| Rear end Gear ratio's? | |
|
+496Brougham toomanytoyz Pooge LandMaster 8 posters |
Author | Message |
---|
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Rear end Gear ratio's? Mon Feb 28, 2011 2:19 pm | |
| Okay so assuming mileage is no issue what is the lowest ratio that will fit our cars and play nice with the ABS ( with a reluctor ring?) I know some guys have the 4.10 's how do you guys like them and is there anything that would be plain old silly like 5.12's?? Just curious, thanks for your responses | |
|
| |
Pooge
Posts : 1700 Join date : 2009-03-24
| Subject: Re: Rear end Gear ratio's? Mon Feb 28, 2011 5:33 pm | |
| I have run 4.10s on a stock car with only bolt ons and it was awesome. At highway speed the car got loud with the 2.5" exhaust drone, but for 75% of driving it was wonderful, if not a bit unpractical, but it was a spare car for me, not a DD.
Doug | |
|
| |
toomanytoyz Club President
Posts : 6876 Join date : 2009-01-20 Age : 47 Location : East Hampstead, NH USA
| Subject: Re: Rear end Gear ratio's? Mon Feb 28, 2011 6:15 pm | |
| I loved my 4.10's. 80 was like 3000 rpms. Still liveable. No drone for me. DO IT!
If I wasn't putting a turbo in the wagon, I would have gone 4.10s. Had them all picked out and everything. Now I got 3.42s.
| |
|
| |
96Brougham
Posts : 819 Join date : 2009-02-02 Age : 36 Location : Easton MA
| Subject: Re: Rear end Gear ratio's? Mon Feb 28, 2011 7:31 pm | |
| I'm torn between 373 or 410.. I'm thinking 410, and if I get an older 93 6speed eventually it would put me at perfecting gearing for a wagon.. | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Mon Feb 28, 2011 9:37 pm | |
| | |
|
| |
sdstick
Posts : 4292 Join date : 2009-03-20 Location : Revere, MA
| Subject: Re: Rear end Gear ratio's? Mon Feb 28, 2011 9:55 pm | |
| | |
|
| |
Machine-De-Zine
Posts : 512 Join date : 2010-11-16 Age : 67 Location : Wrentham
| Subject: Re: Rear end Gear ratio's? Tue Mar 01, 2011 3:02 am | |
| -
A new reluctor ring can be made very simply, if you know how many counts per revolution the front two channels are "looking for" from the driveshaft.
It should be a simple matter of math to determine. If you get that far, let me know if you need me to make one for you.
Also look at your options for changing your tire's rollout (diameter) as this would be the thing to decide upon first, before selecting the perfect R&P ratio.
Also be aware beforehand of the engine RPM you will be happy (or miserable) with at a given road speed.
Maybe it would be a helpful indicator for you to hold your car in 3rd or 4th (no lockup) and drive on the highway a while to see how it will feel driving at sustained higher RPMs.
*
| |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 11:50 am | |
| - sdstick wrote:
- What about the reluctor?
Yeaa can you just buy these? - Machine-De-Zine wrote:
- -
A new reluctor ring can be made very simply, if you know how many counts per revolution the front two channels are "looking for" from the driveshaft.
It should be a simple matter of math to determine. If you get that far, let me know if you need me to make one for you.
Also look at your options for changing your tire's rollout (diameter) as this would be the thing to decide upon first, before selecting the perfect R&P ratio.
Also be aware beforehand of the engine RPM you will be happy (or miserable) with at a given road speed.
Maybe it would be a helpful indicator for you to hold your car in 3rd or 4th (no lockup) and drive on the highway a while to see how it will feel driving at sustained higher RPMs.
