Hi Guys

After installing a set of B&B my car gets boost creep.
My first test was to drive at 25Mhp and floor it, tried that on 2nd, 3rd, 4th and 5th respectivly. It overboost when doing this on 2nd and 3rd gear, it's worse on 3rd gear. On second gear I get up to about 1.05 bar, on third gear about 1.1 - 1.2, somtimes trigger my pressure switch (measuring at manifold. On 4th and 5th gear the wg seems to handle the pressure, at least when testing like this.

Seems to be very similar to what dholling13 is experiencing.
Would I experience any improvement by gutting the wg pipe and what is the best way of doing this?

Could I expect less overboost when the outside temperature gets higher (48F today during my test runs).

Oh, and I am running a HF turbo from Kevin and Blitz dual solenoid boost controller which I have tried in every possible mode (including OFF).
I am measuring boost at manifold.

 

I gutted my wastegate cat and silencer in the exhaust tip and still experienced boost creep. The creap is due to the wastegate pipe not being angled properly and large enough in diameter; my headers are 1 3/4". It's the mid range creep that made me overboost.

I just moved my overboost switch (Stephen Kasper made a device for me) in between the Bosch unit and the manifold; tomorrow I am dyno tuning the car. I currently am running a .7 bar spring with a b&b muffler and striaght thru wastegate pipe. Keep you posted.

Drew

 

I cant comment on the overboost reduction by gutting the wastegate cat and silencer tip, but DAMN it sure does sound good when the gate opens once you have done it!!!

FWIW I did notice a boost creep reduction after I had done it, I do not have overboost problems as I am running standard headers with 1.00bar with a HFS. Prior to gutting I noticed an uneven pattern of boost on the Blitz EBC, after it was a very predictable number according to the setting.

 

What kind of final exhaust do you guys have installed? I have a B&B muffler bolted up to the turbo.

 

I heard that it's hard to gut these thing (wastegate pipe), how did you do it?

 

Sent you a PM.

 

Gutting the waste gate pipe is only going to make it sound really nice. But as for solving boost creep, I doubt it. Best thing to do is invest in a tial wastegate. It controls the boost far better than the factory unit. I had boost creep problems in 3rd-5th gear until I changed the gate and added an EBC. I would also put a larger dump pipe on rather than just gutting the baffle in the rather small factory unit.

Craig

 

Gentlemen,

The over-boost is gone!!! I just got back from the shop where we dyno tuned (dynapacks) the car. With a tial gate .8 bar spring, B&B headers and exhaust, BMC filter kit, the Ultimate Motorwerk's High Flow S turbo, and the good Porsche Doc's magic overboost device (pictured above) with everything else on the car stock the car did:

Rear wheel to the ground - 333 lb ft torque 332 horsepower
AFR's - 11.6 / 1
Boost pressure - 14psi's at the manifold / ez69 unit
.36 gee force (no clue it measured that)

I want to thank Stephen at Imagine for shipping me the parts I needed, Kevin at Ultimate for the turbo, SSI for dyno tuning and all rennlist members who helped me get my car running like it should. I plan on driving it like I stole it except for the crash at the end

 

Hey there ya go!! That little switch was a pain in the **** Congrats and you are welcome.

Yes, the WG will cause an over boost spike problem. If the car will maintain proper boost in upper gears the wastegate cannot vent fast enough down low. Meaning the turbo comes up so fast it can not deal with the air. You know what your car does if you have a restrictive exhaust, well the WG pipe is the same. If there is a restriction in the pipe then the air can not move quickly. You need to guy it with a high flowing system.

They are a bear to remove, either cut the end off and pull it out or use a press and and a pipe and press it out. It is some nasty stuff to remove. Once you get it out you will understand what the restriction was.

 

My WG pipe is just a straight dump off of the Tial. No cat, nothing. I was having the overboost issue as well, but then I took apart the Tial and found a .8 and .3 bar spring in there. I also replaced the overboost swtich, and my car screams now. I am out of town in Detroit currently, but I can take a picture of the WG pipe if you want when I get back. It has a tip on it that matches the one coming out of the muffler.

Bill

 

Anyone have a gutted wastegate they would like to sell ,send me a pm !

 

H&S in UK will make you one up for c.£150.

 

Guttting the CAT is a horrible job as mentioned, I used a holesaw bit and just continually took chunks out until at least you can get some vice grips in there. Once the vice grips are able to get in and get a hold on some pieces it is very easy. For gutting the tip I just got a hold of a heat axe and cut around the outer rim of the baffle. Interestingly the change in sound is only really noticeable when you remove the tip baffle the cat seemed to have very little impact on the sound at all.

 

Thanks Youcef, I will start by removing the wg silencer, Stephen thought that would solve the problem. I have a gas welding equipment with a cutter, will try using that.

 

hi staffan,

on the exterior of the pipe you find some spotwelds. the baffle plate is fastened with these spotwelds in the pipe.
the easiest way to remove the baffle seems to me to cutt-off these spotwelds. problem is, you will have to close some holes on the tip..

fritz