Had 4.10's installed....car tops out at 99mph??!!
 

ok, i have a 99gt auto , i just had 4.10's installed about a month ago or so , i havent really got on the car much that much besides just darting off the line at lights and whatnot , anyway , i was on the highway alone and wanted to see if i lost top-end due to gear swap , the car was hitting rev limiter or speed governor at about 99mph, whats the deal ? when i had gears installed they also burnt me a chip to fix the speedo and they said they "set it up for speed" . can anyone tell me why im not going any faster...? thanks

Did you accidentally have the OD button off?
Other then that I would think the chip is a problem.

no i didnt touch the OD button , ive tried this again a few times, tops out right before 100mph , why would they set the chip up like this? i had it done at mustang magic, long island ny

Humm, well Mustang Magic knows their stuff, so maybe it wasn't the chip. Did you ask them what they thought the problem was?

Did the chip they burned replace your computer?

If not, do you have 16" wheels? 16" stock wheels on a mustang means a speed limiter of 120 mph. And if your speed limiter is still in place I could understand the gears changing 120mph to 100mph...

That's just my guess...

ahhhh i think you nailed it gary , yes i have the stock 16" pony rims , i think thats the prob then, they burnt the chip for those rims and all, ok...i am ordering a set of cobra R's real soon, either 17" or 18" , with new wheels on what kind of top end speed should i pick up?

c'mon......noone else? a hell of a lot of people sure looked at this post, ha

i personally don`t like 4:10`s sure you rocket off the line but the reduced gas milages and highway restirctions sometime don`t compensate 4:10`s are fine if you drag race alot other than that they are not worth it go with 3:73

just my 2 cents

I'm not absolutely sure but I think they have to reburn the main computer or something to change or remove the factory speed limiter.

Sounds like you need to have that chip reburnt to give you a higher stop speed, the limiter is in the computer, have that fixed and you'll be able to go past 99mph... Nothing wrong w 4.10's


Skyler

Why not get the programmer and be able to adjust for gears ,tire size, rev and top speed limiter, and your shift points for the automatic.You can also pick up a few hp in the process.I have the factory 17's with 4:10s and running a trap speed in the 1/4 over what you're claiming as top speed.So ,no problems here.If for some reason your computer thinks you are running faster than you are, would you be putting extra miles on your car?