Tuesday, June 13, 2017

Contemplating Rear Gear Change

I've often considered replacing the rear gear set in the Mustang for improved performance.  My hesitation is with the amount of improvement I would experience versus how it might negatively impact driving at highway speeds and in first gear.   

When driving to the Goodguys show in March, I took the following picture of my gauge cluster.  The cluster shows 70 MPH and 2100 RPM.  However, my wife was following behind and my speedometer showed 70 MPH when I was going 74 MPH.



The current rear gear ratio is 3.25:1.  My rear tires are 26" tall.  My transmission has the following gear ratios:
1 - 3.35 
2 - 1.99 
3 - 1.33 
4 - 1.00 
5 - 0.68

If I switch to a 3.8:1 rear gear, my RPM at 70 MPH would be 2300 RPM which is not too bad.  At 75 which is the speed limit in many places, I'd be at 2500 RPM.  However, I'm concerned about what first gear would be like using a 3.80 rear gear.  

I could switch to a 3.55:1 rear gear and it would be better all around except the performance increase would not be that great since I'm already running a 3.25 rear gear.  At 75 MPH, the 3.55 gears would put me at 2340 RPM.

I calculated these using the following calculator which seems to be one of the better ones I found:
http://www.wallaceracing.com/calc-rpm.php

Sunday, March 19, 2017

Recap of Goodguys Spring Lonestar Nationals Trip

The round trip to the Goodguys show in Fort Worth including driving around town was 454 miles.

For a while, I watched the temp, oil, and a/f guages expecting something to go wrong.  As the miles rolled by, my concern faded as everything went exceptionally well.  In fact, there were no real problems at all.

I expected to have some trouble with the engine temperature.  Despite the temperature outside reached 84 degrees and bumper to bumper traffic, the engine temperature never exceeded 180 degrees.  I suspect the new alternator allows the electric fan to run faster at idle as I previously had some trouble with the temp increasing at stop lights or drive thru's.

The show was great and had more attendance than I've seen before.  This year I did not put the Mustang in the show or run it in the autocross but I might in the future.  However, this was a great chance to run the car and have a great road trip with my son.


As I drove, I did think of a few things that I could do to improve the Mustang for future trips.  Some of them are small but if you don't document them and work to eliminate them, they will always be there.  The ideas I jotted down include:


  • Rattle above clutch pedal when the clutch is pressed.
  • Front speakers are needed to hear the radio with the windows down
  • Passenger window is a little hard for my son to roll down
  • There are a few small holes in the firewall which need to be filled
  • Rattle in driver side rear interior quarter panel
  • Better way to fill with gas without any running out
  • Need to confirm there is no oil usage
  • Rattle on the driver side door pull
  • A/F is a little high when in forth gear
  • Speedo is off 4 mph at 70 (70 is really 74)
  • Better driver side mirror??



Friday, March 17, 2017

Goodguys 7th Annual Spring Lone Star Nationals

Weeks ago, I made hotel reservations for the Spring Goodguys car show in Fort Worth.  I then grew busy with other things and did not think much about going again until this week.  As the week progressed, the weather forecast improved and good weather is expected.

I've not done anything in preparation but have decided to drive the Mustang.  There is no particular reason except I want to take it on a road trip.   My goofy thought is that I will drive it to events occassionally and if they have some type if commemorative sticker, I'll get something small for the rear bumper.

I drove the Mustang to work yesterday and today.  Last night, I cleaned it some, fluid levels, and confirmed my tools and spare parts bin were in the trunk.  Now the only thing left is to do it.

The Mustang is currently waiting in my work parking lot for 5 o'clock to come.