99 vert gears.

[flynfink]

Several years back I swapped the stock gears (3.27) in my 99 for a set of 4:30's on many folks recommendations. Well, that was before $5.00/ gallon or higher premium petrol. I want to get the rpm down to a more reasonable level when crusing the highways and back road, which is what the car is used for mostly.

So, what gears go in?

[SVTSnak]

That's tough...

I'm looking to switch out the stock gears for a deeper ratio (thinkin' 3.73s), but I hear ya on the gas pricing issue...so I'm curious as to see what responses you get. This will help me out too. :D

Then again, maybe I best leave the stock ones in until they figure out what they are doing with this gas pricing crap. LOL :eek:

[nckissfan]

svtsnak, go with 4.10's. That is what I have in mine, and I love them.

[SVTSnak]

Those are a bit steep though, aren't they? What's your rpm in 5th gear, at say 65 mph?

That'll give me a reference to what I'm doing now with the stock gears. :cool:

[nckissfan]

hmmm, I can't remember what the rpm is. But, it is not that steep. The wow factor is awesome. I'm telling you, it's not that bad, and if you are doing gears, you may as well go 4.10's. Your car will feel a ton faster.

[97whitevert]

I've got 4.10's in the 97, and won't change back. I manage mid 20's mpg on the highway, cruising at 70-75.:D Even with teh a/c on and going topless!

[tcrews]

Leave them in. Your gas mileage shouldn't have been affected "that much" by a gear swap. I know when I went from 3.27 to 4.10s in my '97 my mileage changed.......practically ZERO.

What you probably need to change is the right foot, apparently it's too heavy :)

Seriously, driving "normal" between the stock gears and your 4.30s should only see a difference of maybe 1 mile per gallon between the two. Labor to install, reprogramming your computer for the gear change.....how much does 24mpg vs. 23mpg bother you?

I was getting 27 mpg in my '97......when it was stock. My "near stock" '98 only gets 23 at best. And that's with stock gears. I'm thinking a switch to 4.10s will get me a little better mpg just because I'll be able to actually use 5th gear on roads other than the highway.

[nckissfan]

all that running, and biking Jeff does, and his foot is still too heavy:rotf:

[flynfink]

Leave them in. Your gas mileage shouldn't have been affected "that much" by a gear swap. I know when I went from 3.27 to 4.10s in my '97 my mileage changed.......practically ZERO.

What you probably need to change is the right foot, apparently it's too heavy :)

Seriously, driving "normal" between the stock gears and your 4.30s should only see a difference of maybe 1 mile per gallon between the two. Labor to install, reprogramming your computer for the gear change.....how much does 24mpg vs. 23mpg bother you?

I was getting 27 mpg in my '97......when it was stock. My "near stock" '98 only gets 23 at best. And that's with stock gears. I'm thinking a switch to 4.10s will get me a little better mpg just because I'll be able to actually use 5th gear on roads other than the highway.


I disagree (and my foot isn't that heavy). In 5th gear, instead of 1800 RPM at 70 mph (stock gearing), I'm at 2800. Car used to get 24-26, now it's around 20-21 on the open road. If I'm at 75-80 mph, it's in the high teens. I already have an Abbott gearing converter installed for speedo error correction.

[tcrews]

70 mph with 3.27 is 2,000 rpm
70 mph with 4.56 is 2,800 rpm

(oops...just noticed you said 4.30 not 4.56).
That's only going to be 650rpm difference then...

650 rpm difference is not going to affect your gas mileage that much....

If you feel it's really affecting you that much...than switch your gears out. It's your car. I'd be getting rid of the 3.27s in my '98 if I had some extra money to spend on gears.....I find the stock gears absolutely horrible and completely mismatched for these engines. 3.55 and 3.73 not being a big enough difference to even matter.

Which RPM range works for you?

