Cylinder head uprate 0ptions for Gt2871r?

[STEALTHQUATTRO]

Hi guys am running gt2871r on 8L 1.8t quattro block is uprated but using stock small port head!
Av got a large port head am going to uprate but not sure of my options and benefits!
I have been having a little discussion on another thread but moved it to here!

At the moment I have:

Supertech tripple groove Nitrated intake valves
Manganeise bronze guides

I know I need:

Supertech triple groove inconnel exhaust valves
Oem springs

And want to discuss:
1. Av got manganeis bronze guides, wanted to know if anyone have used them?
2. When do I need new lifters
3. When Donizetti need new cams?
4.when do I need new vvt?
5. Do I need new colets?
6. Whats the gain on fast road cams and what's the reliability issues?
7. Is it worth porting or polishing a large port head?

Heres some pics of my head:

 

[beachbuggy]

Why the new thread.. Now I have to read 2 threads to follow what's going on....

 

[STEALTHQUATTRO]

Where is yours? Al cancel mine as I could't find one yesterday.

 

[boost-addict]

im not right in to these audi blocks yet, still learning on there tunabilty, but i know port and polishing and a cam can give good results, especially running a bt.

on that front personally, from experience i would have the cam judged after p&p because torque and power curves will change slightly.
so if it were me. id then have it dyno'd to find the peak points, and have the cam come on just before those points, but this also depends on how drivable you want the car. you may call it a fast road cam but that may not have the right lift and duration your looking for, i had a c20let dyno'd and then cammed by piper. i told them how i wanted it to drive and told them its peak points and after it was fitted it was just a monster for what it was!

do you know what your running. as i dont know the other thread so could be there!

 

[beachbuggy]

I was referring to your main thread, I've been following your tribulations with your car with a keen eye and was just referring to the fact that I have to read both your threads now to see what's happening... Rather than following 1... I will happily your read your other thread, including the cylinder head question posted here, isn't it all part and parcel? Sorry if it isn't I'll just keep an eye on this one as well if that's the case.

 

[STEALTHQUATTRO]

spec is:
1.8t quattro ary, stock head 90k on stock, 30k on conversion
je pistons
scat rods
sach kevlar clutch
jabba sport exhaust manifold
t25 gt2871r hot side: .86 A/R
3' exhaust catback from pipeworx
200 cell cat
genasis 550 injectors
proalloy intercooler
bosch 044 fuel pump
s3 maf
Egt retrofit
Snow performance water meth

Dyno at: 362 bhp

I don't think I can get much more out of this turbo you know! But I may be changing to gr3071 at some point!

 

[STEALTHQUATTRO]

Beach buggy I wNt to throw all the head info on here and leave the boost issue but am dense and don't know how to move it over! Do u hav any idea? Ad rather that than confuse everyone!

 

[superkarl]

Do you care about lag?

And I'd decide what you are going to do first, gt28 or gt30. And again, a lot of these questions come down to how deep your pockets are.

 

[coatesy]

spec is:

Snow performance water meth

i think you should sell me this for £3.56!

but seriously you need to sit down and set a goal for what you want, power wise and money wise as superkarl said.

i mean you have already got a super fast car that could make more BHP with a large port head and especially if you get it ported and polished and if you do get it ported and polished get Andrew off here to do it, his work is awesome.

also read this if you already haven't http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/75685-lots-big-turbo-high-power-info.html

 

[STEALTHQUATTRO]

am sticking to gt2871 for now but as a distant future upgrade to gt3071.
I don't really like the lag but I know theres not much we can do if I prefer higher numbers!

 

[Andrew@A.L.D]

I did a bit of work to wellys large port head ( only the exhaust side ) he saw that the turbo spool was 100 rpm sooner and gain more in power and torque.

I have obtained a damaged ported head done by JNL that i use as a guide line and i'm also looking to develop the head even more thats when i get another large port to cut in the waterjet

I've recently done more work to mine also and found my turbo spools 300 rpm sooner

 

[STEALTHQUATTRO]

Hmm sounds good, I may consider that! Does anyone know the max whp out of a gr2871? As get the A/R 1.06 but they don't do on for gr2871!!

 

[Sam_]

Paul (Tuffty) on here has only seen <350bhp from memory but abroad (and on other engines) it's closer 400bhp but I guess that's dependent on a few factors (rollers, engine/turbo spec, mapping, etc). The one I have lined up is a .86 but I'll have a 2.0. I'd go GT30 if I had more of a choice though.

 

[<tuffty/>]

Max flywheel hp from a GT2871 is around 370hp using a tubular manifold, ported small port head, supertech valve gear, large inlet manifold etc...

