Ghost Ram

some of you already know i installed my cfm+ and grid delete yesterday and on the way home from the shop i had the chance to make a couple wot runs. the first thing i noticed was a boost loss. i have always been able to spike 30-35psi and hold 25-28psi. now it spikes just over 30 and only holds 24psi. i even took the truck out today to do some more testing and still only 24psi boost.

i know others have said they noticed a boost increase of 3-4psi w/ the cfm, but i lost 1-4psi. do you guys think it could have something to do w/ the grid delete? i would re-install the grid to check but......it kind of had a meltdown after doing an experiment to try and keep the grid operational w/ ALOT less restriction (this happened off the truck and is not related to my boost problem)

Green04HO

Less restriction = less boost.

CamperAndy

Boost is measured down stream from the heater and horn. So there should an increase.

Green04HO

I thought CFM had ports in the side of the manifold to measure boost?

CamperAndy

Those ports are for NOS or H2O/Meth injection but could also be used to measure boost but would not be the best place.

Rpainter

why is the intake horn not the best place for a boost gauge???

CamperAndy

Venturi Effect. Could cause a lower pressure reading in the air horn due to the air velocity. That is also why it is a good place for injection.

Rpainter

I installed the cfm intake with a custom grid spacer and put the boost gauge back into the horn just like I had it stock . stock with grid heater I was at 50 psi now I am at 54 psi wot??? any ideas even bought a new gauge and hose still same

Ghost Ram

most guys do report a boost increase. did you install the gauge at the same time? different gauges read different. otherwise maybee it does have something to do w/ the flow inside the horn??? i wonder if it causes a false reading? although i dont know if i could believe that....

anyway, i measure boost at the manifold via boost bolt, and i have definately lost boost. not much, but a loss none the less.

CamperAndy

Your empirical data can not be disputed as it is what it is but there is nothing in the design of the air horn that should have caused the pressure to increase. Was the orientation the same, ie both on the top or both on the side? Also the way the hole was drilled in the stock horn could have been angled in such a way to increase the venturi effect where the CFM horn may be done in such a way to minimize the effect.

I like the boost bolt location on the intake as it is not in the direct flow.

Ghost Ram

maybee that spongy gasket cfm provides causes a leak and wont allow me to hold more than 24psi? just thinking out loud.....

bluechrome

Have checked for boost leaks between The grid delete and intake manifold and or the intake Horn. It could be possible that a gasket is not holding to well.I would Check for boost leaks With a air compressor, start with 10psi and move up frome there with the regulator, Spray soapy water arournd any of the joints. Thats the best way to check IMO.

Ghost Ram

i doubt it would be leaking between the delete and the manifold because i used a new factory gasket and both surfaces were preped well. i could believe a leak between the horn and the delete because of the soft foam gasket cfm provides.

if i wanted to test, where would i install a fitting? i could remove the charge hose and make a fitting to test but wouldnt it leak down through the open intake valves?

Rpainter

I have the gauge installed in the back side of the horn . I first used the old gauge thought something was bad so I nought a new one and repalced it still no change. could it be my custom spacer is about 3/4 of a inch taller than the grid heater??? I made my own spacer out of a solid block of aluminium that I bought off ebay for 8 dollars

bluechrome

Pvc Pipe on the turbo side of the IC with a pressure gauge and a air fitting