Ok if anyone is thinking about flaming telling me to search for the info, read the full post before hand, thanks,


Ok I got a serious carb issue bothering me right now so here it is. I have just put a Weber 48 IDA down draft carb on my car and I dont have a fuel pressure regulator at all right now so I gaurantee the car is gonna run like **** or not run at all, my point being what is the proper fuel presure for this carb cause I have searched and read already some say 2 - 2.5 PSI,
some say 3 - 4.5 PSi. What is the actual correct setting for fuel pressure cause I am getting a regulator tmorrow and the purolator one lets you set PSI as between 1 and 6 I think, and the holley 12-803 or somthing lets you use 4.5 - 9 PSI, so that is why I need to know the exact fuel pressure cause one starts at 4.5 so I dont know if that will be too high and I also read on here that the purolator one is supose to suck bad and wont deliver enough fuel after about 6000 RPM or somthing, man any help would be greatly appreciated as this is driving me nuts.

Thanks in advance,

Ryan.

 

don't get either of those regulators. there is another Holley regualtor that seems to always go unnoticed, it regulates from 1-4 psi. i believe the Webers are recommended to be run at 4.0 psi, but i may stand corrected.

search at www.summitracing.com to get the Holley part number, if that fails, then post again and i'll try to dig it up for you.

 

yeah but racing beats recomendation in the manual says 4.5 PSI for a 13B- 4port thats street ported, Ohh I will have to deal with this later as I am going to Leguna Seca tomorrow for a week to race.

 

well, let's put it this way ... my Dell'Orto is also recommended to run at 4.5 psi (per RB) and the 4.5-9.0 psi regulator was flooding me out to no end at it's lowest setting. fuel was just spitting out through the overflow hole.

i tried everything ... adjusted the floats and all that. the car still ran like crap until i found out about the other regualtor. as soon as i installed that one, and adjusted it a bit ... my car runs fine. so it may be the regulators themselves that are not so accurate.

i guess the question that i failed to ask you was what kind of pump are you running?

 

my opinion on the discrepancy is that with the various gauges that people run, their varying inaccuracy accounts for this. for example, i run a Holley gauge, and it indicates that i'm running 3.5 psi ... but i'd believe RB's recommendation of 4.5 psi before i'd believe the gauge. as i was hinting to before, you'd also have to account for the inaccuracy of the regulator itself as well, which is why i was recommending that you start with the lower pressure regulator, and if it proves to be inadequate, then move up ... but again, it may depend on the pump setup that you're running.

 

i would call a weber place like peirce manifolds, we know what the stock ones like for psi, but not the webers

mike

 

The Haynes manual for Weber carbs says my 48mm side draft was either 4 or 4.5, I don't remember which. I am not sure if that was for all Webers or if they were all different. I will try to find the book this evening and check it out.

 

Well I dont have time to install everything now but I Decided not to install the Holley regulator I got and took it back and got a N.O.S. one that is way better, its adjustable from 1 - 12 PSI and even has a vacum outlet on it I guess to control fuel pressure according to your Rpm's or somthing, anyway thanks guys for the info, appreciate it...

Oh and anyone that ever needs and wants this regulator, the part # is 15810 and its made by nazzz (AKA NOS) lol

 

Here is a pic of my engine bay...
http://www.bcrx7.com/modules.php?nam...ewtopic&t=1510

 

thats a sexy weber....

mike