24# inj.'s, 190lph.......how much boost?

[fanglemeister]

With "this"? Are you asking if a boost-sensitive regulator is necessary with... what exactly? I see you have a Kirban regulator, if you are running the vacuum line (and you should be), then the Kirban is boost sensitive, and will raise fuel pressure 1:1 with boost (likewise cutting fuel pressure 1:1 under vacuum).

I am wondering what "Thumper" heads are, before saying if you need an FMU or not. Here is how I would approach it: Let's assume your car is making 260hp without boost. Then assume your car will make 340hp or so on 6 psi boost. Based on my calculations you should run your 24s under 6psi boost at about 50psi (44+6) to adequately cover the bases. That's a bit higher than the eec will like. If I had 24s on your motor I would probably run an 8:1 FMU at the stock 40psi fuel pressure, and play around a little with a bleeder valve to fine tune the a/f mixture at WOT using a wideband O2 sensor.

[mygt8a4re]

thanx for the info.............i guess im getting mixed up from taliing to jack at Muscle Motors. he said that not all fuel regualtors are boost sensitive & that my kirban is not.
i thought a boost sensitive FPR would raise with boost above the initial set FP. if i were to set the FP at 42 with the vac line off it could still increase pressure above 42 as boost increased...or somthing like that. i know the Kirban wont go above the setting you set it at since the screw/nut on top control that...mabey jack has me confused here........
my thumper heads are stock ported/polished heads, worked by a guy "thumper460"...........just stock castings/cc's........

[fanglemeister]

This is the first I have heard that the Kirban billet regulator does not increase pressure with boost; it is well known that the Kirban regulators for the Bu GN does increase pressure with boost, now I am not so sure about the Ford part! I've emailed Kirban to get an answer directly from the horse's mouth, will pass it on to the group when I get a response.

[mygt8a4re]

cool, i appreciate the help! no offense to jack at MM, but he also told me the novi's had straight cut gears when all the paxton units have helical cut gears...so who knows!

[fanglemeister]

Here's the response from Dennis @ Kirban regarding the billet regulator for Fords:

"It will increase one pound of pressure for every one
pound of boost...just like they do on the turbo buicks.
We make regulators for the grand nationals and all
those cars are turbo charged....plus the entire
porsche market we make them for is turbo charged
cars...it will increase one pound per one pound of
pressure no problem."

[mygt8a4re]

sweet, i think jack will have to do some research....hes giving false information out! thanx for reseaarching that, much appreciated!