thedonk

i bought my truck three months ago and i never could get over the fact that it can onlyt go 58mph comfortably. it tops out at almost 70... i cant be sure because i have 35 inch tires. other than the tired and lift what could cause it to cruise so slow????? i find it hard to believe that 35's make it that difficult for the truck. i would also like more hp because the 300 is known for torque not hp.. i'd like to hear your guys' solutions to my problem and proformace upgrades thanks y'all!

Chris_1

iTrader: (1)

What gears do you have ? If you're running something like 4:56, even with 35's you won't have much top end. Got a tach ? What's it revving at at 70 mph ?

thedonk

idk in the manual it said 8.8 rear but that sounds rediculous.... but idk what gears, i have a mazda m5r2 tranny and yeah 35's..... tach? like rmps???? if rpms then about 2400...

Matthew Burr

have you checked the O2 sensor, could be in limp home mode which would seriously limit the top speed/power

77Ranger460

With stock gears and 35's, I think your results are normal.

Matthew Burr

I've pegged my 86 150 w/4.9 over 85, and with 31s that's going about 5% faster, with 35s he's going 10% faster and should be able to peg it too

77Ranger460

He probably is going faster than he thinks because he hasn't corrected his speedo.

certifiedbodyman

how does one correct the speedo?...I have 31 x 10.50's on 15' rimes, 10" wide on the rear and the same rimes on 30.50 x 9.50's on the front.

Matthew Burr

i'm not aware of any way to do so other than changing the gearing to account for the different sized tires, but who knows, maybe theres an adjustable cable or something

77Ranger460

Change speedometer gear.