Sure Grip vs Non Sure Grip

Author Topic: Sure Grip vs Non Sure Grip  (Read 4624 times)

Offline Black340

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Sure Grip vs Non Sure Grip
« on: October 22, 2007 - 08:48:03 PM »
First.. sorry for the ignorant questions :dunno:

1. what Sure Grip means and what is the difference between Sure Grip vs non Sure Grip?

2. what is the approximare rpm traveling at 60 mph on 4th gear?

Thank you




Offline GoodysGotaCuda

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Re: Sure Grip vs Non Sure Grip
« Reply #1 on: October 22, 2007 - 08:53:55 PM »
Sure grip and non sure grip. Is a limited slip differential, or 'posi' if you are a gm boy. Limited slip, suregrip allows both rear tires to drive the vehicle (ie: leaves two black marks in burnouts, fishtails well :D). A non suregrip, or 'open' differential has only one tire driving the vehicle. Leaves 'one tire fires' when doing burnouts.

Both will drive almost exactly the same in normal conditions. When you want performance you'll want a suregrip. Open diff may be a little easier to handle in wet condition.

As far as the RPM for 60mph, depends on your rear gear ratio and tire height.  :cheers: :working:
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Offline Black340

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Re: Sure Grip vs Non Sure Grip
« Reply #2 on: October 23, 2007 - 02:30:13 PM »
Thank you for the explanation :2thumbs: I have to find out what is my gear radio, the reason why the question is because I was driving on the fwy at  60  65 mph and I notice that the rpms was around 3200 and I don't know if that was normal

Offline 1BADFISH™

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Re: Sure Grip vs Non Sure Grip
« Reply #3 on: October 23, 2007 - 06:57:40 PM »
Easiest way to tell if you have a suregrip is to jack the rear end off the ground. Put your car in neutral and spin one wheel, if the other wheel moves the same way, its a sure grip, if the other wheel travels opposite to the one your turning, then its an open differential.

To estimate your gear ratio, while the car is jacked up, put a mark on your wheel, then spin your driveshaft to see how may revolutions of the driveshaft to turn the wheel one complete turn. Ie, 3:91 gears means if you turn your driveshaft 3.91 revolutions, your tire will make one complete turn.   :2thumbs:  (*This works if your car is a suregrip)

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Offline MEK-Dangerfield

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Re: Sure Grip vs Non Sure Grip
« Reply #4 on: October 23, 2007 - 07:07:48 PM »
Thank you for the explanation :2thumbs: I have to find out what is my gear radio, the reason why the question is because I was driving on the fwy at  60  65 mph and I notice that the rpms was around 3200 and I don't know if that was normal

If you have those kinda RPM's with a 4-speed, you have some tall gears there buddy.  :grinyes: My guess is 3:91's.


  Mike

EDIT: This is assuming your tach is correct. Do you have the Rally dash, or an after-market tach?
« Last Edit: October 23, 2007 - 07:10:51 PM by MEK-Dangerfield »

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Offline fantum

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Re: Sure Grip vs Non Sure Grip
« Reply #5 on: October 23, 2007 - 10:47:07 PM »
Quote
Easiest way to tell if you have a suregrip is to jack the rear end off the ground. Put your car in neutral and spin one wheel, if the other wheel moves the same way, its a sure grip, if the other wheel travels opposite to the one your turning, then its an open differential.

To estimate your gear ratio, while the car is jacked up, put a mark on your wheel, then spin your driveshaft to see how may revolutions of the driveshaft to turn the wheel one complete turn. Ie, 3:91 gears means if you turn your driveshaft 3.91 revolutions, your tire will make one complete turn.     (*This works if your car is a suregrip)

It also works if you do ont have a sure-grip if you find a way to keep one tire from spinning.  One method I used was to put one rear tire on a cement block, spun the other wheel one time and counted the driveshaft's revolutions.


fantum
Mike

Offline Black340

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Re: Sure Grip vs Non Sure Grip
« Reply #6 on: October 24, 2007 - 11:52:03 AM »
If you have those kinda RPM's with a 4-speed, you have some tall gears there buddy.  :grinyes: My guess is 3:91's.


