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best FPR and pump

Posted: Wed Aug 30, 2006 8:42 pm
by bswift16
Am about to go shopping for FPR and fuel pump
any sugestions on which ones ,best combo??
cheers :)

Posted: Wed Aug 30, 2006 11:34 pm
by Brayden
EFI or carby? Whats the setup? Details go a long way. ;)

Posted: Thu Aug 31, 2006 9:03 am
by bswift16
oops :oops: going through a charade turbo carby with a supercharger for boost

Posted: Thu Aug 31, 2006 10:05 am
by Brayden
In which case you'll need a low pressure FPR designed for carby turbo/supercharged setups, and as far as I know Malpassi are the only manufacturer of such a product. Be sure to get the carby turbo version though, as it has the right ratings for lower fuel pressure. You could technically use the original Charade FPR, but I prefer the adjustability of the Malpassi unit.

As for fuel pump, you only need one capable of producing a handful of PSI more than whatever boost you're running. So if your charger puts out a max of 7PSI, then you'll need 12-15PSI of fuel pressure at maximum boost, with about 5-6PSI at idle. Most EFI pumps are designed to deliver 40+PSI, so you'll only need a mildly powerful pump. I tried the equivalent of a VL turbo EFI pump with my Charade carby setup and it was complete overkill - resulting in massive over-fuelling.

Posted: Thu Aug 31, 2006 1:08 pm
by bswift16
cool i was looking at the Malpassi rising rate unit and a Holly blue pump that puts out abot the 15 psi mark. as for boost i havent worked out the max boost i can get from my AMR300, but i only want between 7 and 10 anyway im not building a drag car here :D

Posted: Thu Aug 31, 2006 1:31 pm
by Brayden
7PSI is all that I would run on a stock F8B with a carby and standard distributor. Any more than that I found was causing issues.

Also be aware that depending on pump choice (flow rate AND pressure) your fuel return line mightn't be sufficient to handle the recirculating fuel at idle, so you'll either have to run a new line or set up a relief system as Colin and I have done. Essentially it is a loop that transfers excess fuel back into the pump inlet, but with a valve that closes of the system at wide open throttle.

Ahh yes its all fun and games.

Posted: Thu Aug 31, 2006 8:27 pm
by bswift16
the motor wont be stock im haveing it built by the engine guys to handle about 12 to 14 psi. as for the fuel line im going to upgrade the return to handdle the extra fuel. do you think i will need a larger delivery line or will the stocker cope??
The distributor is my next big challenge, ill probably leave it stock while running in and treating the motor kinda nice.but after that ill get some pro's to have a look at it to see what is best for my set up. would like to go elec but i know thats a big ask.

and YES YES the fun and games :D :D

Posted: Thu Aug 31, 2006 11:11 pm
by Brayden
If you leave the distributor unmodified on anything more than 3PSI you'll kill the motor before you make it around the block. ;) Detonation is a bitch.

Posted: Thu Aug 31, 2006 11:33 pm
by bswift16
well that would sure suck :( any idea on what i should look at gettin done to the distributor???

and stock fuel line to the carb ok?? :)

Posted: Thu Aug 31, 2006 11:58 pm
by Brayden
Stock feed line should be fine. Distributor needs to be modified to cancel advance, and add retard on boost.
Then you set the base advance higher to compensate.

Essentially you weld the shaft solid, then turn the vacuum advance into boost retard. ;)

Posted: Fri Sep 01, 2006 9:10 am
by bswift16
cool will look into that :) i was thinking that because supercharging was a constant boost set up the distributor would work like when n/a, because there is no sudden gain in revs and power as with a turbo.
but i aint gonna take the chance with all those $$$$ im spending :D

Posted: Fri Sep 01, 2006 11:27 am
by Brayden
Any boost in the system requires a reduction in distributor advance, the only difference between a turbo and supercharger is the 'curve' of delivery. ;)