Rear gear change and drivability.

Author Topic: Rear gear change and drivability.  (Read 19371 times)

Offline EFI-Cuda

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Re:Rear gear change and drivability.
« Reply #30 on: January 16, 2004 - 02:09:14 PM »
I think that the Cuda and Challenger are some of the best creations that represented the muscle car era.   But face it, our cars at least 30 years old and although they were great performers in their day, they face stiff competition in todays performance market.   Technology and 30 years of engineering advances and creature comforts can make our cars show their age.  

Having overdrive, whether automatic, 4-speed or 5-speed is a critical step in raising the capabilities and driving potential of our cars.   Overdrive reduces engine wear and interior noise levels and improves gas mileage and vehicle utility.    

I got my A-518 trans right from the mopar catalog new for about $1,400 bucks about 3 years ago.   I had to do some basic modifications to get it to fit, but it has been worth it since I drive the Cuda everyday.    I had a Transgo shift kit installed in the trans which is fantastic for performance.    With this trans I can upgrade to a more performance oriented rear gear ratio and not completely compromise daily drivability.  Based upon everyone's combined input I am considering the change to 3.91s.

Thanks to all who responded and shared input on this subject.  It appears that it has been informative and helpful to many viewers.
« Last Edit: January 16, 2004 - 02:21:17 PM by 1974Cuda360 »
Cuda 408, Ford EFI, Magnum heads, Vortech V-2 Si-Trim, A-518 transmission and 3.23 gears.




Offline oldvamoparfan

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Re:Rear gear change and drivability.
« Reply #31 on: January 16, 2004 - 10:45:49 PM »
I believe the first OD trans in Mopar RWD was in the '88 model trucks, so they should not be too scarce.  I pretty sure the early ones didn't have computer controls, so it shouldn't be too difficult to get them to work in an E body.  There were no big blocks then, but you should be able to get an adapter for these.  I believe OD & low gears (3.91 to 4.56 ect) gives you the best of both worlds, IE; low gear for get away, & high gear for roadrunning.  I concede that the new vehicles have some advantages in options & creature comforts, but muscle cars were available w/ Ac, PS, PB, Cruise, tilt, PW, stereos etc, so they really aren't too hard to live with.  Fact is, most of them ride BETTER than the new lighter cars, & the handling was pretty good too, especiall if fitted w/ a good set of radials.  Also as mentioned already, there is something neat about having a car that isn't just like a few million others, & has style & personality.  I guess I could buy just about anything I might want, & what I prefer is an old MOPAR!!!!!  As for economy, w/ OD, most of the old muscle cars would be quite acceptable, as the main reason for poor mpg on most was low gearing.  4.10 gears were not uncommon, & there were no 5 spds, or auto OD.  In fact, I have owned several big block Mopars that got 19 or 20 mpg on a trip, & that includes a 4500 lb Chrysler w/ 383 4bl, & a  '70 Cuda w/ 383HP, man trans & 3.23 gears.  Either would have done even better w/ OD.  It is still a fact that a really efficient engine can make more HP & better MPG if driven properly.  I too would like to see the facts on any streetable 4 cyl that outruns a 383, even if the 383 is a 2bl at.   Ovmf
'72 Challenger 360,  '05 Dakota,   04 Town & Country,   '82 Yamaha 650 Maxim

Offline gichy

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Re:Rear gear change and drivability.
« Reply #32 on: January 17, 2004 - 09:01:55 AM »
Cuda360

What type of basic mod's did you have to make for the A-518 to fit?  
1974 Barracuda, 340cid, 4 speed OD !!

Offline DodgeFreak

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Re:Rear gear change and drivability.
« Reply #33 on: January 17, 2004 - 05:12:56 PM »
I would personally go for a newer 518 that you can switch the OD on or off...because when racing if you can't controll your OD then it might shift into OD when you dont' want it to...with the OD button you can switch the od off for when racing and then turn it back on when you cruise.......my uncle has an artical about the OD i might be able to find it on the computer about how to set that up..i know on some cars you just wire a direct 12v. or what ever to keep the OD kicked in then when you push the button it cuts the 12v. and kicks the OD out or vise versa....thats just my opinion....i got my 518 out of a 91 Dakota for 150...with the 318
74 Plymouth Duster- restoring

77 Dodge D150 shortbox- as long as i don't change my mind will be a step side dually diesel or a 383 powered truck

04 durango 4.7

Offline oldvamoparfan

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Re:Rear gear change and drivability.
« Reply #34 on: January 18, 2004 - 12:22:38 AM »
Folks, I just remebered, the OD man trans was also available in Aspens & Volares too, as well as mid 70's pickups.  The Od I was referring to in the earlier post was the AT  (518)    Ovmf
'72 Challenger 360,  '05 Dakota,   04 Town & Country,   '82 Yamaha 650 Maxim

Offline 67Vette427

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Re:Rear gear change and drivability.
« Reply #35 on: January 28, 2004 - 11:47:09 PM »
I like the all around performance of the 3:55 gears. I also have a pumkin, 489 case with the 3:55 gears, sure grip and that I may sell.  The thing to remember with low gears is that they are meant to get your engine as close as possible to red line when you're standing still because thats where your power is. The bad thing about gears is that on freeway driving your RPM's will be up, your engine wear will go up, your noise level will go up and mileage will go down. You can play off some the gear problems with expensive overdrives or a lesser expense is tire heights. When I build a motor I try to match the engine performance to the gearing so you may what to look at some of your engine components to see if your problem is there. For example a manifold that starts to perform at 2500 rpm and higher but the cam come on off idle and peaks at 5500 rpm. :)

