My new years mission is to decide on what turbo to buy, been pondering for months : (

Standard cosworth engine with a T34.55 fitted in my Dax at present. I always loved how the power came in when I was running a standard T3 @ 200bhp, so would be nice if I could get back to this and gain another 100bhp ?

Trying to compare the following turbos, but I have not been able to find dyno graphs for a hybrid t3 or a gt28 mated up on a standard internal cosworth.

T34.48 vs hybrid T3 vs GT2871 ?

Really want some proven numbers if they can be offered up here.

Thanks and Happy New Year.

 

Well imo the Stage 2 T3 i had from Turbo Technics was awesome, made 328bhp too @ 27psi peak and your thread asks for the most responsive so if it were me i'd be looking down that route again, especially if you've had one and loved it..

Another option, change your housing to a .48, that'll be like the T3 but pull harder...

 

t34 0.48 would be good, also a well specc'd gt2871r would also be good

 

Gary, out of interest, what kind of power can the GT28s make buddy?? it seems a turbo that gets over-looked to me but can't understand why??

 

Weren't the Rouse spec cars supposed to be more responsive on the smaller turbo they used with additional power over a standard car?

 

Correct turbo from a saab 900 turbo iirc


Luciano

 

What power were/are the Rouse cars??

 

A friend has one, and TBH it is actually very nice to drive. Very torquey low down with the instant but mild boost.
Makes 5th gear very nice to drive compared to a more gutless, but powerful car.

I'm sure you could easily source a good solid 300bhp turbo with very fast spool.

A little TD04 off a Subaru has almost full boost by 2000rpm and can just about scrape 300bhp. And it's a basic oil journal.

So some of the GT range like maybe a GT28 would be a good option.

 

Not sure about that. Even old Saab 900's used ancient T3's

Pretty sure the Rouse has a small frame turbo. ie T25 based. Cant easily get a look at his now though as it's stored away.

But it definately doesnt use a normal Cossie style T3 flange/turbine housing or downpipe.

Just a tiny turbo in general, but does work well.

 

Rouse had T25 and 260bhp and 300Ib/ft and produced noticeable boost at 2k

http://www.rs-ford.co.uk/images/rous...rousesport.zip

 

it may say noticable, but it is better than that.

It's been a few months since I drove it, but it really did feel nice to drive. Better than any other Sierra I'd driven.

 

Boost @ 2k, if only............

 

GT2871 can hit 400bhp if spec'd well, very responsive turbo

 

But how far can you take the T25??

 

In fact 3dr Steve ran a GT28 and produced 405bhp

 

I'd think if someone developed a kit for twin scroll applications using small turbos, you could have say 350bhp with very good spool. Which would really transform the car.

Maybe it's just old age, but instant boost is great even if it doesnt scream at the top end. At least for a car that gets used on a regular basis

 

Of course he did Chris yes, made 405bhp iirc??

 

the small turbo escos turbo can be turned into a hybrid and is very responsive i think turbo technics do them ....

have you thought about some headwork as that seems the best mod on a yb and maybe a inlet cam change then you might not need a different turbo just add a .48 housing to you spec aswel

that should see 370/380bhp with a good mapp seems the best spec for power and response

 

Not a case of needing boost at 2000rpm.

But a Cossie engine is totally gutless low down. The Rousesport outdrives any other Cossie Ive ever driven due to its responsiveness down low.

So unless you're aiming for say 350+, I can see little reason to put up with a laggy setup ?

 

have a look in the sierra cosworth section the is a thread in there about them under "engine specs" its a good read

 

Thanks for the responses so far.

I use the car alot on airfield trackdays and I am losing some time out of the corners.

This run was completed at the end of October last year on the T34.55 on an MSD L8 chip.

Car has a Quaife 3.62 LSD and standard T5 gearbox.

 

Injectors are Siemens 55's and wheel specs are 205/45/16 front and 245/45/16 rear.

 

Well using that above graph as an example....it seems totally and utterly gutless below 4500rpm !!!

I think room for improvement is an understatement. If that's flywheel power, there is no reason a good turbo choice shouldnt be seeing full boost by near 3000rpm.
On that graph virtually nothing is happening until 5000rpm !

 

There are many modern turbo options available that have much better response than the old T3 turbine - and any T4 compressor.
Here in Canada many are using the Holset HX35 with great success. Fantastic spooling for a 46 lb/minute turbo.
The Holset HX35 also bolts up to a standard T3 exhaust manifold.

http://www.turbotekniikka.fi/images/...uperhx35_2.jpg

 

Ive got a .48 exhaust housing sat in the garage and had considered this.

Does the graph below account for the different map, .48 exhaust housing or both.

If I want to improve on this, I guess I will need to consider a smaller turbo ?


Friends Dax running similar set-up to me (Custom intercooler/rad, 4wd head and .48 exhaust housing)

 

Yeah there's alot more boost available there, i'd just see how a .48 houisng with fresh map suits tbh, i don't think you'll have the pull on a T3 tbh, where-as it'll pull that bit harder out of the corners for you on the T34...

 

You sure there isnt an exhaust leak or your wastegate stuck partially open or something ?

Is boost all over the place or stable ?

 

On a .48 houisng @ 30-32psi peak on 55s you should see a nice 350-360 with similar torque too, infact an Inlet cam change would be even better aswell for more torque

 

Boost is stable.

 

Danny will cure it but then it will be more responsive earlier on the revs,so might have to lower the boost abit,so it doesnt spin as you getting out of the apex,cause iam pretty sure it will make some good numbers i can post if you want my dyno print out the 2876 you can see its climbing at 1.25 bar and made 385 with very mild timming,you need to map it any way,and if you dont like it,fit the 0.48

 

Please post, be interesting to compare.

 

inlet cam and mild head work with a .48 and that car would be untouchable and remap

 

i can but forgot to say its from VAUX LET
havent send my logs to SBD,so i quess is more to come,thats with very mild timming.

 

Why not look into the possibility of using a modern turbo design?
I know more people (in the UK) have more experience using the T3/T4 turbos.
Why use such a laggy old turbo design?

 

Happy to look at all options.

IMO however, most cosworths these days either go down the tried and tested T34 route or opt for the bigger GT30 ball bearing range.

Difficult speccing a new turbo if knowbody is running the same spec.

The only Cosworth GT28 users that I have found, had modded engines aswell.

 

not at all , and just to make it clear,i dont try to convise him about the t28,i trully beileve it can wake up from u.

 

Fair enough Dax.
I understand what you are saying. The ball bearing GT30 is a good turbo, but quite expensive as well.
Many of the DSM (Mitsubishi) turbo guys are now using Holset turbos with great success.
As are the Ford 2.3 turbo guys here.
400 hp range and fantastic spooling.
Take a look on the web, and do some research - I think you may be pleasantly surprised.

Cheers

 

the t25 in my rouse is awesome, its so responsive throughout the rev range, more naturally aspirated than turbo. id love a bit more top end pull though as it seems to run out of puff at higher rpms

 

interesting thread

 

The Holset HX35 looks fooking massive, full boost by 3500 and upto 40psi..... ?

Anyone else know much about these diesel turbos ?