*
The road noise at speed wouldn't bother me, my Porshe has gutted cats and a 2.5 full exhuast and it is reallly loud, and the Buick I drove around in 3rd and checked the tack for about 2800-3000 it wasn't silly loud (it's got a stock exhuastany how). Where would I look for number and what kinda calculations do I use? As long as it ins't Diff EQ I can do the math | |
|
| |
sdstick
Posts : 4292 Join date : 2009-03-20 Location : Revere, MA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 12:11 pm | |
| The reluctor is in the rearend, if you need to do any math....wouldnt it be...... A differential equation? I can never help myself....sorry | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 12:13 pm | |
| HAHAHAHA^^^^ true it would be wouldn't it
Does going with 4.10's require a PCM tune too? | |
|
| |
sdstick
Posts : 4292 Join date : 2009-03-20 Location : Revere, MA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 12:29 pm | |
| Your speedo will be off Some wait to make sure they like it before tuning We know a guy that can fix that I think.....cough..Crovo..cough | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 1:02 pm | |
| haha hope theres a mod day coming soon | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 1:26 pm | |
| AAHHH I just checked I got the 2.56 with Posi soo that's supossedly the smaller carrier? | |
|
| |
toomanytoyz Club President
Posts : 6876 Join date : 2009-01-20 Age : 47 Location : East Hampstead, NH USA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 3:55 pm | |
| Yeah, you'll need a new posi. Bob Shirley (search ISSF) makes a reluctor for like 100 bucks. They come up used every once and a while, too. I want to say it's a 13 tooth reluctor. Again, the info can be found on the issf. And yeah, I can adjust your speedometer and shift points for the 4.10's. Just do it. | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 4:33 pm | |
| So I can go from the 2.65 gears up to 4.10's? I just need a new posi and a few other things? | |
|
| |
toomanytoyz Club President
Posts : 6876 Join date : 2009-01-20 Age : 47 Location : East Hampstead, NH USA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 4:40 pm | |
| - LandMaster wrote:
- So I can go from the 2.65 gears up to 4.10's? I just need a new posi and a few other things?
Essentially, yes. | |
|
| |
Fishah
Posts : 1118 Join date : 2009-01-20 Age : 36 Location : Chicago, IL
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 4:41 pm | |
| Wait, but If you have the small 7.5" rear, you will need a new 8.5" pumpkin to put the new posi & 4.10's in. | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 4:44 pm | |
| - Fishah wrote:
- Wait, but If you have the small 7.5" rear, you will need a new 8.5" pumpkin to put the new posi & 4.10's in.
This is what I was wondering, becuase I have Posi does that make the rear pumpkin an 8.5" or do the 2.56 rears have a 7.5" rear regardless? | |
|
| |
Fishah
Posts : 1118 Join date : 2009-01-20 Age : 36 Location : Chicago, IL
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 5:32 pm | |
| - LandMaster wrote:
- Fishah wrote:
- Wait, but If you have the small 7.5" rear, you will need a new 8.5" pumpkin to put the new posi & 4.10's in.
This is what I was wondering, becuase I have Posi does that make the rear pumpkin an 8.5" or do the 2.56 rears have a 7.5" rear regardless? You must have a Ruler/Tape Measure... | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 5:43 pm | |
| If I had a garage or a drive way that wasn't flooded I would've measured it before I asked I'm not that Inept I'm just lazy and wanted a quick answer | |
|
| |
sdstick
Posts : 4292 Join date : 2009-03-20 Location : Revere, MA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 6:16 pm | |
| - LandMaster wrote:
- I'm just lazy and wanted a quick answer
Been there, done that. Wish I knew the answer I'd spell it out for you. I bet if you look in the Drivetrain stickies of ISSF it'll tell you | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 6:45 pm | |
| True, I hope I can still remember my ISSF password | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 7:58 pm | |
| OKay soo from what ISSF's sticky on rear axles it said the GM8 RPO code is a 8.5'' rear, buut the 2.56's had a series 2, what's the difference between the series 2 and series 3? | |
|
| |
toomanytoyz Club President
Posts : 6876 Join date : 2009-01-20 Age : 47 Location : East Hampstead, NH USA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 8:05 pm | |
| - LandMaster wrote:
- OKay soo from what ISSF's sticky on rear axles it said the GM8 RPO code is a 8.5'' rear, buut the 2.56's had a series 2, what's the difference between the series 2 and series 3?
