basically i will be pushing 660 hp to the ground NA, and will be dumping 150 shot of n2o.

im looking for what size injector i would need. i do not plan on putting anymore n2o than that, so looking for a safe setup for ~800 hp.

 

Using the formula #injector = (HP x BSFC)/ (# of injectors x duty cycle), for your NA setup, you will need at least #52 injectors, assuming a maximum of %80 duty cycle and a safe .5 BSFC. Same injectors will be fine if you spray a wet-shot of nitrous, but for a dry shot, you will have to step them up to ~#63. Also, you can always go a little bigger. Good luck.

 

Check this out Fuel Injector Calculator

 

660 hp to the wheels NA Is that even possable on a NA LT1 Good luck if you don't mind let us in on some of the Parts you chosse for your build up..

Thanks Sean

 

thx for the info. i guess i want really thinking, on a dry n2o setup, then i would have to account for the 810. but im running wet. i only need to worry about the pump in that case.

so for 660 is what i need to aim at.

is there an easy way to find out what BSFC i am running?

 

What are you planning on running for 660rwhp n/a? And how did you come to the 660 # in spacific?

As far as BFSC that site quoted above says-

 

I think your hp numbers are way optimistic unless you are planning a super exotic motor. I think it's not even possible with 23 degree heads and pump gas. I doubt there is any reason you will need injectors larger than ~40lbs/h.

Rich Krause

 

i really couldnt tell you everything that is going into the motor, becuase im learning this as i go along. the motor is being bored .030 over and being stroked to a 383. i know that a lot of the internals are going to be kieth black. as for CR we are shooting for around 12 or 13:1. large cam (numbers to be determinied) and most of the other regular bolt ons.

anyways, before i decided to let Ray Stevens (engine builders name) touch my car, he had another 383 96z that he did that he let me ride in. this thing screamed. he showed me a dyno sheet where the car was rated 658 at the wheels. no spray envolved. anyways, we are building mine for low alt, so it will be about 580 in denver, and should hit ~660 when i get back to sea level.

 

as for heads, i bought lt4 heads before i met ray. we are still in the process of getting the block out of the car, and havent got everything to the machine shop yet. We are unsure if the heads will be able to produce what we need, but we will see.

 

Not to get off topic but i just hate to see you set your hopes to high. If you look at jimlab's $30k+ 396 with AFR 215rr heads he only put out high 6xx Fwhp. So in reality you are going to be a lot lower than even that # unless you are going with some 18* heads or better... and therefor not going to need 50+# inj.

 

Mindgame's 15-degree head 383 put down ~550 RWHP NA on pump gas. My 397 should be in the 570-580 RWHP range when finished and tuned, and we both have heads that flow in the ~335 cfm range and fairly big solid roller cams. I've got a Hogan's sheet metal intake which is likely responsible for some of my advantage over Mindgame's engine, and of course, another 14 cubic inches.

To put another 100 horsepower to the ground NA, it'll take a lot more than a point or two of compression. Your heads will have to be the baddest 23° SBC/LTx heads anyone's ever heard of, and you'll need a solid roller so big that the car will be nearly unstreetable and definitely won't run on pump gas. It'll probably have a ~1,500 rpm idle too.

I can see 650-660 at the rear wheels with nitrous on top of a ~500 RWHP 383, which isn't out of reach with a really good set of ported LT4 heads and a solid roller, but if you're going to make 650+ RWHP NA, you've got your work cut out for you. I suspect that the dyno sheet you saw was on the bottle, not NA, but of course I could be wrong.

 

Sure would love to see that dyno sheet...actually, no, would like to see the car on a dyno with N2O or blower disconnected and lay down that much HP. Seems quite ridiculous, I call on Ray Stevens.

Sorry to hit ya with the bad news, but if anyone could hit that HP mark it would be Jimlab or Mindgame, along with a very select few other members on this board.

 

Just an example from Thunder Racing's Dynojet dyno:

Most NA hp ever produced on their dyno: 540 rwhp from a 4XX cid LS6, 330 cfm heads, 12/1 compression, and a quite large solid roller cam going through a 6 speed.

Another car made 48X rwhp through a loose race converter / automatic and ran 9.70's at the track.

In my experience, it is difficult to get past 450 rwhp NA and very, very rare to see someone get past 500 rwhp NA.

Mike

 

1.7 hp per cid on a street car in Denver..hell no.

8500 rpm nascar motors with HUGE heads, etc only are at about 2 hp/ci

Horsepower loss due to altitude, in my experience is exponential, a stock LT1 will lose 60-75 up there. Theres no way 660 will be 580 in Denver. A normal 400-425 rwhp at sea level heads/cam 383 Lt1 will lose 80-100 hp.

 

Just curious.... if your engine builder can produce 660rwHP from an NA setup, how come you have to ask US what size injectors to use? He should know.

I dyno'd 670rwHP with an M6 and a 250-shot of juice!. I guess I should have gone to Ray Stevens instead of Second Street Speed .

To answer your tech questions.... a very efficiently tuned max performance, fuel injected engine should be able to do better than 0.45 #/HR/HP BSFC. But when you use the formula for injector sizing, you need to use flywheel HP, not rear wheel HP.... so, if you are running a T56, to get 660rwHP you will need make about 760flywheel HP, or if you are running an automatic, you will need a TH400 with a loose convertor, so figure you will have to make 835flywheelHP to net 660rwHP.

Are you beginning to see why people are a little skeptical of your claim of 660rwHP on an N/A setup?