Spectator

iTrader: (1)

Running 5.5 PSI. Cant go above that. The car doesn't care what I do to her, she never goes over 5.5 PSI.... I think a boost controller is in order.

So I went to the dyno on saturday. Ran 191.8 rwhp with 5.5 PSI and an average AFR of 11.3. What do you guys think? Is that good? I'm stumped that running stock boost with 720cc secondaries on an S4 motor, I have more HP at the wheels than stock on the flywheel.

And the guy at the shop told me that If I put it a boost controller, I would be able to go up to 10- 12. But I always been told that a boost controller doesn't increase boost, but limits it. I do understand though that it could hold the wastegate closed until I hit 9-10 PSI and then open it accordingly to keep that boost steady...Is that right?

Also, What AFRs should I be looking at if I run 9-10 PSI? Still 11.3? How can I reach this if I already have 11.3 on 5.5 PSI?

And for some reason, I cant upload my Dyno graph.

idsigloo

The boost controller will limit the level of boost seen by the wastegate thusly making the wastegate open at a higher boost. 191.8rwhp is good for 5.5. Are you using 9.0 or 8.5 CR rotors?

88rxn/a

iTrader: (6)

load you graph on photobucket, then here.

a boost controller CAN raise boost but it CANT lower boost

BlueTII

A boost controller increases and controls boost, in your case it would not control it lower than 5.5 psi

Spectator

iTrader: (1)

8.5

But what about my AFRs? If I install the boost controller, and run at 9-10 PSI, wont my AFRs go up in the range of 13 or so?

I have 720cc secondaries and a SAFC-II

p4nc7

iTrader: (1)

That is damn good for 5.5 psi. 'Grats on the results.

Aaron Cake

iTrader: (1)

11.3 at 5 PSI is a tad rich. High 11s would likely yeild a bit more power.

At 10-12 PSI, you'll probably want to be safe and go for 11.5 or slightly richer on the stock ECU. If you have larger injectors installed, you'll need a way to tune them (S-AFC, etc.).

p4nc7

iTrader: (1)

Apparently he's got an S-AFC 2, I think in regards to that he's fine.

Spectator

iTrader: (1)

What I'm asking is, I already have a SACF-II, on stock settings. And I am running 5.5 PSI boost with 720cc secondaries, wich gives me 11.3 AFR...

If I run 10 PSI, how the hell can I add more gas if I am already on stock steeting? What is stock settings? 80% injector usage?

Aaron Cake

iTrader: (1)

The S-AFC will let you add a little fuel, but it's limited by how much the stock ECU will allow. It's better to use larger injectors and use the S-AFC to remove fuel.

Spectator

iTrader: (1)

I have been told that 720cc secondaries are fine for 10 PSI. Is that right?

88rxn/a

iTrader: (6)

on a stock turbo yes.
RE-wire your fuel pump to!!!
BTW:
is your fuel pump stock??

Spectator

iTrader: (1)

Nope its a walbro 255lh.

I'm just wondering how to add more fuel....I was supposed to be running mad rich on stock boost....but I ain't...

bleh....

88rxn/a

iTrader: (6)

well, opening the intake and exhasut will yield more power= needing more fuel

the stock ECU uses the boost pressure sensor to ADD more fuel when you turn up the boost ( i cant remeber how much it max's out at) but i think you can go to 10LBS.

just be careful and at the least use a wideband while turning up the boost.

ive read that people actually restrict the line going to the wastegate with a paperclip to get more boost but i wouldnt reccomend it. to much boost and BOOM!
**edit**
im going to use the AEM tru boost
its a boost gauge and controller all in one
260 bucks for one!!
slick way of adding boost while getting a nice gauge!

classicauto

iTrader: (3)

Just shy of 60% is stock.

If your S-AFC is zero'd and you're acheiving 11.3:1 @5.5psi, then you've got plenty in it to turn the boost up to 10psi. Just go slow

Spectator

iTrader: (1)

Cool, thanks Classic....again.

MaczPayne

iTrader: (5)

I wouldn't boost more than 11-12 psi, the turbocharger becomes inefficient after that point. Instead, invest in a good EBC to improve boost consistency. You'll get a better power curve. Check out my sig.

Phantomkid

thats pretty amazing numbers. are you sure you dont have higher compression. what mods do you have if you dont mind me asking. As they were saying use your SAFC2 to control the fuel to be able to feed the beast at 10psi. I would really like to see your numbers at 10psi if you dont mind. Is your motor freshly rebuilt? street port? i just dont see how you could get such high numbers off stock boost. There also is a fuel cut off you should be aware off im not really sure i believe it is around 8 to 9 psi. Jeeze i hope i get numbers like that on 5.5 congrats bro

Phantomkid

o i forgot to mention the top mount is said to loose effiency around 10 or 12 psi

The Wankler

iTrader: (14)

You may want to port yout wastegate. Mine was ported a bit, and I had problems controlling my boost. Rotaryshack ported it again WAY bigger. Now, I can control my boost well. If you find boost creep after adding that controler, consider porting the wastegate.

rx713bt

iTrader: (4)

5.5 PSI is so low. Is there something wrong with your car?

CrackHeadMel

iTrader: (2)

i second the rewiring of the pump, i just finnaly did this this weekend, fuel pump sounds like it does with 14v running though it even with the car off. i will have to pull fuel from my entire fuel map

and low 11's are overkill imho, mid high elevens is what i would shoot for in your situation (no timming control)

MaczPayne

iTrader: (5)

+1 on rewiring the fuel pump. The very first thing I did with my car was renovate the old fuel pump wiring. I feel safe knowing that my fuel system always works reliably.