I need to do a bit of fuel system upgrading for a nitrous kit I bought. I'm not sure if I should go with a higher volume in-tank pump or an in-line pump in tandem with my stock pump. Can anyone offer me any advice? If I go with the in-tank I will use the Walbro kit. If I go with an in-line pump I will use the Accel #74702. Can anyone recommend anything else?

I've been doing alot of research lately as my inline is dying and I'm not going to a intank pump. Inline pumps in order from lowest flow to highest.

edit: These are all high pressure pumps for EFI, rated at 45psi.

42GPH Berry Grant 16051 $141

43GPH MSD 2225 $90

45GPH Mallory 4060FI $141 (rebuildable)

50GPH Vortech T-Rex 8F003-265 $195

50GPH BBK 1602 $239

58GPH Holley 512-105 $139

67GPH NOS 15763 $179

80GPH SX Performance 18201 $269

90GPH Aeromotive 11101 $289

90GPH Paxton Granatelli 8001688 $399

110GPH Mallory 5110FI $239 (rebuildable)

There is actually another option that you did not list John.

Thats a Ford in line pump which was used on their F150s between 1987 and 1989. The pump was mounted to the frame and pumped a pressure of 45 psi.

I'm not sure how good they are, but Ford used them for 3 years.

Thanks guys. When you install an in-line pump do you leave the stock pump in the tank and connected? Does the in-line draw throught the stock pump?

I know the in-tank pump is a pain to install but it is worth it. In line pumps are loud very loud. I had a T-Rex inline pump for just 3 weeks and replaced it with a 255lph Walbro and now I can stand to sit in the car.:lala: :lala: :lala:

Will the Walbro support a 400hp engine with a 100hp shot on top pf it? I have no fear of swapping the in-tank pump. I am ,however, scared of making another bad decision about aftermarket parts.

I have the Holley inline pump, 45PSI/255lph.
It makes a little noise.
It shouldn't bother me after I get my radio hooked up right since the music will drown out the sound of the pump.

If this ford pump was for a stock application, I wouldn't even consider it.
Not enough GPH.

Here's how you can determine how much fuel pump you need. Remember there are 3.8 litres in a gallon.

http://www.lt1intake.com/engine_nitrous.htm

The Ford pump was a stock application. I'm not sure however what the rated GPH is. I've heard of a few people using it though without any problems.

I have however dug a little bit deeper in the issue and noted a few other masnufacturers have used in line pumps successfully. A few of the Datsuns (200 and 280 models) as well as Volvo, VW and BMW on certain models. Again - I have not checked the GPH so I'm not sure if they would be useful for a V8 application. Its just interesting to note several upper end manufacturers have used in line pumps successfully without adverse noise levels or mechanical failure.

John, thanks for the link. I did the math and came up with 39gph on just engine and 54gph with a 150HP shot. If I compare these numbers to the numbers found at http://www.autoperformanceengineering.com it looks like I can get away with using the Walbro 255 ltr/hr pump. I'd run a "hotwire" to the pump to ensure adequate voltage. Does this sound correct to you?

I would not run a "hotwire" to the pump, I would use a relay.

The "hotwire" method I was going to use was a method posted by Mr. Burgess on the electronics board last week. I think this is the thread...........

http://www.thirdgen.org/techbb2/show...threadid=73706

Again, Mr. Millican thanks for your help. Does it sound like I should be able to get away with using the Walbro 255 in-tank?

The Walbro unit I bought is a higher pressure one. It flows over 60psi with no troubles, which is excellent for nitrous on a higher HP motor, and superchargers/turbos. Now when you start to run 250-500 shot of nitrous, THEN I'd think about an In-line.

That wiring method sounds like a good idea. I think I might do that on my car.

Great info, John. Man I can't believe how much info this board's collective population has.

What is your current 'loaf of bread' pump..............a Paxton?

Did you consider Bosch pumps? I have one on my 406 that is a Jaguar factory part number...........seems I have no clue what the lph/gph rating is but just wondered if you included them in your research and just didn't post results.

Thanks again for the info...............

Yes, I have an old Paxton Granatelli that's on it's last legs. I want the Mallory 5110FI due to it's 110GPH rated flow at 45psi and it's a rebuildable pump.

When my pump started to get weak I went by the advice of someone and put a Turbo TA pump in my car. After that gave out, I decided to do it the right way. I purchased a Bosch pump and installed in the tank. Yes it does require some extra work to pull the tank out but it truly is the best place for the fuel pump. High pressure pumps are designed to push fuel, not pull it. Being in the tank, the pump benefits from the cooling effect of being submerged in fuel. These pumps are capable of supporting 600-700 hp.

www.geocities.com/dzperf

Who sells the Bosche pumps other than TPIS? Are they better quality than the Walbro's?

Not through a 3/8" fuel line. Which is what we have stock.

So, can you leave the stock pump in, and run them both? Or do you cut the pump wires and relay it to the in-line?

I thought I remember reading years back that Walboro made an inline pump around $100 that worked great...

Is this issue that your motor is putting up more HP than stock, or is my information wrong?

Mathius

I just want more power, and heard that this would be a good idea. But, I dont know where to start on installing it. Can the stock pump stay in?

actually those pumps were in use from 85-91

It was my understanding that the accel 74702 pump is able to be mounted in-tank? I also think this pump was used in porsche 911's ? I also believe there is a difficulty with providing a pickup filter / sock to the inlet. I'll post back with a definitive answer. Or can anyone else confirm? ALOHA