Simple question what is the difference between the GT3071 & GT3076

When do they make boost from and till????

 

5......

 

Seriously,

My Dad has a 71 on his car with a .82 back end which comes at about 3500rpm, revs till 8200rpm without much noticable drop off. Think it produces peak power about 7500rpm.

I think AJC has a 76 on his car and that spools like a T34 but I'm not sure what his limiter is.

The difference is 5mm larger diamter on the rear wheel.

 

front wheel...

 

the 3071 one is 5 trim smaller front wheel and will produce around the 450 hp mark and come in very quick and suits a road engine very well..
The 3076 is for 500+hp and needs to be suited better towards a higher revving engine..

cheers danny

 

Danny, 3071 will do more than 450..comfortably on the correct Spec...

 

Ok if you want to run 2.5 bar it will do 480 hp but as a rule with say 2 bar held youd expect around the 450 hp mark..at the end of the day its all down to speccing the engine to suit the boost,high cr and gt turbos work very well and if the mapping is good yes you can see more hp....


cheers danny

 

Danny,

Just a quickie, how would one work on a standard engine do you reckon, that's cams, no headwork nothing??

I'm just curious if they'd be a GOOD replacement for a T34 that's all

 

i prefer the 2871 still makes 400hp but comes in earlier and holds well up to limiter if you want it to spool quicker use .64 rear housing or .83 for full hp compared to t34 spools around 500-1000 revs earlier depending on spec and housings

 

I can answer that one Pete works very well on a standard engine, totally wipes the floor with any T34


Luciano

 

Yes!! Sorry, front wheel!

 

Anymore thoughts on this Chris??

 

Yes i'm getting a GT3076 for mine

 

Fantastic Chris, make a HUGE difference that bud..

 

Danny, its the compressor wheel diameter not the trim which is different.

3076 = 76.2mm / 56 trim
3071 = 71.0mm / 56 trim

depending on which 3071 it is, there are also some potential differences on the exhaust side, some of them are a 56.5mm/90trim exhaust and some are 56.5mm/84trim, and others are the same as the 3076 at 60mm/84trim

The smaller exhaust ones will really struggle to break the 450bhp barrier, the 60mm/84 trim ones will do it relatively comfortably though on the right spec engine.


In terms of the difference on an engine, about 500-750rpm later spool typically and a little more laggy as well.

I personally think the 3076 is one of the best turbos around for most 2 litre engines, but on a standard YB the 3071 seems better suited for a road car generally as YB's tend to be relatively unresponsive for the same turbo than superior engines in this respect such as the vauxhall LET engine or Mitsi Evo engine, where bigger turbos seem to perform better in terms of response.
(mainly due to the stroke difference I should think)

 

Chip,

So do you think a 3071 would work well on standard cams/head aswell mate?? basically as a T34 replacement Turbo??

What can a standard YB push out, about 420-430 max??

 

Yes they work VERY well like that.
In fact when I next revisit mine thats what I will more than likely do to it having seen the results several other people have had on YB's with these turbos that I have sourced for them, was going to use a mar-m shafted T34 ive got, but starting to change my mind now having seen how well these 3071 work.
Cossierich being a prime example, go and have a look at his thread.


Yes that seems to be a reasonable ballpark if correctly mapped on a GT3071

 

ive changed from a tt t38 to the 3076 and to be honest i didnt get the massive difference i had hoped for.. it does drive different and pulls very well.. think i expected too much really..

 

Should have seen you with an extra 50lbft and 50bhp really in most cases!

What power did you have before and what do you have now?

and what boost were you running before and after?

Who mapped it both times?

Whats the spec of the rest of the engine?

 

Gibbo, if i changed i think i would, i'm currently on a T3...


What power/torque was your 38 making Gibbo??

Remember, if you were near 450 or so and the 3076 is making 470-490, that's not a HUGE jump tbh, but surely it should pull more to the limiter on the 3076??

How do your spooling characteristics feel in comparison??

 

Bear in mind there are two types of T38 as well, and they are about 10% difference in size.

 

first time round it was set up at A1 which was really an off the shelf chip but did go really well . had it like that for about 2 years and didnt have it on the rollers.. ran 30 psi on the t38..
now been mapped at reyland on the 3076 runs similar boost and did 498 ..
its 7.2:1 martin fitted bd15 inlet and 14 exhaust . guess a better inlet should be next . its got a modded 2wd one on their at min its copyed the jenspeed style one.
it is better dont get me wrong but i was just hoping for an amazing difference..

 

I suspect a ported head might help reveal a bit more of the difference between the two mate.

498 is still pukka though

 

Ive got a GT3071 on mine, 2wd saph with standard cams, ported inlet manifold and head, grey injectors, superchips chip and a few other bits, mine seems to make boost alot later than the T35 i had, once the clutch is done ill report back with a dyno result to let you know what power i achieved with what ive currently have, any predictions ?

 

Which did you prefer Paul?? HONESTLY?? ......forget about power, just road use and spooling quality??

 

forgot to say it has an old tuoring car head on it too.. martin said his rollers are not too favourable to the 2wd so would probably be a little more than that.. he didnt want to go too far with it as he hadnt built the engine himself so a bit of an unknown to him..
its the best ive ever had the car now tho its so smooth and nice to drive ..

 

What spec turbo is on CossieRich's?

 

To be honest Pete i cant really comment to much as the clutch is in need of replacing, i literally bought the turbo when it came up and just tried the car a couple of times to check for leaks etc.

For the amount of time the clutch held the car made boost later than the T35 but held the power in alot longer up the rev range, the T35 felt like it was running out of puff, car still made 349bhp/370ftlb, i just wanted more power all the way through which this turbo feels like it will achieve.

 

where is the best place to get the gt turbos?

 

got mine from reyland as the whole kit...

 

Gt30 with the largest exhaust wheel

 

Good place to go

 

i must admit, i really like the idea of a gt3071, cossierich's is a prime example, i know he run 2.5 bar of boost but still to make 480hp is a great achievment.

i was convinced a t34.63 was a great everyday road turbo, but the more i see of the gt30 the more i like it!

when and if i do ever get another cossie, i think i'll go down this route

 

T34 is more robust though.

 

what best to go fo internal or external wastegate what are the pro's and con's?

thanks

 

Matt,


Still is imo, tried & tested and can take pretty much any abuse, i say "pretty"

I'd NEVER rule T34s out of any equation...

 

Dearer and more power.......

 

really? ive heard t34's dont last very long and have heard them referred to as pretty much being a yearly service item lol!
i have no experience in them myself tho

 

T series turbos are SAID to be stronger than GT Series uints, NOW PLEASE don't quote me on that FFS else i'll have everyone on my case..

I think when you push 35-36psi through the T34s like some have then maybe they'll expire after time, but i've never had any problems with mine running @ 32-33 psi..

 

i did love my t34.55, but i'd like to be 430-450hp for my next one, and a t34.63 will be screaming like a girl to achieve anything over 400hp.

still, got to buy the car first!!