I dont suppose anyone has heard anything about this turbo, good or bad, from other forums they may have come across?

My orginal idea was to get a GT3071 with internal wastegate, but after reading on the MLR forum they have had problems with compressor surge, which worries me a bit and not wanting to suffer with it. I noticed on ATP that there is a GT2876R aka GT25/40R which seems a bit more suitable and is fairly effcient as well, as well as being a couple of hundred quid cheaper.

Link for the turbo is here

Nope not heard anything, but it does look a better bet that the 3071R which has reputation for overboost higher up in the rev range.
the 25/40 looks like you'll be wanting to run 1.6 bar plus , it will only get efficient above say 5000rpm?

regards

Joe

thats my plan Joe, 1.6bar with tailing off to 1.4bar by 8000rpm

Begggars,
I'd double check on the actual spec of the turbo as there are various 25/40's in existance all of which appear to be significantly different to one another. IIRC JOHNS used to run one on his 2 litre coupe

Jamie

hehee, I thought you might be moving that limiter

Joe

will you go for an external gate beggars, I've seen your manifold modified with a bypass pipe for the gate.
rich

Where?

*ponders on screamer pipe

Oh yeah, that sounds like an awesome idea.

I dont know what turbo minifreak is running on his coupe engined punto, but i think it's some sort of monster. Might be worth speaking to him?

his isn't a roller bearing for a start, but some massive T4 sized turbo which is waaaaaaaaay too big (personally) for what i want

That's me told then.

the Nissan boys seem to like them they can produce 450 hp and full boost at around 4.5krpm(which aint a problem with cams and headwork as they can rev to 8500rpm) on sr20det, the garret version does anyway I know hks do one but don’t think its as powerful my bro has a sx and was on about fitting one so I heard all about them but he decided to go for a Greddy t518z instead as it makes a bar around 3 k full boost at 3.8 and is rated at 420 hp(on sr20 det) i think you should go external wategate though if starting a new project as for that sort of power all the yanks say the external gate increase the efficiancy and also give much better boost control.

yeh screamer pipes sound ace! some people adapt the downpipe so that with an internally wastegate'd turbo you can still have it, 2 seperate pipes from turbo exit, aids exhaust flow at full throttle as wastegate gases arn't mixing and creating turbulance. think ive seen the 200sx boys doing this over on their forum.

ok I its the risi manifold but you would join it the same on the near side just by the collector, and run a pipe down. IC pipe will have to take a wider run to clear the gate. But externals are known to control boost well as long as the right size is chosen. And then you can have a screamer, or twin tail pipes that actually mean something.

rich

My old turbo was not that similar I don't think - it had the T04E 4" compressor cover, the GT25 turbine housing (same as GT28) and the compressor wheel was from a GT30 or GT32 I think but the turbine wheel was just a larger trim GT28 number.
Don't forget that turbo has a T2/T25 flange not a T3 like your manifold has

I would also go external wastegate if I were you as I reckon I could get another 40-50BHP out of my current setup just by fitting one.