knuts82

Is it possible to spool up a pair of ON3 76MM journal bearing turbos with a 4.8, running 10-1 comp. ported 243 heads and a .620 custom ground turbo cam, backed by a powerglide with a 4500 stall in a 68c10. I have the turbos but wondering if I should ditch them before they are used. Im building tubular headers and it will be running a e85 blowthru carb on a vic. jr. intake.. Im going to start the build as soon as its to cold to drive it for the winter. I already built the motor.

lavoy

iTrader: (2)

e85 produces allot more exhaust gasses then pump gas so that will help however ultimately it comes down to the exhaust AR and turbine trim.

knuts82

They are .96ar
3.0" Vband outlet

Inducer- 74.5mm

Exducer- 65mm

lavoy

iTrader: (2)

the exhaust wheel will also have a trim , like p trim q trim s trim ect this is basically the number of fins and the pitch or angle of them, the more aggressive they are the faster the turbo will spool at the cost of some restriction. .96 are is fairly large , i run a single turbo on a stocik 4.8 at pump gas mines a s trim .96 ar and the comp is 74 mm it spools pretty fast but my old 72 mm with .68 ar exhasut and q trim spooled much faster .

knuts82

p-trim

71 chevy

iTrader: (18)

Short answer is no.

I had twin 70s on my 4.8 and it was not very responsive.went to twin 61s and that was better but still big IMO.
In both cases i had the .68 ar and was on e85