Hope that helps a bit :-\
1 of 1 Mr Norm's T/A/ 2015 Hellcat, sublime/ 13 Power Wagon

Offline oldvamoparfan

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Re:Rear gear change and drivability.
« Reply #36 on: February 08, 2004 - 12:11:24 AM »
If you use taller tires to lower engine speed on the road, then you also cancel out the low speed acceleration advantage of the lower gears.  This can be calculated by figuring distance travelled each time tire turns for the different sizes & calc % difference.  It could be used as a temporary fix for occasional road trips, then change back to lower tires when acceleration type usage is anticipated.  I have seen more than a few guys put huge tall tires on their rides not knowing what it does to "effective" gearing, as well as to speedometer accuracy.  Changing tire height also requires changing the speedo gear to keep it right.  Same is true for changing rear end gears.   Ovmf
'72 Challenger 360,  '05 Dakota,   04 Town & Country,   '82 Yamaha 650 Maxim

Offline 360 'CUDA

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Re:Rear gear change and drivability.
« Reply #37 on: February 08, 2004 - 01:11:42 PM »
That is all true of course but having a taller tire gives
you more tire on the ground for better traction, ask any
drag racer. These new cars and ricers with the twenty
inch+ wheels  have a distinct advantage with this setup
and a five or six speed transmission and a super low
first gear. That's one of the reasons why the viper is so
good, it takes all these factors plus a wide chassis and
a great engine to put out a world class car. The major
disadvantage is Vipers are heavy.Knock 500 pounds off
a E-body or a A-body, make it wider, add a high
high horsepower aluminium engine with wide and tall
tires and a six speed the 5.0s and Vettes will have a
problem.
I have always built cars that looked like they just came
out of 1975 but I think it' time for a change..............


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Offline moparbowhunter

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Re:Rear gear change and drivability.
« Reply #38 on: February 09, 2004 - 12:20:29 AM »
hey 360 not to hyjack this post but i just noticed in the pic or your car, is that a pearl white paint on your car? i just love pearl white!!!!!!
70 Barracuda

Offline 360 'CUDA

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Re:Rear gear change and drivability.
« Reply #39 on: February 09, 2004 - 02:30:56 AM »
Nope just some acrillic enamel I shot on in 1997

phord HO white


five bucks a quart at the paint store, just sorry it's  
dorf color

It was seventy degrees out the other day when we
shot the pics and the sun was bright

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« Last Edit: February 09, 2004 - 02:34:21 AM by 360cuda »

Offline oldvamoparfan

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Re:Rear gear change and drivability.
« Reply #40 on: February 09, 2004 - 11:04:34 PM »
True that the drag guys run really tall tires w/ really low pressure for a large foot print, BUT the really soft part is really only good on the strip where the length of the trip is short, & there are no turns in the road.  It is also true that they are probably  running 5.88 gears & no lengthy highway trips are anticipated.  I think we are talking here about cars that not only want to accelerate, but are also able to do a little road running too.  At least that is what I am talking about.  I believe I stated that earlier.  If all you are going to do is run at the strip, then by all means run 20" tires & 5.88s & heck w/ the Overdrive, manual or automatic.     Ovmf
'72 Challenger 360,  '05 Dakota,   04 Town & Country,   '82 Yamaha 650 Maxim

Offline 360 'CUDA

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Re:Rear gear change and drivability.
« Reply #41 on: February 09, 2004 - 11:37:33 PM »
Also I was thinking of the C4 corvette when it came out
in 1984. It was all about the tire contact patch. and
short sidewalls. Put those new wheels on the Camaro
of that year and the that car handled better

Viper or Prowler wheels on a 'CUDA  with some
"green brick" modifications and look out

Offline oldvamoparfan

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Re:Rear gear change and drivability.
« Reply #42 on: February 11, 2004 - 09:03:31 PM »
Short sidewall tires (IE; low profile such as 40 or 50 series) will improve handling on a smooth surface, but the trade off is they are not nearly as good as higher sidewall tires on rough or less than optimum surfaces.  The flex in the sidewall is the first part of your suspension system that comes into play, and actually absorbs much of the initial shock of bumps.  Very short tires can not do this.  Go back & check the round track racers anywhere, but especially if the track is a little rough.  Also, ride quality suffers w/ shorter tires.  Now I know from all the 30 series stuff I am seeing now days that a fair amount of people dont care about rough road handling or ride, but I wouldn't be afraid to bet that most of the people on this thread are not willing to tolerate the resulting ride.  Again, if you are not going to ride the car, then it doesn't matter.  I plan to ride mine a lot.    Ovmf
'72 Challenger 360,  '05 Dakota,   04 Town & Country,   '82 Yamaha 650 Maxim

Offline 360 'CUDA

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Re:Rear gear change and drivability.
« Reply #43 on: February 11, 2004 - 09:41:36 PM »
That's not a problem in Gilbert Arizona
No pot holes, no cracks, rubberized freeways, no rain,
no snow,no windshield wipers, heater, tread on tires

You could drive 350 days a year in a car like I described
with no problems

I'm from Long Island so I know what you folks go
through but for the car hobby, I live in paradise...



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« Last Edit: February 11, 2004 - 09:43:07 PM by 360cuda »

Offline Carlwalski

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Re:Rear gear change and drivability.
« Reply #44 on: February 11, 2004 - 09:46:52 PM »
The Cuda's Looking chunky 360!! :D I like, I like  ;D
1970 Dodge Challenger R/T
White, License Plate, 0A-5599
540ci Aluminium Hemi, F.A.S.T EFI
TF-727 Gear Vendor OD, Dana 60