Another Boost Question!

[waad_uk]

Hi Guys, Sorry I know this has been covered many many times before, but i just want a quick answer to my current boost pressure.

I am currently seeing about 10-12 PSI with foot flat on the floor. I have searched the forum, but keep seeing various figures. My car is completely standard. Is this too low?

If it is too low, that would give me some encouragement as my mates S3 kicked my **** the other day !

I also noticed that the little rubber hose from the front of the inlet manifold had split. I have replaced this with some other braided hose I had. What is this hose. Does this feed the ECU?

Cheers!

[4WheelDrifter]

I think 0.8 bar is ok for a stock ABY, but you should get 1.1 bar overboost.
I'm just a simple 3B owner, so I'm sure an ABY owner will correct me if I'm wrong.

[HPmuirt]

I think 0.8 bar is ok for a stock ABY, but you should get 1.1 bar overboost.
I'm just a simple 3B owner, so I'm sure an ABY owner will correct me if I'm wrong.

See this thread amongst others for the stock and chipped boost levels.

Dunno about these 'simple' 3B things, but 0.8 is too low for a superior ABY

Cheers n

Si

[waad_uk]

Thanks for your replies.

So I guess I will be tracking down a boost leak then. I will try to knock up an adaptor so i can test the boost hoses etc.

I will also pull the codes later. I pulled the codes last week and got 2413. I cleaned the MAF hoping it would be that. Would this be restricting the boost?

[waad_uk]

Are they any of these boost leak kits still floating about for sale? Has anyone managed to make their own?

I found where that braided hose went. It goes down to the intake side of the turbo. I the WGFV?

[ross25480]

boost prob

Hey pal my stock ABY boosts to 18psi in 4th 5th and 6th gears not to sure about 3rd cant remember. Are you sure you have an aby as 10-12 psi is 3b teritory.

[HPmuirt]

Hey pal my stock ABY boosts to 18psi in 4th 5th and 6th gears not to sure about 3rd cant remember. Are you sure you have an aby as 10-12 psi is 3b teritory.

The ABY boosts to 1.15 Bar (just under 17 PSI) in overboost mode in 4th, 5th and 6th.

Not sure Lee is around anymore with those kits, but several members have them, so where are you based?

Cheers n

Si

[waad_uk]

Im based in Essex, not far from Maldon.

Yeah the car definately doesnt feel 230hp quick, It is quick, but seems to be holding back.

I think I will have a go at making up a leak kit.

[waad_uk]

The more I think about it, the more I cant help but feel that there is somthing holding the pressure back.

It always get to 12psi on the line everytime. I guess this frequency valve thing could be the cause?

[S2central.net]

Yes - the WGFV can be the cause of this problem. On an ABY you should be seeing a peak circa 1.1 - 1.2 bar on overboost (WOT in 4th or higher).

Other reasons for not hitting target boost are as follows - some are dirt cheap - some not so... in no particular order -

- Boost leak caused by a split or loose hose. Top candidates are the intercooler o-ring, MAF hose of throttle body hose.

- Is th throttle cable going 100% to full throttle position ? Boost is regulated directly off throttle position so if the cable is slack or restricted then you wont see full beans. Also check the electrical signals on the throttlepot.

- Dodgy MAF maybe. Expensive to replace for investigation...Come to a forum meet, find a friend and blag their MAF to see if there is any difference.

- Loose spark plugs - sounds bonkers, but this is a common cause of 'air leak' on the S2 as the plugs can work loose over time. Sometimes the problem is made worse by folk overtightening them.

- Have you tried RESETing the ECU by removing the 'MOTOR' fuses for a minute ? This clears any stored fault codes that might be telling the software to prevent you boosting beyond 0.8bar.

- Oh and the other one is a high water temp alarm that is wired into the ABY ECU which prevents use of maximum boost if it thinks the engine is too hot. This is a different signal than the one used to warn of high temps on the instrument cluster. Not a common fault, but seen & documented before...


Search the forum for more info on all of these. Your problem is not likely to be unique.

Paul

[S2central.net]

Oh and the others I forgot (my bad) -

- Faulty MAP inside the ECU

- Faulty ambient pressure sensor (F96) outside the ECU - passenger side A-pillar behind the trim.


Paul

[waad_uk]

Wow thanks for the great help guys!

If anything, this problem will help me find my way around the car better!

[1975DCS]

I have a 3B with 270-280 bhp chip. Yesterday I gave it my first full throttle.
The results where a little over 1.0 bar at 5000 rpm and less over that. I think that is okay. From about 50 in 5th gear it only peaks at around 1.2 bar, this seems a bit low to me...