  Mike

EDIT: This is assuming your tach is correct. Do you have the Rally dash, or an after-market tach?

Mike I have the Rally dash, are big tires make any difference ?  :clueless:I have on the back 16x8 with 285/60/16 which I am planning to change (for more conventional look ) with Rallys 15x8

Offline MEK-Dangerfield

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Re: Sure Grip vs Non Sure Grip
« Reply #7 on: October 24, 2007 - 11:58:05 AM »
Mike I have the Rally dash, are big tires make any difference ?  :clueless:I have on the back 16x8 with 285/60/16 which I am planning to change (for more conventional look ) with Rallys 15x8

Can I change my answer?  :lol:

Wow, you already have tall tires, and that will help keep your RPM's lower. I think you might have 4:10's in that rear end of your's if your tach is accurate. Keep in mind these originals need calibrating once in a while, so if your's hasn't been touched in a few decades, it might be reading higher than it should.


  Mike

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Offline Black340

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Re: Sure Grip vs Non Sure Grip
« Reply #8 on: October 24, 2007 - 02:26:06 PM »
Well this is what I find out so far:

1. Wheels out of the ground + both turning on the sam direction and same speed = suregrip :bananasmi

2. 1 full wheel turn = 4 turns on the U-joint.. QUESTION :that means 3:90s or 4:10s??

and if any of those radios are OK for occasionally FWY driving? 

Offline MEK-Dangerfield

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Re: Sure Grip vs Non Sure Grip
« Reply #9 on: October 24, 2007 - 06:28:05 PM »
Well this is what I find out so far:

1. Wheels out of the ground + both turning on the sam direction and same speed = suregrip :bananasmi

2. 1 full wheel turn = 4 turns on the U-joint.. QUESTION :that means 3:90s or 4:10s??

and if any of those radios are OK for occasionally FWY driving? 


I still say you probably have 4:10's. Even if they are 3:91's, you can live with 3200 RPM for a few minutes on the Hiway, but I wouldn't want to drive too far that way. Meaning, less than a half hour. That's just my opinion.

We still don't know about your stock tach being accurate though. Look, if you send me a PM with your name and address, I can send you an after-market tach, and tell you how to hook it up and compare it to your stock tach just so we know we are dealing with true numbers. I also would appreciate it if you send it back to me.  :grinyes:


  Mike

Mike

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Offline Black340

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Re: Sure Grip vs Non Sure Grip
« Reply #10 on: October 25, 2007 - 11:53:14 AM »
Hi Mike..did you gor my PM?

Offline fantum

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Re: Sure Grip vs Non Sure Grip
« Reply #11 on: November 23, 2007 - 07:24:31 PM »
If you've changed the tire diameter to a larger size than the original your speedometer will be WAY off.  The same is true if you've changed the rear gearing.  One way to check this is to check the odometer just prior to driving a measured mile, and checking it after you're done.  If the odometer has progressed less than a mile, you need to change the speedometer gear in the transmission.  Another way is to get a friend with a calibrated speedometer to drive with you at a specified speed - first you drive 60 mph (for example) and have them tell you how fast you were going, then you have them drive 60 mph and see how fast your speedometer is reading.  This will help you stay out of trouble with the law if you are using the wrong speedometer gear.

There's a website (sorry I don't know it)  where you can determine the gear you need to order.  Hope this helps.


fantum
Mike

Offline Black340

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Re: Sure Grip vs Non Sure Grip
« Reply #12 on: November 24, 2007 - 01:38:05 AM »
Thank you fantum :2thumbs:, I do have large size tires on the back 285/60/16. Mek-Dangerfield send me a tach and after comparing with the factory one the rading was 300 hundred rpms difference. Factory shows 3300 at 60 mph Mike's tach 3000 at 60 mph.

Offline Ornamental

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Re: Sure Grip vs Non Sure Grip
« Reply #13 on: November 24, 2007 - 09:05:30 AM »
...There's a website (sorry I don't know it)  where you can determine the gear you need to order....

Could this help?

http://www.mymopar.com/speedometer.htm
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