R32gtr Hks T04r Not Enough Boost

[BHDave]

Out of interest, when you replaced the spring, was the new one alot higher rated than the one you removed? Because thats what throws me.

Is the outlet a vband as well or a 2 bolt flange? No hope of blocking that off?

[wrxkilla]

hi

yeah, i was at first thinking the other one was a 0.9bar spring.

so i purchased a 1.3-1.7 spring setup(this requires 2 springs)

So yeah its a lot higher rated.

so thats the thing, if i have a 1.3-1.7 spring in there, why wont the sucker stay closed until then.

yes its v-band on both sides.

http://www.hksusa.com/products/?id=697

thanks for all the thoughts.

[JH32]

Could you not try changing the waste gate with another one that you know works? Perhaps one off another car. As you say, it's a good idea to eliminate as many variables as possible

[wrxkilla]

Ah most definately!!!

I would love to, but cant find anyone with a same wastegate...

As i'd need the same size V band connector thing.

Dont want to start welding and killing pipework.

let alone me convincing them to let me have a use for a night.

mick

[JH32]

Are there no shops in Brisbane that might be able to help you out?

Subzero? Mercury?

Sorry I don't know too many names of shops over there ...

Perhaps even try posting up in the QLD section and see if someone can lend you their wastegate for an evening?

[RNS11Z]

see matty spry from pits tuning... pretty sure he could help you

[wrxkilla]

not being funny,

ive already been to 1 workshop and paid for them to test everything, dont want to walz into another and them charge me for the same things.

the basic prognosis i got out of other workshop is something is wrong with wastegate.

so thats why im troubleshooting...

What i really need is a Recplacement wastegate i think.

But impossible to find anyone with the same one...

Just annoys me as i have inspected the current one and it seems fine.

thanks

Michael

[YBSLO4]

Are you running a BOV at all?? If so what is the spring tension setting on that? If it hasn't been adjusted, then its obvious that 0.9 is its limit at the moment and is opening in the same manner a wastegate does, and hence the 'vaccum leak' people have suggested. Its similar to how the 'bypass-valves' work on an indy car by venting intake pressure as a means to control pressure.

Sounds silly, but it hasn't been mentioned and its an obvious stand out offender in many situations and is often overlooked.

[wrxkilla]

but its an external wastegate, and its venting to atmosphere.

its working fine and opening up and SCREEEEAming at 0.9 bar.

i cant see how a leak with the bov could cuase that.

[Beer Baron]

mate, is it possible the exhaust housing, or front pipe, or exhaust is too small and causing back pressure which is forcing the wastegate open? you already don't have a car correct?

[wrxkilla]

hey rich

what you mean already dont have a car?

i have another car yep.

backpressure, ok ive thought this one as a small off chance.

you think its possible?

I might drop exhaust off the front pipe and see.....

mick

[T04GTR]

yeah have checked all gaskets, doesnt seem to be any leaks.

although most guys here are missing the point.

Its running an external wastegate venting to atmosphere.

The wastegate opens and starts screaming at 0.9 bar. and you can hear it! lol

So its defo something with the wastegate i thinks?

ok. im now convinced that the wastegate is the problem.(screems out wastgate with no vac lines on it !)

to do a final test you need to hook up a boost feed to the top half of the wastegate.(next to the threaded bolt for adgusting the spring tension)

to efectivly use the boost pressure to keep it closed.

if this doesnt fix it then il be scratching my head!!!.

[nemz]

wait you said your running a 70mm wastegate?... sounds like its too big for a t4.... my mate has a t4 and he only has a 38mm wastegate i think u need similar size to turbo? like 38 with t4 and 70mm would go with a tt or t8 or some shit?

[wrxkilla]

hey nemz, yeah its using a hks 60mm wastegate, and i am of the opinion that a smaller wastegate maybe 50mm would be a little better suited due to the fact that yu will gain more control with a smaller gate.

although this one help, its sure not the exact problem.

OK T04R, I will plumb a brand new vaccum line in there today and try that...

let you know

thankyou very much

Michael

[Beer Baron]

hey rich

what you mean already dont have a car?

i have another car yep.

backpressure, ok ive thought this one as a small off chance.

you think its possible?

I might drop exhaust off the front pipe and see.....

mick

<{POST_SNAPBACK}>

ooops, i meant 'cat' as in you already have a no-cat system. was just thinking if the cat was still there it could be the resrtriction and is forcing the wastegate open with back pressure.

it definately sounds like (backpressure somewhere) that's the only solution you haven't tried yet, as it seems you've tested just about everything short of a new wastegate. i say drop everything from the front pipe back and see what happens. worth a try for sure.

[wrxkilla]

Ok tonight re-tested some vacuum line connections.

Tried positive pressure to both ends of the wastegate.

Just positive pressure on the top end, just positive pressure on the bottom end. Nothing on both ends.

All scenarios leave it the same, spikes 1.1bar settles backwards to 0.9bar.

I think i will drop the exhaust of the front pipe this week and see what that does.(see if there are any backpressure problems) - highly doubt it with such a free flowing system (but maybe the apexi control valve is playing up)

Will let you know how i go....

Thankyou All

Michael

[wrxkilla]

heres a couple of pics for anyone that wants.

[JH32]

That's a huge sucker !!!

My Tial 38mm pales into insignificance next to that thing

[hungry6]

Is it me, or am I not seeing everything there, where is the diaphram?

[Bl4cK32]

Id say the same as nemz...your wastegate may be too big.

From my simple view, the bigger the wastegate, the more air that goes out of the turbo. You want more air through the turbo, than out the exhaust for boost....try a 45mm ext. gate (turbosmart make a 48mm one?)

Use Sk's formula to find out what you need if in doubt....ill find the link and post it

Here tis : http://www.skylinesdownunder.com/forums/sh...ead.php?t=30726

Edited September 4, 2005 by Bl4cK32