Tightest Posi?
Tightest Posi? I am tired of inside wheel spin in spirited street driving - which differential has the highest bias for the 7.5" rear?
- Torsen T2-R
- Auburn Pro
- Eaton Posi
I also do some drag racing and occasionally get one wheel spin during burnout. I understand that my 98 SS has an Auburn stock (which is still apparently still good with about 50 lb-ft bias torque).
Thanks,
Steve
- Torsen T2-R
- Auburn Pro
- Eaton Posi
I also do some drag racing and occasionally get one wheel spin during burnout. I understand that my 98 SS has an Auburn stock (which is still apparently still good with about 50 lb-ft bias torque).
Thanks,
Steve For what it's worth, I had the stock Torsen in my '01. I would occasionally get the one wheel peel during spirited street driving through the turns. I can't say it ever did a one legged burn out though. Overall it wasn't too bad. It seemed to be worse when I would make a hard right hander under heavy throttle.
All that I've heard from Road Racers is that the Torsen T2-R is the best bar none. But you are limited to the 7.5" rear. For those who upgrade to a 12bolt or a nine inch they go with the Detriot Tru-Tract which aparently is not quite as good as the T2R but better than other offerings.
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you say spirited driving, sounds like on the street to me. The t2r is an amazing addition to our cars. Now, it kinda sucks on for every day driving. Its not safe in the rain unless you are very carefull, and if you ever get caught in snow/ice (even a little bit) you are not going anywhere since it does not work properly unless both wheels have some friction.
When it is working right, you will almost never spin just one wheel unless you seriously unweight (like lift one), which is where the problem in bad weather/loose traction comes in. When you exceed your rear tracktion, especially in a turn, get ready to see the road (or track) in the wrong direction :-)
When it is working right, you will almost never spin just one wheel unless you seriously unweight (like lift one), which is where the problem in bad weather/loose traction comes in. When you exceed your rear tracktion, especially in a turn, get ready to see the road (or track) in the wrong direction :-)
Originally Posted by Killer_Bluebird
All that I've heard from Road Racers is that the Torsen T2-R is the best bar none. But you are limited to the 7.5" rear. For those who upgrade to a 12bolt or a nine inch they go with the Detriot Tru-Tract which aparently is not quite as good as the T2R but better than other offerings.
Originally Posted by rushman
you say spirited driving, sounds like on the street to me. The t2r is an amazing addition to our cars. Now, it kinda sucks on for every day driving. Its not safe in the rain unless you are very carefull, and if you ever get caught in snow/ice (even a little bit) you are not going anywhere since it does not work properly unless both wheels have some friction.
When it is working right, you will almost never spin just one wheel unless you seriously unweight (like lift one), which is where the problem in bad weather/loose traction comes in. When you exceed your rear tracktion, especially in a turn, get ready to see the road (or track) in the wrong direction :-)
When it is working right, you will almost never spin just one wheel unless you seriously unweight (like lift one), which is where the problem in bad weather/loose traction comes in. When you exceed your rear tracktion, especially in a turn, get ready to see the road (or track) in the wrong direction :-)
I have a weak stock limited slip now, and want to replace it w something more aggressive. I'm into road racing, and the car is primarily a daily driver, so I don't want a spool or a diff that has the manners of one. I love powersliding! But I don't want to make the car undrivable in the rain or unsafe (especially for my wife) to drive.
I'd love to see more info on this subject!
Also FWIW I put an auburn-not a pro- in a 2wd S10 (it sucked, would spin 1 tire all the time), and an eaton posi in my 04 Silverado 2WD. The silverado was lowered w Hotchkis suspension, when I autocrossed it it would spin 1 regualrly. Still better than the stock POS diff but not really what I wanted 4 performance drivng.
Last edited by subtlez28; Oct 25, 2006 at 10:06 PM.
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Originally Posted by LS1-450
I agree, T2-R or Detroit Tru-tract are great for road course racing or spirited street driving. The T2-R in my 8.8 is awesome.
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First, there are 3 different Auburns, not just one, just as there are different levels of Torsens. This is important to know when statements like "I had an Auburn and it sucked" come up. Also, remember a pickup has very little weight in the rear and leaf springs, which makes them prone to spinning sooner anyway.
A T2R is 100% streetable. Most all of my customers drive their cars on the road and it's not a problem. My ex-girlfriend drove my '91 a lot with a T2R. She's not a bad driver, but this was before she really autocrossed or anything. Still I felt she had enough brains and the diff wasn't scary enough for me to say she couldn't drive the car.
