Simple boost reference mod straight from Holley

[ghittner]

Here it is straight from Holley for all that want to do boost reference modification for themselves. Looks simple to me. Like 10 minutes!!!! Download this and keep.

[Wet Dream]

Thats it? Seems simple enough.

[ghittner]

yup, and I don't know why everybody keeps it such a closely held secret I hope people get this picture. I asked and asked for it and no one would help.

[TIMINATOR]

Most double pumpers do not have that setup, with the spark port like that. Just the vacuum secs that no-one uses have it. Thats why I didn't mention that mod. TIMINATOR

[Cheap Thrills]

Here
http://www.***boat.com/image_center/...ower_Valve.jpg
C.T. :wink:

[ghittner]

750 dp's exact as the picture. list # 4779-70750 Please let us know the mods for the "other type" double pumpers. Thanks from all of us!

[Warp Factor]

What's the advantage of boost referencing supposed to be?
The prop boats I've seen with it ran rich on the bottom and fouled plugs.

[schiada96]

What's the advantage of boost referencing supposed to be?
The prop boats I've seen with it ran rich on the bottom and fouled plugs.
Think of it as a cheap mans map sensor. Instead of blowing the power valve closed it makes it open at the right time. A blown boat with refrenced valves will run cleaner.You can run the primarys and secondarys a few numbers leaner and it will idle better.

[sgdiv7]

What's the advantage of boost referencing supposed to be?
The prop boats I've seen with it ran rich on the bottom and fouled plugs.
It is for part throttle (crusing) so the engine does not run lean at a higher rpm cruse. I drilled out the power valve restrictor holes a little at a time and droped the jet #'s so when I was at crusing speed which was 2500 rpm & 0 boost for me, the fuel mixture was right. I wound up using a 2.5 power valve for my aplactaion. I have a flatty with 29 gears.
If the boats you saw doing that would play around with power valve sizes alone they could make air fuel ratio much better. I did that first. I wanted the best fuel mileage I could out of a blowen engine crusing and still have the wot fuel mixture.

[Blown 472]

Think of it as a cheap mans map sensor. Instead of blowing the power valve closed it makes it open at the right time. A blown boat with refrenced valves will run cleaner.You can run the primarys and secondarys a few numbers leaner and it will idle better.
What does the idle circut have to do with the power valve and jetting???