234 replies to this topic

[svanh1993]

Hey guys has any one ran a gt2871 on the 1.8 I know every one is running 16g turbos etc I'm guessing it's slightly smaller than the 2871 how do you guys think it will go boost will be around 10-12 psi on 10.0.5 compression cheers guys

[leadfoot]

if it's any bigger than the 16g and you street the car you don't "need" it the 16g has plenty of puff for that boost level on a 1.8.

my 1.8l is no std 1.8 and it doesn't even come close to touching all of the available CFM of the 16g.

the biggest deciding factor for me would be the turbine "hot" side if it's any larger than the 16g it will be laggy if it's the same as a 16g then sure why not but tbh a 1.8 is right in the middle of the compressor map for a 16g possibly allitle low on it actually.

the reason we all run 16g's when the 2l boys go bigger is because they are a considerable improvement over our little td04 13t's for us running a 16g is like a 2l running a td06 20g

[svanh1993]

That's fair enough well I already have this brand new turbo just out of curiosity what does the td05 16g compair too in the garret range gt25?

[Ian91]

Is a gt25 a disco potato? It wouldn't be to different to a 16g I wouldn't think, I know a few guys running potatoes on their 4agze engines which are only a 1.6l and if it was way bigger it would be terrible on such a small motor, unless they get a better power range due to high revving.

[VIN18M]

Hey svanh1993, sorry I haven't replied to you om yet, it was a long one with a lot to take in.

 

I'd suggest running something smaller on a stock bottom end than that turbo, mostly because you'll be running it way below it's efficiency range with the boost you'll be able to run. I wouldn't think that a bottom end running 10.5:1 compression pistons will hold up for too long on 12psi with that size turbo. You'll be pumping a fair amount of air into the engine. You could run less, but that will involve changing the wastegate actuator and making up a custom mount for one with a lighter spring to run 8-9psi.

 

Is it a genuine Garrett turbo? You might be better off selling it and buying a brand new Td04 and running that at 10psi and getting some change $$. This will also mean you can use a standard exhaust manifold.

 

Believe me, on a high comp bottom end, you want a really responsive little turbo. You can't run high boost anyway, so you're best off going with a smaller turbo and getting as much low down torque out of the setup as you can.

 

Speaking from experience high comp/td04l turbo is an amazing combo, more than enough to spin the wheels in 1st and 2nd (3rd in the wet). Also, it's nice to know you can give it heaps without worrying about throwing a rod.

[VIN18M]

Is a gt25 a disco potato? It wouldn't be to different to a 16g I wouldn't think, I know a few guys running potatoes on their 4agze engines which are only a 1.6l and if it was way bigger it would be terrible on such a small motor, unless they get a better power range due to high revving.

GT2871r is a T28 with a ball bearing centre and a bigger exhaust housing from memory. 

 

I've heard of people running these on 4agze engines too, and they are big for that setup, but the numbers these guys are getting speak for themselves.

[svanh1993]

Well I was more so looking so see the difference between. The td05 And the gt2871 yea this is the disco potato I had one of these years back on 8 psi on my patrol it was awesome I'm trying to find out how much bigger it is than the Td05 I mean people run huge turbos on civics so I don't see that this will be bad on low boost

[VIN18M]

As far as I'm aware this will be around the same size as a big 16g, but with the added spool benefit of being ball bearing.

 

It'll be fine on low boost, and you've got the high compression of the engine to give you power off boost. The car should drive the same as it does now when it's off boost, and then hit hard when the turbo spools up. Being a ball bearing centre and being on a high comp engine means it'll probably make positive pressure by 1,500 - 2,000rpm.

 

Do you know what spring rate the wastegate actuator is? As this will determine your base boost level.

 

The only concern you'll have will be how much boost the rods will take. You also want to make sure your tune is spot on, as any sign of detonation will be a big deal on this setup.

[svanh1993]

Yeah mate thought it would be that size all I know is theu spool early and get abit more it's between the 16g and 18g on the top end but spools earlier than the 16g was wondering if any one threw this on a custom manifold like I'm doing ? As for the actuator it's a 7 psi spring so max boost would be 14 give or take but wasn't going to run that I was thinking max 12 I'm looking towards spool rods any ways for the amount of money they are I think it's worth it 12psi should hold well with a good tune if anything should be about the same power figure as a 9.0.1 on 20psi but better off boost ofcoarse I know for sure it's all in the tune because have a look at Mazda sky active something like 13.5.1 for turbo and 18.1 compression for non turbo and the turbo definetally isn't small what so ever and pushing 220kw NA imagen the turbo version on the 6psi an# this being a 2.3 liter

[jack be nimble]

Im excited. Anything about disco is exciting.
And potatoes make chips, i like chips.

win win.

[svanh1993]

Could be a good Hong I know every one he're goes Mitsubishi turbos nothing wrong with garret borgWarner or hks

[leadfoot]

we just use mitsu stuff because it works and fits with minimal mods

[evo-gsr]

Im excited. Anything about disco is exciting.
And potatoes make chips, i like chips.
win win.

Disco biscuits are better.

[GSR]

Gt2871r is not a disco potato.

Gt2560r is equivalent to s14/s15 t28 turbo
Gt2860r (disco potato) has bigger turbine wheel but same or similar compressor wheel.
Gt2871r has same turbine wheel as disco potato (gt2860r) but bigger compressor wheel. There are also three different trims from memory.

Best to refer to garrett website for compressor/turbine measurements in order to compare it against 16g td05h.

As far as I remember 16g is relatively close match to smallest trim of gt2871r.

[svanh1993]

Turbine trim on mine is 76 and compressors trim is 48
What are the 16g

[GSR]

With the trims you've given me, your gt2871r has compressor wheel with 49.20mm inducer and 71mm exducer. Turbine wheel with the trim 76 has 53mm inducer and 46.2mm exducer. And you have options of having .64 A/R or .86 A/R exhaust housings.

 

16g td05h has a compressor wheel with 48.3 inducer and 68mm exducer. Turbine wheel has a 56mm inducer and 49.2 exducer. Exhaust housing is 7cm^2 which is equivalent to .49 A/R.

 

Pic below might make it easier to compare

 

In conclusion gt2871r has a slightly bigger compressor wheel but smaller turbine. However has a larger A/R exhaust housing than 16G TD05H.

 

If you wish to get into more detail which one is more suitable you might want to use calculators available online to plot engine demand data at various boost levels and rpm against compressor maps.

[VIN18M]

What site did you get that comparison from GSR?

Good info!

[GSR]

I created it myself, however data is from garrett website and this forum.

[svanh1993]

Yeah sounds about right I have the AR.64

[leadfoot]

with that ar ratio i'd expect boost around 3500-4000 it's a fat back end made for 2.5-3l engines