I tell u what i am thinking, Adam and Mikes (am motorsport manifold) gt28rs with a 64 AR. All Mike and adams harware kit, a go for a safe 300-320bhp. I cant see why a Gt28r with a 64 ar cant make nice power on the Ibiza.
 
28rs should make 300whp with ease. Won't fully spool to about 4k though. There's only so much lag you can cope with. get a turbo thats in by 3k and runs to 7.5k. Maximise your powerband at the same time as maximising power.

I've got about 265whp, and I've had more ooh sh1t moments in the last 1000 miles than I've had in the previous 300,000. Un fortunately your brakes don't improve because you get more power. Put this kind of power in an ibeza and don't respect it at your own risk
 
Wilko did you go the full ihi kit manifold the lot. Jabba told me i could make 300bhp on a stock manifold. I have heard the Gt28rs is a little laggy and runs out of power at 7200rpm, the .64 ar being the better one out of the 2.
 
I bought manifold, turbo, oil line in, water line in, exhaust adapter.
Manifold is good. Turbo can be had for half the money, oil and water Line fit (sort of)
used a tt maf housing, and Porsche gt3 injectors with a 4 bar fpr.

The car just makes 300hp (real) at 1.25bar sustained boost. Guys in the states make 250hp on a 28rs on a standard manifold, with a lot of work. This is 290hp ish. At high boost, you may make 300hp on a standard manifold, but it isn't very healthy. My standard manifold was cracked to hell and back after the e05.

The kits good for 330-340hp max with good fuel, proper tuning etc, etc. But to be honest it's enough. I reckon turbos ruining wastegate shut at 1.4 bar at 7000rpm, which is no more than 330hp. Sti spec C uses this turbo, and litchfield imports get 333hp out of it on a 2l with lower compression ratio. I guess they are pretty much maxing out the turbo.
 
Gt2871r peak power is at 6750rpm, IHI is 6692rpm. IHI looks like it makes 117bhp @ the wheels at 3500rpm. The gt2871r looks like 120-125@ the wheels at 3500rpm. And both cars seem to be making 180lbs ft at 3500rpm roughly. I know dyno are diff, but intresting to see figures so slose to each other in just about every dept. Theres people on here with more knowledge than me whats there take on it?.
 
Dynos are different, and the jabba dyno is low load, so the turbo apears to spool up later than it does in reality. Mines hitting full boost by 3.5k, so 300lbft, and making 1 bar by 3k, so >250lbft. Its making 0.5 bar by 2.5k which is 190lbft ish.
I made about 170 whp at 3500 at jbs a couple of weeks ago.

Dynos can be very misleading, as load applied makes such a difference to spool up and also top end power.


The 28rs appears to be aproximately 10-15% bigger in rated airflow capacity from the few charts that I can find, so it's going to spool a little slower than the IHI, but they're both ideal turbos for this engine, retaining wide useable power bands. What use is a turbo that doesn't spool until 5k+?

Also have you noticed how many blown engines have started popping up in the states, now they're pushing 350whp and beyond.
 
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It looks like the Gt28rs ia making 170bhp @ the wheels at 3500rpm and 225lbs ft at 3000rpm and 280lbs ft at 3500rpm. The Gt28rs does look like a nice turbo. It map well be an option to run it at 18.5psi/18psi to the redline and aim for a true 300bhp and about 265-270 whp.
 
Maybe i have got the bhp bug, 300bhp in my ibiza on a Gt28rs and not running it to the death may be the way forward. Not pushing it so hard may be the best option. A true 300bhp Ibiza should still be enough to continue my Scooby Slaying.
 
Remember, you don't want too much torque as its the torque that will break things.

I'd prefer to have 350bhp 290lbft than 350bhp 320lbft.... or atleast until I uprate a few things (Gearbox!).

Ben
 
Ben your driving style will have much more to do with breaking things than actual torque. The torque generated is not enough to make things fail directly. It's the shock loading that'll break things. Lots of wheelspinning, getting air and then landing on ful power, or any other 11/10's behaviour that puts large shocks into the drive train will break stuff.

torque is just down to boost levels. At 18psi, an IHI will make the same torque/power at the same revs as a 28rs. If you want high power, low torque, then you need big revs, which can be just as damaging as high torque, especially to your gearbox.

Run either turbo at 21psi, you'll get 320lbft. You'll just make power earlier in the rev range, and heat will become a problem quicker.
 
Agree about the driving style and shock loadings.

I did however think that running higher revs to achieve big power without too much torque was more friendly on the gearbox (Synchros being the exception). I do know however that high revs stress the engine.

Ben
 
I spotted on vortex a gt28rs with a .64 ar running a constant 17psi it made roughly 250bhp and 250lbs ft at the wheels give or take a few single digit numbers. It was running a little rich and required some fine tuning i think. But its still 280bhp 280lbs ft roughly. Running a constant 18.5psi and leaning it out a little i am sure it would see similar figures as Wilko is running.
 
Right, i've had enough of this big turbo bollocks which has no answer. I will be keeping a very low profile until a concrete kit turns up. So enjoy yourself gents, i am gonna spend my ihi money on going out with the boys on the lash. Catcha later.