Trust TD06-20g stage one

[EVOIV]

Awww...that's the whole point of an external wastegate isn't it? What's the use if it's not going to dump straight out to atmosphere? I used to do that. Great sound when it opens at full boost!!! To me, an external wastegate is like a BOV. Although they do have functionality (reduces lag/better boost control), everyone knows that the real reason is for the sound. Be that a whoosh or a bark. A whoosh and a bark is even better

Let me know how the car sounds when the turbo is spooling. My previous turbo made a much louder noise than my standard one at present. It was a kinda high pitched noise that got louder.

You should get no probs from the cops unless you zoom past them at full boost, cos that's the only time you will ever hear the wastegate. Just be careful, that's all.

Hope the results are good!!!

[EVOIV]

Hmm...it just occured to me, looking at your picture of your turbo and wastegate...does that mean that you have cut a hole into the exhaust housing of the turbo? I believe that a wastegate has two outlets. One usually bolts onto the manifold, where the exhaust gases enter the wastegate...and then the other outlet is for the wastegate piping to flow out to excesss exhaust. Am I right in assuming that you have cut a hole in the exhaust housing? If so, how was this done?

[EVOIV]

Is that the TIAL wastegate? Also, I think you'd be very lucky if you got full boost before 3500rpm. Unless your max boost is 7psi? It is a very large turbo, exhaust housing anyway.

[GTS-t VSPEC]

Yes, a hole is cut into the exhaust housing. Done with a milling machine.

[GTS-t VSPEC]

I'm pretty sure it was a turbosmart one:D

[EVOIV]

Hmm...I guess it will have to be quite precise and smooth as to not disrupt exhaust flow? Me myself I would personally stay clear from tampering with turbos, especially the exhaust housing as it's designed to flow smoothly. But then again I'm no expert

[GTS-t VSPEC]

Yeah, but I sam the design, and it was tapered very nicely, so as not to cause too much turbulance, and Grant has been doing turbo's for 15+ years, so he knows what he's doing.

[nv033]

if the fuel setup is done right with a good tuner max power will be approx 250kw@rw no dramas whatsoever.... boost kicks in for me round 4500....this is not laggy at all on the street...good choice of turbo for the rb25...i made this figure on 1 bar of boost

[GTS-t VSPEC]

Amu, So you think 4500 for full boost doesn't feel laggy on the street?

[EVOIV]

I can see what you're saying, but no matter how well you do it it will never be as smooth as it was originally. And seeing that exhaust gases are going to flow through this real fast, it will cause some form of turbulance problems. Would even cause more back pressure than normal and wouldn't that disturpt the flow of the exhaust gas and affect the spinning of the turbine wheel and the whole turbo as a result?

amu: I think the 20G could produce more than 250kW@wheels. Probably more closer to 300kW@wheels? You said boost kicks in at 4500rpm and this is not laggy??? Or did you mean full boost (1bar) at 4500rpm?

[nv033]

that is full boost.... no way you can achieve 300kw on a 20g ....the 25g yes if all other things are done with it as well... between gear shifts you a still on full boost...that is the most important aspect dont you think.... everyday driving is below that... so there is an advantage there in itself

[GTS-t VSPEC]

By fitting the external wastegate off the dump you can have vastly varying pressures on the wastegate and it makes the boost control more difficult. The setups I've seen done with the wastegate on the exhaust housing have all worked well, much to my sursprise aswell.

[EVOIV]

Oops! Sorry, I forgot that there was a larger one - the 25g. I think 1bar at 4500rpm is still a little laggy for street use...but then I guess it's all to personal preference. I used to have a GT3037S on my 2L and that wouldn't make any boost until 3500rpm. So 1bar probably around 4500rpm...and I thought that was a little too laggy for street.

[nv033]

i dont think there is any major difference besides the heat factor having the wastegate mounted there....saves on manifold cost and my m8 has done it and it doesnt skip a beat

[nv033]

where talkin about different motors here 2l vs 2.5l would see dramatic differences in drivability

[EVOIV]

Hmmm...would be interesting to see a car with that setup. I've never seen it done before. But in most setups the wastegate is mounted on a separate pipe off the exhaust manifold, and don't manufacturers usually tune the length of the manifold for equal pressure?

[GTS-t VSPEC]

Rob has kept the stock manifold, as the TD-06 he has mounts directly to it:D

[EVOIV]

amu: In terms of driveability, I am strictly talking about *when* the turbo starts making boost...not really considering whether or not the car is on/off boost between gear changes. And to me, my personal opinion is that a car making 1bar at 4500rpm is a little laggy for street. Just my opinion, but other people may think that's fine for the street.

[nv033]

the way i think about it is ... its doin the same job....air from the manifold will enter that pathway before it enters the front of the turbo so no differences.... just there to waste excess air

[nv033]

fair enough evo... instant boost and a push of the throttle.... but the more power you chase the more lag you get... simple as that!!! =)