Wolf,
The K24 hotsides are a little too big for a 1.8L motor, so for a punchy minimum time-to-torque setup I would go with any of the following depending on the budget:
Billet K16s
Alpha 28s
EFR6258s

I am leaning towards the 3rd option myself, working on a solution to try and get them to fit in a stock-location frame/setup...

 

gtx2863 comes in 0.57 or 0.72 free float v-banded housings, I would get the .72 as the other might be too small for higher boost.

the .72 A/R as far as I know is what the alpha tial uses too.. even for A3076

I would keep my external WGs and headers and just bolt on the turbos, another way is to reinstall my old ported stock headers and buy some Alpha28 and sell the whole turbo kit I run now (turbos, headers, waste gates, lines, etc)


by the other hand, I ve seen some GT-Rs running nicely on 2867s, being able to get 800whp and some use the TIAL turbine housings

Also they use EFR 6758 that corresponds to GTX 2867 ... the EFRs on stroked racing engines did over 1100hp !!!! 2+bar E85. 1 bar by 2500rpms and 2bar @3200rpms on a 4100cmc high CR engine

To be honest I was excited about the 2871s... mneah....




For sure they should be cheaper and work well. If you have already the K24s then it might be the best way to go

I used a regular stage3 clutch for my old A3076 setup @1.55bar..

 

Fadi,
Keep in mind you can't run as much boost on a stock M96/70 as you can on a VR38DETT, meaning you wouldn't be able to take advantage of a higher flowing compressor wheel. Don't discount Tial's own .64 and .82 A/R V-band housings for the gt28 as well...

Here is a stock m96/70 running 1.4bar + meth + straight pipes with an EFR6258, hits all the right spots on the compressor map as you can see:


http://www.turbos.bwauto.com/afterma...6_wrsin=92044&

 

So if I wanted really quick spool say using E85 at lower boost the EFRs or Alphas would be ideal. I was going to do a huge build and go for a 1200 whp beast but the roads in NY are just so ****ed up and are SO unlikely to improve that I cannot see where I would get use for a hyper car.... 650 rwhp - 700 and 600 talk would be good here

 

Great link from BW, thanks! Now I have work to do

 

I have been running GT2871 since 2007. Spooling is very fast but lack of top end. I ran with a tuned GT-R many times and I get a car length and half before he got into full boost.

 

Ce mai faci

The EFR6758 looks interesting if I understand all the numbers

 

Have you built the engine or done rods etc ?

 

No, I'm not at that power level; I'm only running at 510+ awhp. I could get more fuel to get her up near 600 with the same turbos but I'll also need tranny works. I know I have to get engine or rods works if I went GT30xx.

 

TY mate

 

Alpha housings at .63/.64 - not .72
I think the 2871 in .72 would be nice. I've also been battling internal gates for a year on 28s. Just put externals on and it's rock solid

Stay with you external setup, and run a 2868 or 2871 - it will hit harder that k16s

 

I'm going alpha 3076 with an EBC

 

aren't you already at 600+ with tim setup? no need for 3076 to much lag and to big for these #'s. drop billet wheels into your k24 and your at the place you want for 1/3 the cost

 

i was thinking 3076 more friendly for a stock engine ? and have good potential when built later...

 

Having the smallest turbo to reach the desired HP is my goal and if you arent limited by other factors, I guess should be also everybody's goal.

So if lets say my goal would be 700hp, both gt28 and gt30s for example will do it, but gt28 should be better as they will provide the better powerband.

Now the question is if we want to maximize a gt28 setup at some point we are going to increase boost, even we run a 63, 67,71 whell, gt or gtx... and the turbine will not be able to keep up, the turbine wheels are all the same, gt28... the only difference is the housing that might increase a bit the flow.

Looking on the garrrett site, I can say that a
-gt28 0.64 A/R will flow 17-18 lb/min
-gt28 with the bigger 0.86A/R will flow 21lb/min

that is a bit more than
-gt30 with 0.63 flows 20.5-21 lb/min

and
-gt30 with 0.82 flows like 23 lb/min

Some have some translations between lb/min and whp, I will leave that.. but knowing a gt28 0.84A/R will flow like gt30 0.63A/R should give us a good information of how close these two turbos should be if they run the same compressor wheel.

I am sure the gtx71 wheel is huge for the gt28, exaclty how the gtx76 wheel is for the gt30 turbine, will need a lot of boost and perfect setup to maximize the turbine and still be somehow efficient, the idea is why would I choose

gtx2871 over gtx2867
or
gtx3076 over gtx3071

if the compressor wheel is too big and we leave hp on the table anyway? I dont know to answer this... some are doing gtx3076 with 1.02A/R and that should be ok, maybe with a big housing the gt28 can do a good job too? I dont know..

Looking on the compressor wheel graph of all the gtx28 compressor wheels, I would do at least the 67mm as I'd like to be able to do some high boost now an then, the 71mm wheel is questionable as might be too big and the 63mm wheel is optimal for the guys that can stop the HP hunting...