Ok some of you know, some dont. but i have upgraded to some mastercraft MT tires. i am new to all this, and i knew the speedometer would change. i was noticing just now on the freeway was going 50(on speedometer) and when i tryed going faster, i had to push a bit harder to get it to budge more. is it possible to fix that? what programming and all do i need?
What you are suffering from is lack of gearing.....your effective ratio had dropped enough to cause adverse effects on the highway because of the addition of the larger than stock tire size. You are out of your target torque curve. Your truck possibly had 3.73s and 28's in stock form...jumping up to a 31 dropped that ratio down to something in the area of 3.30. Only way to cure a sluggish truck after install of larger tires: shift down a gear for more rpms which will get you more torque to keep or gain speed or install a new gearset.
Speedo calibration will do nothing performance wise.
Speedo calibration will fix the shift points, doesn't add any performance, but it helps some. But like Fx4wannabe01 said, gearing is probably the most effective way to fix your performance.
EDIT: 'D' as in drive? That has nothing to do with your gear ratio...you have to buy a new set of gears and an install kit...that or find a complete axle with a higher ratio, such as 4.10...What ratio do you have now? You can check on your door tag for the AXLE CODE.
To figure out your actual speed: Figure out the percentage difference in tire height from stock to new tires. Them multiply that by a number(in your example, 50).
For example: my truck came stock with 30.5" tires. I now have 34.8" tires. The difference is roughly 10%. Since the addition of larger tires makes your speedo read slower than you really are going, at 50(on the gage) I'm actually going 55.
More wear on the transmission, but not a huge deal, your tire size isnt too large. But if you can deal with the 'slower' performance, you'll be fine. Alot of people stay like you are. If your speedo bothers you, you can have it recalibrated that or use a gps.
Your mileage will drop a bit, but that comes with larger tires (more weight and such). what engine size do you have? 2.5/3.0/4.0?
If a 31 actually measures 31", at 50mph of the gauge, your truck is actually going 56.6 mph.
If your truck has 3.73's, your effective ratio is currently 3.30...so it drive like it has 3.30's. To get your truck to drive just like it was stock on stock tires, you'd need 4.22:1 gears...but since those aren't out there....4.10 or 4.30 are your options for being a 2wd.
My truck is close to identical to yours, I have a 3.0 with 3.73 gears. I have 32x11.5 tires, more weight/taller tires than you. I live with it for now. Hope to find a 4.10/4.56 rear end sometime, but its not the most horrible thing. Fix your speedo, and you will feel like your going faster, because the way you are now, you are going faster than you think you are.
no problem, there comes a price with modification, but in the end you will be happy.
Cyberdyne 9901 <-- CHEAPEST speedo calibrator i have found, wish i would've waited to find this. Your shift points will be fixed, and you will know that you are going the actual speed. Hence, you will not feel like your truck is sluggish.
Gears. Drive it for a while. You can probably live with it. If not, then start saving!
damn thats alot.....with that, that fix's the sluggish driving for sure? what else is it good for?im so sorry for all this, really appreciating all the help.
also whats a good computer to get that will fix the speedometer? you said somethin about aftermarkets not working.
Aftermarket Performance Programmers (such as the XCAL) will not fix the speedo your truck...but the CYBERDYNE box will fix it...you have to install it by splicing into the Vehicle Speed Sensor (VSS) wire. Pretty simple install tho.
oh ok. wow really appreciate all this help, you guys are my heroes. ill have to look into buying it soon. thing is, getting it without a credit cars :/. it really sucks not being able to have one, and all i got is an atm card with a savings account. thinkin about going checking so i could buy things online besides money order( newegg.com haha, im a nerd :P).
but yeah, really appreciate the help. 1 more question about this, is there maybe a better one out there? im willing to spend up to $80 if its necessary... if not ill go with this one.
haha you'd have to spend $88!!!! I have the dakota digital unit currently. It works perfectly for me. and the install is real easy. Its waaaay cheaper than the Superlift Truspeed and the Jet Accuspeed.
ok, you will benefit the most with an auto trans. as for the cyberdyne unit, i personally have never used it. but im sure that it is simple. If you can get someone to buy you a unit soon, get the dakota one through ebay. It is $55 shipped. I can guarantee that will work, and can walk you through it
EDIT: for the cyberdyne, im sure that all you have to do is install it, and then mess with the little dial that it has. Looks similar to the superlift unit. Regardless of what unit you get, you MUST calibrate it. a GPS is very handy to get it near perfect.
'99 Ford Ranger XLT
3.0L 2wd Stepside
Fabtech 5.5 w/ Bilstein Shocks
32x11.5x15 BFG A/T on 15x10 AR Baja Wheels