How sideways you get is a matter of how much gas you give it. Use your head and it's completely safe. Put some idiot 16 year old in the car and watch him wrap it around a tree in the rain.
We've sold about 100 T2R's over the last few years. Everyone who has one really likes it, me included. I recently opted to run a Auburn Racer's diff in my autox car for a few reasons. Not any better than the T2R, in ways such as wear, it's worse.
I can help you with any rear you might be looking at. Torsen, Auburn, Detroit, Eaton, and any of the different models of each. Happy to tell you what I know, and offer an opinion if you want it.
A T2R is 100% streetable. Most all of my customers drive their cars on the road and it's not a problem. My ex-girlfriend drove my '91 a lot with a T2R. She's not a bad driver, but this was before she really autocrossed or anything. Still I felt she had enough brains and the diff wasn't scary enough for me to say she couldn't drive the car.
How sideways you get is a matter of how much gas you give it. Use your head and it's completely safe. Put some idiot 16 year old in the car and watch him wrap it around a tree in the rain.
We've sold about 100 T2R's over the last few years. Everyone who has one really likes it, me included. I recently opted to run a Auburn Racer's diff in my autox car for a few reasons. Not any better than the T2R, in ways such as wear, it's worse.
I can help you with any rear you might be looking at. Torsen, Auburn, Detroit, Eaton, and any of the different models of each. Happy to tell you what I know, and offer an opinion if you want it.
__________________
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Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
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www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
Yes, Sam u r right. I didn't mean 2 write off an entire brand by my 1 bad experience. I actually opened this link w the intent to edit my post to note it was not an auburn PRO.
Only in the interest of conversation (I do value your advise-as obvious by my sig, and purchase record), I do have some food 4 thought. The auburn I had was new-but again not a PRO-, in a truck w a stock 4.3, with narrow tires. I agree that this is a prone to spin setup...but with less traction, it should make it easier 4 the diff 2 spin BOTH tires. My best example of where the "sucked" statement comes from is: backing out a slight uphill driveway, under light throttle, rt wheel gets on grass, I literally could no longer back up, spun the rt like mad! This is open diff behavior, and doesn't make me feel good about the serious $ I spent to add the auburn. Its pretty hard 2 convince me this diff had much in the way of bias torque. It also "sucked" any time you loaded one side in a corner
.***just my experience with an Auburn (not PRO)*** 
Also, I have had GOOD experience w/ Eaton Posi s. And the main problem with my silverado was likely lack of suspension travel (bind was likely nearly lifting the inside wheel) it was worst when on banking. My point is only that more bias torque would have been of benifit there also.
My goal is not to bash either brand, just throwing in my experiences FWIW.
So at the risk of being accused of high jacking the thread, I just wanted 2 know what diff would least likely let an unloaded tire spin, w/out going overboard, and acting as a spool.
Only in the interest of conversation (I do value your advise-as obvious by my sig, and purchase record), I do have some food 4 thought. The auburn I had was new-but again not a PRO-, in a truck w a stock 4.3, with narrow tires. I agree that this is a prone to spin setup...but with less traction, it should make it easier 4 the diff 2 spin BOTH tires. My best example of where the "sucked" statement comes from is: backing out a slight uphill driveway, under light throttle, rt wheel gets on grass, I literally could no longer back up, spun the rt like mad! This is open diff behavior, and doesn't make me feel good about the serious $ I spent to add the auburn. Its pretty hard 2 convince me this diff had much in the way of bias torque. It also "sucked" any time you loaded one side in a corner
.***just my experience with an Auburn (not PRO)*** Also, I have had GOOD experience w/ Eaton Posi s. And the main problem with my silverado was likely lack of suspension travel (bind was likely nearly lifting the inside wheel) it was worst when on banking. My point is only that more bias torque would have been of benifit there also.
My goal is not to bash either brand, just throwing in my experiences FWIW.
So at the risk of being accused of high jacking the thread, I just wanted 2 know what diff would least likely let an unloaded tire spin, w/out going overboard, and acting as a spool.
I have a T-2R (from Strano) and it does indeed improve the limit
of traction in corners. The bias ratio is high. I can feel the inside
wheel lift and scuff but keep on accelerating to the limit of the
outer wheel traction.
