Gt3076r - Wastegate Leaking

[MR 33]

Hmm hope i don't have this problem! My 3076 will be up and running very soon, most likely going with a bell mouth dump to try and aviod this problem.

[STATUS]

On closer inspection Craig has a valid point. Looking at your pic the flap is off centre to the machined hole.

i second that, i would get him to increase the machined lip around the gate hole just to be sure, i reckon the left hand side is sitting up on the rough casting... not in the machined ring.

[dangerman4]

what waste gate actuator are you running?

is it the stock 8 psi one?

maybe try a heavier one say 18psi.

also with the flapper would it be possibe to do a 3 angle valve grind on it to increase the seating area?

[dangerman4]

here are some pics

**EDIT** sorry should've added i know it is leaking as i can hear it on the screamer pipe, and when i put my hand over the screamer pipe (can feel gasses) to create a seal the exhaust note changes slightly...

are you using a dump gasket? ie a ford xr6 gasket?

that seperates the wheel from the gate?

[1400r]

the turbo housing is divided into two section completely sep from each other

on the turbo side of the dump it has a smaller pipe weld into it so when fitted upto the turbo it pushes inside and seals even more

his using a copper crush gasket

the actuator seems to be wrong for the application seeing as you cant preload the crap out of it

at full tight it is maybe half a cm away from the arm at the arms full closed postion

this would also mean you'd have to bleed off a yeap of air via the boost controler to get the correct boost

(assuming its not running close the boost level you want just using the arm as it is)

I say buggar it and run it up again

[Cubes]

The std screw on bit for the actuator that came with my gt3076 was too short; I had a longer one made up.

I have around 2mm preload which grabs 15psi and with the actuator at full reach allows the flap to open almost 90degree's.

2mm is approximately what the std turbo and std actuator has factory.

If you place too much preload you will experience boost creep as the for every extra mm preload you place on the gate you loose with the max opening angle.

Starting to go a little OT but what the hell.

The only downside with very little preload is especially with the garrett 1bar actuators with the kink in the rod is they are lazy. With just the actuator I was seeing 8psi at 2500rpm, 11psi at 3000rpm and then 15psi at 4500rpm.

With a cheap ball/spring bleeder on it it was making 19psi at 3100rpm. Thats a huge improvement in peak boost. ~1400rpm.

For myself I was told the GT30's will boost creep if you don't run with a Bell mouth or at least put some effort in to the dump pipe and design it as HKS do.

HKS have created the opening of the wastegate pipe as large as possible; this allows maximum gas flow with no hard edges for the gas to hit.

The problem with the usual 3" and 2" wastegate style dump with the GT30's is when the flap opens it is unable to open a full 90degree's which would allow the full 2" opening of the wastegate pipe to be utilized; when its open say 45degree's with reasonable preload it partially blocks that 2" opening which is why these style dumps almost always boost creep with the GT30's.

I followed the advice of who does the tuning on my car and with the std sized flapper but with a .8 rear I experience zero boost creep on the 3ltr by running minimal preload and a nice open bell mouth. Yes with out a boost controller boost is lazy but who cares thats what an ebc is for.

HKS dump opening attached.

All IMO.

[RB30-POWER]

wastegate creep intensified by the high back pressure in that housing?

changing preload will not change crap, should be used to set max flapper opening only.

tried a heavy duty 14psi actuator or such?

[huddy]

i ordered a 14psi actuator - so i assume that is what it is.

i'm not trying to solve the response issue etc at the moment. just eliminate the leaking - i'm coming to the belief that it possibly doesnt seal when the flap sometimes seals in a different position. (flap not fixed position)

i'm under the impression that 'if' i didn't go for the screamer setup then i wouldn't even be aware of the leaking issue...

*sighs...

Edited February 25, 2008 by huddy

[dangerman4]

plan G

grab a g clamp or similar contraption and clamp the sucker shut.

if you remove the actuator arm at the pivot point and then wiggle the flapper to see if you can feel a happy spot where it wants to shut, then clamp it shut.

this then will prove if its the gate the actuator or the dump design.

i have a sneeking suspicion that is not the wastegate but the main outlet not sealing properly.

due to not using a ford gasket.

this copper gasket you mention is something you made or the cheap crap you get from an exhaust shop.

also have you had the dump flange milled flat?

come to think about it im not sure why the dump needs the peice of pipe welded on the flange as its a different hole to the wastegate you just need a propper gasket.

[huddy]

thanks for all the brainstorming guys

on that last sentence - i agree and originally it did not have the pipe welded onto the flange... but it was leaking so first thoughts was 'must be the dump design..'

the gasket was provided by and has been used by the exhaust maker (Andrew) many times previously and had no problems whatsoever on many other setups (including screamers)

i will try the G Clamp idea to suss out if it is the actuator (i doubt it though as it's brand new, and has a LOT of tension on it already)

any more ideas for me to try???

[nizmo_freek]

Just a quick question

How much should a wastegate flap actually open, i am using a hks 3037 pro s turbo kit which comes with the hks dump that Cubes posted a pic of, but i have noticed if i desconnect the actuator arm and try to open the wastegate flap using the part that the actuator rod clips onto i can only move it about 1cm untill it hits the dump pipe.

Does this sound normall?

Im sure it would be fine as HKS surely wouldnt have overlooked this and would have desinged the kit to work perfect.

[dangerman4]

thanks for all the brainstorming guys

on that last sentence - i agree and originally it did not have the pipe welded onto the flange... but it was leaking so first thoughts was 'must be the dump design..'

the gasket was provided by and has been used by the exhaust maker (Andrew) many times previously and had no problems whatsoever on many other setups (including screamers)

i will try the G Clamp idea to suss out if it is the actuator (i doubt it though as it's brand new, and has a LOT of tension on it already)

any more ideas for me to try???

when the extra peice of tube was welded onto the dump flange was the flange milled flat?

the heat from welding it would have worped it to some degree.

and just so you know the ford xr6 gasket is stainless steel multi layer jobby that cost around $16

if your flange is flat and you run one of these you can completely remove it from the problem list.

[huddy]

Hi Dangerman

well once again i 'assumed' it was flat when the work was done...

...saying that though I JUST REFITTED IT ALL UP AGAIN...

and it is NOT leaking!

so i am completely clueless... as it seems to be inconsistent... i will keep an eye (or ear) on it to hear if it leaks again - if it does, then i'm thinking wastegate flap (when it rotates).

thanks, i will keep this thread updated.

[Simon-S14]

why did you not weld the gate flapper solid while it was off and eliminate it all together??? cause if it leaks you have to take it off again....

[huddy]

trying to eliminate 1 thing at a time... I wasn't definite it was the gate leaking

...and time... (not the actual welding... but for me to find the time to go get it done before prac on saturday!)

[huddy]

well i re-assembled it all and no more leaks!!! had it tuned...still no more leaks!!!!

making 262rwkw atm on my RB24

[dangerman4]

being the waste gate is metal on metal it would either seal or not seal.

so im sticking with the dump not being 100% flat and this time you have stuck just the right amount of goop in the right spot to seal the turbine from the screamer.

glad its fixed either way.

[Twisted_SIL80]

nice power... what boost huddy???