squealingtires

iTrader: (14)

Maximum recomended dry shot for this:

402 stroker, stock fuel pump with flowmatched/flowchecked SLP 36# injectors. The heads are equivelent to ETP 255 with a ported Weiand intake, BBK 80mm TB, and LS6 MAF if that matters.

With what I've got, what would be my limit for a dry shot to stay on the safe side?

I've read that 125 is ok on a stock 346ci system with stock fuel supply and I'm not sure how the larger displacement is affecting the duty cycle on my injectors. A lot of people are recommending 42# injectors. Just looking for some advice.

Race Car Driver

I don't know why you would stay with stock fuel pump, but if you are, 30# injectors and a 100 dry shot might work OK.

squealingtires

iTrader: (14)

Yeah, the stock fuel pump has gotta go but the "until then" scenerio is what I'm after. Thanks

383LQ4SS

iTrader: (33)

I wouldnt spray anything. I would expect that motor to make ~500 rwhp and just about exceed the stock pumps capacity all by itslef let alone on nitrous. Upgrade immediately to a Walbro intank 255 lph or better yet a Racetronix plug & play if possible. Depending on what you make NA you may not have enough pump for your new motor.

Get a Walbro 255 lph intank, hotwire kit and something like Casper's Voltage booster along with 42lb injectors and youll be good to about 700 rwhp total.

squealingtires

iTrader: (14)

Thanks, I appreciate the great advice. I'll hold off on the nitrous until I get the fuel system squared away. I was thinking the stock pump was getting close to the limit however the air/fuel has been showing pretty rich at WOT (Autometer guage kit). My new engine hasn't been fully tuned yet, just a mail order deal so a full tune is in the plans right now. Would an engine tuner need to have the nitrous system working to be able to fully tune an engine which will see occasional nitrous use? Does this affect the NA performance/mileage if it were tuned for nitrous?

Robert56

iTrader: (2)

What dry kit you going to run?
Robert

cantdrv65

iTrader: (3)

Absolutely do NOT spray a 402 on the stock pump....

Race Car Driver

That's what's so weird about this site. Users ask questions, get varying and differing answers and presumably make decisions based on the results of their "poll." Very unwise.

NitrousDirect

iTrader: (1)

I'd like to see you upgrade your fuel system first

383LQ4SS

iTrader: (33)

as long as its a site where anyone can post there will always be differing views. Its up to the in staller or operater to sift through the info and make the best decision possible. I dont think too many people here are steered in the wrong direction.

If there is a conflict of opinion then take the most conservative route for safety sake

SantaCruz163

iTrader: (6)

I agree with pretty much everyone. Why chance you burning out your brand new 408 over a fuel pump? Don't leave anything to chance when it comes to nitrous, or any high performance setup for that matter. Just wait till you know you have a supporting fuel system to meet your nitrous needs then spray to your hearts content.

Noyzee

iTrader: (37)

throw a pump in it, and hit it wit 200 and go nuts!

Race Car Driver

Noyzee, 11,000 posts? Hey, dude, get a job! Good luck this year>

dirty2kTA

iTrader: (3)

an inline pump might be an option you could look into.... by the way why are you set on a dry kit? there are a few credable shops here in houston that told me 30s were fine w/ that set up if you have a fuel pump to go with it...

Noyzee

iTrader: (37)

i have a job, i own the place. lol and i have been a member for a long time!!

thanks.

squealingtires

iTrader: (14)

I've got an Edelbrock dry kit. plumbed with 150 shot nozzles, fuel pressure safty switch, WOT micro switch and the button on the shifter are the only safty features. Still waiting to hear back from the guy I bought my car from as to what fuel pump was is in there. He was running a superchared LS1 so he might have an aftermarket pump installed but I won't know for sure until I drop the tank. So in the mean time I'm just being cautious and assuming the stock pump is in there.

Anybody see a problem with a 150 shot on the SLP 402 stroker kit mostly concerned with the rings. I need to figure out what the ring gaps are...anybody know top and bottom?

MakoLS1

With what you have I would at least get a 255 pump and some 42lb SVOs.

PREDATOR-Z

I've sprayed 150+ dry regularly on stock block for almost 2 years now. The 402 should not be different. Tuning is where it is at as well as emple fuel supply.
The only parameter that needs a close eye on is your MAF.
Can it handle the 600+ Hp.
Just make sure it is calibrated correctly.

squealingtires

iTrader: (14)

whoops! Upon further investigation i'm running 39# SVO's (not flowchecked) with a GM Performance fuel pump flowing somewhere near 225 gph. It should support 550 hp.

So I guess the injectors should be flowing about 43#/hr is that right in our cars?

I'm gonna go with the Walbro 255 too.