as title really, im trying to decide what to do next,

current spec is greens, 3bar, t3 and 1.5bar peak holding 1.3bar. 500 style cooler etc. mapped by enhanced performance, and she's making around 300bhp.

now i want a bit more power, and the turbo is on its way out (i hope, its starting with a bit of blue smoke on overun) but i dont want to loose the punchyness of the little T3 if possible.

So if i just chucked a t34 (.48 or .63) on there and an MSD chip, its gonna make about 340bhp? is it really worth it for an extra 40?

and if i then have it live mapped i will be gaining a bit extra, but how much? at what cost?

i think realistically i would like 380-400bhp, i dont want to start spending mega money on gt30's etc, and dont want to start taking the head off if it can be helped, im not sure what headgasket is fitted but it "should" be a good'un.

opinions?

 

Either use a 4x4 t3.60 with a 360 t-bearing that will cope with a good 28 psi spike.
It will supply enough cfm for around 330hp, and the torque will be 350 lb/ft + at 28psi.
It's only weakeness is 5th gear the limits of its power will start to show around 5800 rpm, where the boost will start to fall off. But for an A road racer or trackday power, a maxed out a t3.60 is so responsive .

If you are after 380 hp then I use to have a t34.63 in a sapph,
Everyone moans about lag but if its peaking over 30 psi and holding around 26 psi, then lag isn't an issue. I've heard that the .48 exhaust housing can either be modifed or is a straight fit onto the t34 compressor. I think with a t34 .48 you can max out around 360-370 hp with 380+ lb/ft torque.

The beauty of the old t series is they can be rebuilt for very cheap providing the shaft and wheels are in good condition.

 

I dont think you will get 370honwith a .48 housing

 

yeah i think your right, probably raround 360hp, but i know if you run them over 30 psi they can provide a huge wideband spread of torque.

 

T34.55 is a nice turbo

I only noticed a slight difference for the first few days after changing from a T3.

Mine made 372bhp

Steve

 

its also trying to find a t34 nowdays, there Ł900 new, couple extra hundred and you can have a gt30

im trying to find a t34 at the min with a .63 ex housing but none are available, id go gt30 but dont think its a wise move on a grp a head gasket and std head bolts

 

Ive got a brand new garret T34 with .63 housing for sale if your interested drop me a PM as i wont get a topic reply notification

 

Get a small turbine wheel GT3071, will still do 400bhp and spools nice and quickly.

 

its deffo worth it, but IMO not on greens as they are better suited to a T3 and on a T34 you have to cap boost to prevent it leaning out,

So ideally go T34 or similar, and swap to 55lb or greys which will allow the turbo to run flat out making 380+ bhp on a T34.63.

 

What James or Chip said

Injector change is a must though

 

Ive just re-spec'd my saph from stage 1 and T3 to T34.48 with greys, wanna run around 27psi and am hoping for about 360-370. Getting it set up next week so will let you know the difference. I loved the quick punch of my T3 but i think with the small housing and high boost the T34 it shouldnt be much different

 

55 housing is a nice place to be Fraser, will give you that little bit extra power too, mine made 355bhp/360ft/lb @ 30psi when Sheady Rollered it a few months ago..

Chip's dead on though, a 3071 will piss 400 VERY safely and last for-ever @ 400bhp and can have the spooling qualities of the T34...

 

hmmm might have to price up a GT3071, i have been looking for a while now for t34's and theres not too many around.
what sort of power will a 3071 push flat out? so if i get bored again it should be a bit easier. inlet cam next i presume?

t34.63 and 55lbs sounds perfect at the moment though, .55s are going to be even rarer and like said i think i would be daft to buy new when the 3071's not too much more.

 

3071 flat out will do 500 on the correct Spec mate, Doug's Escort did, Richie's saff is around 480iirc so plenty of scope pal, that's what i'd opt for if i were you rather than ringing a T34s neck...

Although, i do think T34 Cossies are a great road car imo..3071 are also...

 

I always found the standard T3 on my 4x4 saph ran out of steam at the top of 3rd gear

the T34 (i had a .63) is a huge difference.

I always wondered how 4x4s broke 3rd gear, till i put a t34 on, the torque difference is very noticeable.
(msd 'Stage 3' closed loop setup was on mine too)

 

Please note lads, im on about the smaller turbine wheel GT3071 than the one most people on here use.
Its spools quicker but doesnt make as much power (will still piss 400 though on the right engine)

 

what is the 'right engine' though? mine is completely standard?

