help me build up my fuel system

[heavy_chevy29]

i need more fuel in higher rpms. im running stock lines and a holley mechanical pump thats feeding a motor that make 576hp. i ran it at he track a couple of time before the end of the season, and when i pulled the plugs they are lean at WOT. so over the winter im going to intall an electric fuel pump, with bigger lines and a regulator with a return line. what do you guy reccommend for a fuel pump, and what size lines should i run (i was thinking -8an or -10an). also what are my options for getting the fuel from the tank, should i tap into the factory lines or get the tank sumped. also later on down the line i plan on running about a 150-175 shot of nitrous. please let me know what you think.

[johnjzjz]

567 HP- 3500 lb car the slide rule said 10:40 @ 127.5 MPH --- even if the cars weight is 4000 pounds its still a 10:80 car @ 123 MPH and you dont have a fuel cell ???????????? stock tank in the car ?????????????? what track lets you do that --- a clean shot at 150 will make a 4000 pound car go 9:99 131 mph --- just looking at it from numbers alone -- jz

[bubba428]

Originally Posted by johnjzjz

567 HP- 3500 lb car the slide rule said 10:40 @ 127.5 MPH --- even if the cars weight is 4000 pounds its still a 10:80 car @ 123 MPH and you dont have a fuel cell ???????????? stock tank in the car ?????????????? what track lets you do that --- a clean shot at 150 will make a 4000 pound car go 9:99 131 mph --- just looking at it from numbers alone -- jz

how can you know that? what about tires? transmission gearing? rear gears?

[bubba428]

put a high flow holley pump on it. http://store.summitracing.com/partde...5&autoview=sku
that one should do ya quite well

[heavy_chevy29]

the car weighs 3600lbs with me in it. i ran a best of 11.720 at 116mph(at island dragway). from what i can tell the plugs appear to be pretty lean up top. the car lauches like an animal but seems to fall on its face up top. i do not have a fuel cell and id rather keep it that way. i dont wanna have to build a fire wall for the back. its still a street car. so my plan was to sump the stock tank with 1/2inch fittings to -10an line to the pump and -8an line to the regulator and carb. once all that is done im going to get it dyno tuned so i can see what the A/F is doing. the engine made 576hp and 582ft-lbs at the crank. i forgot to mention that. i would expect to see this car run very low 11s or very high 10s on all motor at about 120ish.

[NJSPEEDER]

Originally Posted by bubba428

how can you know that? what about tires? transmission gearing? rear gears?

there are general conclusions about performance that can be drawn from the most basic outline of vehicle power. they assume the rest of the combo is pretty much optimized already, so they are enough to get a good idea, not an exact predicition.

[NJSPEEDER]

Originally Posted by heavy_chevy29

the car weighs 3600lbs with me in it. i ran a best of 11.720 at 116mph(at island dragway). from what i can tell the plugs appear to be pretty lean up top. the car lauches like an animal but seems to fall on its face up top. i do not have a fuel cell and id rather keep it that way. i dont wanna have to build a fire wall for the back. its still a street car. so my plan was to sump the stock tank with 1/2inch fittings to -10an line to the pump and -8an line to the regulator and carb. once all that is done im going to get it dyno tuned so i can see what the A/F is doing. the engine made 576hp and 582ft-lbs at the crank. i forgot to mention that. i would expect to see this car run very low 11s or very high 10s on all motor at about 120ish.

the easy way to do it would be to look into one of the complete fuel system solutions out there. a few guys i know have had good luck with the aeromotive solutions. the kits come with lines, pump, regulator, and all of the fittings needed to get the job done.
jsut watch out with some of the less expensive kits, you want your return line to be bigger than the feed line. some of the less expensive kits will only include one size line to use.
good luck with it.

[deadtrend1]

Originally Posted by NJSPEEDER

...you want your return line to be bigger than the feed line...

