[Fast SVT]

I was wondering if it would make sense to go with a shorter gear in the Cobra for runs on the bahn.

I'd like to keep the RPM's down while cruising around 120mph and changing the gearing shouldn't be a big deal on the street since it is a twin screw that already makes too much TQ down low.

Thoughts?

[roy]

You mean shorter gear as in higher numrical axle ratio?

[Fast SVT]

I'm talking about a 3.14 or so as opposed to a 3.55.

But I think I screwed up the terminology and should have said 'longer'.

[Werner-96GT]

There is a certain optimal gear. If your final drive ratio is too long (too low the number), the engine will not reach the rpm in highest gear where the maximum power is, and you won't reach the top speed. A too short of a final drive (high number), the vehicle will rev to death before reaching Vmax.

Having said that, it makes me feel uncomfortable that one can get his driver license for 15$ doing a multiple choice test, and then coming to Germany and driving at speeds twice as high as in the home country.
(this isn't about you Fast SVT, it is a generic observation)

[Fast SVT]

Germany has many more issues of greater concern than US service members coming to Germany and having fun on the 'bahn.

I think 3.27 or something close to that is the next gear that Ford offers next to the 3.55.

With 600rwhp I'd be going through the 1/4th around 128 or so MPH at the top of 5th with the 3.55's.

This post has been edited by Fast SVT: 17 December 2009 - 06:56 PM

[roy]

Fast SVT, on 17 December 2009 - 06:05 PM, said:

I'm talking about a 3.14 or so as opposed to a 3.55.

But I think I screwed up the terminology and should have said 'longer'.

I run 3.50 gear with a .75 overdrive and a 25.66 tire dia and hit 192mph at 6500 rpms in 5th. In 6thgear at 3000 rpms my cruise speed is 130mph.
So depending on your transmission 5th and 6th similar performance should be had with your 3.55 gears. If your really pushing some Hp numbers going to a lower numerical number shouldn't be a problem.
There is a excel spreadsheet on here that you can add your specific data to, see what might and might not work for you.

Don't worry about Werner , he just disgruntled he had to pay out bookoo money just to drive a 90hp 4cyl Golf . Where we started out with V8's with upto 4 times that power level.

[Silverflash]

i have a buddy that just did that to his 07 he is very happy with it because it keeps the rpms down and raised his top end at little as well as gas mileage

[AUTOBAHN]

Just remember if you use a calculator spreadsheet it wont adjust for wind resistance and road friction.

I think you have plenty of power for a different gearing .

Mike


Werner, .
We have to have our State side Driver's License before we can obtain one here. I had my Learner's permit when I was 15.5 years old. At 16 I obtained my Driver's License with a Written & Driving Test .

[01cobra896]

To give you an idea, I run 4.30 gears in my 01 Cobra and can top out at around 180mph. At that point I am at around 7000rpm. I can cruse at 85mph all day long and the motor is at 3000rpm. With your 6-speed, if you want to run a constant 120+, you will be in the higher rpm's, no matter what you do. Otherwise you will severely handicap your car on the bottom end. I would stick with the 3.55's until you get the car over here, drive the car and see how it feels and go from there.

[Fast SVT]

A good alternative would be to switch to the viper spec .50 6th gear.

[01cobra896]

Do your research before spending the money, the difference between the Viper-spec transmission and yours may not help you as much as you think. If you do decide to go that route, save your stock tranny and drivetrain. I will take it off your hands.

[Fast SVT]

I'm just talking about having the 6th gear changed out on the tranny I have, if possible and affordable. I want to add an aluminum fly wheel anyways (already has a 26spline input shaft).

[01cobra896]

Your stock flywheel is aluminum and honestly, I would keep it. I have one in my car and I am happy with it. If you change out the gears, I think you will have to swap both 5th and 6th. I seem to remember reading that somewhere. I am happy with my 3650 for now but I have a feeling it may not last much longer.

[Fast SVT]

So why does everyone seem to change out their fly wheel?

Well changing 5th and 6th make sense anyways....thanks for all of the input.

[01cobra896]

Honestly, I have no idea. I got mine for a very good price so I swapped it out.

[intimidator]

With stock gears and stock tire diameter in 6th at 134 mph the rpm are ~4000
With 3.55 rear, Viper Spec T-56 and stock tire diameter in 6th at 166 mph the rpm are ~4000

[dagamore]

will a T-56 bolt up to a S197 gt?

[NateR]

Yes, it will bolt to the motor, but that is about it. you wouldn't be able to use it without some serious modification...

