2.1 Build. - GT3071r or GT3076?
 

Anyone shed some light on these turbos?

Looking at a 3071R with 11 Blade set-up or a GT3076.

Can anyone shed some light on power difference and spool on a 2.1?

Stock position?, what's more important spool or power etc.

The 71 will spool slightly better but will run out of puff at under 500 probably make 450 ish.
The 76 will spool slightly after depends on housing size but will make 500+.
If rotated I'd deffo go with 76.
Your 2.1 will be decent in spooling to power the 76 with minimal lag and will work well.
On a 2.0 I'd be forced to get a 71 unless it was rotated.
Hth

Hi,

thanks.

its a Standard position Turbo.

I was aiming for 500BHP but with decent spool not to loose driveability.

However ive been struggling to find the information comparing spool on a 2.1.

Any idea how much later the 76 will spool over the 71?

I think you will struggle to get 500 from a 71 tbh as they are a 475hp rated turbo I believe, but with more boost and meth and also the 2.1 should be achievable.
I don't think there will be much it both, but your 2.1 will deffo help and avcs? Harvey uppipe? And should comfortably make 500.
They say, no turbo has lag, you're just in the wrong gear at the time.

yeah 71 will max out at 450 im told.

so what im trying to do is weigh up the 71 with spool + 450bhp against a 76 with later spool (But how much?) + 500BHP+ (no cost in replacement).

Pass on the up pipe+AVCS off the top of my head. i know eeverything has been replaced/build to suit.

off topic a bit but as an example down a 1/4, 3071 will be quicker off the mark. but will the 76 pass it and have a higher trap speed/faster time?

Bang some meth in there too, that will help achieve more boost.
Tbh, if you're talking about a 1/4 mile, I think the 76 will make it to the line quicker. It will come on harder for longer and that's the sacrifice you get, you can't have both.
If it was me, a 2.1 with good headers and uppipe (Harvey), avcs etc I'd get a 76, add meth and more boost.
Also check what size housing it's got as I believe there are different sizes which will affect spool and power depends on how big exhaust housing is, (the smaller= better spool and less top end, bigger=more lag and more top end etc etc.) think they come in 6,7,8cms

But it all depends what you want also, but I believe the 2.1 can cope better with a lager turbo unlike the 2.0 which will cause slight lag.
I'm on a 2.0 and I have gone for a smaller spooling turbo 400+.
I did have a gt3071r but it had a 7cm hot side so I sold it before fitting it as would be laggy on my car.

I will eventually go for a 2.1 next and bang a bigger turbo on if mine blows lol

Me personally would go rotated gt30 do it one time or if you really wna stick with stock position then 76 but as busta said use harvey smith uppipe

Thanks,

Wont be adding meth to the car, not yet anyway.

Its a Blob so belive that has AVCS. up-pipe i recall a discussion about GT Spec. Downpip is a Miltek 3" right the way through centre etc and out the back.

Ill be running a Aftermarket ECU so either a Alcatek/Link or Syvecs mafless with 1.8Bar of boost.

Engines already built and running a 3071R. But down again for the Injectors & ECU.

Still weighing up the turbo i have tho.

so youd say 76 too.

When can you expect these to make full boost by on a 2.1?

currently my 71 makes full boost (1.55Bar) @ 3800

Shouldn't be much later around 500rpm the most

Go for spool and less power, you will have a faster car.... It sounds like you are sacrificing drivability just to be able to say you have 500hp....

3800 is a nice time to have full boost, and I dont see why meth isnt an option. A splash of meth in the tank and a bit more boost and youll be knocking on 500 anyways. Meth isnt a big deal, add 10ltrs before filling up with fuel, do 10 miles to let it mix and switch maps to the meth map, use right boot and grin! No need for bigger turbos and less power band ;)

Although I do think the GT30s are laggy, I was doing full boost of 2+bar (2.2 or 2.1 and bleeding off to 2) at 4k~ and doing over 500hp on a standard position turbo, unless you are going to go rotated then obviously that will give you less lag...

If you already have 71 in then work with that first until you want more.
You can get that to work with a bit of meth and boost.
Also get a syvecs, controls boost, timing etc better so allows for more.

Thanks Guys.

Might stick with the 3071R and see how it goes. as ive yet to run it with more boost and larger injectors.

Where do you source meth from?

Jenny chem BD Additive.

Make sure to get it mapped for it though

Thanks mate, will take a look.

Yeah of course wouldnt want to reck the new engine!