GrandSportC3

How many HP can I expect to gain by changing from mech. to electrical fuel pump?? I have read that it could be as much as 10 HP... However - I would like to see actual dyno results...

Allthrottleandsomebottle

Only way you would see any gain IMHO is by cooler fuel/more fuel and if your PSI is to low for you application.
I installed a NASCAR type heat spacer system on my MECH FP along with 1/2 " SS fuel line from tank to pump. Percolation disappered and I gained a max of 1/10 in the 1/4 on my SB 331 cid. It sure idled and ran better though w/o installing an electric. Of course I dont have 400 cid or more either :eek:

CFI-EFI

I have no idea what you are running, but in general, if the mechanical pump is supplying the need, an electric pump will give you nothing. A fuel pump isn't a horsepower "maker" like a cam or heads. It is an "enabler". In other words, a change to the fuel system, including a pump, doesn't make power, it allows the power the combination has, to be made. The answer lies in whether the present pump is "up to the task" or not. Good luck, and...

RACE ON!!!

Taijutsu

Can you tell us more about the "heat spacer"? I like the idea of cool fuel and cold air.

Allthrottleandsomebottle

Sure can,
http://www.sealsit.com/fuel.asp
I saw it in one of my Eng books back in early 98'.
Under $40 and drops fuel temp in that area 10-15 degrees
Called the maker and grilled them good.......all the right answers.
The original application was for Robert Yates Belt Drive to keep hot oil from entering the the fuel pump cavity. Makes sense to me & it works!
I bought mine from CV products
http://66.155.51.113/default.aspx
:cheers:

GrandSportC3

I thought that there would be at least a 1 - 2 HP gain.. The mech. pump is pushrod operated and therefore takes at least minimal HP to operate.. I could imagine that at higher RPM - it could make at least 2 - 3 HP difference...

My current fuel pump is a 120 GPH Carter fuel pump with 6 PSI fuel pressure.. This might be too little... I noticed that I was running pretty lean at higher rpm's on the dyno... Don't know if it was because of my jetting or because of the fuel pump.. More fuel pressure wouldn't be bad for sure..

CFI-EFI

The altenator doesn't run for free, either. Even if you COULD gain 1, 2, even 3 horsepower, what do you expect to gain from it?
Six pounds isn't bad. Too much pressure will overpower the needle and seat in the carb and cause flooding.
Next time you have the opportunity to run the higher rpm range under load, connect a pressure guage near the carb and see if the pressure drops off or not. It is a shame to chase a problem with dollar bills, if you have an alternative. Good luck, and...

RACE ON!!!

GrandSportC3

Well - usually 10 HP = .1 faster ET..
5 HP = .05 better ET.. My best ET so far is 12.068..
.05 better ET would bring me much closer to 11's...

I WILL!!!

CFI-EFI

Frankly, I don't see it. But what the hey! Go for it.

GOOD!!!

GrandSportC3

It's not a expensive mod either...

Jvette73

What was the weather on race day? Weather can effect ET far more than a tenth. If it was hot and muggy when you went 12.06, go back on a cool dry day and you should do better. it all depends on the jetting also. You see some guys setting up weather stations and making jet changes between every run. Crazy aint it? anyway, if yur runnin a carb pressure is not important as stated above. So long as the supply is there, its all good.

GrandSportC3

The temperature was around 65 degrees and it was not too humid when I had my 12.06 run...