Help Reaching 400kw On Gt35r

[DRIFTER]

Have you seen any more power Nathan from more boost?

Surely valve float isnt too far off

my standard coils were breaking down at 23psi and i haven't had a chance to put it back on the dyno since i replaced them.

how do you guys control boost with those sort of setups? wastegate mounted off the exhaust housing?

i changed from a .82 to 1.06 (havent yet retuned) and added a bigger gate (44 to 48mm) and it started to boost creep madly from there.

i've got a twin scroll manifold with twin 38mm gates, so far boost control hasn't been a problem but we'll see what happens when the 1.06 housing goes on.

[STATUS]

how do you guys control boost with those sort of setups? wastegate mounted off the exhaust housing?

i changed from a .82 to 1.06 (havent yet retuned) and added a bigger gate (44 to 48mm) and it started to boost creep madly from there.

the manifold is probably your issue the gate pipe exit angle is pretty severe and we have had to mod a few to make work properly.

[SirRacer]

here is an original picture of the manfold. URAS do you have any pics of your modified ones, would be interesting to have a look. id also be keen to have a look at a few that are straight out of the housing.

its since had the wastegate pipe moved further into the gas flow, and ive upgraded for a 48mm gate (from a 44).

i think just putting it off the housing will solve the problem once and for all hopefully. the manifold maker has been mucking around with this for ages now and i dont really want to spend the $$$ on a 60mm gate even though that will fix the problem.

will be interesting to see what sort of power i can get.

8.5 comp ratio with stock r32 head with valve springs and camgears 1.06 housing. 310kws came on the .82 on 19psi.

Edited October 15, 2009 by SirRacer

[r33_racer]

Wasnt there a thread about this somewhere....all merge collector manifolds with gt35r turbos and up seem to have this issue...the manifolds flow so well that it bypasses the pickup for the gate, smaller turbos on those manifolds seem to have enough back pressure in there to force gas out the wastegate.

To fix it, the wastegate pipe needs to protrude further into the gas flow inside the collector to catch more gas and direct it out...otherwise block it off and put the wastegate off the exhaust housing. Weve done that fix several times now and it works great. The manifold builders know of the issue, but i dont think they like the idea of disrupting the excellent flow they have through there. But i think perfect boost control is quite important. Probably abit more so then having perfect exhaust flow/spool.

[R31Nismoid]

Wasnt there a thread about this somewhere....all merge collector manifolds with gt35r turbos and up seem to have this issue...the manifolds flow so well that it bypasses the pickup for the gate, smaller turbos on those manifolds seem to have enough back pressure in there to force gas out the wastegate.

To fix it, the wastegate pipe needs to protrude further into the gas flow inside the collector to catch more gas and direct it out...otherwise block it off and put the wastegate off the exhaust housing. Weve done that fix several times now and it works great. The manifold builders know of the issue, but i dont think they like the idea of disrupting the excellent flow they have through there. But i think perfect boost control is quite important. Probably abit more so then having perfect exhaust flow/spool.

Yep - i even tried a quick search for it last night actually hehe.

Pretty sure it was the 1.06 housing ye?

I remember a thread on it, quite detailed, but just didn't have the time to find it.

Would be 12 months ago now at a guess.

[STATUS]

Wasnt there a thread about this somewhere....all merge collector manifolds with gt35r turbos and up seem to have this issue...the manifolds flow so well that it bypasses the pickup for the gate, smaller turbos on those manifolds seem to have enough back pressure in there to force gas out the wastegate.

To fix it, the wastegate pipe needs to protrude further into the gas flow inside the collector to catch more gas and direct it out...otherwise block it off and put the wastegate off the exhaust housing. Weve done that fix several times now and it works great. The manifold builders know of the issue, but i dont think they like the idea of disrupting the excellent flow they have through there. But i think perfect boost control is quite important. Probably abit more so then having perfect exhaust flow/spool.

Its just plain bad design, 90 degrees off the collector is never gonna work on genuine high hp stuff and it doesn't. We have had to extensively modify them (dual outlets to gate) to work properly.

[SirRacer]

you dont have any pics of your modifications do you trent? would be interesting to see how they look.

will have a search now for that thread also and leave up a link if i can find it.

[GTR1993]

I put the gate off the turbine housing, went from 23 psi minimum to 14 psi minimum.

[SirRacer]

do you have any pictures mate. would love to see how it looks

[mico]

heres a pic of one off the housing, but its on my xr6t.

[SirRacer]

Thanks mate, that looks good.

I found another from the Heat Treatments world record holding GTR. This is from their new turbo setup (looks nasty).

http://www.htlracing.co.nz/images/200935020th002_008.jpg - I thought the distance between the housing and the gate is quite interesting.

[mico]

hmmm, no idea why they would do that. i would have thought for optimal operation of the gate and gas flow, the gate could sit right on the housing. so that the piston/button in the gate is level with the inside surface on the housing. no doubt they would have their reason tho.

[SirRacer]

i also wonder whether having the gate coming out of the housing is much better for spool. considering the fact that exhaust gas spools the turbo, having it run through the exhaust housing (and therefore wheel) rather than been bled off, must be a tiny little bit better flow and responce wise?????

[TiTAN]

your gate isnt open when the turbo is spooling up, either way the exhaust gasses are going through the turbo

[Jap_Muscle]

having a gate off the housing has nothing to do with spool. all it does is control boost. not how fast it makes boost.

the downside to having gates off housing is that you pretty much kille off any chance of a resale as it's not a highy wanted modification. personaly it just seems very backyard job.

that's my view on it anyway.

just remember you don't have to have theg hate off te housing. it is 99% th fault of a badly designed manifold. although it is alot cheaper then buying or sometimes modyfying the manifold

Edited October 17, 2009 by Jap_Muscle

[Adriano]

Well i guess its a catch 22 situation, a manifold which gives better spool will have less flow to the wastegate, hence worse boost control. I would say thats why Kiers GTR runs that setup, best of both worlds

[Jap_Muscle]

I'm sorry buddy but you've got it completely wrong. the only reason a manifold has problems controlling boost is of poor design. if you bought a manifold like this you either

a. do not know how a forced induction system works

or

b. you wasted money on a shit manifold.

you need to understand that building boost and expelling boost are just as important as each other. if you only have one your fooling yourself

[mico]

not poor design at all, its poor placement of the wastegate port.

[DCIEVE]

I'm sorry buddy but you've got it completely wrong. the only reason a manifold has problems controlling boost is of poor design. if you bought a manifold like this you either

a. do not know how a forced induction system works

or

b. you wasted money on a shit manifold.

you need to understand that building boost and expelling boost are just as important as each other. if you only have one your fooling yourself

I'd be blaming the guy making the manifold not the end customer! The manifolds in question come from the most popular manifold makers in Aus....

[Jap_Muscle]

not poor design at all, its poor placement of the wastegate port.

which is poor design

I'd be blaming the guy making the manifold not the end customer! The manifolds in question come from the most popular manifold makers in Aus....

aint you also running his manifolds?

Edited October 18, 2009 by Jap_Muscle