Hi all,
kinda new to S2ks but ive been doing a lot of research around and i cant really find many people using smaller turbos. I see heaps of GT30+ sized turbos floating around on stock motors and built motors but i dont see anyone using something like a GTX2876. I thought those turbos would suit the motor really well (stock motor) for a good solid power band with earlier spool (seems like F20Cs dont build boost very quickly). I mean, im coming from the EVO world where getting full boost mid 3700 RPM and making 400whp is pretty simple. And im not expecting anything insane (9k revs gives you a nice powerband) but even the new BRZ/86 kits are using GTX2876 turbos and making 400whp. Just wondering if anyone has used a smaller turbo around here?

 

Some folks have done it. Problem is, a 9k redline requires so much more cfm to keep torque from dropping off. A 3076 or 3071 on a good manifold will spool instantly and make power all the way to redline on these motors. Why limit yourself to 400whp with a gt28 when you can have similar spool and 500whp (gt30) or 550whp (gtx30)?

 

I would actually really like to see someone do a gtx28, I havnt seen one on a s2k yet

 

Would be a tire spin monssssta

 

http://www.evans-tuning.com/dynos/20...275tq-aem-ems/

I feel the gt30's spool very well and carry power all the way to redline. This is the only example of 28's I have seen in the past and it looks like it makes great power.

 

I have a gt3076r run 10psi and have a little over 400whp. Turbo spools at about 3500 and hits full boost at about 4500 and carries to 9k. Evos have a much smaller rev range to consider as well.

On a road circuit the f20 will stay in the 5800 rpm range when going around corners so when you hit the gas out of them you'll make really nice power but not too much to make the car unpredictable.

 

Yeh at 9000rpm the cfm required to prevent drop off must be bigger, something like a 28 turbo prob would be too small. good point

heres an evo 20g comp turbo with a surge ported cover:


I just love the insane spool on the evos with stock sized turbos which can still break 400whp, but if you realise the F20 has another 2000rpm range i guess a GT3071/6 would suit pretty well in that case. I find it all very interesting. Im thinking to move over to an s2k from my evo, the evo is great but kinda boring. You dont feel like ur driving it. Not to mention how insanely tight packed it is. I did the gearbox, possibly the hardest thing ive ever done on a car. Its not made to fit there, same with the turbo back exhaust, nothing is made to service, its made to fit perfectly when packed.

s2k looks like a good project car, its a drivers car

 

Nothing drives like an s2000 in the price range. Thats a fact. Boost it and upgrade suspension and brakes and you'll have a budget super car.

 

yeh the community seems really good too which is a massive bonus!

 

I think the new GTX3067 Garrett is releasing (they showed it on their Facebook page) would be the perfect 400whp turbo. IMO, the GT28 turbine wheel is too small for the S2000 (because our engines flow a ton) and will choke off the engine on the top end. The GT30 size turbine has proven to flow well enough in the 400whp-500whp range. The GTX 67mm compressor wheel flows a little under 50 lbs/min, so enough for plenty of power. With the 67mm compressor wheel being smaller than the 71mm and 76mm compressor wheels, the turbo should be snappier.

I owned an Evo before stepping to the S2k; the Evo is phenomenal, no doubt, but it's a less engaging drive IMO. I know of a couple other S2k owners who have come from the Evo.