Engine RPM: 2007.34323826472
Vehicle Speed: 70
Read End Gear: 3.27

Engine RPM: 2179.22583970634
Vehicle Speed: 70
Read End Gear: 3.55

Engine RPM: 2289.72179777596
Vehicle Speed: 70
Read End Gear: 3.73

Engine RPM: 2516.8523782524
Vehicle Speed: 70
Read End Gear: 4.10

Engine RPM: 2639.62566499642
Vehicle Speed: 70
Read End Gear: 4.30

Engine RPM: 2799.23093776364
Vehicle Speed: 70
Read End Gear: 4.56

[SVTSnak]

Wow, looking at it broken down that way, it does seem like he might want to keep the 4.30's in.

It does seem worth it for me to go to 4.10's instead of 3.73's. It just seems like a huge difference, but apparently not when you use the "overdrive" 5th gear. 4.10's are only 500 rpm over stock...that's really not that much and I'm sure the "bottom end" increase with the gears are well worth it.

I'd consider keeping your 4.30's then...but totally up to you. :thumbsup:

[scorpio]

i have 3.73's in my 01 and i wish i would have done 4.30's or 4.56. takes forever to get into the power on these cars.

[cobrabitn]

If I had a mod motor car naturally aspirated, I would have 4.10's in it. I drove Lisa's Cobra and it really woke the car up and the fun o meter was almost off the scale!

Jeff, I voted you leave the 4.30's in because it is a pain in the a$$ to have to get them swapped out, not to mention the cost. My stock 94 got 23-24 back and forth to work and 28-30 on the highway with the cruise set at 65 mph.

I've slowed down to 65 and the cruise set and the mileage has gone up from driving 70 mph.

My advice is that you drive a tad slower and you'll see the fuel mileage won't make a big difference. JMHO cause you asked for it. :)

[Karnick]

I would say leave the gears which seems to be the general thought. I put 4:10's in mine and the I went from getting 21 per gallon to 20 (city driving) I would suggest adding a right foot mod... different driving style, i find I get my best milage when I shift around 3k.

[ProfChaos]

svtsnak, go with 4.10's. That is what I have in mine, and I love them.


nckissfan is right. On my '96 Cobra, I have Ford Racing 4.10:1 Gears (http://store.summitracing.com/partdetail.asp?autofilter=1&part=FMS%2DM%2D4209%2DG410A&N=700+400070+302897+115&autoview=sku) with Moser 31-Spline Axles (http://www.americanmuscle.com/moser-31spline-88-axle-9498.html?productid=moser-31spline-88-axle-9498&channelid=FROOG), and I love the combination--it is both zippy and efficient, especially when cruising the highway.

cheers, :cheers:
--Professor Chaos

[SVTSnak]

Thanks for the info Prof. Looks like I'll be looking into 4.10 gears.

Where are you all getting the Ford Racing gears from? Directly from a dealer or is there a better place to buy them from? I think I saw one dealer and the gears alone were like $400 and that didn't count installation. :eek: :(

[rpalmer]

Hey, it's not an economy car, right?

4.10's for the street, 4:30's (or higher) for the strip.

-RP

[Lumpydogs]

4.10s seem to be the magic gear for NA 99-01 Cobras, unless the car is going to be primarily a drag car then go higher.

I've had my 4.10s installed in the '01, since 2003. No issues and only maintenance is the annual gear oil change deemed necessary because of on-track events.

[Tnmustcobra]

Just curious, but what would top end be for a 97 Cobra running 4:10 gears? Anyone able to run the math? Figure redline around 7000 rpm in 5th gear. I have the 3:73 gears which I could definitely feel the improvement in acceleration, but I feel the 4:10 would help a little bit more. Wish I had put in the 4:10 the first time, but my car is primarily a track car anyway and not my daily driver, so mpg is not an issue for me.

Thanks,
David Morrison

1997 Mustang Cobra
1987 Porsche 944 N/A
2004 Ford F350 Dually
1988 Mustang AV8SS Unlimited Race Car (sold) :(