Why haven't we all tried this out? I can't find the article or the images he created, but the best I can do is redo it in paint.

He doens't use 3 wastegates, but they should be cheap and perform as desired.

Imagine a standar compound turbo setup, then consider 3 wastegates that: bypass the high pressure turbine, bypass the high pressure compressor, bypass the low pressure turbine.

So long as the high pressure bypasses have 5-10lb less rpingrate than the low pressure bypass, everything should 'work.' That doesn't say much about the predictability of power output though!

 

you drew a compound setup not sequential. compound is good for diesels where you need insane boost levels(60+) I was going to do a sequential setup similar to what I think your talking about. I was going to buy a 50 or 60mm ebay wastegate then build a manifold with a split collector pairing cylinders 1 and 4 on one side of the collector and 2 and 3 on the other half. was going to run two identical turbos and have all 4 cylinders(the split collector) feeding one turbo which would be internally gated. then off one half of the collector I was going to run a 2"ID weld el to the big wastegate then to the second turbo.(which would also be internally gated) then I would set my internall gates to my desired boost(was thinking 15psi or so) and the big wastegate would be played with on a dyno. I would put a boost controller on the big wasteage(the control gate for the second turbo) and adjust it untill I got the best transient response to bring on the second turbo. anyone who has driven a rx7 twin turbo knows how theres wasn't the greatest. it would boost 10psi on the first turbo then fall to 8psi as the second turbo spooled up then back to 10psi. also one last thing that needs to be addressed would be a reed valve or big check valve for the second turbo on the outlet side to prevent the first turbo from just blowing boost out the inlet of the second turbo. a simple flapper valve will do the trick for this was going to make one into the end tank of the intercooler. end result is cool and all but don't we have enough traction problems to begin with? alot of work to just fry the tires even worse. lol maybe an autox or road race car could benefit better. a simpler way to do it is just an exhaust brake on the downpipe of the second turbo thats controlled with a actuator of some sort.

 

The enter key, try it.

And yes, this is a sequential setup. Please read my quick description again and notice the location of the three wastegates.

 

where is an engine with that style setup all working ?

 

I believe they use this setup on a newer deisel 3.5 ton truck. Regardless, this setup comes right out of one of Ricardo's articles. I did not make it up, engineer it, or anything. I'm simply promoting an old design I have only read about..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Si Shane &raquo;</TD></TR><TR><TD CLASS="quote"> Regardless, this setup comes right out of one of Ricardo's articles. </TD></TR></TABLE>

??

 

I'm sure there are many Ricardo's who study engines, but I believe the article was jointly published by Harry Ricardo and one other. I have spent the last 20 minutes trying to find it in google, I know there is a public .pdf floating around.

Maybe someone else can chime in?




Modified by Si Shane at 9:03 PM 4/10/2008

 

why again ??

 

Faster response, of course.

 

theres a supra on youtube with 1,000 hp 3 turbos

 

on a FWD ? lag is good sometimes.