|
Author
|
Topic: Is this true?
|
adragon8u
Gearhead Posts: 4857
From: Oceano, Ca. member# 2895
Registered: Mar 2003
|
posted 09-20-2003 04:39 PM
   
I was talking to my bosses dad the other day, and he said that the reason my car seems like it could use one more gear and my speedo is off by about 10 mph, is because the rearend is for a stick and I have an automatic. does this sound correct? and if so, can I put taller gears in it, or would i have to replace the rearend with one for an automatic?
thanks in advance.------------------
66 coupe
289
C4 auto
"someone who knows how will always have a job working for someone who knows why"
http://webpages.charter.net/adragon8u/mystang
IP: Logged |
Fastymz
Moderator Posts: 18590
From: Reno Nv USA MEM#1240
Registered: Apr 2001
|
posted 09-20-2003 05:00 PM
I think he meant the rear end GEARS not the rear end.You can change to any ratio rear gears you want without changing the rear end out.Do you know what ratio gears you have now? A taller gear will reduce the rpm at speeds,but give you less grunt off the line.Your speedo could be off because some one changed out the rear gears or the trans was replaced with one with a different speedo gear in it.------------------
SCOOP 2.26 60'S
14.9 @ 90.86MPH 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
IP: Logged |
adragon8u
Gearhead Posts: 4857
From: Oceano, Ca. member# 2895
Registered: Mar 2003
|
posted 09-20-2003 05:08 PM
I know that the engine is not original, and the tranny may or may not be original. I've taken a quick look and don't see a tag on the rear end. Is there another method of identifying the rear end? as far as what my bosses dad was telling me is that standard trannys had lower geared rearends. I do think i need taller gears though.------------------
66 coupe
289
C4 auto
"someone who knows how will always have a job working for someone who knows why"
http://webpages.charter.net/adragon8u/mystang
IP: Logged |
Fastymz
Moderator Posts: 18590
From: Reno Nv USA MEM#1240
Registered: Apr 2001
|
posted 09-20-2003 05:17 PM
What rpm are at in 3rd gear at 55-or 60mph.Also need to know how tall your rear tire is too ?Check out this site it will give you idea of what gears you have now,and what you might want. http://www.ring-pinion.com/calculators/calculatorsind.html
------------------
SCOOP 2.26 60'S
14.9 @ 90.86MPH 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-20-2003).]
IP: Logged |
adragon8u
Gearhead Posts: 4857
From: Oceano, Ca. member# 2895
Registered: Mar 2003
|
posted 09-20-2003 05:42 PM
thanks for the link scoop! the rear tires are p195/75r14. Don't have a tach so i'd just be guessing on the r's, they just "feel" high.------------------
66 coupe
289
C4 auto
"someone who knows how will always have a job working for someone who knows why"
http://webpages.charter.net/adragon8u/mystang
IP: Logged |
Fastymz
Moderator Posts: 18590
From: Reno Nv USA MEM#1240
Registered: Apr 2001
|
posted 09-20-2003 06:35 PM
quote:
Originally posted by adragon8u:
thanks for the link scoop! the rear tires are p195/75r14. Don't have a tach so i'd just be guessing on the r's, they just "feel" high.
I know in my car has 24.5" tall rear tires and 3.40 gears at 3000 rpm I'm doing about 65 mph. It does seem high at first.------------------
SCOOP 2.26 60'S
14.9 @ 90.86MPH 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-20-2003).]
IP: Logged |
ekbeanctr
Gearhead Posts: 679
From: Middlebury, IN USA
Registered: Dec 2000
|
posted 09-21-2003 09:52 AM
I think you can tell what gears you have by jacking up the rear of the car (Use jackstands before getting under it). put the car in neutral and have someone turn the rear wheel slowly 1 complete turn while you count the number of turns the driveshaft makes. An example - If the driveshaft turns 3 times while the wheel turns 1 then you would have 3:00 to 1 gears. I think most automatics are down around 2.7 to 1. If you had that your motor would not be over revving. However since you have an automatic if your gears are higher , say 3.50 to 1 then the motor would have to run faster.------------------
Have a Wonderful Day
CandyApple 65 Fastback
351W, Hooker Super Comps,4 Speed
Versaille 9" Rear End
Global West Front End
[email protected] [This message has been edited by ekbeanctr (edited 09-21-2003).]
IP: Logged |
adragon8u
Gearhead Posts: 4857
From: Oceano, Ca. member# 2895
Registered: Mar 2003
|
posted 09-21-2003 10:45 AM
thanks ekbeanctr, i'm putting it on stands today to put on some undercoat, i'll try that method.------------------
66 coupe
289
C4 auto
"someone who knows how will always have a job working for someone who knows why"
http://webpages.charter.net/adragon8u/mystang
IP: Logged |
mustangboy
Gearhead Posts: 774
From: Ont, Canada
Registered: Mar 2002
|
posted 09-21-2003 07:56 PM
Just make sure both tires are turning equally when using this method or you'll get a false reading.Sometimes its just easier to hold one wheel still(if its not a posi) and then you have to double your results.eg 1.5 turns would equal 3.------------------
1968 mustang j-code sprint.13.69@101 306cu.in, stock ported heads,weiand exellerator,650 holley DP,hedman hedders,comp 292 Magnum cam,4-speed,8 inch 4.11 detroit locker http://mustangsandmore.50megs.com/MembersPics/mustangboy.html [This message has been edited by mustangboy (edited 09-21-2003).]
IP: Logged |
Hemikiller
Gearhead Posts: 583
From: Killingworth, CT
Registered: Feb 2002
|
posted 09-22-2003 12:42 PM
When you compare your daily driver that loafs at 1800 ~ 2000 rpms and then drive an early Mustang that'll cruise at 2500~3000, then it sure will feel high. A 3.00 rear with 26" tires will turn 3K at 75mph.Get a tach so you can get an real RPM figure and go from there. My friends Challenger feels like it's turning all kinds of rpm at 60, but he has 2.73 gears with 25.5" tires. Every car "feels" different.
IP: Logged |
adragon8u
Gearhead Posts: 4857
From: Oceano, Ca. member# 2895
Registered: Mar 2003
|
posted 09-22-2003 01:21 PM
yeah, I think a tach would be a great investment right now. Speaking of which, I seen a really cool add on radio for a car that mounts on the column and looks just like a tach. A guy brought it into the radio repair shop where I used to work to have it repaired. very cool!------------------
66 coupe
289
C4 auto
"someone who knows how will always have a job working for someone who knows why"
http://webpages.charter.net/adragon8u/mystang
IP: Logged |
Mustangsandmore Forums
UBBFriend: Email This Page to Someone! 