That said, this amount of bias -will- let you spin them both and
that is not something to take lightly. One wheel peels are at
least directionally stable.
I wouldn't want to go back though. It just takes care of
business and feels natural.
of traction in corners. The bias ratio is high. I can feel the inside
wheel lift and scuff but keep on accelerating to the limit of the
outer wheel traction.
That said, this amount of bias -will- let you spin them both and
that is not something to take lightly. One wheel peels are at
least directionally stable.
I wouldn't want to go back though. It just takes care of
business and feels natural.
Has any one tried a stock Torsen with stiffer springs (not suspension but the springs in the differential). I remember talking to some old racer that would run stiffer springs in the stock differential on a class limited car, but I'm wondering if that is even worth the hassle for the possibly limited gains. Just curious.
There are no springs in a Torsen.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
There are no springs in a Torsen.
Last edited by cam; Oct 27, 2006 at 10:33 AM. Reason: spelling
The older GM version never did use springs. I know they said they did, but we had a prototype unit in one car, and it didn't have them.
As for the Ford T2R's, unless they just changed it, the don't have the springs either. But, I haven't seen one in the last few months.
As for the Ford T2R's, unless they just changed it, the don't have the springs either. But, I haven't seen one in the last few months.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
As for the Ford T2R's, unless they just changed it, the don't have the springs either. But, I haven't seen one in the last few months.
The current FX4 8.8 units are spring preload type. I assumed they were old stock T2R's but according to a post I read the bias is not quite as high as a T2R but the 4x4's need preload for hanging wheels/rock crawling etc.
Can't say for sure on the GM Torsens. I only had stock units
Oh, a truck unit.... That's different (and good to know). Of course, I don't think I'd have used a Torsen in a off-road rear diff anyway since they go open when you dangle a wheel. I guess that's what the springs are about, trying to keep some load on them, but they don't really work that way.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
Impressive, I just took a look at Torsen's website ( www.torsen.com - they do not sell direct, so hopefully this isn't a sponsership issue). Looks like I'll be giving you a call 4 one soon Sam!
I wish I had known about these b4 I put the forementioned Auburn and Easton units in my pickups. Sounds like these elliminate the issues I was having.
But, when something looks to good to be true...........is there some deep dark side I should know? Is the bias spring over powered when under hard acceleration?
**the T-2R has a bias springs**
"By adding preload springs (this is design specific), the TORSEN T-2R will stay locked with low torque inputs. This allows the vehicle to maintain drive, and thus momentum and mobility, during extreme conditions such as inside wheel spin or lift in a corner, or starting from a complete stop on split µ grade. When the ring gear torque overcomes the preload, the unit will differentiate and bias normally, behaving like a conventional Torsen T-2. This is particularly useful to drivers who compete in road racing and autocrossing, as well as drivers of unladed pickup trucks, or SUVs who have to deal with poor weather conditions, or an occasional off-road trail, or for anyone who wants the best traction possible for their street car. The current applications for the TORSEN T-2R include the Ford 8.8 inch axle, the GM 8.5 inch axle, and the GM 7.6 inch axle"- http://www.torsen.com/products/T-2R.htm
The site is quite informative, but obviously not intended to point out it's product's flaws.
I wish I had known about these b4 I put the forementioned Auburn and Easton units in my pickups. Sounds like these elliminate the issues I was having.
But, when something looks to good to be true...........is there some deep dark side I should know? Is the bias spring over powered when under hard acceleration?
**the T-2R has a bias springs**
"By adding preload springs (this is design specific), the TORSEN T-2R will stay locked with low torque inputs. This allows the vehicle to maintain drive, and thus momentum and mobility, during extreme conditions such as inside wheel spin or lift in a corner, or starting from a complete stop on split µ grade. When the ring gear torque overcomes the preload, the unit will differentiate and bias normally, behaving like a conventional Torsen T-2. This is particularly useful to drivers who compete in road racing and autocrossing, as well as drivers of unladed pickup trucks, or SUVs who have to deal with poor weather conditions, or an occasional off-road trail, or for anyone who wants the best traction possible for their street car. The current applications for the TORSEN T-2R include the Ford 8.8 inch axle, the GM 8.5 inch axle, and the GM 7.6 inch axle"- http://www.torsen.com/products/T-2R.htm
The site is quite informative, but obviously not intended to point out it's product's flaws.
Last edited by subtlez28; Oct 27, 2006 at 08:39 PM.