How much HP or air flow can stock S4 injectors support?

S4intheOC · 11-28-2005, 04:10 PM

I know 3- guys are out there with them, but what is approximately the limit? Would 400 crank hp be possible?

Thanks

Kevins42 · 11-28-2005, 04:17 PM

Somewhere in the 300whp to 400bhp range, I'd guess that's where it would max out with KO3s.

S4intheOC · 11-28-2005, 04:34 PM

Aren't some of the 3- guys (KO4s w/o fueling) out there running 315 or so whp? Is that because they got an aftermarket fuel pump and FPR? I'm just trying to figure out what the stock system is capable of.

EdyJun · 11-28-2005, 05:11 PM

Injector: whats a safe psi to run on stock fueling? look for it under engine.

EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help)

DAP@EPL · 11-28-2005, 07:05 PM

the stock housing. With my APR v5.0 Stage 3-, that was 305 hp at the wheels on a dynapack dyno and 93 octane.

IIRC it worked out to around 370 crank hp. 400 crank hp would probably be about the absolute upper limit of the stock injectors before you started getting dangerously lean at the top end.

-Dave Pramanik

S4intheOC · 11-28-2005, 07:43 PM

a good idea to have water/methanol injection to suppliment the stock fuel system. Plus it would help reduce IATs, EGTs and add detonation resistance. How much headroom do you think I'd have w/ my 2+ set up on 100oct (assuming no H2O inject). I'm dynoing this Sunday and from what I've seen on here, similar setups make around 285 at the wheels. So I might have about 20 whp potential left in the stock fuel system?

Thanks again.

S4intheOC · 11-28-2005, 07:47 PM

DAP@EPL · 11-28-2005, 07:59 PM

I can't really comment on how much wheel hp you'll see as it really depends on the specific dyno and the conditions on that day.

FWIW, I don't think the K03s are capable of flowing enough air to max out the stock injectors without being stressed beyond their limits. You shouldn't see anything above 280-290 g/sec on a K03 chip unless you somehow increase boost beyond requested levels.

And thanks on the sig. I like yours as well.

-Dave Pramanik

S4intheOC · 11-28-2005, 08:11 PM

Squeeze for one. It wouldn't take much to go from 280 to 300 g/sec. Secondly in conjunction with water injection there are guys on the aquamist boards that mix in 30% RC car Nitro fuel (which itself is a mix of mostly methanol and some nitro) and that adds extra oxygen and fuel. They say the results are very noticeable on the highend. So, I'm not saying I'd get to 400 crank hp by the pure turbo only method, but it'd still be sweet and something different too!

But, I'll probably just end up waxing my clutch anyways so none of this matters. :P Knock on wood. But we'll never know till we try.

<edit> I try.

No one else is gonna run nitro water injection + squeeze. LOL

DAP@EPL · 11-28-2005, 08:13 PM

at the top end.

-Dave Pramanik

11-28-2005, 04:10 PM	#1
S4intheOC AudiWorld Member Garage is empty, add now Join Date: Sep 2005 Posts: 511	How much HP or air flow can stock S4 injectors support? I know 3- guys are out there with them, but what is approximately the limit? Would 400 crank hp be possible? Thanks __________________ 2001.5 Nogaro S4 6spd WMS / EPL built and tuned. Tials.

11-28-2005, 04:17 PM	#2
Kevins42 AudiWorld Senior Member Garage is empty, add now Join Date: Jul 2003 Location: Allentown , PA Posts: 1,373	WHP or at the crank ? Somewhere in the 300whp to 400bhp range, I'd guess that's where it would max out with KO3s. __________________ ASP stage 3+

11-28-2005, 04:34 PM	#3
S4intheOC AudiWorld Member Garage is empty, add now Join Date: Sep 2005 Posts: 511	Either, I can figure it out from what ever you guys give me. Aren't some of the 3- guys (KO4s w/o fueling) out there running 315 or so whp? Is that because they got an aftermarket fuel pump and FPR? I'm just trying to figure out what the stock system is capable of. __________________ 2001.5 Nogaro S4 6spd WMS / EPL built and tuned. Tials.

