year, by which time you will be pulling the head and asking "what are these marks?"

[cotbu]

You shouldnt need to go back for a retune over a 1 pound increase, but i didnt tune your car.
Normally they do have overboost protection, knock protection ,speed ,ign and fuel cuts, but again the builder and tuner should know what\where they are.

Post your dyno graph, logs and your fuel and timing maps.
don't let that guys post scare you, find a good tuner and get mapped, that's all you can do until you learn yourself.

[TurboTiger]

How experienced is your tuner? Has he worked with SR's before? You should be over 300whp assuming there isn't another issue you're not aware of.

[blksylv]

are you in richmond, va? if so who's your tuner?

[Zeph331]

You shouldnt need to go back for a retune over a 1 pound increase, but i didnt tune your car.
Normally they do have overboost protection, knock protection ,speed ,ign and fuel cuts, but again the builder and tuner should know what\where they are.

Post your dyno graph, logs and your fuel and timing maps.
don't let that guys post scare you, find a good tuner and get mapped, that's all you can do until you learn yourself.

I dont have any timing or any kind of log. All i have is the Dyno graph but ill try to find it and post it.

I did some testing today, the car would peak out @ 14 IGN timing around 7000. (reading off my commander)
13" @ 6000
12" @ 5000
11" @ 3000 - 4000
21" @ Idle (not sure why ever since i install my apexi the idle went up but ok)

Fuel is roughly around 74% Inj Duty @ 7000 pulling 11.3 ish AFR
Idle is 12.0, Easing into boost is( 3000 - 4000ish) 10.9 - 11.0

Before i had S15BB on Stock Ecu and 370CC 10 PSI. I pulled 226WHP
now i have apexi, before tune was like 192WHP after this tune i have 215WHP. Thats why i was quite confused at the numbers :S

One other thing i changed between these tune is i swapped out my Trust Catback with a straight through Buddy club Spec 2.

[R3cK]

i made 235whp on 0.6bar with a stock redtop and t25g

[Croustibat]

Hi guys i have a question, is this the limit of S15 turbo?

I was on

-Redtop SR
-Apexi Djectro
-550CC
-S15 BB Turbo
-Intercooler
-Exhaust
-WalBro 255

All my tuner could get out of it was 215WHP on 10psi. And said there was Fuel Shortage
This is the kind of power i think u can make on Stock ECU 370? I dont have a Boost Controller yet, but i just needed to tune the car to run.

I was kinda underwhelmed. I think i was expecting atleast 220 - 230. Is this the limit of 10psi? or do i need to go to a different tuner

Tuners don't do voodoo magic, and that is why you need to get your car sorted BEFORE getting it tuned.

If you have a fuel shortage at 10psi, it means there is a problem. Fuel regulator, fuel filter, fuel pump, fuel pump wiring, injectors, at least one of them has gone wrong.

It also means the car will have to be remapped (at least the fuel map) once it is fixed. You have at least one problem that needs to be fixed before any mapping can happen, so fix your car first. I suspect the fuel pump wiring here. check voltage at the pump when it is running. There should be the same voltage at there is at the battery. If it is not, time for some wiring.

[cotbu]

The dyno graph might shed some light,
If you are loosing fuel pressure, etc.
I do think you might need to find another tuner, but check codes, boost leak test, check fuel pressure, run a barrage of test and replace some of the cheap parts like fuel filter.
The fuel pump hot wire is an good way to make sure the fuel pump has good power, but that Walbro pump hates being run low on fuel, so if you ever tried to see if the fuel gauge light comes on, you should probably replace that Walbro.

The real problem is you are not happy with the power, but you aren't saying if the car runs crappy.

Sent from a Highly Tuned Note 4.5!!!

[Zeph331]

The dyno graph might shed some light,
If you are loosing fuel pressure, etc.
I do think you might need to find another tuner, but check codes, boost leak test, check fuel pressure, run a barrage of test and replace some of the cheap parts like fuel filter.
The fuel pump hot wire is an good way to make sure the fuel pump has good power, but that Walbro pump hates being run low on fuel, so if you ever tried to see if the fuel gauge light comes on, you should probably replace that Walbro.

The real problem is you are not happy with the power, but you aren't saying if the car runs crappy.

Sent from a Highly Tuned Note 4.5!!!

Roger that.Will do all the test.

Actually, now that i think of it. I did use a Z31 Fuel Filter since last year. Maybe switching to Z32 will flow more being it larger. Will try that out this week

But yes The car Drives and boost fine. Its just im not satisfied with the numbers haha. Dyno might be wrong too, but i highly doubt thats the case

[Croustibat]

Check the fuel pump voltage first, it takes a couple of minutes, costs nothing and has more chances to be your problem.

[cotbu]

Maybe switching to Z32 will flow more being it larger
very common misconception, i meant if its dirty or clogged.

The fuel pump should be checked at idle and under load, pressure and voltage..
it could have 14v at idle and drop below 12v under load. that may not be the pump, but the alternator not doing its job correctly. i would then suggest you run tests on the alternator.