Inliners International Forums General Discussion Hi Performance FPR for Boost

I'm trying to track down a FPR to use with a carburated turbo setup. The only one i can find is Mallory Part # 4309. Anyone know of any others

RevOD,,,,

You can use the standard Holly P.A.W.
P.N. HOL-12-803 $25.95 or so??
You just need to install a vacuum/boost sense hose to the top of the regulator.

BTW,,,, what carb are you planning on using?


MBHD

Just anywhere on the top side? Im using a Holley 2bbl 500cfm

RevOD,,,,

Yes, you can drill & tap for am 1/8" NPT
& install a fitting to hook up your boost ref hose.

Also the top adjustment screw I believe has a hole in the allen set screw.It vents to atmosphere,if I remember correctly.
Plug that hole up w/rtv ,silicone sealant.

If I can find mine,, I'll take a pic & sent it to you.
MBHD

Thanks I appreciate it. I have that exact one on my car already Ill have to look at it and modify it this weekend.

There is a Vent under the locking nut on the top. I tapped a 1/8 barb fitting into it and smeared some rtv over the hold and it holds just fine... Thanks for the tip.

Here ya go. Drilled, Tapped, and sealed.

Looks good.
Hope the fitting does not go in too far into the cap? Might interfer w/internals???
That is a 1/8 NPT?

Also, did you look inside the allen/hex key set screw, might be vented?

MBHD

No I cut the fitting short so it would not interfere. The fitting is 1/8in NPT ~ 1/4 hose that was all they had at the time.

There is no vent in the hex head just right under the set screw a small valley. It is sealed air tight.

Excuse the ignorance, but why do you need to install a boost reference hose to a fuel presure regulator for a carburated boosted motor? I ran an electric fuel pump with a FPR set to about 6-7 lbs (if memory serves correctly) and ran with little to no problems with my draw through turbod' 250. Or am I missing something, there aren't to many local guys that know a whole lot about this type of setup, and I found this site after I was already running the motor.

On a draw through you do not need to. But on a blow through you do since the fuel bowls are fighting against the added pressure.

Plus you need to install the plastic floats when you are blowing through a carb.

Advantage of blowing through, you can use an intercooler.

MBHD

Yes I did install a BG Duracon plastic float in the Carb.

RevOD,,,
since you have the turbo apart,
I would highly recommend enlarging your wastegate flapper valve hole.(maybe even installing a larger valve?
I have an assy ,new,w/a large vave, all you would need to do is weld the arm to the shaft, (easy!!!!!)))
That way you should not get boost spikes & be able to control boost better.

MBHD

Usually you can open it up a bit, (just make sure not to open the hole too big where the valve contacts first) (close to the pivit arm side)
Make sense?

MBHD were going to run a External WG so that should not be an issue.

Rob,On a blow through if you do not increase the fuel pressure under boost the carb could run out of fuel and the engine will die.And when the engine runs out of fuel it shuts down fast.

Thanks for clearing the mystery up. Learning new stuff everyday hanging out here, its great!