im building a 396 that will eventually have nitrous, but im just concentrating on setting it up na right now. ive decided that id like to use the stock lines for now, and figure the nitrous system out later once i get the car running for a while. what im asking is, what do i need for now? im thinking the racetronics wiring kit and a walbro 255 pump? on stock lines and regulator, would that be enought to support 500 at the wheels on a 396 cid engine with an le3 top end and all supporting mods? i know i recently got alot of adivice in my "500/600 rwhp 396" thread, but ive decided to worry about the nitrous system later, and just concentrate on getting the car to run well na for now.

 

For sure the stock lines and regulator will be fine. You MIGHT even get aawy with a stock pump if you upgrade the wiring and use a voltage booster to it, but a 255lph is a better solution assuming you don't mind dropping the tank.

Rich

 

The problem with a voltage booster is:
a) It is a patch, not a fix
b) It costs way more than the fix, which would be a 255 lph pump.

That power range is right on the ragged edge, I just wouldn't be comfortable doing it on a car I care about.
Either way, put a hotwire harness like the Racetronix on it. Vastly superior to factory wiring.
I used the trap door method on mine. A little tough to cut holes in the body, but when one of the lines came loose this spring all I had to do was open the door, reattach the line, and close it up again.

 

dropping the tank doesnt bother me, ive got no rear end or exaust in the car right now, which is why im doing the fuel stuff now. i might drop it or just do a trap door incase i need in later its already there. anyways off topic... ive seen the 255 pumps rated to 600 hp, assuming thats at the fly, ill be *hopefully* about 50 horse away from that at the fly, which to me is also pushing it. what should i do? i know im not into dual pump territory yet, possibly with the spray but that wont be for a while. so what do i do to be on the safe side? whats walbro make thats bigger than a 255? thanks guys!!

 

Nothing AFIK. Just stuff 2 of them into the fuel tank.

 

AFIK??? sorry lol. dont know that one... and stuffing 2 in there will not bother me a bit if thats what needs done. that just seems like way overkill for my combo NA. and i dont wanna skimp or anything, but i just didnt think running 2 constantly was a good idea? gotta be something in between shouldnt there be? thanks guys!!

 

AFAIK = As Far As I Know
There is a Bosch that has slightly higher capacity, but at twice the price of a Walbro. The most common solution is dualing Walbros.
You don't want to run both all the time. The correctly implemented dual pump solutions have a triggering device for the second pump. For example, if you have Nitrous, you could use a WOT switch or something called a Window Switch. I use a Hobbs switch b/c I run FI.

 

He doesn't need dual pumps. There are two versions of the Walbro 255. One of them is "high pressure" and flows 255 LPH at a higher pressure, which means it will flow more than the "low pressure" 255 LPH pump at 43.5psi. Read what rskrause posted.

 

when you say read what rskrause posted, are you saying i should use a booster? i probably will go with dual pumps later, but not yet. i just need a solution for now... he didnt really say anything about a high or low pressure pump. so your saying i need the high pressure 255 but still run it at 43.5 ? thanks!

 

There seems to be some confusion here.
First, don't use a booster. Get the volume you need from the pump itself.
Second, you only need one 255lph pump at this time. If you do increase your horsepower requirements, you need to plan on a second pump at a later date.
Third, when you install the 255lph pump, be sure and install a hotwire kit to support the increased current demands of the new pump.
Lastly, it is true that Walbro makes a low pressure pump, but any vendor worth their salt knows that our cars need the high pressure pump. The model number is GSS340.

 

ok awesome this helps alot. so your saying this GSS340 will be enought fuel for my combination right now? and add a second later with the spray correct? thanks for all the help guys! also the hot wire kit, will i need to drop the tank for anything or will i be ok installing that to with just a trap door? thanks guys!

 

In order to access the pump you must either drop the tank or cut the access door.
The Racetronix kit contains an excellent hotwire kit and a Walbro pump. All the fab work is done for you, so it is pretty much plug-n-play.
There are excellent threads on this site concerning adding the second pump. It's not rocket science, it just takes preparation and careful execution.

 

i know that, but im saying will i be able to access all the plugs for the fuel pump for the new harness with just cutting the access door?

 

Ah, I see. Yes, you will be able to access using the door. I did mine all at the same time. Part of the kit (the pump part or the hotwire part, IDK) required that I replace two of the wires inside the tank, from the bulkhead connector to the pump itself. Just a heads up.

 

I would rather drop the tank than cut a hole in my car.

Rich