The carrier. AKA, the posi. You just need the correct install kit for the carrier you are using and it'll be fine. | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 8:13 pm | |
| Schweet then I'll probably ask bob shirley to make me a reluctor ring and I'll be in buisness | |
|
| |
sdstick
Posts : 4292 Join date : 2009-03-20 Location : Revere, MA
| Subject: Re: Rear end Gear ratio's? Wed Mar 02, 2011 8:59 pm | |
| - Machine-De-Zine wrote:
- -
A new reluctor ring can be made very simply, if you know how many counts per revolution the front two channels are "looking for" from the driveshaft. It should be a simple matter of math to determine.
If you get that far, let me know if you need me to make one for you.
| |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Thu Mar 03, 2011 1:50 pm | |
| Ah yesh. Well if he could help me to figure out the math, I'd rather support Machine ze nine . I'm in no hurry to get this done, beside the litle car is all in Pieces taking up my garage | |
|
| |
Machine-De-Zine
Posts : 512 Join date : 2010-11-16 Age : 67 Location : Wrentham
| Subject: Re: Rear end Gear ratio's? Thu Mar 03, 2011 3:10 pm | |
| The math is real simple. It can be calculated for by using your present functioning ABS speed sensor tooth count and your R&P ratio, provided you don't change the roll out (diameter) of your front to rear tire sizes.
Just determine how many times the speed sensor cycles on and off per rotation of the ring gear with your current R&P ratio, and with your new R&P ratio you want the same frequency.
I would bet that the number of teeth on your current R&P factory gear set-up (on the pinion) multiplied by your current ratio will equal the number of teeth on your front rotor speed sensor ring.
Your new pinion mounted speed sensor ring will have correspondingly fewer teeth than your present set-up, because your pinion will be turning at a higher RPM, given the same road speed.
I should include the following warning directly out of the 1996 FSM:
CAUTION: Once the rear wheel speed sensor ring has been removed from the differential drive pinion gear, a new rear speed sensor ring must be installed. The press fit may be lost if the rear speed sensor is used more than once. This would allow the rear speed sensor ring to rotate freely on the differential drive pinion gear shaft causing a significant reduction in performance of the antilock brake system, which could result in bodily injury.
Personally, I like the roughly 35 lbs weight savings when the system is shelved.
The system is entirely "stand-alone", with no interface with the on board ECM.
Without ABS, you re-assume all responsibility for the control of your vehicle in a panic stop.
The machine shop is relocating currently, and wont be taking new work until we are settled in, but . . .
Bob Shirley's last contact info was e-mail at: rshirley@earthlink.net and I believe he was asking $110 USD then.
* | |
|
| |
Machine-De-Zine
Posts : 512 Join date : 2010-11-16 Age : 67 Location : Wrentham
| Subject: Re: Rear end Gear ratio's? Sat Mar 12, 2011 10:07 am | |
| - Two more sources for the S.S.R. (speed sensor ring) or pinion mounted "ABS reluctor ring".
Drive Train Specialists for the 4.10:1 R&P ratio, #DTS GM 26018947 @ $100.00 having a 16 tooth ring count. (temporarily out of stock)
. . . . . . . . or . . . . . . . .
Clear Image Automotive for 3.42:1 R&P set @ $15.30ea having a 20 tooth ring count. for 3.73:1 R&P set @ $27.80ea having an 18 tooth ring count.
I am pretty sure there are several other good sources, I just happened to stumble across these two.
