i am doing some number crunching and would like to know what is the max hp that has been run w the stock (550/850) injectors?

single turbo or OE setup... either is fine, just looking for a max real dyno number.

howard

 

i have done just under 290whp pushing the stock injectors on a small single.

 

thanks for your response.... do you know your duty cycle?

 

I did 353rwhp on PFC, stock twins, water/meth at 14-15lbs with a decent street port. Injector duty cycles were high 90s and air/fuel was 12.0:1 towards the end of the pull. Not ideal but the ALS(E&J) took it like a champ. Dyno was probably resding 15-20rwhp high. Car did run with/outrun other cars trapping low 90s in the 1/8th mile. I later ran 16-18psi steadily on a Pettit ecu, but would hear detonation on 3rd and 4th gear pulls. Never dynoed at that boost level with the Pettit. Guessing 350-370rwhp but not safe by any stretch.

 

I have seen 330whp on a dynojet with stock injectors and PFC. Engine didn't last long.

 

300rwhp/295rwtq @ 98 percent duty cycle stock twins @ 12psi, car ran 11.9 in the quarter mile.

 

Very impressive I have a FD with custom manifold but I'm using a hybrid S5 t2 turbo on 12.5 psi of boost. My mods are full exhaust 3 inch, Pettit intercooler, Micro tech lt8 ecu, and wideband. But despite the ecu and smaller turbo I have no idea if the stock fuel system will be up to the task. I'm definitely going with a aftermarket fuel pump but really don't want to use upgraded the rails and lines yet. I guess will see the AFR when I start tuning...My project is almost done

 

I did 315whp at 13psi with M2 ECU, M2 Intake, M2 Large SMIC, 3" DP and RB CB. Unknown IDC

 

I cant believe it that's crazy

 

400.3whp, 100% duty cycle, streetported motor,17-18psi and race gas. Raised fuel pressure.

The worst way to do it and funny it lasted till i went single.

 

That's how the car should come stock

 

thank you to all the respondents, i do appreciate the helpful info.

howard

 

i made 296whp on a dyno jet at 91% duty cycle. street port, 61mm turbo, fmic, supra fuel pump. that was 2 years ago.

 

Totally going about this the wrong way, the science of horsepower is long proven when applied correctly. Which you don't Howard no offence.

The injector setup is

2x 550cc + 2x850cc (assuming 43.5psi rail pressure)
However the standard rail uses ~36psi pressure

The lower fuel pressure derates the flow by sqrt(36/43.5) = 0.909
So the peak flow at static wide open is

(2x550+2x850) * 0.909. So you have 2545.2cc/min to play with. Assume your gasoline has a density of 0.75. That means you have 1908.9 grams of fuel per minute to play with.

Because lb/min is what garrett use, I will change over to those units.

453.6 grams per pound of petrol. So you have 4.21 pounds per minute of fuel flow...

We combine our petrol at 11.5:1 parts mass for mass because that is about as lean as these engines will tolerate at those power levels.

That means we are throwing in 48.42lb/min of air, with our 4.21lb/min fuel

Now the best BSFC I have seen evidence for is 0.63lb/hp/hour.

To turn lb/min into HP we just

HP = 4.21lb/minute of fuel / (60 * 0.63) lb/hp/minute

HP = 401 Brake Horse Power.

We are talking about a front engine rear drive manual transmission car. It is widely accepted in engineering circles that the driveline efficiency is 0.83, or 83%.

Take off your loss figure. 333rwhp.

Period.

If you dyno a figure more than that your dyno is not correctly calibrated, or you are not using a Wankel rotary engine. I'm not calling shenanigans on 350rwhp if it was tuned to 12.0 AFR. That would suggest you achieved 0.6BSFC, which is really good for a rotary.

But really anything more than that I don't believe. 400rwhp not a chance.