I ran the 15.60 on 266/70/17nitto terragrapplers....(by no means a real light tire)....the tires I got on there now are 275/70/18....I know the wheels are heavier. But imo I was expecting somewhere low 15's......I know my mods aren't a lot, but these exact mods alone on my old truck (rcsb4.8) took off almost an entire second on my ET. And I was running a Hypertech programmer on that truck, not a custom tune. And I had the exact billet specialties on there.....(I just kept the wheels and put em on this truck.) Im going to see Wheatley in the morning.....hopefully he can tell me whats going on.

 

a 266/70/17? Holy **** that's a weird tire size LOL

 

haha, Im sure he meant 265... but u do realize 275/70 is taller than 265/70 right? its very small but there is still a difference. Approximately 1.5 inches bigger (1.74 if u want exact)

I dont really think that would make a tenth of a second difference especially after the mods. However those tires are a heavy SOB

 

yes i meant 265.....ya i know there heavy.....I'm thinking of getting some Proxes ST II 285/60/18.....anyone know a ballpark estimate of what these things cost per tire? Cant find em on discounts website.

 

That extra tire height difference might have taken everything from your mods and just slowed it back down and that's aside from them being heavier. You might be able to squeeze more out with those tires on there, but with only a 325 under hood you don't have much torque to make up for weight gain and effective gear loss.