FIRECHICKEN

iTrader: (3)

Sooooooooo.......
Theoretically, what would be the outcome of running a twin turbo set up on a V8 with the turbos hot side not being exactly the same? However, the cold side is identical.

project89

iTrader: (1)

are u saying the turbine housings/wheels arent the same or the headers arent the same?

different headers are ok, but if the turbine sizes are different u could run into problems

FIRECHICKEN

iTrader: (3)

The headers will be exactly the same however the turbine housing and the turbine are slightly different sizes both the inducer and Exducer sizes are different by a marginal amount. I'm wondering if it'll cause significant problems or if it will act more like a bi turbo set up where one spools faster than the other?

project89

iTrader: (1)

what are the turbine housing size differences , are we talking on is a .81 and one is a .84? or is it like a .63 and .8x

same with the turbine wheel sizes

FIRECHICKEN

iTrader: (3)

I'm not 100% on the numbers of the AR on the housings but I calculated the turbine wheels at a 57 and a 59 trim if memory serves me right.

project89

iTrader: (1)

that is all need to know info

FIRECHICKEN

iTrader: (3)

Ok. For arguments sake lets say one is a .84 and the other is .80

I'm not looking for specifics just theory on how the two turbos will play together....

Orr89RocZ

iTrader: (20)

I wouldnt be worried as much if its .80 vs .84 with same wheel. If its not same wheel you could experience bank to bank variations in backpressure and intake manifold flow dynamics problems imo. Just a guess here. Different wheels would cause different spool times, so one exhaust bank has pressure against the exhaust valves, the other does not at a certain point in time. This imposes abit of a flow dynamic issue when all 8 cylinders are fed from same plenum. Other side has limited backpressure so its breathing across the cylinder chambers more like an atmospheric engine while other side may suffer more reversion at first. Could lead to distribution issues in airflow and fuel, and then awkward crank loading. Ideally bank 1 would take a different cam profile than bank 2 but thats not easily done. One turbo spooling first would pressurize intake and make one bank act like a blower since it doesnt have backpressure on the valves yet due to slower spoolin turbo

Boost control would be harder to do i think accurately, since both wastegates ref the intake boost and one turbo starts making pressure before other so both gates start to open even if the other isnt ready yet.

Then again these could be small issues and not have any issues. Kinda hard to say but i dont like the idea to run different wheels or exhaust sides. Even similar dimension wheels could have drastically different blade profiles so flow completely different and change spool up times. Its best to use identical units imo

FIRECHICKEN

iTrader: (3)

Thanks for the good info. I think I'll run the turbos I have for now. The turbines are different measurements but only slightly. Once I get all the bugs worked out of my build I will probably upgrade to more reliable turbos when budget permits.

How is it some of the inline turbos like the ones on the diesel trucks manage to make it work?

project89

iTrader: (1)

thats cause they run one turbo threw the other