H0SS302

I get worse GM with my 3.73s than I ever did with my 4.10s... City driving owns me. And 4.30s are basically no different than 4.10s like TJ pointed out. There is no reason not to get em.

teej281

That settles it. I'm getting some 4.30's soon.

TRUEBLUE3934

With mods that allow for higher revs, and only a limited amount of miles driven each year... 4.30s may be what you are looking for. The difference in rpm between 4.10 and 4.30 is 5%, so 150rpm around 3000rpm.

My only experience with 4.30 gears was in a '86GT that had a different first gear ratio in the trans. I HATED those gears because 1st gear was a waste unless I had my slicks on at the track. Currently, I cross the end of the 1/4 at ~6300rpms with my 4.10s which would be 6615rpm with 4.30s (too many rpms for me).

Soldier GT

Just wondering. Anybody running 4.30's with a S/C?

teej281

^You must be smoking the peace pipe because with 4.10's and your tire setup you are looking at trapping right at 6000rpm with your timeslip in your sig. You'd be trapping at right around 6250-6300rpm with 4.30's...care to expand upon that? Use cliffyk's calculator at this site to do some digging.

http://www.paladinmicro.com/PalMFrame00.htm?wks=spd

TRUEBLUE3934

LOL
My best ET was 12.5 but only at 110.5mph. I have trapped 112.7-113.1 more than a dozen times, just not on that pass. Also, as you are probably well aware, the accuracy of the tachs (and ability to read it accurately) is not dead perfect. A tire with only 11lbs of air is also not fully inflated and thus has a smaller circumference (more rpms to go the same speed). The difference in rpms between 4.10 and 4.30 IS 5%. The link you provided calculates I would be running 6116rpms at 110.5mph (not taking into account low tire pressure). That would be 6422rpms with 4.30s.

You with me now???

Harryman2002

Hahahaha, awesome sentence blade!!!!
I believe that is sig worthy.

teej281

I really gotta say I still averaged over 24-26mpg highway with my 4.10's, and that was driving at like 75mph or better. I loved my 4.10's, but I'm going to go to 4.30's this time around.

boduke0220

seems like on the highway the 4.10's are better than the 3.27's because the motor isnt lugging at 70 @ like 1500. it actually has usuable power on tap, therefore it doesnt have to work as hard thus not using as much gas as you'd think, or am i totally off?

teej281

Youre about spot on with my thinking. The decreased load on the engine is balanced out by the higher rpm being turned so it equates to about the same gas mileage.