denali_on_26's

iTrader: (26)

ok i bought a turbonetics T78 with the f1 wheel and a .96 ar with an upgraded 4" exhaust exit in the hot side for a 370ci motor now i just purchased a 408 rotating assembly..
my question is will this turbo still do good with the 408 i am looking to run 15-16psi on pump gas....

TurboBerserker

iTrader: (1)

Yeah, it should be good for that psi range. I ran a GT70 to 15psi (but it was out of gas there).

denali_on_26's

iTrader: (26)

what about waist gate??
i just bought a TAIL 38mm will that be enough for the 408

LsxCody

iTrader: (3)

I think that's alil small for a 408. Prolly work aight

05crew

iTrader: (6)

i had a 76 on a 370, then when the 370 went, i put a 408 in. the 76 did not last long, like 500 miles, i dont know if there was some metal in it that i just could not get out of if the 408 was to much backpsi for it, it just started smoking...lol

so i had a long talk with tom nelson at NRE, because he is the **** and he is building a lot of RPMs motors, and he told me a 78 with a F1 wheel would be good to around 700 or so but if i want to "quit bullshiting" than step up to the plate" so i got a 88mm BB, from him and he took it apart and played with it..lol but if you are look to go around 700 u should be good. im sure you can get a little more out of it.

and the 38 should be ok, but you could just go to a 44mm wastgate just so you dont have to do it all over. im running a 44mm

thats just the way i went with it...should be done with the fuel set up next week and the off to the dyno and go for broke!

TurboBerserker

iTrader: (1)

A 408 at 15-16psi is going to be around 700-750 rhwp. The 78 will be fine there. If your back pressure is too high, change the turbine housing to a 108

The Tial 38 is likely too small.

JakeBrakeIH

iTrader: (22)

FWIW Im gonna be running a Garrett GT4202R with a 74mm compressor and 1.15 A/R exhaust on my 408


EDITED...

kbracing96

iTrader: (26)

That turbo has a 74mm inducer, which is what turbo sizing is generally done off of, but still plenty big. Thunder made good power with it on a 403.




I think the T78 will be fine on the 408, just build it to run in the 2000-6000 rpm range and take advantage off all the low and mid range torque that motor/turbo will make

icedenali

how's the fast does t78 on 408 spools up? i kno it will spool a lot faster then small imports, when spool begins? and max boost by what rpm range? i have feeling it will spool really really fast with 408. does it got a lag on turbo?

JakeBrakeIH

iTrader: (22)

Corrected...still LOTS bigger than my MP-76!