Why so? (not saying you're not correct, just wondering why, for my own knowledge)

[bubba428]

I think its to help keep from having any kind of back pressure on the fuel rail

[johnjzjz]

Originally Posted by deadtrend1

Why so? (not saying you're not correct, just wondering why, for my own knowledge)

if the return line is larger their is no influence in the system caused by the restriction at the fitting angles and the liner inside the hose, the type of liner can and does cause a fluid drag the better hose has a very very smooth inside - the end result is the fuel pressure is much more constant and almost free of bubbles and has less temp added to it - as Tim said the better kits come with smooth angle fittings and correct inside diameters so fuel soaping does not occur the china stuff only works for an engine stand photo -- its all in the little things that cost the most -- jz

[johnjzjz]

Originally Posted by bubba428

how can you know that? what about tires? transmission gearing? rear gears?

Ok to answer : their is a tool all who take racing serious have to look and make sure your not being snookered by the bunch yea use this size tire and this gear WRONG -- and MOROSO makes a Power Speed Calculator # 89650 jeg summit carry it - and its not perfect it does not have a tire spin adjustment or weather correction factor - but it can take lots of guess work and with everything you might want to change and the affect of that change mathematically -- mine is 25 years old my guess its yelloow from age any way i paid 2 bucks for it i think now their 10 i dont know but worth the buy --- jz

[johnjzjz]

Originally Posted by heavy_chevy29

the car weighs 3600lbs with me in it. i ran a best of 11.720 at 116mph(at island dragway). from what i can tell the plugs appear to be pretty lean up top. the car lauches like an animal but seems to fall on its face up top. i do not have a fuel cell and id rather keep it that way. i dont wanna have to build a fire wall for the back. its still a street car. so my plan was to sump the stock tank with 1/2inch fittings to -10an line to the pump and -8an line to the regulator and carb. once all that is done im going to get it dyno tuned so i can see what the A/F is doing. the engine made 576hp and 582ft-lbs at the crank. i forgot to mention that. i would expect to see this car run very low 11s or very high 10s on all motor at about 120ish.

i do not belive cutting and welding bungs in a stock is a good idea but i have seen it before however:

Sfi balancer spec 18.1 > 10:99 and quicker

nitrous bottle in the car must have relief valve and be vented

axle retention device as well

sfi shield on trans bellhousing neutral switch and reverse lock mandatory 10:99 quicker

roll bar 11:49 and quicker / conv 13:49 and a roll cage 10:99 and quicker

and sfi jacket and gloves 13:99 and quicker Nitrous all as per new 2008 and i looked quick might have missed something - their is a thing now about engine Lower engine containment device - 1:8 in the book you might want to ask this year looks to be a little different with that you can do with what equipment in the car -- jz

[heavy_chevy29]

i wasnt going to wled bungs in the stock tank. i was going to get one of those somp kits from competition engineering and have the local radiator shop weld it on. im not to worried about the nitrous because it wont be added until much later, maybe next year.

i have:
sfi balancer
9'' rear with axle retainers
neutral safety switch=reverse lockout

and the cage will come soon

thanks johnjzjz, as usaul you are a huge help

[johnjzjz]

Originally Posted by heavy_chevy29

i wasnt going to wled bungs in the stock tank. i was going to get one of those somp kits from competition engineering and have the local radiator shop weld it on. im not to worried about the nitrous because it wont be added until much later, maybe next year.

i have:
sfi balancer
9'' rear with axle retainers
neutral safety switch=reverse lockout

and the cage will come soon

thanks johnjzjz, as usaul you are a huge help

when it comes time to tune it a dyno is not what we use - we use the track and if you go when we go i can show you the what and how : a book that has everything in the car written down that you know is very helpfully it will allow me to look at all the specs and changes you made and what happened based on race tickets < if your tickets are all over the place and not close i can show you if its spinning the tire slipping shifts or just nosing over from jetting - just by dividing the numbers on the ticket --- tell me more about the car for me its all in the nuts and bolts hahahhahahhahaha --- jz