12a streetport, 47 OER sidedraft, gt35R (turblown Stage V), will be running 15 psi, intercooled, blowthrough. What fuel pressure should i be starting out at at an idle and what do i set the pressure gain at on a rising rate FPR? What pressure and flow rate fuel pump do i need?

Thanks

 

You should be running a 1:1 rising rate fuel pressure regulator not a progressive rate and you should set the base pressure to what ever the carb needs for proper operation.

Ryan

 

This is a good setup:

http://www.aeromotiveinc.com/products.php?prod=209

Complete A1000 System for single carb (includes: 11101 Pump, 13204 Reg, lines etc.), P/N 17242

Just make sure you connect the pressure source on the fuel pressure regulator to the carb hat( positive pressure only) and not the intake manifold ( like an EFI application). You just don't want the regulator to see vacuum.

Here is the regulator only

http://www.aeromotiveinc.com/products.php?prod=20

 

So is this pretty much rule of thumb? This is the second time I've heard that and I was just wondering why this is?

 

Thanks Elliot! I suppose I could just email you these questions... haha

 

Well if it increases fuel pressure as boost increases ( which is refreced from the carb hat/plenum) it will never recieve a vacuum signal I would deduce will make the FPR cut the fuel way back, this will cause it to run lean... bad

 

So is this just a carb thing? I've just had a couple reputable tuners do this even to efi cars however others say to connect it to a vac source so I'm confused on this subject.

 

1:1

 

what carb is best for a blow through? will a weber 48 ida work ok? also can you run a intercooler with that? I am seriously thinking of getting rid of halteck for blow trhough fed up of tunning that crap for no reason..and no running car yet because of it..

 

A four barrel. You will have a larger range boost pressure that you can run. A two barrel is limited to how much boost you can run because it only has one primary circuit, with a four barrel you get at least two.

 

on a fuel injected engine you want the FPR to source manifold vac, cause when it's under vacuum, it helps "draw" the fuel out of the injector, just as when its under boost, it tries to "push" against it. so, when you source manifold pressure, you always maintain delta.

it's different on a carb because your base fuel pressure is set to make it run properly using that vacuum at idle (but without reducing fuel pressure, just like an n/a carb) and just off-idle, as long as everything else is setup properly, and only needs to compensate against boost pressure in boost.

 

Run the carb at 3PSI to start with. Do a highway run, go through first second and third gear. If it bucks at all then up the PSI. Also make sure your floats are correct. Then boost.

 

i have a weber fuel pump with filter that is specifically made for weber carbs if you want i willl sell it to ya. its brand new