External Waste Gates

[Mr Revhead]

yeah I've been waiting for that to appear....
I'm not a turbo geek, but I didnt think it's made it to the aftermarket yet.
Or even mainstream auto use.... Only car I know (I know there will be others though) that uses is is merc A class

[FLAWLES]

Since talk of waste gates, has any one used variable geometry turbo in an aftermarket application? What do they use to control turbo? ECU output to a stepper motor?
This tech makes wastegates obsolete.

I beleave some IVECO engines use a system like this, havnt looked much into it tho
i also think its a soleniod that adjusts it

may be something different

[sergei]

yeah I've been waiting for that to appear....
I'm not a turbo geek, but I didnt think it's made it to the aftermarket yet.
Or even mainstream auto use.... Only car I know (I know there will be others though) that uses is is merc A class

997 Turbo Awesome car, my dream car.

[Mr Revhead]

I was just wondering if Porsche used it, as I do recall reading something lately that used it

[Mr Revhead]

yeah I've been waiting for that to appear....
I'm not a turbo geek, but I didnt think it's made it to the aftermarket yet.
Or even mainstream auto use.... Only car I know (I know there will be others though) that uses is is merc A class

997 Turbo Awesome car, my dream car.

hang on, you LIKE something??

[sergei]

I think it is relatively easy to make a controller coupled with stepper motor.
I wander why racing crowd didn't pick up this tech, as this far superior to wastegate type of boost control.

[sergei]

yeah I've been waiting for that to appear....
I'm not a turbo geek, but I didnt think it's made it to the aftermarket yet.
Or even mainstream auto use.... Only car I know (I know there will be others though) that uses is is merc A class

997 Turbo Awesome car, my dream car.

hang on, you LIKE something??

If I didn't like anything I wouldn't be so frustrated .

[Mr Revhead]

I think it is relatively easy to make a controller coupled with stepper motor.
I wander why racing crowd didn't pick up this tech, as this far superior to wastegate type of boost control.

In what class? Who use's turbo's other than WRC?
Also it's not yet widespread, afaik. so choice of turbo would be limited. What are the using on the diesel Le Mans cars?

[sergei]

I think it is relatively easy to make a controller coupled with stepper motor.
I wander why racing crowd didn't pick up this tech, as this far superior to wastegate type of boost control.

In what class? Who use's turbo's other than WRC?
Also it's not yet widespread, afaik. so choice of turbo would be limited. What are the using on the diesel Le Mans cars?

I mean enthusiast racers, those people who turn up to rally in their kit cars or replicas, who wouldn't want full torque from 2000rpm to 8000rpm, and virtually no lag? I doubt that turbo with that tech is expensive, as they put those turbos in Diesel Golfs and Hiluxes.

[Mr Revhead]

are they available in the aftermarket yet though? thats what im getting at

[sergei]

Could not find anything, but it is possible to source an OEM item.
Here are interesting pics:
http://www.diyefi.org/forum/viewtopic.p ... &sk=t&sd=a

[79rolla]

I think it is relatively easy to make a controller coupled with stepper motor.
I wander why racing crowd didn't pick up this tech, as this far superior to wastegate type of boost control.

but you dont get the mean external noises tho bro....

for it to get to the modified scene there has to be a demand for it.. witch comes from exposure, so until it starts getting used in wrc or the like with good results or more accessible production cars use them it will take a long time to catch on

[Akane]

Since talk of waste gates, has any one used variable geometry turbo in an aftermarket application? What do they use to control turbo? ECU output to a stepper motor?
This tech makes wastegates obsolete.

the VATN turbo? There was 1 guy who had it on a SW20 (I think he actually had 2), IIRC they actually have an actuator that controls the opening and closing of the vains, and have their own oil recirculation system too I think? It was at least a good 5 years ago, they failed to take off tbh, just way too complex.

[iOnic]

Yep Pouya from Madpsi (madpsi.net) had two VATN turbos on his SW20. That sort of technology is far too complicated for a motorsport situation IMO. A well thought out wastegate/turbo combination is all you need as has been proven for decades now.

[cat007]

I'm not sure about that eh. Most cases I have seen where people have tried to control the described boost levels with GT3582Rs using 44mm or less wastegates have had issues with creep, one of my mates has a 1.06a/r GT3582R and he has been fighting boost creep with his 48mm wastegate using a Sinco manifold.

By 'unstable boost' I thought you meant it was hard to keep it consistent, not boost creep.

If the boost fluctuates but doesn't creep - you're wastegate is probably too big. But yes, if you are getting boost creep, generally the wastegate is too small and cannot vent enough.

Careful on the theory of "the more boost you run the smaller the wastegate needed". Sure if you're wanting more boost, you have less gas passing through the wastegate - but - if you're pushing more boost, 'generally' you're flowing a whole lot more as well - so you WILL have more gas going through the wastegate.

Also the flow ability between a 46mm and a 50mm is HUGE compared to a 38mm and a 40mm....

[steve murch]

the biggest problems i see is the poor mounting of a waste gate,
as a rough guide line
32mm= 400hp
38mm= 500hp
42mm= 650hp
44mm= 800hp
46mm= 950hp ( rsl honda made 990hp on this size gate)
50mm= 1000hp
60mm= 1200hp
70mm= 1600hp ( ive made afew of these over the years)
this is just a guide line but in saying that if your running a 46mm on a setup making 500hp and over boost the gate isnt the problem.
many times people dont get the idea of how exh gases flow,if you cant see the direction of exh gas flow then nor can the gate thus over boost.
the only time these sizes change is when it comes to a rota as they are a very efficient air pump thus i always step the size up.

[Lith]

^ Yeah still trying to work out what the problem is with some of these, I know people who have used a 38mm wastegate with a GT3582R and been able to hold 15psi fine on an RB25DET - but with the exact same kind of manifold (ie, wastegate placement vs collector) on an RB30 running the same turbo there is nasty creep.

[Lloyd]

The variable stuff has been around a lot longer than the Porsche design. If the vanes are designed right you could probably get away without the control system and just run it off the actuator already fitted. Though I'm sure aftermarket computer wouldn't have too much trouble running them

[MAGN1T]

Moving parts in an exhaust system are always a problem for long term reliability.
That's one of the reasons why wastegates use poppet type valves instead of butterfly valves. Any butterfly valve will eventually jam. GTOs use an "active exhaust" which is a butterfly valve, You won't find one still in working order.
BTW I've built 2 turbo setups without wastegates. Only for lowish power street cars but if the turbo is sized sensibly, they're not essential.Chances are I'll be building another without a wastegate, Only because I can and it keeps the cost down.

Steve

[steve murch]

the old days when you sized the turbine hsg to suit the boost level required/load had alot of draw backs such as lack of boost without the load.
most new trucks today run vnt or a gate with a smaller exhaust hsg thus increases boost response dramatically and full economy improves as there's no need to thrash the vehicle to gain the performance.
the cost of gates these days is pretty minor compared to buying the turbo and for peace of mind i wouldn't suggest anyone does a setup without some sort of gate control unless your running a 18 wheel truck.