My 20" Boss 338's are 30 lbs. a corner heavier than the stock 15" with 235-75's. And that's unsprung, rotational weight.
I've posted this before, but, when I was into MTB's, the rule was that for every pound taken off the wheels, was equal to 3 lbs. off of the frame. So that extra 30 lbs. that the 338's weigh is the equivalent of 90 lbs. of sprung weight, per corner. Or a total of 360 lbs. of extra weight. My MTB wheels had been modded to reduce weight by grams!
Not only do you have to get that extra weight rollin', but I can really tell that that weight's there when turning or stopping. Find myself having to gear down more on longer climbs.
They are hard on the gas mileage around town. Flat highway driving, not so bad. Throw in some hills & the gas gauge starts to go down much faster.
Trying to get some people to understand even the most basic concepts behind excessive unsprung weight is a lot like beating your head against a brick wall, even on forums catering to people with high performance stuff like SRT8 owners. Makes me nuts to see someone with some expensive mods and pushing 500HP or better with a set of cast tombstone 22" "replica" wheels on their ride, but hey; it's their money and they have to drive it. Fortunately the guys that are spending real money with heavily modded cars are already smart enough to go forged.
(there are several 1K HP cars on that forum, dyno and track proven, some of them STREET DRIVEN).
I moved up to forged when I started building my black '94 C2500LD; back in early '08 I bought those Centerline Smoothie 20's and haven't really looked back, other than the CL deal I got on those Boss 338's for the maroon C1500. Even the stock 20's on my SRT8 are lightweight forged.
Wish the backspacing was better; I'd run a set with adapters on the truck, but just not gonna work.
I have a question for you guys. I have some 18" 338's. I lost a center cap off the front wheel. The tire shop owner took a look and his best guess was that the heat from the brakes distorted the o-ring that holds on the center cap.
Dang.
$20 later, I got another center cap. Lost the same one within a week. Went back to the shop, and he replaced it for free. I haven't put it back on because I can't keep going through them like this. Do you guys have the same style cap? Have you had any issues or know of any way to fix this?
I'm thinking about pulling the wheel off and seeing if a snap ring will grab it from the backside. More durable than a rubber o-ring, and yet still removable.
I'm guessing you have the redesigned ones with the "dome" style center cap? Looks like it from the pic. The older, flatter cap (the ones that won't really fit the front hubs without a spacer) is just held on by tabs that are the same piece of plastic as the cap itself. There's not even a stiffening metal ring like the Boss 308's I put on my old Suburban. Have had no problem with them coming off, and they ride right on top of the hub & bearing cap, despite the 1/4" spacer I used to make them fit.
Here's a thought; if the O-ring is what is failing, consider that the ring is probably some super cheapo rubber that was just whatever they had that was the right size. Take one down to the Carquest or NAPA and ask to see their O-ring assortment. You might find some that are for a particular application like a water neck seal, that fit, and might hold up better. This is what I did when the O-rings that hold my Centerline caps on eventually failed from being removed/reinstalled too many times.
I don't think you can mix up the wrong caps on the Boss 338's; they redesigned the center bore completely, I don't even think they are the same size at all.
Richard
