How high can I take 460's on my 1.6 at stock fuel pressure without exceeding 80% DC?

 

My DCs are 62% max, at around 205rwhp on a Dynojet. 13psi, 465cc Rx7 injectors. They'd probably be good to 230ish?

 

I think that with a dead on tune, you will get 250rwhp. What engine management are you running. I switched over to megasquirt, and will probably squirt on all my cars now. It is awesome.

 

275, or so, perhaps a touch more

 

so what are the calcs you people are using to come up with these numbers? Seems like people generally have differing opinons of how far things will take you, and i'm too lazy to do the numbers myself right now. What BSFC #'s are most accurate with our 1.6 and 1.8l engines?

 

I'm going to be running MS.

 

I use .55 as based on my dyno results, it's the number that seems to work the best.

so

460cc / 10.5 = 43.8 lb/min

43.8 x 80%DC / .55BSFC = 63BHP x 4 = 254BHP

 

damn. the 305's i just bought from you are useless, then ;-)

 

yeah i use .5 most of the time even though my dyno sheets indicate .47 or so it just gives me more leeway. 80% DC is easy to acheive on 460's i had that at 13-14 psi easy 90+% i didn't like that so i went 550's now i am below 80% at 14-15 psi.

 

nah just throw in a FPR the 305's will still get you to 200whp.

 

yeah, i know. i just wanted to poke some fun at brain. :-)

 

These RC Eng based calcs are too pessimistic. Even if you're running on the stingiest mustang.

My 440's made ~260 WHEEL hp at 74% duty cycle. 260/74*80=280
**** math guesstimates. There's real world.

I have RC nozzle type injectors, and would assume them to be slightly more efficient than pintle type rx 460s, and would expect equal power between them.

 

So by your numbers i am at 300whp? sweet that is the best compliment youve given me yet Ben

 

nope. i was also assuming well tuned.

 

the one guy on the other site made like 530whp with 750cc injectors, same math would get you 325whp on 460s. sr20dets also seem to be able to get around 250whp with 370cc injectors. this would also mean my 620s would get me to 438whp lol!

 

They could be jacking up the base pressure.

In my Talon I made 280hp on 450s with 37psi of base pressure. 460s in a Miata with 50psi of base pressure should physically flow enough fuel for over 280hp.

 

zing

 

on my 1.8, I did 260 wheel at 12psi on RX7 460's..... don't remember the duty cycle, but we had plenty of injector left

 

Awesome guys, that's what I needed to know, thanks!

 

Yep this guy is pretty much on the ball.

460cc should get you at around 320rwhp.

Here is a cool lil spread sheet that might help you guys out.