11-28-2005, 05:11 PM	#4
EdyJun AudiWorld Super User Garage is empty, add now Join Date: Dec 2002 Posts: 2,719	This might help Injector: whats a safe psi to run on stock fueling? look for it under engine. EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) __________________ 2000 Audi S4 STG 3 FATS = 3.66 w/ 91 oct AIM: EdyJun 11 September 2001 In their honor. In their memory. <font color="red">---------------------------------------------------------- <u><big> <a href="http://homepage.mac.com/edyjun1/S4/index.htm">EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) </a> </big> </u>---------------------------------------------------------- </font>

11-28-2005, 07:05 PM	#5
DAP@EPL Audiworld Sponsor Garage is empty, add now Join Date: Jun 2000 Posts: 19,700	The stock injectors start to lean out between 310 and 325 g/sec as indicated on the Hitachi MAF in the stock housing. With my APR v5.0 Stage 3-, that was 305 hp at the wheels on a dynapack dyno and 93 octane. IIRC it worked out to around 370 crank hp. 400 crank hp would probably be about the absolute upper limit of the stock injectors before you started getting dangerously lean at the top end. -Dave Pramanik __________________

11-28-2005, 07:43 PM	#6
S4intheOC AudiWorld Member Garage is empty, add now Join Date: Sep 2005 Posts: 511	HMMM, thank you DAP. So if I ultimately wanted to get 400 @ the crank it might be a good idea to have water/methanol injection to suppliment the stock fuel system. Plus it would help reduce IATs, EGTs and add detonation resistance. How much headroom do you think I'd have w/ my 2+ set up on 100oct (assuming no H2O inject). I'm dynoing this Sunday and from what I've seen on here, similar setups make around 285 at the wheels. So I might have about 20 whp potential left in the stock fuel system? Thanks again. __________________ 2001.5 Nogaro S4 6spd WMS / EPL built and tuned. Tials.

11-28-2005, 07:47 PM	#7
S4intheOC AudiWorld Member Garage is empty, add now Join Date: Sep 2005 Posts: 511	BTW...I love your sig pic. __________________ 2001.5 Nogaro S4 6spd WMS / EPL built and tuned. Tials.

11-28-2005, 07:59 PM	#8
DAP@EPL Audiworld Sponsor Garage is empty, add now Join Date: Jun 2000 Posts: 19,700	100 oct. runs cooler so you can safely run a bit leaner than on pump gas. I can't really comment on how much wheel hp you'll see as it really depends on the specific dyno and the conditions on that day. FWIW, I don't think the K03s are capable of flowing enough air to max out the stock injectors without being stressed beyond their limits. You shouldn't see anything above 280-290 g/sec on a K03 chip unless you somehow increase boost beyond requested levels. And thanks on the sig. I like yours as well. -Dave Pramanik __________________

11-28-2005, 08:11 PM	#9
S4intheOC AudiWorld Member Garage is empty, add now Join Date: Sep 2005 Posts: 511	Well there's other ways to flow more air. Squeeze for one. It wouldn't take much to go from 280 to 300 g/sec. Secondly in conjunction with water injection there are guys on the aquamist boards that mix in 30% RC car Nitro fuel (which itself is a mix of mostly methanol and some nitro) and that adds extra oxygen and fuel. They say the results are very noticeable on the highend. So, I'm not saying I'd get to 400 crank hp by the pure turbo only method, but it'd still be sweet and something different too! But, I'll probably just end up waxing my clutch anyways so none of this matters. :P Knock on wood. But we'll never know till we try. <edit> I try. No one else is gonna run nitro water injection + squeeze. LOL __________________ 2001.5 Nogaro S4 6spd WMS / EPL built and tuned. Tials.

11-28-2005, 08:13 PM	#10
DAP@EPL Audiworld Sponsor Garage is empty, add now Join Date: Jun 2000 Posts: 19,700	Gotcha. Well the safest way would be to have a wideband handy to make sure its not running too lean at the top end. -Dave Pramanik __________________

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