One for Drifter or Adam L

[haz's S15R]

Hi guys, didn't get much chance to speak to anyone at japfest (adam!) but you two seem to be running the high power setups and I'm after a bit of advice.:nod: My car is presently running 388hp and my ultimate goal is to run 450 - 500 ish. I have the "bolt on" mods required to do this but was interested in your thoughts on my proposed internal setup. I'm planning on running 8.5:1 90mm pistons, liners, forged rods, stock crank and my current stage 2 top end. I have 1000cc top feed injectors and was thinking about upping fpr to 4 bar - any thoughts??

Anybody's thoughts are welcome!!!!

Thanks, Haz

 

[Adam L]

You don't need to run such large diameter pistons, why not go with stock bore or a .5mm hone if the bores are slightly scored? That'll save the block from being scrap in the future. You'll want a fpr anyway for those injectors with a top feed fuel rail, so you can fiddle with fuel pressures depending of what boost pressure you run? You're just going to increase the injectors flow rate with higher pressure rates and I seriously doubt you'll be maxing those injectors at that power level.

 

[haz's S15R]

I was thinking of running 90mm pistons because that will give me a 2.2 and with the stock crank I can still have a 9000rpm rev limit, also liners are recommended for engines pushing any more than 450bhp...
I already run a fpr and top mount low impedance 720cc inj. but these are at 86% duty at 7250rpm and I'm only running 390bhp, I thought that drifter had maxed his 3bar 1000cc inj. and that had held him back on his last attempt at mapping, I was hoping to avoid this by upping the pressure and running a more substantial pump...
I'm planning on running a 3071 at roughly 1.4 bar so just don't want to make any mistakes at the buying stage!

 

[Adam L]

You may want to look into a solid lifter conversion if you're planning on revving that high, bit its not really needed with a turbo of that size I'd have thought. The 2.2 cc increase won't help overall power, it'll just help the turbo spool up a little better and increase torque. You may need to run more than 1.4 bar too, as that sounds a bit optimistic on a 3071 for 450bhp. I ran that last year and was nowhere near that output, albeit on a stock engine, cams will help but not 60-70bhp worth.

Scott did get close to massing the injectors but as you say that was on standard fuel pressure, I'm sure he changed the pump for the Stealth type apt supply though.

 

[drifter]

Just seen this

Fuel wise, I'm running a massive Mazworx -10an fuel rail, with a Sard FPR, 1000cc injectors and the Aeromotive stealth fuel pump. I am at the point where injector duty is a problem, main reason for this is size of the supply pipe from the pump to the FPR/rail. My plan is to replace the smaller Sard FPR with an Aeromotive -6an jobbie, bigger fuel lines from the pump and change the rail so that it's fed from both ends with a centre return. That should cure any starvation to the rail, and make the supply more even. I've also hard wired the pump to make sure it gets max voltage. I could just up the pressure, but it might not make a difference if there's not enough fuel flowing.

Re the engine, the one thing I regret the most after having my engine built was not installing liners. To be fair though, I never intended to go this far I wouldn't go bigger diameter pistons, stick to normal oversize. If my engine does fail for any reason, it WILL be getting a full 2.2ltr stroker kit though If you want 500bhp then go for the GTX3071 with the smaller housing and it'll be pretty responsive. Mine is mapped to 8000rpm on hydraulic lifters, but with a full Ferrea valve spring kit to stop valve bounce. It doesn't stop pulling.....ever If you wanted a bit less have a look at the GTX2867 as it could be just the job for a fast response mid 400bhp

 

[haz's S15R]

Thanks guys, thats just the sort of advice/help i was after to avoid screwing stuff up!!!:rotfl:

One last thing, does anyone know what sort of bhp you can sqeeze from a gtx2871??? I keep hearing that it will push the same quantity of air as the old gt3071?

 

[drifter]

The GTX2867 will be close to the GT3071 I reckon, so mid 400's at a push. Mazworx ran a group buy on the SXOC, but I don't think anyone has on fitted and mapped yet