[Werner-96GT]

D & D Performance offer a complete kit to install a 6-speed into a 05-10 Mustang:

http://www.ddperform...hp?cPath=108_95


BA21 05-10 Mustang GT 6 speed Transmission Installation Package



The complete package consists of a new TR-6060 6 Speed Transmission and all the parts needed for installation in an 05-10 Mustang GT. The TR-6060 is the next generation T-56 rated at 700 lb-ft torque with heavy duty 26T input and 31T output shafts. It is orginal equipment in the Mustang GT-500 and similiar to the 6-speeds used in the Corvette, Camaro and Challenger.

Installation kit includes bellhousing, crossmember, short throw shifter, shift handle, leather shift knob, Leather upper boot, lower boot, mounting hardware and a custom one-piece aluminum driveshaft.

* Requires 26T clutch kit not furnished with the kit, but available at D & D.

This post has been edited by Werner-96GT: 18 December 2009 - 11:42 AM

[Ranger]

i just added a 3,73 instead of a 4.10 to a 05Gt ... and the driver is happy with it leaving the 4,10 and not using 3,55...

it depents on what you want .. cruising or fasting ... mileage

[Fast SVT]

Yeah, I am seriously going to look into just swapping 5th/6th gear.

[intimidator]

Fast SVT, on 18 December 2009 - 04:17 PM, said:

Yeah, I am seriously going to look into just swapping 5th/6th gear.

If you do this, get the Syncro kit too.

[Beaster]

Unless you plan on doing a lot of long road trips, I don't think it's worth it. You'll spend a lot more time in the 0-120 mph range than you will above 120mph.

****

Oh, and Werner....Just to ease your mind...

Most Americans start driving when they're 15 years old, so every soldier who comes here already has at least a couple of years of driving experience before they get on the autobahn - unlike your typical German 18 year old...

And, driving on the autobahn is easier than driving on a crowded American interstate. Even though the speeds are higher, traffic is lighter and more predictable - in America, the traffic is heavier, you can pass on both sides, and all lanes of traffic travel at roughly the same speed - so you have to be more aware of your surroundings....

Plus, I don't think German driving schools give their students much time behind the wheel driving 200+ kph...or do they?

It doesn't matter how much you pay for driving lessons or how hard the test is - there's no replacement for experience and no cure for stupidity.

So American drivers are no more dangerous on the autobahn than young German drivers....

Their cars, on the other hand...

This post has been edited by Beaster: 11 January 2010 - 11:41 AM

[workmangc]

Fast SVT, on 18 December 2009 - 09:17 AM, said:

Yeah, I am seriously going to look into just swapping 5th/6th gear.

As far as I am aware you cannot swap the .50 6th gear into a ford spec T-56. I could be wrong, but I'm pretty sure I spoke to someone at "The Gear Shop" or somewhere. If I recall correctly I was considering buying a used T-56 and having it refreshed and the final gears swapped at one point when looking into this.

[alloyOO7]

Fast SVT, on 17 December 2009 - 05:44 PM, said:

I was wondering if it would make sense to go with a shorter gear in the Cobra for runs on the bahn.

I'd like to keep the RPM's down while cruising around 120mph and changing the gearing shouldn't be a big deal on the street since it is a twin screw that already makes too much TQ down low.

Thoughts?

I thought I was the only one who had this idea...Well I have actually done it. I went from 3.31's to 3.08's on my 07 GT and I love it on the bahn. I am N/A with simple bolt on's, not near the TQ you have either. As a side benefit, unless you have an optimized suspension and drag radials you probably can't use all of your TQ at launch anyways (probably not even 3/4 of it). Useing a taller gear will actually make it easier for you to consistently launch hard and put the power to the ground. Another potential benefit, you may even be able to get through the 1320 without having to shift into 4th gear. This is easily 4 tenths. I learned this lesson back in the states with a 4.9L V8 Fiero. It was out of a Cadillac and when the trany went out we put in the trany off of an el'dorado with 3.08's (Vs the 2.79's it came with). Our best 1/4 mile run with the 3.08's was actually 3 tenths SLOWER than our average run with the 2.79's even though we were launching harder. This was b/c the tranny could no longer clear the 1320 in 3rd gear...That extra shift negated all of the harder launch advantages. Needless to say we have 2.79's back in that car. Anyways, I really enjoy 3.08's on my GT and having done the calculations will now be able to clear the 1/4 in third gear with 18's on the back vs having to shift into 4th gear before. Looking forward to seeing what affect it has on my 1/4 mile time slip this summer...Hope you find this post useful...