 

Still can be donr Fraser, a cam change would help obviously and slight headwork, but they can be used..

 

The right engine is one with decent vavle and ring seal and a good exhaust and a decent inlet plenum etc.

And of course the mapping is absolutely vital

 

hmmm interesting, i will price up a few bits and get saving, got to do the clutch this month as mine started to slip on the dyno at the weekend.

Mapping would either be MSD or turbosystems, i will have to speak to them closer to the time.

 

interesting read this! as im gona be doing the same, t34,55 im looking at thow. but 2 be truth full my t3 at 22psi hits it and holds it, 12.9 last year at pod felt strong all the way threw the gears. iv no complaints from my stage3 4x4 with msd chip

 

Forget T34's. If you are buying a new turbo then it may as well be a GT30. The GT3071 I have has given me 480bhp and 475 lb/ft on a standard port head, no fancy inet manifold, no fancy exhaust manifold.

 

Personally can't think why you would bother with any of the old skool turbo's with BB stuff similar in price and the increased tuning potential.

Also if your going for new injectors i wouldn't waste your money on 55Ib and go straight for 83Ib

 

More or less standard internals in my car with my 30/71, engine has been rebuilt though, 420bhp 400 ft/lbs


Luciano

 

The T34.48 can run 380 no problem, as the man at CR Turbo's did on his 2wd sapphy.
I had the choice, and the dosh to go BB route, but for me it spoils the car, a step in power and not a more linear curve is nice imo.
I run a T3/34.48, that is a T3 comp housing machined out to take a T34 inducer, and a RST rear section, with cossie .48 turbine, mine holds 300bhp at 17psi, starts boosting at 1400rpm, full boost by 2500rpm, just for reference, it's 360 with step seal and drilled ring, so when mapped again will be around 380 with punchy road manners on petrol, lpg should see around 300bhp, but with massive torque benefit, and switch at the 300bhp mark to petrol.
tabetha

 

tell him about your ob07 cam steve.

 

I bet yours would make more power and torque with one

Steve

 

Wait till I get my car up to Macclesfield and we'll take a spin out, then tell me if you like that spec. Then you'll know

 

380 bhp no probs from a t34.48 lol

I ran mine at 36psi and held it flat out to the limiter, the wastegate could have been welded shut once the spike had been controlled, and it made 370 bhp 420lb/ft
so I wouldn't say it's no problem, more like impossible as they simply run out of puff top end.
Good for torque and punch but no good for ultimate bhp.

T34.63 will do 380 bhp.

For the record I have a graph from my t34.48 showing 470 bhp, I guess it depends what you believe lol.

 

Ps ignore my typos lol I'm on my phone with fat fingers!

 

Dumb question maybe, how far can I go on a T3 boost wise before it kills itself?

 

T34.63,55 lb siemens,MSD chip,380 bhp makes a really nice road car.

 

oooh you bitch. Bet it wouldn't, iv'e just taken 1 out of mine.


at least mines not pretending to be a cossie..

 

Sounds like a plan! what spec is yours again? t34.63 on light blues?
i think i will get the clutch sorted and then get looking properly for a t34.63, if nothing comes up second hand and im gonna buy new it will be a 3071.

 

200 block, Mahle SCS spec 7:6:1 pistons, light blues etc. etc. So should be pretty quick

I'll send you a PM when its all mapped up and ready for a little Sunday drive to the Cat n' Fiddle

 

Depends if its a 2wd or 4x4 turbo,

If it has a standard 270 degree bearing then
the max safe boost thresholds would be around 0.8 bar.

With the housing drilled and threaded and the 270 bearing screwed down
max safe would be about a bar.

Or with a 360 bearing screwed down to the housing it can take 30 psi of abuse..

 

So going on this Tabs/James, do you think with correct mapping,Spec etc a .63 housing is good for 400+ then?? surely Turbo longevitiy would be an issue then??

 

Of course it is, 420bhp has been seen on a T34.63.

 

As above, a 360 bearing is a worthy upgrade, then its not really boost limited particuarly, you just need to be careful not to overspeed it.

So 30 pounds in the midrange is no problem at all, but you obviously wont be getting that 6K on a YB as the engine breathes too well for it!

 

Its not really a good place to go, but its certainly possible to achieve.


GT30 makes SO much more sense though, will do the same power with less strain on itself or the engine.