Gear change - Pros and Cons ?

[Dustman]

After doing some research I've noticed quite a few of you changed gears ....... what ratio would Y'ALL consider just 'right' ?
3.33 ?

What's the 'stock' ratio anyways ?

Who's a good supplier to get the gears from ?

Too many damn questions, I know

Thanks for any infos on that subject !

 

[Kenneth Krieger]

I have an 05 Comm. Edition with S/C, and 3:55's and I think they are the perfect ratio. Great performance in any gear when you want it, and in 6th gear on the open freeway at 80mph, your turning 1,700 rpm and I have gotten as high as 25mpg. On a recent trip from Phoenix to Flagstaff then to Sedona and back to Phoenix, we went from 1,100 ft in altitude to 7,200ft in altitude. I averaged 21.7mpg. I will admit we didn't go over 90 mph but still had a great time!
IMHO 3:55's are the best ratio to go with. Call JonB at Parts Rack. That's where I got mine, and he had the best price by far.
Stock ratio is 3:07, and I believe they are used for milage along with top end of over 200mph. I'm not going to go 200mph, so the 3:07's had to go!!!

 

[ILLSMOQ]

After doing some research I've noticed quite a few of you changed gears ....... what ratio would Y'ALL consider just 'right' ?
3.33 ?

What's the 'stock' ratio anyways ?

Who's a good supplier to get the gears from ?

Too many damn questions, I know

Thanks for any infos on that subject !

stock = 3.07

supplier = parts rack or unitrax

My opinion on gearing for having fun everyday;

if you are going to make bigger power 550rwhp to 800rwhp the 3.33 is a good gear.

if you are keeping it close to stock 3.55 would give you a more noticable gain

if you are going to make huge power "800+rwhp"stay with the stock gear.

I am making about 700rwhp and have the 3.55. 1st and 2nd on a cold day are useless....on a hot day it will still hook. 3rd gear sticks and pulls very hard. I do most of my runs on the freeway and the 3.55 really shines there.

.....the only draw back to me is I have to shift sooner than my buddy MikeR and since we are at similar power levels I take him until I have to shift into 5th then he catches back up to me because he is able to stay in 4th longer.

If you a building a quarter mile machine and want to go with a gear that will help you maximize your quarter mile times...some of the others would be able to help you better than I can....same thing on a road course car...I dunno what works best there.

I love the 3.55 with the paxton.

also 6th gear is totally useable with the 3.55. never used 6th with the 3.07.

 

[Viper X]

ILLSMOQ has given you pretty good info.

Gear selection really depends on how you intend to use your car and opinions vary.

On a road course, 3.07's work better most of the time.

At the drags, power level dictates gear selection. You really want to go through the traps pulling hard in 4th gear if possible so adjust accordingly. Keep in mind that tire height affects gearing and there is a much better selection of sticky tires in 18 inch sizes, which means generally shorter tires.

3.07's work pretty well all around and tend to hold up better than other gear sets.

It would be nice if our OE transmissions had lower 5th and 6th gears.

Dan

 

[johnk]

I have an 05 Comm. Edition with S/C, and 3:55's and I think they are the perfect ratio. Great performance in any gear when you want it, and in 6th gear on the open freeway at 80mph, your turning 1,700 rpm and I have gotten as high as 25mpg. On a recent trip from Phoenix to Flagstaff then to Sedona and back to Phoenix, we went from 1,100 ft in altitude to 7,200ft in altitude. I averaged 21.7mpg. I will admit we didn't go over 90 mph but still had a great time!
IMHO 3:55's are the best ratio to go with. Call JonB at Parts Rack. That's where I got mine, and he had the best price by far.
Stock ratio is 3:07, and I believe they are used for milage along with top end of over 200mph. I'm not going to go 200mph, so the 3:07's had to go!!!

Same setup and 100% agree. And if you're going through the expense of a gear change step up to the Quaife as well.

 

[PowerKraus]

Even though there are probably over a 1,000 posts on gears, this post provided...yet more good info. I always like to see posts that reflect one's actual experience(s). Thanks !

I have a follow-up for ya' ILLSMOQ....please address <<.....the only draw back to me is I have to shift sooner than my buddy MikeR and since we are at similar power levels I take him until I have to shift into 5th then he catches back up to me because he is able to stay in 4th longer...>>

What is the MPH, during a WOT speed run and when shifting from 4th to 5th, and the mph for your buddy when he tops out in 4th. I've seen all the 'conversion charts', but would like to know your mph, and that of you'r buddy.

