My 4:56 gears are installed and the fuel mileage results.!

[slicks2003]

Ok, first out of the hole performance is great and it now can smoke the tires all day long. Feels much quicker and it seems like it's in the start of the power band around town now. A local shop in my area who is big into drag racing (he has 4 drag cars) charged me $300 for the install.

I did a base line mileage check prior to the 4:56 gear install, the mileage was 13.5 -14.5 around town (varied speeds) and 20 - 21 highway at 60 mph.

Now with the 4:56's installed, around town is 16.5 - 17.5, at 60 mph highway its 18 - 19 mpg.

I'm happy with the results..

[xs-cash]

best thing you can do for your ssr.

[true520]

Ok....you have my attention.

Where did you get the 4.56 gearing...

AND, can I put this in an 05, 6 speed?

Thanks, Mitch

[RUN ROD RUN]

Did you get the speedometer corrected for those new gears?

[slicks2003]

Originally Posted by true520

Ok....you have my attention.

Where did you get the 4.56 gearing...

AND, can I put this in an 05, 6 speed?

Thanks, Mitch

Got them at Summit Racing.

Strange Engineering RS01-885456 - Strange Pro Street Ring and Pinion Sets - Overview - SummitRacing.com

[slicks2003]

Originally Posted by RUN ROD RUN

Did you get the speedometer corrected for those new gears?

Yes..

[Flassh]

Originally Posted by true520

Ok....you have my attention.

Where did you get the 4.56 gearing...

AND, can I put this in an 05, 6 speed?

Thanks, Mitch

The gearset for a manual transmission is available, but is not the same as for an automatic.

[slicks2003]

Originally Posted by Flassh

The gearset for a manual transmission is available, but is not the same as for an automatic.

What he said ^^^ The 6 speed I believe has a 12 bolt.

[sangus]

Wow. I've been watching the 4:56 discussion and this one caught my eye. I guess I'll have to save the lunch money (again) to get this done. Hopefully, someone in the Dallas area can do the install and the adjustments to the systems (I wonder if the $300 expense can be matched, in Dallas?)

[hdflstf]

Originally Posted by slicks2003

What he said ^^^ The 6 speed I believe has a 12 bolt.

9.5" 14 bolt.

[slicks2003]

Originally Posted by hdflstf

9.5" 14 bolt.

I stand corrected, thanks..

[slicks2003]

Originally Posted by sangus

Wow. I've been watching the 4:56 discussion and this one caught my eye. I guess I'll have to save the lunch money (again) to get this done. Hopefully, someone in the Dallas area can do the install and the adjustments to the systems (I wonder if the $300 expense can be matched, in Dallas?)

I have checked my mileage a few times, 16.5 - 17.5 mpg around town repeatable (as long as you drive like a normal person).. I would think the cost is going to be around $300 - $450.. I thought I got a great deal at $300.

[true520]

Thanks guys,

I think this will be my first MOD! May just order up the exhaust at the same time.
I am leaving town for a few days, so I will start Monday trying to find someone to put this all together!

Thanks again!

[TLC5 in CT]

Originally Posted by slicks2003

I have checked my mileage a few times, 16.5 - 17.5 mpg around town repeatable (as long as you drive like a normal person).. I would think the cost is going to be around $300 - $450.. I thought I got a great deal at $300.

I'm trying to understand how your gas mileage can be better with a 4:56 diff. vs. a 3:73. It seems to me it should be worse.

[slicks2003]

Originally Posted by TLC5 in CT

I'm trying to understand how your gas mileage can be better with a 4:56 diff. vs. a 3:73. It seems to me it should be worse.

Nope, with 3:73 it takes more TQ and HP to move 4700 lbs then a set of 4:56 gears. The motor works less. I'm not the only one who saw and increase in MPG with a 4:56 gear swap.

[XLR I FL]

Originally Posted by slicks2003

Nope, with 3:73 it takes more TQ and HP to move 4700 lbs then a set of 4:56 gears. The motor works less. I'm not the only one who saw and increase in MPG with a 4:56 gear swap.

A few of questions;

1. Did you fix the ABS issue that is mentioned in the Notes section?? If so, how?

2. Did the $300 cover the speedo correction??

3. What was the general RPM change?? I'm guessing 2-300 RPM--around town and at highway speeds.

Regards

Jerry

[hdflstf]

Originally Posted by XLR I FL

A few of questions;

1. Did you fix the ABS issue that is mentioned in the Notes section?? If so, how?

2. Did the $300 cover the speedo correction??

3. What was the general RPM change?? I'm guessing 2-300 RPM--around town and at highway speeds.

Regards

Jerry

4.56 gears will get you really close to a 20% increase in RPM for any given speed versus the 3.73 gears.

