The V8 Owners Forum -

Ok the first question, depends on this answer if i need to ask any more, im getting 2 t3 garret turbos, would these be ok for a s,b,f 347, or are they to small, all advice welcome rich

depends how big they are,T3 is just the family.

You really need the .63AR exhaust housing, which was only ever used on the first "big turbo" escort cosworths.
The more common .48AR may be on the small side, causing too much back pressure in the exhaust.

The turbo for sale in the for sale section may be better suited, although it would take a while to spool because of the large exhaust housing.

Im not sure about size, im picking them up in janaury, they are the ones ivanheow had for sale on here, under xj 220, to be honest i know nothing about turbos, i need to know if i can use them the sbf or just the rover, rich

Right - they were a nice set of turbos.
The for sale thread has gone, as I plotted a compressor map for a rover.
They will work on a rover and will work on a bigger engine if the exhaust housing is .63ar - which they may of been from memory.
The compressor was a super T60 i think.

I'm running T34's on my 5.7, which is the biggest T3 hot side mated to a T4 Cold side (hence the name T34 - it was the original 'hybrid' turbo). The T60 would of worked on mine also, especially at low boost.

Ok cheers, once i get them i will put the sizes up, and see what they are ok for, rich

theres the map , you can roughly go 1 lb/min for each 10 bhp ,so its about 300 bhp at 15 psi worth of air for each turbo , ,then a bit more at higher boosts.they seem to max out at around 310 bhp on the cossies ,thats with the .48 housing .
shame the for sale bit was wiped off ,as this was all on there .

regards robert

You can use this turbo calculator to work out the size for twins, you just need to half the number of cylinders - this is for a 4.6 at 6psi:

http://www.not2fast.com/turbo/glossary/ ... tyCycle=85

About half way down, you will see the option to plot the compressor map - select super-t60 - you will see that you are "on the island" at 5500RPM

Basicly plot it at low and high rpm, low boost and potential future boost and make sure you stay on the island and to the right of the surge line.

For the sake of history - i've saved the images:

So heres a 6psi low boost (stock engine) example:
3000rpm start of boost:

5500 max rpm: (~300-350BHP)


And the forged internals lower compression example:
3000RPM (you wouldn't see 15 psi at 3k rpm anyway)

and max rpm: (~400-500 BHP?)


So this compressor suits a 4.6 from low to mid boost setup - stick your other engine details in and see what you get.

eliot ,these t3's are 60 trim not super 60 ,in case theres any confusion.

ok why do i put half the cylinder numbers in, is it because of going twin turbo.?, im not very clued up on these things rich

bones wrote:ok why do i put half the cylinder numbers in, is it because of going twin turbo.?, im not very clued up on these things rich

Yes. Each turbo provides 50% of the flow - but the calculator doesn't understand twin turbo's - so you just half the size of the engine instead.

ok the exhaust housing is a A/R 48, so that i guess is to small for a 347 sbf,can they be changed rich

hi rich ,

the a/r tends to govern the max flow thruogh the turbo on the ex side , if a cossie will make 300 bhp plus on this a/r ,then it will work at a 300 bhp load of ex gs flow on any engine , so those a/r's will work on 600 bhp for 2 ,if you go to a bigger a/r you will get later spool and more top end power ,if you go smaller then more bottom end boost and less top end ... best thing is try them and see how it goes ... the housings have the same flange size ,so a swap after its built is not a problem ,i think the next size up is a .6 something ,which is quite a jump .

regards
robert

morning, thanks for the reply, not bothered about top end as car mainly going down 1/4 mile strip, and road use now and again, the engine i might use them on is a 302 s.b.f = 5.o ltr ,ive got a forged stroker crank which takes it out to a 347 =5.7 ltr, ive also got pro 1 alloy dart heads, with what ive got so far be ok with the turbos, am going to use eagle h-beam rods and probe pistons, but the compression seams high on them, edelbrock 750 carb and edelbrock pro performer inlet, would these still be ok with turbos, so many ???? rich

id say theres a fair few bits you dont rreally need rich ,
a stock crank and engine size would be fine ,the revs dont need to be high with a turbo ,

the pistons want to be around 8 to 8.5 to one for 10 to 15 psi boost ,

the ally heads will be good if they have smallish street size ports ,

um ,really the great thing about turbos is you dont need to get stuff thats strong for high rpm ,and you dont need to have a big engine ,a 5 litre is quite big enough ,if fact ,dont the 5 litre blocks start to crack over 550 bhp ? or is that something else , i thought i read about that on the tubo mustangs forum .