Black98LS1

OK guys, I've got a 02 RC w/4.8 auto...mods in sig. I'm wanting to get everything I can out of it without KILLING my mileage. I drive approx. 100 miles/day for work, 90% hwy miles, and cant afford a big loss in mileage. I'm getting around 16mpg right now because I cant keep my foot out of it. What would I get the most noticeable gains from and with the least drop in mileage, a set of 3.73's or a mild (2200-2500) stall???

Any feedback appreciated!!!

Deckhand

iTrader: (1)

tci3000 converter.. as long as you have a posi


since most of your driving is highway miles.. your converter will lockup (at around 55mph) and will be just like the stock stall.

vanillagorilla

iTrader: (1)

A stall won't affect your gas mileage on the hwy, because it will be locked up, just like the stock one. However, you mentioned that you can't keep your foot out of it. Does that mean your truck doesn't have the power to move itself along at hwy speeds, or you have a led foot? What gears are in there now, and what tire size are you running?

Scream

iTrader: (6)

If you don't already have a posi, the converter won't do you much good. The G80 is on borrowed time as it is.

I personally would get gears and an Eaton first, but that will affect your gas mileage more than a converter. If you're going to be racing it w/ any kind of regularity, I would definitely get rid of the G80 before it grenades and causes you a hefty repair bill.

Black98LS1

vanilla, I honestly cant keep my foot out of it. Coming out of a H/C LS1 into a truck with a 4.8 was a rude awakening...it runs good, but is pretty gutless under 2500-3000rpms as im sure you all know. I have 3.42s now and have a slightly taller (265-75-16) tires that were on the truck when I bought it. Scream, I am almost positive I dont have a posi, and I dont race the truck at the track, just occasionally on the street. I just wanna give it the ***** to fall out and pass someone without a mile between me and oncoming traffic.

p.s. - I plan on throwing in a low lift 212/218, or possibly a 206/212 sometime in the future when my money tree starts blossoming, so a stall would probably be my best bet if I were planning on a cam swap anyway, right?!? I know this will drop my mileage even more though...

vanillagorilla

iTrader: (1)

A stall will help you with passing for sure, but having a tire just over 31.5" and 3.42's isn't helping. Check your glove box for a sticker with the RPO's on it. If G80 isn't on there, then you don't have posi. Trust me, a stall with no posi sucks for your one tire.

A stall isn't going to help power under 2500-3000, in fact if its not locked up, then it will be slipping and it wil feel like it has less power. A cam would be best complimented with a stall like you said, but as for power under 2500-3000, its hard to say depending on what cam you choose.

I would ditch the 3.42's especially with those tall tires, or get a tune. A tune won't hurt mileage and it will help power across the whole rpm range. Gears might hurt your mileage and they might not. It will help torque multiplication, so you might not have to keep your foot in it as much.

Those 3.42's and a 31.6" tire is about equivalent to you running a 2.73 in an A4 f-body with 245/50/16. That should help you put it in perspective since you used to have a TA. Hope that helps!