tomkay

Could not find anything in my searches that addressed this issue. This is on a 2008 4.6 with Whipple I/C s/c, 5 spd & 3.55 rear. I did the 8-rib conversion over the winter and everything seemed ok. I did decrease my s/c pulley from 3.625 to 3.50, but what I didn't notice was the recommended crank pulley also increased from 6.5" to 7.0". Now I have seen boost hit 11.0 psi and I am worried about the engine/tune. I believe I was hitting between 8 & 9 before the swap. Lately the engine seems to shudder/ run rough when under load. Still runs ok but just does not seem as smooth/quick revving as it used to be. I also should add that I almost fell victim to the Ford FAKE oil pressure gauge as I was down about 1.5 qts when I checked the dipstick after only 2000 miles of driving. I had gotten on it fairly hard on a very hot/humid day and noticed a clatter from the motor so I took it easy all the way home and that's when I found out about the oil. Not really sure if the clatter was oil related or detonation. Do I need to have it tuned and if so can anyone recommend a good tuner in NJ/PA/NY/CT area. Appreciate any help you can offer.

hammeron

the clatter almost certainly was pinging and it's good that you
recognized it and have started taking it easy. a dyno tune is
going to be the best option if there's something local to you.

tbar

Pulley change requires at tune update.

Simon1

Custom tune for sure.

808muscle

JDM is in your area.

http://www.teamjdm.com/

moosestang

1.5 qts down is nothing. My wifes 3.5L chrysler 300 was down 3 qts! It only holds 6. Now I check the oil every 2k miles and always have to add some. Chrysler considers this amount of oil consumption to be normal for this motor!!!!!!!!!!!! Uses about 1.5 quarts every 3k miles.

Diabolical!

Not always. If the fuel injectors you use for your current tune are adequate to provide fuel for the increased PSI, then your tune should be fine. The MAF sensor reads the increased air and provides increased fuel. If you start to get pinging, then you may be getting blowout from the increased boost and need to tinker with the timing a bit, but I went from a 3.25" pulley to a 3.125" pulley with no tune update (cleared it with lethal performance and my own tuner before I did). So far, everything is fine.

siggyfreud

Think with that small of PSI change he'd need to tighten up the plug gap at all?

Diabolical!

That's another option, if necessary. There are different ways to attack ping. Plugs, timing and octane. Ideally, higher octane is your best bet, but anything that doesn't come from a pump gets expensive fast.