Made a trip to the track today, a few months ago I was running 15.3s no problem. I added LS1 fans, TB spacer, Hypertech 180* stat, and MSD 8.5 mm wires since that time. I also threw on some 18" MB Motoring Precise on 285/60s. My new times were consistent 16.1s. I know the tire size is bigger and the weight is MUCH more on these wheels, but damn I didn't expect them to slow me down by a second. Just doesn't sound right to me. Anyway, on a good note I beat a Dodge turbo diesel that had an upgraded turbo and fuel system with other goodies and manual tranny and he launched in 4wd. Other than that my night sucked ***. I was even getting even races with a Cavalier that only had an intake and exhaust. From now on, my stockers go back on the truck before I hit the track because this thing couldn't get out of its own way tonight.

 

Would the lack of a retune for the new tire size have anything to do with this?

 

I think a lack of a retune will slow you some. My truck was tuned for my 20s. I think the way the tranny shifts is part of what changes if its tuned for bigger wheels. Since your new rim, tire combo is bigger and heavier it will slow you down. I noticed my acceleration slowed some when I put my 20s on.

 

Bigger, heavier wheels will slow you down considerably. I'll keep my nice, aluminum factory wheels, thank you.

 

I don't think I will be going out there again to race with these 18s, I think factory wheels and my 255s will do me just fine. I was expecting 15.1s before the wheels and tires so when you think that you lose 1 second with them that is a lot. I like the way they look so I will probably keep them to cruise on but the larger tire and heavier wheel just make it so much slower. I think the weight of the wheels makes much more of a difference because your engine has to work harder to turn them. I did some nice fat burnouts though .

 

Yeah, more rotating mass will kill your ET's.

 

I used to think the same thing. Before the charger I ran 15.8's all day with the stock alloy 16's. I put on my 22's, and ran 15.9's consistent.

They are light 22's, Weld Evo's, but they are still 22's and weigh more than stockers.

 

Damn, I'm glad you can handle them. I beat 4 of the 5 diesels I ran at the track last weekend, but the cummins that went 12.3 was alittle too much for me to handle on that slippery *** track.

 

Yeah, there was a ford diesel that wanted to run me after that race so I said sure why not. The guy was old and even had handicap plates on his truck. He said he beat all of the trucks there and wanted to run me. Afterwards I found out he was running meth injection and a shitload of other mods. Needless to say I got my *** handed to me. Next time I'll put the stockers back on and surprise a few unexpecting victims.

 

i hear that the tb spacer causes all kinda troubles some times, i know it slowed my older 96' truck when i put it on there