I was pretty much set on 4:10's, but the more I think about it, I'm wondering if 4:30's would be the better choice. I was thinking back to my boss 302 maverick I built in the late 70's. I started with 4:56 and after I blew my 8", I went to a ford 9 inch with 4:11's. I noticed it had lost a little of it's punch. I had a 67 F-250 4x4 with 4:56 gears and it was an absolute torque monster. Maybe 4:30's wouldn't be too much gear for the street. It didn't cause the maverick or my truck to have over heating problems in the summer, which is a concern. My stang isn't so much a DD. We don't drive it in the winter at all. We will be driving it to work in the summer between me and the wife. How hard would the 4:30's be on gas compared to 4:10's? I guess what I'm looking for is for someone to tell me the reason I shouldn't go with 4:30's and see if that out weighs the positive aspects. I know that gears is one of the best mods as far as bang for the buck, be it a sports car or 4x4. Come on guy's, convince me either way so I can nail this mod down and move on to the next. I'll be doing the gear swap late winter, early spring for the summer driving season, "thanks for the input".
Another gear ?
- Thread starter ranger04
- Start date
xtweakerx
New Member
Five Oh Brian
Member
I had 4.30's in my 2003 Mach 1 (manual trans) and currently have 4.10's in my 2007 GT (automatic). The only reason I didn't do 4.30's in the 07 is the overdrive ratio isn't deep enough with the new automatics (.71). My Mach 1 had a .62 overdrive and the new GT manual have a .68 overdrive so they can get away with more gear.
That said, 4.30's would be fine in a 2005+ GT manual. 4.56's might be OK, too, as your GT won't be much of a DD anyway. For those of us with automatics, 4.10's seem to be the ideal gears.
Fuel economy won't be much different than the stock gearing as the overdrive is so steep. In the old days before overdrives, having just a 1:1 trans ratio in high gear really screwed with fuel economy with steep gears. Overdrives negate most of the gearing change, however, so don't fear the gear!
That said, 4.30's would be fine in a 2005+ GT manual. 4.56's might be OK, too, as your GT won't be much of a DD anyway. For those of us with automatics, 4.10's seem to be the ideal gears.
Fuel economy won't be much different than the stock gearing as the overdrive is so steep. In the old days before overdrives, having just a 1:1 trans ratio in high gear really screwed with fuel economy with steep gears. Overdrives negate most of the gearing change, however, so don't fear the gear!
My future plans are to some day go FI, but at the price of a pro charger, it won't be for a long time unless I hit the lotery or something. So as for now I'm going to build na. Do headers, intake, udp's and so on just to have fun with it and mod until such a time as I can go FI. Thats sorta what got me thinking, since it will be some time before I can go FI, 4:30's would be a good punch on a na car with some bolt on's. I love that neck snapping excelleration and since I don't have cash for FI, what better way to snap your neck than with some steep gears.
Brain, did you run hot at all in the summer with the 4:30's in your mach? Probobly not as the overdrive makes a big difference. I had a 65 fairlane with a hypo 289 and 4 speed, with the 3:90's it was fine, I went to 4:56's and the little bastard would over heat on hot days. It was a strip car by then, so it was no big deal, just ice it down between runs. If none of you guy's have any issue's with the 4:30's, I'm pretty much sold at this point. I don't know why 4:10's were embeded in my brain untill now, "Yeah", I need not fear the gear, or do I? My old neck isn't as strong as it once was ha ha.
Brain, did you run hot at all in the summer with the 4:30's in your mach? Probobly not as the overdrive makes a big difference. I had a 65 fairlane with a hypo 289 and 4 speed, with the 3:90's it was fine, I went to 4:56's and the little bastard would over heat on hot days. It was a strip car by then, so it was no big deal, just ice it down between runs. If none of you guy's have any issue's with the 4:30's, I'm pretty much sold at this point. I don't know why 4:10's were embeded in my brain untill now, "Yeah", I need not fear the gear, or do I? My old neck isn't as strong as it once was ha ha.
kooldawg6
mine works really well and can take a fair amount
The only reason I can think of not going with the 4.30s is if you run a shorter rear tire than stock. Say <26". I'm giving thought to getting 4.30s in a few yeaers if I don't go F/I.
