Richiec77

iTrader: (3)

It really does look like a ****. I'm ******* dying over here.

smokinHawk

iTrader: (48)

wouldnt it be better if you wernt blocking off the downpipe but instead put one large wastegating in one of the up-pipes.
that way under the preset boost all the exhaust gasses go to one turbo, then as you hit say 10psi, the wastegate opens and feeds the other turbo.
youd probably need something like a 60mm gate

parish8

iTrader: (6)

i think it would work in either pipe. if you block it before or after the turbo there wont be any air going thru it so it shouldn't matter much.

the pre turbo air would be less effected by a restriction and could get by with a single 60mm gate i bet.

chuntington101

i think its been discribed above but i will give imterpritation of it anyway! lol

why not just mount a throttle body in the hotside of one turbo???? then you can force the exhaust gases to go one way into one thtough one turbo! this would be great for street driving!

then when you wanted more boost then you could have the throttle plate WOT activavted! they take a couple of seconds to open but i bet you could get a faster one using a bigger electric motor or even a boost operated on!!

i have seen these valves used on Evos to vent the exhaust gas staright out to help spool and power! will see if i can dig it up!

and i think you should do some testing! hehehehe

thanks Chris.

Wet 1

iTrader: (4)

Interesting idea.

The only thing I see as a concern is the obstruction to flow by placing the WG(s) in the down pipe... even a single 60mm gate would choke flow a fair amount. I like the idea of using a large electric cutout (sliding) for this, but I don't know how quick they react.

Give it a shot, I suspect it would work as planned. As stated above... it's easy to fab and convert over if it doesn't work.

Innovative thinking Dave.

smokinHawk

iTrader: (48)

exactly why i said to put it in the up pipe instead of the down, the biggest wastegate is what a 60mm which is about 2.4" close to the normal 2.5" pipes you use for your up pipes
the downpipe would have to taper to that which would restrict flow, id think youd want the downpipes 3" or bigger.

Moralesrx7

iTrader: (1)

here is how a rx7 setup would look like on a V8 this would be the ideal set-up now if u noticed both intakes go to one and in a 7 there is no maf so they dont so if u go sd tuning u would run two filters (best way no one way valve and allow each turbo to have the largest cfms to suck in ) hope this helps oh i forgot in a rex the second turbo is prespooled slowly by the valve slowly opening where i have a cutout shown in the pic,also there is a another valve on the second turbos charge pipe that is open to air intill the boost reachs a set boost level and opens(which meets up with the 1st turbos charge pipe) that way the 1st turbo doesnt spin the 2nd backward.

Wet 1

iTrader: (4)

I agree with you about the placement, but I still wouldn't use a WG... they disrupt the flow too much even when wide open. Ideally you'd want a blade type valve (like a TB) or a sliding valve (which doesn't have the shaft to disrupt flow), you'd want something that offers open and straight through flow. In order for the valve to be able to react fast enough, I'd think some type of boost referenced diaphragm actuator would work very well assuming you could find (or make) one which would stay closed under the pressure until you wanted it open.

I say build the damn thing... it will work!

RyanJ

Why not a big single with a valve that restricts the opening to the turbine side? Then opens at a set pressure or speed to allow use of the whole turbo. Call Jose, he'll explain.

ddnspider

iTrader: (26)

Isnt this already what they have in summit called the "super B" or something for diesels?1 turbo flows into a larger turbo after a certain value or something like that?

smokinHawk

iTrader: (48)

no that is compound charging

wolfy

iTrader: (1)

what about an elec exhaust cutout wired thru a boost referenced relay? it sounds like youve got it pretty much all thoughtout except for the "check valve" in the downpipe...just thought id throw this out there...

-cam

lulu

here's another interesting sequential setup approach.

lulu

Maybe something like -> this <- could replace the wastegate and could be quicker than an electric exhaust cutout.

chuntington101

lulu thats the sequential setup for the new 'performance' opel 2.0ltr diesel engine! looks great and a test driver said that it was seamless power all the way to the red line!!!!

this does rewquier some enginering and a lot of pipe work! but it could be done!

Chris.

NXRICKY

iTrader: (1)

I could see an issue with air surging. #1 turbo duning all the work until #2 is needed. once the #2 is needed the the gates or flappers open and a huge amount of flow is going to hit both sides of the #2 Boost pressure trying to spin out to the air filter, and exhaust trying to spin out the down pipe. At that moment in time what will happen, not sure, but your boost should show a stumble or dip until #2 can catch up.

Interesting for sure.
Ricky

lulu

Yeah and I know the new twin turbo diesel engine from BMW will use a setup similar.

lulu

Yeah, for those previous diagram shown, this could be an issue. On a twin turbo setup like porsche, they have a valve on the intake side to avoid the this and the exhaust valve do open before the intake to help the turbo #2 to build pressure and avoid surging. I have a schematic at home, I'll post it tonight.

stevieturbo

On paper, its a nice idea, and does have massive potential.

Supras used it, as did twin turbo Subaru Legacy's. Im pretty sure both cars suffer what some Subaru guys call the "Valley of Death", which is the horrible bit in between when you switch turbos.

If mainstream car makers cant get it to work perfectly, and they would spend millions trying, it isnt going to be easy to get a good workable setup without that backing.

But if you have the time money, and skills to try it, it would be great.

RyanJ

You'd spend a 1/10th on a single with a valve or a ball bearing turbo custom made for you. But hey...if you want LOGS running into a maze of pipes, some being closed, causing sun-like surface temps and the cost of two turbos, pipe, valves, etc. go ahead.