compound turbos

[galoush]

Hey everyone i was thinking of setting up two turbos in the compound configuration seen on diesel trucks . A small say TA 49 -Te60 up to about 12-15 psi and have my 70GTQ .85 housing for the top range 15 + ???? . What do you guys think about this other than the extra welding, piping and what not to construct and two wastegates . Has anyone done this ?

 

[GNVYUS 1]

Sequential setups are not only a PIA ( especially since we are not set up for them ), but the most powerful Supra owners switch from sequential to single due to efficiency and high end power.

 

[galoush]

I was looking at a similar post regarding this last night , the supra sequential is different , I mean one turbo blowing into a another ussualy one small and on big , a few Diesels run this type set up . I may try to do it just for something diffrent if i get bored .

 

[UNDER-PRESSURE]

I like the idea.

 

[boostingbuick]

I feel that running a small turbo into a large one in our cars will not be efficient enough to be worth the effort. The small one will need to keep up with the large one and will heat the air a lot and will spin very fast, and the large one will be fed hot air and will only need to compress the air slightly, spinning slower and not having it run under it efficiently range. Plus so many of use are running a large turbo, 70gtq, with low spool up time and making big power. Compound turbos need to be matched and will be hard to find a good set up without a lot of trial and error.

 

[Dusty Bradford]

Compound turbos have to be matched to each other to avoid surge or overspeed and the only reason you see these on diesels are for very high boost levels. Not uncommon to see 250+ lb of boost on pulling tractors.

It would most likely look cool yet be the slowest twin turbo GN in history

 

[galoush]

I have a 70 GTQ and i hate the slow spool up time , the car already has Nitrous on it so im going to prob play with that to spool it up fast w/o changing the conv to a higher stall .

 

[notacarlo]

Well, Stall change is A LOT cheaper than experimental compounding.

 

[Hot Air]

Aren't some of the OEM's doing this? Look at how they are doing it and go from there. My guess is that it will be very complicate to pull off.
Conrad

 

[galoush]

I just thought it would be kinda cool to do something diffrent ........ I dont really want to re stall because the turbo prob. needs a 3800-4000 stall to spool good but thats not really ideal for alot of driving .

 

[SS/GNX]

So then get a dual ball bearing turbo... that will spool faster and still be cheaper than sequential. What stall do you have now?

 

[galoush]

i think its around 3200 , im going to try the nitrous to spool it hard , that or i was going to replace it with a 6776 BB .

 

[SS/GNX]

Thats the turbo to get with a 3200 stall... NO LAG !!!

Its what I am getting... and I too have a 3200 stall.

Sell the nitrous kit and your turbo, get the 6776 BB... Done. Problem solved.

 

[galoush]

nothing i had the 70GTQ up for sale but i have had no takers , thats a better option than selling my beloved nitrous , which is totaly set up so i dont want to remove that .

 

[SS/GNX]

Ok, dont get rid of your beloved nitrous then... but keep tryin to sell your turbo...

that 6776 BB is what you need. Not two inline turbos.

 

[galoush]

As soon as i test the Nitrous with the 70GTQ ill report back , unless i sell it but i havent any takers so far , the nitrous is set up to shut off at 16psi , i only want to use it to spool at this time , ive run it in past the full 1/4 ...ALOT but i think the car has enough crap on it to do something w/o it plus the bottles will last longer . The 150 jets are in for the spool up :smile:

 

[19TTA89]

As soon as i test the Nitrous with the 70GTQ ill report back , unless i sell it but i havent any takers so far , the nitrous is set up to shut off at 16psi , i only want to use it to spool at this time , ive run it in past the full 1/4 ...ALOT but i think the car has enough crap on it to do something w/o it plus the bottles will last longer . The 150 jets are in for the spool up :smile:

If you only want the nitrous for spooling...throw some 50hp jets in and Hit it for about 2 sec.that should be more than enough to spool it and the bottle will last a hell of a long time.If your car can hook with a 150 off the line...then go for it...But I would only activate it for 1-2 seconds...That is all you need for spool.

 

[MAX PSI]

Aren't some of the OEM's doing this? Look at how they are doing it and go from there. My guess is that it will be very complicate to pull off.
Conrad

Cat is the only one with a dual turbo set up. Both Cummins and Detriot use what Cummins calls a VG turbo. They can change the angle of the fins on the turbine wheel. All three manufactures came up with these designes to make up for the lack of low end power on their motors due to tighter emissions.
With that said, it could be done on our cars but would it be worth the extra cost and hassle? Ther are soo.. many turbos out there to match any possible combo.