My not having immediate access to a front rotor S.S.R. to physically count the teeth, I did some quick calculations: 2.56 x 27 = 69.12 or roughly 69 2.76 x 25 = 69.00 or roughly 69 2.93 x 23 = 67.39 or roughly 67 3.08 x 22 = 67.76 or roughly 68 3.23 x 22 = 67.83 or roughly 68 3.31 x 21 = 69.51 or roughly 69 3.42 x 20 = 68.40 or roughly 68 3.73 x 18 = 67.14 or roughly 67 4.10 x 17 = 69.70 or roughly 70 (a bit high) 4.10 x 16 = 65.60 or roughly 66 (a bit low) 4.56 x 15 = 68.40 or roughly 68 4.88 x 14 = 68.32 or roughly 68 Anybody want to take a guess at the front rotor count? Or be willing to pull one up and count the actual teeth. My guess would be 34 or (68 divided by 2 = 34). {68 seems like too many!}
* Note: These figures were only extrapolated guesses, as I do not have the actual tooth counts. The 4.10:1 may be 17 on the pinion, I don't know. If someone out there has the actual teeth counts, a working knowledge and applied theory of this system, please step in and teach us all.
Last edited by Machine-De-Zine on Sat Mar 12, 2011 11:05 am; edited 1 time in total | |
|
| |
Cadet57
Posts : 4481 Join date : 2010-03-14 Age : 36 Location : Chicopee, MA
| Subject: Re: Rear end Gear ratio's? Sat Mar 12, 2011 11:02 am | |
| - toomanytoyz wrote:
If I wasn't putting a turbo in the wagon, I would have gone 4.10s. Had them all picked out and everything. Now I got 3.42s.
You're putting a what in the where? SWEET | |
|
| |
Machine-De-Zine
Posts : 512 Join date : 2010-11-16 Age : 67 Location : Wrentham
| Subject: Re: Rear end Gear ratio's? Sat Mar 12, 2011 11:44 am | |
| Nice!
$15.30 to Clear Image instead of $100.00 plus.
What brand gear set did you get and which carrier unit? I have had very good success with the Eaton TruTrac. I then install a solid spacer kit (with selective shims) to properly pre-load the pinion bearing's inner races and pinion yoke-nut. That has several durability advantages over the stock "crush-collar". It makes the pinion assembly much more resistant to bending loads while under power. Also it allows you to achieve an excellent pinion yoke-nut pre-load torque, without compromising the pinion bearing preload. 25 lbs/in with new bearings.
I do not recommend using the Gov-Loc G80 LSD, having replaced countless X-ploded specimens. Check carefully the condition of the axle's load-bearing surfaces, and if pitted, install the axle-saver pieces that relocate the roller surface away from the damage.
You probably already have the FSM, however. . . The SA Design #170 High Performance Differentials, Axles and Drivelines by Joseph Palazzolo is a very good companion book to read. | |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Fri Sep 02, 2011 8:01 pm | |
| Alright I'm reviving a dead horse here, I am finally in a good position to install some gears, I was looking at the Clear image and was thinking of going for 3.73 (possibly 3.42) gears and the tru trak posi unit, I currently have a series 2 carrier (posi unit?) if I replace the whole thing the reluctor gears but with a series 2 carrier will I have issues? All respones and answers are greatly appreciated.
| |
|
| |
LandMaster
Posts : 258 Join date : 2009-09-03 Age : 33 Location : Waterford, New York
| Subject: Re: Rear end Gear ratio's? Wed Sep 07, 2011 3:10 pm | |
| okay So this is what I found, and talked to a few local shops about it, as long as the housing is the right housing ( In my instance an 8.5 inch rear) the 2.56 carrier has a larger flange on it so the gears are in the right place inside the housing, BUT if you replace the posi unit like any sane individual would do when changing gears as long as the carrier is for an 8.5 inch housing you can use that carrier with a proper gear set IE series 2 can be replaced with a series 3. So research aside no it's time to do some shopping | |
|
| |
Sponsored content
| Subject: Re: Rear end Gear ratio's? | |
| |
|
| |
| Rear end Gear ratio's? | |
|