I am running a 4# lower and my Autometer boost guage is only showing a maximum of 10psi. Here lately my truck seems like it's not as responsive as it once was. I was out running my truck today and all that I could get out of my boost gauge was 10psi. It was 85 degrees while I was testing this. Shouldn't I be seeing around 12-14 psi with the 4# lower and air kit? Is there any way to tell if my belt is slipping? I am running a Goodyear Gatorback belt part # 4080680. Is this the right belt length?

 

My autometer boost gauge sticks at around 9 psi.. Once i hit the top of 2nd and it shifts to third, it lands on 12.

The last time i dyno'd, the place was able to tap into the vacuum system and give me an accurate read, which was 12.5 throughout the entire rpm band.

What kind of pulley are you using? Single or a 2 piece interchangeble?

Humidity and heat play a significant role in boost loss.

 

The vacuum line to your gauge may also be kinked.

 

Flying ****- I am running a JL 4# lower with the factory upper. Do you think that I should run a 1/2 shorter belt or stay with my current belt?

 

HANKFAN, I would stick with the 68" belt you've got. I am running the same belt and pulley (basically) and have noticed no slippage whatsoever. I believe it's best to have the least amount of tension on the belt possible (just enough to avoid slippage), since the non-caged pulley does put some bending stress on the balancer shaft.

I too have noticed that my boost only jumps to about 10psi, and just nudges past when you stay on it. I know the factory guage is not accurate at all though, so I'm not sweating it too much.

 

Naw, i played the belt gauge. I use the recommended belt for the 4#. I doubt you have any slippage. Just take the weather into account. When was the last time you changed your fuel filter btw?

 

I just recently changed the fuel filter.

 

Mine does the same with a JL 4 lower and I see about 10 in first gear and it climbs a little in the other gears. I don't know... I figured 12psi everytime I stepped on it.

 

when i had just my 4# lower, chip, and filter I was reading 12-13 psi on a cold night. In the heat and recently in the summer I was only reading like 11 pounds or so. So I put on the 2.8 upper and I am pushing around 14 on the gauge now. could heat have to do with it hankfan? thanks, shane