hey guys im looking to go to a bigger turbocharger- i have been looking into a MPT70-

my set-up is a rearmount 4.3L with a TH400 and transbrake. (transmission will come with the turbo) i only rev out to about 5700rpm- do you guys think the mpt70 is a little big to give me a usable power band? plan on around 12psi for it or 550whp

i want a turbo that will not run out of breath up top like the turbo i have now. i like it cause it will give me an option to upgrade to more power if i want. ---- i think from a dig i will be okay on the Tbrake-

but how do you guy think it will be from a roll?- to much lag?
any other ideas on a good turbo size?

 

i am not sure you'll be near 500+ hp @12 psi
I have typhoon with a 4.3 and I have 58 mm on it now
and i am at 16 psi and i am not near 500 hp and i have
had it at 22 psi and i am not out of turbo it might be
getting close to 450 at that point. mine is a "P" trim
exhaust wheel with a .81 housing and i have no problem on spool up

 

Depends on the hotside. On a rearmount you might have a lot of lag if the hotside is too big.

 

im sorry dont know why i said 12psi- was talking to my buddy about the turbo fox we are building- i plan on running about 20psi- are you running a PTE turbo? i want around 500whp on this- i know its a balanceshaft but im sending the block out to be cryo'd - what kinda WHP are you @ on 22psi- i just dont want boost to fall off in the upper rpms- i plan on reving to around 5700 to 5800rpm on a custom grind 270ah camshaft.


also the turbo isnt that far back- its just under the passenger seat-

 

I dont understand how the turbo you have isnt big enough already, althougn I'll be happy to buy it when you take it off .

That exact turbo(TO4E 60-1, .81A/R) on my friends STS LS1 Camaro put over 500hp to the ground at 8psi. And on top of this, they do it with a 38mm wastegate proving the turbo isnt too small. If it were too small, there would probably be mucho boost creep with an 5.7liter and 38mm wastegate.

 

i dont have a .81 a/r- something smaller i think its only a .71 a/r- i wanna get a .81 if i stay with this turbo-

 

my cam is .510 lift [email protected] 111 ls
i don't know what power ti has on high boost because
my tuneup is off . but I guess @22 once tuned right
it will be near 425 ish

 

@ the wheels?

im going with a custom grind 270ah camshaft prolly one of the next things i will do with ls1/ls6 valvesprings. thats just a ton of boost on a 6cyl only to make 425whp.... but is that All wheel hp if so i would have a bit more power but alot less traction... i would like to run a bigger turbo so i dont have to run that much boost but if your getting good spool out of your 58mm and its not dropping off boost in the higher rpm then i guess its okay.

 

a MP t70 will be to the left of the surge line during spoolup from what im seeing.

i wanted a t70 for my 4.3L too but i went with a 60mm turbo instead, i figure it will give much better response

do you have a stock cam? if so switch that out first that will make a huge improvement

 

my next mods are a cam / stall and maftpro ----------

how much do you think i could gain from a custom grind based on a 270ah-

im running a t3/t04e 60trim- ported/clipped/balanced- do you think it will be fine to 450whp?




im on s10forum- i havent seen you on there in a while boosted thrills-----

 

What turbine wheel and housing? I had T3/T67's with P-trim turbine wheels and .82 A/R housings. Flowed tons more air than Stage 3 wheels in .48 A/R housings, there's a lot of disparity between exhaust wheels and that can have a huge effect on power output.