How should it act?

I was guessing that it would stop boosting around the PSI of the spring. I heard the stock spring would compress at 6psi and open the wastegate fully.

I went driving tonight like that and it would go to about 10psi.

Just curious what other cars do with no boost controller hooked up.

James

 

mine goes to around 6.2 PSI with a 3" TID and everything else stock. You must have an exhaust system of some sort

 

Do you have the vacume on the wastegate hooked up or just open to the atmosphere. Because if you just have vacume from the manifold to the wastegate, that's stock and yes you should see stock wastegate spring boost levels which differs from S4 and S5. I think it's 6.4 and around 7.5 for S5's.

 

I just hooked the compressor housing nipple to the wastegate.

Yeah, I have a 2.5" DP , midpipe, N1 duals and a stock tid with a cone filter.

Maybe I should put a zip tie around my wastegate actuator rod and see how much it is moving.

James

 

Yeah, no cats and open exhaust will allow it to spool way more freely and give you more boost. Have you hit fuel cut yet or do you already have an FCD?

 

Got a hks fcd. So that isn't a problem. I wanted to keep playing with it tonight but that stupid metal pipe where the bov plugs into keep blowing the metal piece out the bov hose plugged into. Werd.

And then I was installing that rear camber link. What a bitch!

 

Setup: stock intake, gutted cats, stock 91 turbo - 135 in 5th 13PSI – detonation (my own fault) - cracked apex seal.

New setup: J-spec from an automatic, ported waste gate, stock intake, gutted cats - 5psi in 1st 6psi in other gears.
So - J-spec S5 automatics have a 6spi waste gate.

Experiments:
Grounded open the stock boost control - no change.
Bypassed the stock boost control - little (.5psi) change.
Short hose from waste gate Tee to TID – 6-7psi.
Block off waste gate hose all together – Instant boost to 11psi (near disaster) so now I’m sure there’s nothing wrong with the turbo.
Restore normal waste gate function.

Reinstall FCD.
Time for an upgraded fuel pump & boost controller.

 

Well, I just got a vacuum pump from autozone....i think it can do pressure......i am gonna go see if this rod is moving......i just cant believe it makes that much boost with out a controller.

I didn't even floor it and let it go wide open in 3rd.

James

 

I just checked this out a few weeks ago.

My S5 turbo pressure tap outlet hooked directly to the wastegate actuator will allow you to max out at 5 psi (depending upon your intake and exhaust mods). That 5 psi is IF your wastegate can control you boost. If you boost creep due to mods obviously you will get more than 5 psi.

The actuator starts to open about 3 psi and is open at 5 psi. The S5 boost controller delays the opening so more boost is allowed.

If you disconnect the wastegate totally the boost is insane and you better have the fuel and timing to control that beast. The boost response is very quick if you can keep the wastegate from opening prematurely. Don't do this unless you know exactly what you are doing--you could blow your engine easily. I did it just to see if my exhaust was holding me down to 5 psi--turns out it wasn't.

I plan on running a good boost controller, haven't decided on electric or manual yet. I'll be leaving the stock GSL-SE muffler in place to help control boost. My system works perfect as my un-ported wastegate can control boost with no problem.

Scott

p.s. I hooked it up like an S4. Obviously the stock S4 wastgate allows some boost creep above 5 psi.

 

Like my old engine above - The stock waste gate gets overrun when you open up the exhaust.

That 10psi you're seeing is pure boost creep.

 

Time for new ECU.

My car is staying parked until I get my microtech.

I already learned my lesson.

 

Boost Creep .....or is that post creep to the top?