My setup is in the sig.. I just got the truck.

It has a diablo flip chip burned for a 6# pulley.

I want longevity for my lightning and cooler temps, etc.

Should I take the 6# off and put the 4# on.. its interchangable

What's the difference in power, etc? Details plz

 

Just pull down the timing and try to add some fuel (if you have the Predator). The 6lb is not the problem. It's too much ignition advance and lean-out is the problem when the weather turns cold.

 

I would feel more comfy with the 4# no matter what..

If I just interchange it in.. what would be the result>?

 

I can tell you from 3 seasons of racing MY L, that I run as fast AND FASTER with 4lbs, than 6

SO although YES you will see a drop in boost, it DOES NOT mean you'll see a drop in ET

BTW, it's worked out this way on Spray AND OFF
My Combo was 4 lower and 2 upper, and pretty much everytime I've been at the track I've tried both boost levels while racing,
(as said off or on Spray), the results are always pretty much identicle

Even the last passes of the season, 11.9 on 4lbs, 11.8 on 6lbs,
(but the 6 had a MUCH BETTER 60ft), the 4lb run actually had more MPH in it too.

My new set up will be 6lb lower and a 3/4 Upper (2.7")
But on Race day I think I'll be using the 6lb lower + 3.0" Upper
+ 150 - 200 HP of Nitrous ; o )
wooooooooooo hooooooooooooooooo............

 

I pass 6# guys on the top end

Tell you what I think to be about perfect for your set up, w/o spending too much.

Port the blower and put the 4# on. I speculate that your A/F numbers would be just about perfect with the current tune. And if anything maybe a little fat on the low end.

Rich (see my web page for my mods)

 

I personally liked the 4# and ported Eaton. On the dyno (3 pulls) I made just over 14 PSI and on the last pull actually hit 14.9 PSI on a mid 60* day. Truck made just under 420 RWHP with a/f's in the low 11's.