Boost did tail off a bit IIRC but its still an internally gated piece of kit and if you are heading towards 400hp in the future then an externally gated GT3071 is where you want to be... check out the kit StaceyS3 is using for is build...

The T25 internally gated GT30 I had originally is pretty much topped out at 380ish hp... T3 0.63 hotside will work fine on a 1.8 but have seen good results using a Tial v-band 0.82 hotside on a stroker...

You don't need to port the large port as it flows very well as std but generally you only need to open the exhaust ports if the exhaust manifold you are using has larger runners as the LP ex ports are larger than SP ex ports anyway... all you do on the inlets as a rule is smooth and port match as they are fairly open anyway and while there are +1mm valves available they are not needed... Bill runs nearly 600hp on a ported LP head with std size valves...

What you need to do on your LP head as a minimum is...

Get the head checked for cracks (pressure test) and make sure its not warped....

Replace the valve guides with the ones you have as they will be fine and you already have them so you may as well use them...

As you have triple groove valves already you can reuse your existing springs retainers and collets but bin off the SS exaust valves and get inconel ones... this will give you a rev limit of up to 7.8k tops on a street set up... if you want springs then I believe Cat Cams do a set that work with OEM collets

If you want to do it properly of course I would bin off the lot and go single groove valves (they come with collets) and supertech titanium retainers and springs

That will give you a head capable of supporting GT3071 power and more....

Optionally you can replace the followers (roughly £200 a set) if you think they are worn and maybe cams... the IE street cams look good on paper but are never in stock...

All this of course is dependant on budget and what you are willing to spend to get the end result... its easy to get to a point of diminishing returns.... if building a race engine then use new stuff everywhere if you want to be sure nothing will fail due to it being old... for a fast road car then its not going to matter so much

<tuffty/>

 

[Sam_]

I assume that was a .64 Tuffty? The .82/86 seem to get good results?

 

[superkarl]

I assume that was a .64 Tuffty? The .82/86 seem to get good results?

bigger AR and bit better top end, but you sacrifice spool.

1.06 would be ****ing stupid on our 1.8.

 

[<tuffty/>]

I assume that was a .64 Tuffty? The .82/86 seem to get good results?

It was 0.64 yeah... but it was designed for the smaller GT30 turbine rather than the full sized one... wasn't a fantastic design tbh and just run very hot... in hindsight etc... but it all adds to the learning experience...

GT3071r comes without a hotside typically so you spec to what you want... they typically come with the the std larger comp housing and 4" inlet too... mines got a modded GT28 housing and outlet to keep it compact...

Personally I wouldn't go internal gate on a turbo bigger than a GT2871... Garretts don't seem to do a decent enough housing to cope with it...

If I had my time again I would go GTX3071r, 0.82 Tial housing, external gate and stroker... from the results (power/torque wise) on the LCR we had in a while back it would be perfect for a quattro setup...

<tuffty/>

 

[Sam_]

Yeah, that's what I was asking. I presume the 370bhp was with a .64 as they tend to make a touch more with the larger housing (certainly when bolted to other 1.8-2.0 engines and on other 1.8Ts) but higher up like you say.

 

[Sam_]

If I had my time again I would go GTX3071r, 0.82 Tial housing, external gate and stroker... from the results (power/torque wise) on the LCR we had in a while back it would be perfect for a quattro setup...

<tuffty/>

Yeah that would be an awesome setup.

I read about creep on the T25 framed internal gated GT30s but again someone mentioned a larger housing helped there too but I can't find the link now. That was for an SR20 engine though.

 

[<tuffty/>]

T25 is just a little too small at that power level tbh... 1.8's need quite a lot of boost to get the power out of them... this enevitably generates heat and we all know the end result of that...

Since swapping to the T3 0.64 and external gate my EGT's are much lower and spool etc seems unaffected... will soon see once I have the inlet on etc and get the old girl on the dyno...

<tuffty/>

 

[Sam_]

Yeah you need to get it done! Keen to see it do well. I want to do something similar, eventually.

 

[badger5]

t25 internal gated GT30 do creep... like a mofo...

porting.. but external gate is the way fwd for me.. especially on GT30 and bigger turbos

when "better" is mentioned, it does not make it spool quicker or account for breadth of the power/torque..
I would always lean twds a smaller hotside on a road car as unless its built to rev and owner wants to have to rev it to get it to go and spool, the few extra top end bhp potential will be at the cost of overall spool, and width of the power delivery

 

[STEALTHQUATTRO]

Is it true parts ware differently? So I could't just use the least worn lifters out of both 1,8 ADR head and 1.8t ARY head to get the best of both?
Just wondered as the ADR lifters don't look very worn.
Ta