whats the best turbo for going 400 bhp (roughly) on a cossie ? The engine is freshly re-build with low comp pistons no valve cut outs std cams and no head work its been build with a multi layer head gasget , high pressure oil pump and water pump all new nuts and bolts and gasgets the car has a t34.48 on it at the moment and running greens . i'm looking to change the turbo as the one i have is on its way out. so wondered what turbo is the best route to achive around 400 bhp or is it no way possible with this spec ? i know injector and chip change will be needed . also i dont want the car to be really laggy and un driveable on a daily basis .
i know its a big ask but any help/advice greatfull acepted

 

I'd say... put a .63 rear housing on, get the blades cut back a bit and try and find a slightly larger front housing, i had one like that on my old saph and it was awesome,

 

And the cut back blades made it less laggy despite the general concesus being that it makes it more laggy, my boost was a bit high at 37psi spike but it tailed off to 29 at the top end and was uncatchable round the streets etc.

 

37psi !!! on T34.63. what injectors were u using.

 

gt3071 works really well but T34 is tried and tested and reliable as fuck

 

Greys.. it was 37 spike but gradually tailed off to 29 at the limiter, so loads of fuel left to be safe,

 

Rebuild what you have to a .63.

Live map it with MSD. done.

 

im running light blues and a t34.48 it made 388hp with 375lbft on scs dyno with fuck all lag 30psi spike holding 26psi at the top,recommend that all day long.

 

what about a t38 or are these laggy ?

 

laaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaagggggg ggggggggggggyyyyy

 

t34/55 at 30 psi job done.

 

55 housing is a good call IMHO, although probably wont quite make 400, but who cares if its 387 instead or whatever, will still go the same in the real world!

 

I had a universal turbos t38 on my saff with a set of light blues and it felt awsome and wasnt laggy

 

True on the .55, you'll get very near 400.

 

at what revs would the turbo come on boost ? t34.55, t34.63, t38.??

 

a REAL 400bhp is the question.........(t34 u'd be lucky).....jmo

 

t34-63 for me too! its just a great turbo that gives no hassle!

 

as close to a real 400bhp with out just being not useable on a daily basis if i choose to

 

i did 370bhp 420 lb/ft on a t34.48, on our std engine off the shelf 55lb siemens package at 36psi

the same with a t34.63 will get you darn close to 400, but imo the .48 rocks for road use

T34s rarely hold much boost to the limiter as the compressor is so small a yb consumes all the air easily at high rpm, a .48 will end up with 20-22psi at 7k with the wastegate welded shut

 

i was told a t34 would be on its limit for 400bhp and would probibly not last long at oost levels needed to make 400bhp. i'm up for the siemens 55lbs

 

the .63 will get you close if you can live with it, in its nature it will make its power at higher rpm,

i personally would go with the .48 on our 55 siemens package , its fookin awesome! run it at 32psi and its reliable


i can do 30%off tomorrow on the chip!

 

its a good deal james cheers but i stll got to make my mind up on turbo choice or even exhaust housing choice lol

 

i had t34.55, siemens 55lb, msd chip, 500 cooler, 3 map bar, stock motor engine & CR

30 psi peak, holding 25/26psi

made for a awesome road car, would hammer m3's all day long, i could have upped the boost a bit more, but decided to leave it at 2 bar (30 psi).
It got absued everytime i drove it and never missed a beat (apart from split water hose!)

 

This thread is making me hard.

 

ha, get on with your build then you can actually drive yours!

 

where the best place to find a .55 exhaust housing ?

 

mine is running a ggr 34.63 peaking at 34 and holding 30 psi, 3 bar ,500 cooler, stock engine,rughly 380bhp maybe a bit laggy and as james says comes on song higher up the revrange ,but when its goin you aint got time to look at the clocks to see what speed your doing.

 

whats the lag of a t34.63 and a t38 is the loads more lag on the t38 or are they about the same ?

 

turbo technics will be a good place to start

 

38s are more laggy without doubt

 

if it was me id have a t4 coming in at 22 psi rising to 32 psi by 5500 rpm and a 7800 rpm limiter. thatl see a genuine 170 mph whenever you feel like it

 

i would say the t38 is laggier[sp] than the .63,but a lot depends on how the spec has been put together .

cheers james

 

i'd have the t34 over the t38

 

cant find that ggr code on there website ?

 

what bhp and torque would that be scoobyslayer?


cheers james

 

listed as much spec as i can in my first post , there is nothing speical in the spec

 

he never found out, by the time it came on boost the dyno was closed and the guys had gone home

 

well i was on bd14s with a virtually standard port head and she made 472 bhp 342 lbft.
as long as it was revved between 500 - 7800 rpm it was relentless power.

i think i may have to go and get my speedo vid and post it AGAIN lol

 

that would be nice but i have only just re-built the engine and would not want to pull the bottom end apart again to uprate bits to take that spec turbo

 

your engine spec suits a T34 quite well imo,