[XLR I FL]

thanks for one of the answers!!!

I forgot to ask if the carrier and pinion bearings were replaced as part of the change as well.


Regards

Jerry

[DOOPHUS]

Originally Posted by hdflstf

4.56 gears will get you really close to a 20% increase in RPM for any given speed versus the 3.73 gears.

What's the RPM increase with 4.10s, Art?

[RUN ROD RUN]

Originally Posted by DOOPHUS

What's the RPM increase with 4.10s, Art?

Don't know the % but at 70MPH, I'm @ 2300/2400 rpm vs 2,000 RPM before I had the gear change. I might be off a little. I'll check again tomorrow.

[MnMsToy]

Originally Posted by DOOPHUS

What's the RPM increase with 4.10s, Art?

My best guess is a 10% rpm increase for 4:10s

[DOOPHUS]

Originally Posted by RUN ROD RUN

Don't know the % but at 70MPH, I'm @ 2300/2400 rpm vs 2,000 RPM before I had the gear change. I might be off a little. I'll check again tomorrow.

Originally Posted by MnMsToy

My best guess is a 10% rpm increase for 4:10s

Thanks, Jeff and Mike . . . I'm kinda surprised it's that much.

[RUN ROD RUN]

Originally Posted by DOOPHUS

Thanks, Jeff and Mike . . . I'm kinda surprised it's that much.

I think you can find that information in Jim G book.

[slicks2003]

For what its worth, my RPM at 65mph is 2300. With the 3:73 is was about 1900 - 2000.

[Mike in AZ]

The automatic transmission truck numbers are like this:

Changing 3.73 to 4.11
4.11/3.73 = 1.101877...
This yeilds a change of 10.2% in RPM at any given speed in any given gear. It is also an approximate 10.2% increase in rear wheel torque for any given engine rpm.
Your engine rpm at 75 mph will go from 2200 to ~2424
Your engine rpm at 100 mph will go from 3000 to ~3305


Changing 3.73 to 4.56
4.56/3.73 = 1.22252...
This yeilds a change of 22.2% in RPM at any given speed in any given gear. It is also an approximate 22.2% increase in rear wheel torque for any given engine rpm.
Your engine rpm at 75 mph will go from 2200 to ~2689
Your engine rpm at 100 mph will go from 3000 to ~3668


Photos below are from my stock automatic SSR (3.73 gears) with a "perfect" (GPS validated) speedo reading. I used a little "windage" on the RPM numbers because of camera parallax error. The rpm values for a stock 6-speed will be approximately the same in 5th gear as the automatic values below.

Regards,

Mike

PS..... you might note that the "Traction Control Offline" light comes on above 95mph.

[TLC5 in CT]

Originally Posted by slicks2003

Nope, with 3:73 it takes more TQ and HP to move 4700 lbs then a set of 4:56 gears. The motor works less. I'm not the only one who saw and increase in MPG with a 4:56 gear swap.

I guess that means one should switch to 4:56 gears if most of owner's driving is around town and stick with 3:73 if most driving is highway.

[slicks2003]

Originally Posted by TLC5 in CT

I guess that means one should switch to 4:56 gears if most of owner's driving is around town and stick with 3:73 if most driving is highway.

Well, depends on each persons view. With the 3:73's on the highway I was getting about 19 - 20 mpg. Now I get 18 - 19 mpg on the highway (not going over 65mph). Not a big sacrifice for such a BIG improvement in performance. If I wanted MPG, I would have got a VW..

[JOHN317]

Originally Posted by true520

Ok....you have my attention.

Where did you get the 4.56 gearing...

AND, can I put this in an 05, 6 speed?

Thanks, Mitch

I did with Help from Joe DeLano LC32. Best money ever spent on the SSR. It really important to get a good shop as the alignment of the gears is critical to avoid whine.

[Cash]

Originally Posted by XLR I FL

A few of questions;

1. Did you fix the ABS issue that is mentioned in the Notes section?? If so, how?
Jerry

I have had an intermittent issue with my ABS light which started after swapping to 4.56's. At the same time I painted my callipers and actually thought I may have done something to a sensor during this process.
Can anyone elaborate on the "Notes" section or what this is in refererence to?

[slicks2003]

In case anyone is interested, I have had absolutely no issues with the 4:56 gear swap..