I haven't been this angry in awhile. I am on the edge of shedding some tears. Usually when my Mustang breaks down it is something simple, you classic mustang guys can relate, right?

Well anyhow, I finally got my car back today, some upgrades were done, (electric fan, pulleys, new radiator, possi, traction bars) good stuff. Anyhow I had the gears changed to 3.80, they were at 3.05.


So I pick up the car it is running great, but as I drive it more and more, I realize that something is really wrong here. I knew the top speed would be down but not by this much....

Of course I tested it out to see how everything worked together, the thing only goes like 90MPH, this is messed up, wouldn't my car do like 90 if I had 10.0 gears (dunno if those exist, but you get what I'm saying), I mean a lot of old skool cars have 3.90 and 4.11 gears and do like 120 and some change in the 1/4, yet, my car in the 1/4 mile (what it was built for) can't even complete it.

So I get home, pretty pissed about it, I know something is jacked up, well as I come to a stop I notice this really annoying screeching sound, at 1st I thought it was coming from my exhuast, but no, it's the engine. so I pop the hood take of the air cleaner, and hear the sound coming from my carb. I manually rev the carb and I notice as more gas is applied the screeching goes away. so I take it for a drive, and it is doing normal (well, normal like it was, which wasn't normal.)

I take it home, let it sit for awhile, then I go to turn it on, and it is broken! piece of ****. It is making the sound like when you have your car turned on and you keep turning the key, that grinding sound, isn't that great.....

so I sit here, with a car that I just spent a ton of money on to improve it, I waited forever to get this stuff done, and I get a piece of crap that is broken.

All I want is a car that works and can go its proper speed, I am not too familiar with gear ratios, but come on, a car with 3.80 gears going like 85-90MPH tops, what the hell? I just want a car that works, and can complete the 1/4 mile, I know for sure my car would do 100MPH+ in the 1/4 easily, but ya, it only go like 90, so it would only be able to do like 3/4 of the race. This has to be incorrect big time.

Well......I had to vent my anger, but can someone give me advice, did this guy do a shotty job? that is what I am thinking, so I shouldn't get mad at the car, I should get mad at him, but that doesn't help the fact that my car (which is pretty much me) wasn't running correctly, and now is not running at all

EDIT: Also, with possi I hear you wear out tires faster, I hear a lot of rubbing and such, is this normal?

 

There is just too many places to start.

Lets see.....

What have you done to the motor besides pulleys and an electric fan?

If you have a basically stock 289....then yup....you're gonna be out of breathe at about 90 or so.
Why is that...simple really....you car has a RPM range that it can work effectively in. The higher ratio rear moves you up and through RPMs faster and sets your final drive RPM significantly higher when you are in the final drive ratio of 1:1. This is a lesson alot of people spend a lot more money to learn than you just did...you have to completely think through the combination of performance parts you intend to use on the car and make sure they wll work to compliment each other. I am sure your car has a nice fast jump out of the hole now with the 3:90 gears, but you have made the conscience decision to trade of your top speed for that faster acceleration.


What OD tires do you have on the car? If you aren't currently a 26 inch OD tire in the rear you can 'eek' a little MPH out of the car by increasing the tire hieght to 26. My buddy's 66 has 4.11 with a 289 that goes to 5500 RPM....and a 24 inch tall tire....he is dead at about 80-85.

As for the restart problem grinding, not enough info, but I think based on what you said was the starter making a grinding noise....check for bad ground, check for bad starter....not really a big problem.

 

Sound's like you've spent some serious bucks. This may not be what you want to hear but you may have gone for too much gear. You have a C4 don't you? The combination of gears, and a non-locking converter will put you at some pretty steep revs at 90 mph. I don't know what height your tires are but that will contribute also. Years ago I ran an AMX with 3.91's, 4spd and 25" tires. I went through the traps at 5000 RPM at about 96 MPH. My 69 has a C6 and I run 235/60-14"s (25" tall) in the rear. I had 3.89's and found them to be a bit too much for general cruising. I changed them out for 3.25's and the car has much better manners now. Maybe your next upgrade should be an OD transmission?

 

Well I kinda calmed down now, this morning (couldn't worry about it in the dark) and I figured out that the starter was loose, so I tightened it, and it starts fine

Anyways, I am not sure what my tire size is.

and my engine isn't stock it is a 302, with pretty much everything, headers, carb, manifold, ignition, cam, etc.....

so I drove it today and it still does the 85-90 range revving out at like 6,000rpm.


I dunno, I think I might have got the wrong gears, perhaps the wrong ones were put on, and I got a lower gear by mistake.

So on Monday, I'll take it back and I'll get the gears checked, but I think they must be lower, if not maybe I'll go to like 3.25 or 3.55, but my feeling is that these are prob lower than 4.11 right now, also the rubbing in the back is still present, I need to get that checked also, just turning into parking spots and reversing makes it rub.

but ya, overall good news now it is just a matter of fine-tuning a few issues.

 

What size tires are you running in the back??? I run a 295 50 on 15x7 wheels and hardly ever rub. Sounds more like the front is hitting the fender instead of the back.

 

I have nothing, that hasnt already been covered. So I just wanted to try and cheer up. Because I feel for you man. Id be angry out of my mind. Take it easy, try not to yell too much at the mechanic that did that to your beautiful machine.

 

Well, I have come to the conclusion that I just bit off too much gear for my car. I called the mechanic and he said that he double checked and all, he said something could be wrong with the tranny, but I don't think so, b/c someone in this thread said that his friend had this similiar problem.

So what should I go with now? 3.25 3.50? I sorta fear that 3.50 will still be too low for my car. I am kinda bummed out now though, b/c I would imagine with a higher gear it will have more pull that it did when I had the 3.05, not near as much as with these 3.80, but you can't have the best of both worlds I gotta do what I gotta do, to have my car be able to drive in normal conditions.

But the mechanic messed up the rear, it seems that when he took off my air shocks and put them back on he didn't do it right, and the air has decreased in them, I told him that the tires are rubbing in the back and he said he drove it without air in the air shocks and there was no rubbing, so he makes up excuses not to use the airshocks, which is BS

so I gotta find out what gears to go with now, and then I need him to fix the rubbing.

 

scratchy im running a 302 in my 64.5 with plenty of horse power...the 3.5 gear is as much as you should go if you are running a C4 tranny...i would put in the 3.25's like i have done until you get a aod tranny then it would be time to put the 3.90's back in. but i hear a lot of people prefer the 3 speed tranny if you are interested in turning the 1/4.

get the 3.25's

 

ya, 3.25 it will be, still kinda dissapointed that I can't have the 3.80's, but hey I gotta do what I gotta do, so I will go ahead and do that, then I will have to get the rear end reassembled correctly.

 

Well I got the new gears ordered, and the airshocks are still working, I guess I just thought they were looking a little low, as far as the rubbing go the mechanic and a few other people I have talked to say that is normal for possi, I guess it is a vibration that goes through the axle, and it will go away as it breaks in. I guess I over-reacted about the whole issue, but I am just glad it is all taken care of now