Again, Thanks !

 

[johnk]

Top speed in 4th in a Gen3 with stock size tires (345-30-19) with 3.55 gears is ~137 @ 6k rpm.


With a Paxton at stock boost, just about perfect. (for me too, I try not to exceed 137 in every day driving.......)

 

[Hamrhead]

I've got 3.55's in my '06 coupe and I love them. MUCH improved over the stock 3.07!

As mentioned above, 6th gear can now be used. Even at 60mph it has plenty of pull.

My car is closer to stock than others (DC Tune, Green Filters, Corsa Track, 3.55's), but 1st gear is much more fun now! At the strip, I shift into 4th slightly after the 1/8 mile @ around 100mph, so I'm in it for quite a bit until I go through the traps.

Much easier to drive through town and other slow situations.


Drawbacks? They cost me $600 to get installed plus the price of the gears! Hopefully you can find a shop to do it for less $$$.

 

[94EmeraldGreen]

I put 3.55's on my 94. Absolutely loved them. My next viper will definitely get the same mod.
1st isn't so looooong and It makes 6th gear usable.

I thought with traction it would improve my 1/4 mile times, but was not the case.
I ran the same times with the 3.55 gear. Also twisted a half-shaft trying to improve the time.

I think 3.55 is the way they should come from the factory. on the highway using 6th alot,
I...(don't flame me)... calculated 23 mpg on a 400 mile drive (6 hours gets boring) from Maryland to North Carolina.

It's just better in every aspect.

Just make sure you know what you are doing, or the installer does. It will be noisy if not set up right. The a-holes who I let install mine (showtime automotive in Rockville, MD) did a terrible job and I dealt with noise for over a year before I got it set right.

 

[Dustman]

Thanks everyone - FANTASTIC responses, great facts and I DID get my answer(s)

Seriously thinking about doing this mod down the road !


Well, ONE more question for the ones of you that have done the gears, how did you get the speedometer re-calibrated ? Do the gears come with an adjustment calibration ?
Just wondering ?!

 

[Hamrhead]

Well, ONE more question for the ones of you that have done the gears, how did you get the speedometer re-calibrated ? Do the gears come with an adjustment calibration ?
Just wondering ?!

I can't speak for the Gen1&2 cars, but on the SRT's the speed sensor is in the diff housing, so I've been told. It automatically adjusts - no calibration needed.

 

[ROCKET62]

I can't speak for the Gen1&2 cars, but on the SRT's the speed sensor is in the diff housing, so I've been told. It automatically adjusts - no calibration needed.

I think your right about the calibration not being needed - but I believe on the SRT, the vehicle speed is grabbed from the wheel speed sensors which are mounted behind the wheel hub - which also explains why no adjustment is needed for different size tires.

I would like to hear more feedback from the 3.33 crowd.

 

[ILLSMOQ]

I think your right about the calibration not being needed - but I believe on the SRT, the vehicle speed is grabbed from the wheel speed sensors which are mounted behind the wheel hub - which also explains why no adjustment is needed for different size tires.

I would like to hear more feedback from the 3.33 crowd.

Vehicle speed is picked up from the ABS tone rings behind the wheels.

A gear change will not change your speedo reading.

Changing the tire size will throw off the speedo. Taller tires will cause the speedometer to read slower, and shorter tires will cause it to read faster.

 

[Dustman]

GOOD STUFF guys, thanks


How 'time-consuming' is the gear change ?


(for example, I NEVER would've thought changing the stock exhaust would be such a time consuming hassle )

 

[ILLSMOQ]

GOOD STUFF guys, thanks


How 'time-consuming' is the gear change ?


(for example, I NEVER would've thought changing the stock exhaust would be such a time consuming hassle )

swapping the gears or swapping the third member?

I'd say swapping the third member is on par with doing the exhaust swap...of course you would need the appropriate tools.

Swapping the gears is a bit more involved.....look here

ratios below 3.55 are much more forgiving(less chance of noise) than ratios over 3.55.

either way you decide to go, post up if you need some help.

 

[MikeR]

Id order up a whole new exchange rear end. Your stock posi is going to break if you drive hard. Get a Quaife and a gear change. For about 3k, you can have a whole new assembly and swap out rear ends. You'll have a better rear end, a better posi that works and you wont break it.

Call Jon at Parts Rack and order one up. You will love the new mod. And Id go with 3:33. Its the best in between gear in my opinion.