My car is an 07 GT/CS with 18's, I'm going to have my stock rear wheels widened to 10" to run some fatty's, may go alittle taller if anything, but not shorter. I'm from the old school where the stink bug look was in. I don't won't the tires to stick out a foot, but for sure to fill the wheel wells. There was a link on here for a place that can widen or shorten stock rims. If I widen my stock 18" to 10", what do you think is the biggest tire I could run without jacking up the rear or something?
kooldawg6
mine works really well and can take a fair amount
ranger04, the limiting factor will not more than likely be tire height, but if you have your factory wheels widened from 8.5-10", you may run into clearance issues inboard as your backspacing is not going to change(the additional 1.5" will be all to the inside). My 18x10" has 7.44" of backspacing. Your 18" polished wheel has a backspacing of 6.82". Another 1.5" will take it to 8.32"(nearly an inch more than mine). It appears I have enough clearance for another 1" or so before it starts interfering with the shock tube. The issue with your wheel may be that they can't change the backspacing. If so, it will be wide with a wide tire, but it will not be any further towards the fender lip than you are currently. As far as tire size, you will be able to easily run the Nitto 555 295/45(28.3") with 100% stock suspension. I would love to find a taller rear tire for mine
burke07gtcs
New Member
I love my 4:10's... I too have an auto, and I think 4:30's would be too much for a daily driver, that wont see much track time.. Highway cruising at 75 or so and the rpm's are a manageble 2,500-2,600.. If i went non-centrifigal, i would have went 3:73's..As traction is an issue now with my set-up..No more power for me until I get some bigger meats..
Well then, I guess widening the rim isn't such a help. I've never had 18" tires before, I haven't even looked to see whats out there yet. My first 2 mods are going to be gears and a shifter. You say those 295's will fit my stock rims are no? I believe there 8.5" wide. Thanks for all the reply's, sounds like 4:30's get the nod so far.
Five Oh Brian
Member
Overdrive kept things cool in the Mach 1, even with 4.30 gears. It turned 2,800 rpm's at 80 mph, and just 2,100 rpm's at 60 mph. My 2007 GT automatic with 4.10's turns the exact same revs as the Mach 1 with 4.30's (different overdrive ratio and tire height). No cooling issues or durability issues of any kind - gotta love technology and overdrives.
Top speed is improved, as well, not that anyone really needs to go 150+. But, with more gear, you can actually accelerate harder in 5th gear to reach max speed than with factory gears and the overdrive ratio. For example, my car had a theoretical top speed with 3.31 gears of 213 mph, but aerodynamics and lack of horsepower/gearing would prevent anything over about 145 or so. With 4.10 gears, my car has a theoretical top speed of 172 mph. I'm sure aerodynamics and lack of horsepower would still prevent reaching that, but it would push harder and higher on the top end than with the stock gears (maybe 155 or so?).
kooldawg6
mine works really well and can take a fair amount
The Nitto 295 is ideal for the 10" width. I was reffering to if you had your wheels widened. The 295 will fit your 8.5", however it would look odd. The sidewall would be drawn in 3/4" on both sides of the wheel(1.5" difference/2). That would be ok if you go with a taller profile tire, such as a 29-30". 275 is usually the norm as far as max width for the rear on the 8.5" wheel. There are many different wheels styles that would allow you to stagger and still look very similar to your stock wheels.
Here is the link to Rev Wheel(brand wheels I just purchased).
http://www.rev-wheel.com/oe/180c.html
OK, the place that widens the rims does it in 1/2 's, what would be the shortest widing of my rims I could get away with that wouldn't effect my back spacing too much and still allow me to run 295's, 9" or 9.5" maybe?
The highway rpm's sounds good with 4:30's, I never run over 70mpg. The only place I really travel to is back home in W,Va, the speed limit here in Ohio is 65, same in Pa and maryland that I travel through, W,Va is the only state that the speed limit is 70 mph. I set the criuse acouple mph over the posted speed to keep me out of trouble. I bet the 4:30's will make a big difference once I get into the mountains, I should be able to climb in 4th and 5th gear instead 2nd and 3rd. With all the twisties, should be a blast. It was fun when I took the stang down this past summer, but for sure needed more gear. Should be able to hang it in the turns on the way up as well as comming down.
The highway rpm's sounds good with 4:30's, I never run over 70mpg. The only place I really travel to is back home in W,Va, the speed limit here in Ohio is 65, same in Pa and maryland that I travel through, W,Va is the only state that the speed limit is 70 mph. I set the criuse acouple mph over the posted speed to keep me out of trouble. I bet the 4:30's will make a big difference once I get into the mountains, I should be able to climb in 4th and 5th gear instead 2nd and 3rd. With all the twisties, should be a blast. It was fun when I took the stang down this past summer, but for sure needed more gear. Should be able to hang it in the turns on the way up as well as comming down.
xxrequiemxx
Member
kooldawg6
mine works really well and can take a fair amount
kooldawg6
mine works really well and can take a fair amount
The Nittos I got were $225 each from a local tire place.
Discount Tire has the Nitto for $191.
http://www.discounttiredirect.com/direct/findTireDetail.do?c=1&sw=false&cs=295&pc=40192&rd=18&ar=45
Discount Tire has the Nitto for $191.
http://www.discounttiredirect.com/direct/findTireDetail.do?c=1&sw=false&cs=295&pc=40192&rd=18&ar=45
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