joblo1978

iTrader: (14)

A buddy of mine recently had a backfire (most likely not enough fuel) on a 150shot and grenaded his FAST. He's got some power goals and was considering a 408. I explained to him he could meet his goals for less money freshening up his 100,000+ mile 346 with forged pistons and rods with the stock crank. We didn't look long but the PRC 227's look like some sweet heads and I think he's considering a FAST 102mm. He's currently running stage 1 LS6 heads from TSP and a 228/228 cam with full bolt-ons. He enjoys running the spray but I don't think he enjoyed the backfire much. I think he is looking towards a high-revving street/strip car that will handle a 150-200 shot when he feels like it.

This is just currently in the planning phase as he is saving cash to get his build together.

What would you guys recommend for something like this? Obviously some fuel pump and injector upgrades are in order to prevent this from happening again, but give us your input on cam, piston, and rod selection. Also input on engine machining, intake options, and any other advice.

Thanks

Jonnie Bravo

iTrader: (3)

Well if he wants something that is high reving then I personally would not go with a stroked bigger displacement motor but forged what he currently has. I would go with something light and go with a bigger cam then the one that he currently has installed. Not knowing what his current nitrous set up is it's hard to comment but I personally am a big fan of a properly built direct port setup and if he is wanting a 150-200 shot and you're building a new motor, then I would look into running a two system kit with a 100 shot first system and 150 second.

joblo1978

iTrader: (14)

He is running a NX MAF kit, he can support dual stages if needed I believe. I mentioned this to him also. He sais the 150 is enough for him, but I say he will want more after he gets the feel for it. Better to overbuild than underbuild anyways.

He ran 100 shot for years with no issues. First night on the 150 and it went.

BTW, his engine seems to be fine after the backfire. He actually completed the pass with a huge hole in the intake. Braking was a problem obviously, but he did finish the pass. He just installed a used LS6 and it started with no issues.

garygnu

may be epoxy the hole in the intake,or buy the piece upper shell ,lower shell,that is damaged.the prc227 would make great power with a custom cam.

waterbug1999

iTrader: (3)

I ran 100 shot with no problem too, I bump up to 150 shot and bang, big backfire right before half track.. 5 of my 8 plugs had melted the tips off, ran out of fuel. Instead of my intake blowing up, the pressure came out, went in the hood and blew it in half.

1baaadz28

iTrader: (9)

I had the same problem, ran 75,100 fine but bumped upto 150 and the first time i tried to spray it blew the backside out of my intake. so now im ''OVERBUILDING'',(forged 383,all callies internals, 2 stagedirect port 125 and 200)

zacht

iTrader: (18)

how were you guys running out of fuel with a 150? was it on the stock pump?

i was running a 50 and went to a walbro 255 and a hotwire kit.

were your problems the pump itself or because you were pulling fuel from the rail???

waterbug1999

iTrader: (3)

At the time I had a 255 walbro and was pulling fuel from the rail, they are only rated to 500-550hp. Just found where it maxed out, I since added a standalone and replaced the pump (it went out) to the racetronix pump and hotwire kit.

zacht

iTrader: (18)

hm interesting. just read of people going 150 shots.... so the first time was you didnt have a hotwire kit? do you think thats what did it?

waterbug1999

iTrader: (3)

if u run a stock motor and a 150 shot, youll be fine..

I had heads/cam/90/90 set up pushing 415-425 at the wheels.. So, do the math and u can see where the pump runs out.

zacht

iTrader: (18)

ah duh. true. hm. i have a h/c/i setup im doing this winter. but also wanted to go 150 on that. so you think i need a dedicated fuel system for that?

might hit up some sort of race fuel low pressure setup....hm....

waterbug1999

iTrader: (3)

you might be able to get away with it having the hotwire kit, not too sure..

Were just saying that on a 255 alone it runs out at the 500-550hp level so be careful. If you have the $$ for a standalone that would do the trick.

zacht

iTrader: (18)

yeah, i also have a wideband, and hptuners, so i guess if it starts going lean, ill have to watch it. might put in a fuel pressure sensor and log that into hptuners or something...