View Poll Results: For '99 996 owners (with DE experience, if shopping again for 996 what would choose?
Multiple Choice Poll. Voters: 31. You may not vote on this poll
Limited Slip Differential--a MUST HAVE for '99 996 C2?
03-23-2007, 02:16 PM
#16
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i'm no mechanic, engineer, or expert of any kind, but isn't LSD less important for a 911 since most of the weight is over the rear, thereby giving a bit more traction (versus a front-engined, rear-wheel-drive car, where more traction is needed)? just an uninformed thought....
03-23-2007, 02:52 PM
#17
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Apparently this reasoning is why Porsche engineers don't think LSD is required on the 911 either. They figure 99.95% of their new-911 buyers (median age of 70) aren't real "racers"--they just like to drive a racing legend (the 911). Unfortunately, I'm part of the 0.05% that would actually drive his 911 as intended--although I'm no racing legend as a driver LOL 
Originally Posted by Nine9Sixer
i'm no mechanic, engineer, or expert of any kind, but isn't LSD less important for a 911 since most of the weight is over the rear, thereby giving a bit more traction (versus a front-engined, rear-wheel-drive car, where more traction is needed)? just an uninformed thought....
Last edited by SleepRM3; 03-23-2007 at 08:02 PM.
03-23-2007, 03:31 PM
#18
First, I think this is way over rated. An LSD isn't going to drop multiple seconds off you lap times or make you a better driver. The amount of power transfer with the factory diff is very low. For really top drivers, they can gain control (mostly powering out of corners) with a more race oriented diff. The RSR diff seems to be the best for the track. Not a lot run guard diffs or swap to LSDs on these cars, mostly because there are very few who will open one of these transmissions up. It would be a very different story if you were talking about a GT3 or a 993 with a G50 based transmission.
With all that said and done, if I were to look at a 99' I would look for one with the LSD and no traction control. This is very theoretical, becasue just for the production improvements, I would prefer to look at a 2000+. Keep in mind that Porsche best driver Walter Rohrl ran the exact same best time (8:17) with a 99' ROW M030/LSD Carrera Coupe as he did in an 02' ROW Std/non-LSD Targa on the Nurburgring. Although the Targa had 20 additional HP and the later improved chassis revisions, it also had about 250 extra lbs.
With all that said and done, if I were to look at a 99' I would look for one with the LSD and no traction control. This is very theoretical, becasue just for the production improvements, I would prefer to look at a 2000+. Keep in mind that Porsche best driver Walter Rohrl ran the exact same best time (8:17) with a 99' ROW M030/LSD Carrera Coupe as he did in an 02' ROW Std/non-LSD Targa on the Nurburgring. Although the Targa had 20 additional HP and the later improved chassis revisions, it also had about 250 extra lbs.
03-23-2007, 08:01 PM
#19
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Thread Starter
Limited Slip Differential Article
A good article on Porsche limited slip differentials.
http://guardtransmission.com/velocity.htm
http://guardtransmission.com/velocity.htm
Originally Posted by 02 Carrera
First, I think this is way over rated. An LSD isn't going to drop multiple seconds off you lap times or make you a better driver. The amount of power transfer with the factory diff is very low. For really top drivers, they can gain control (mostly powering out of corners) with a more race oriented diff. The RSR diff seems to be the best for the track. Not a lot run guard diffs or swap to LSDs on these cars, mostly because there are very few who will open one of these transmissions up. It would be a very different story if you were talking about a GT3 or a 993 with a G50 based transmission.
With all that said and done, if I were to look at a 99' I would look for one with the LSD and no traction control. This is very theoretical, becasue just for the production improvements, I would prefer to look at a 2000+. Keep in mind that Porsche best driver Walter Rohrl ran the exact same best time (8:17) with a 99' ROW M030/LSD Carrera Coupe as he did in an 02' ROW Std/non-LSD Targa on the Nurburgring. Although the Targa had 20 additional HP and the later improved chassis revisions, it also had about 250 extra lbs.
With all that said and done, if I were to look at a 99' I would look for one with the LSD and no traction control. This is very theoretical, becasue just for the production improvements, I would prefer to look at a 2000+. Keep in mind that Porsche best driver Walter Rohrl ran the exact same best time (8:17) with a 99' ROW M030/LSD Carrera Coupe as he did in an 02' ROW Std/non-LSD Targa on the Nurburgring. Although the Targa had 20 additional HP and the later improved chassis revisions, it also had about 250 extra lbs.
03-24-2007, 12:19 PM
#20
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Originally Posted by Ray S
PM JimB about the necessity of and LSD on the 996. If memory serves he has extensive experience with and without. Additionally, he's one of the quickest 996 drivers out there.
I've tracked 996s with no LSD, with an OEM LSD and with a Guard. Most drivers would be very hard pressed to tell the difference. The combination of great suspension, lots of weight and lots of rubber really negates the need for an LSD. Do I have one in my race car? Of course but I'd never worry about one in a street-track car. There really aren't that many corners where, when driven properly, you generate meaningful wheel spin. T7 at Sebring and T7 at Putnam come to mind but even then a little spinning can help get the car headed in the right direction.
Some cars like the Mustang have LSDs to compensate for crappy suspension not because Ford is building a better sportscar than Porsche. Just look at Grand Am cup. The 997s you see racing are very close to stock. The Mustangs and GTOs are full factory race cars.
BTW, I've been told the factory LSD is pretty weak and won't last long on the track so if you find one it probably isn't working anyway.
Jim
03-29-2007, 10:05 AM
#21
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Thread Starter
Quaife Torque-Biasing LSD Good Enough?
Jim, based on your experience as an expert 996 racer, would a Quaife torque-biasing (1-way) LSD be good enough for my needs? My 996 would see very little track time (3 to 4 DEs per season?). My local Porsche expert (Terry Heath of EuroMotorworks http://www.euromotorworks.com/ ) can install a Quaife LSD in my prospective 996 purchase for $3216--parts and labor (the GT LSD would be $4036; and the GT3 LSD would be $4339--parts and labor). Thanks!
Originally Posted by JimB
I've tracked 996s with no LSD, with an OEM LSD and with a Guard. Most drivers would be very hard pressed to tell the difference. The combination of great suspension, lots of weight and lots of rubber really negates the need for an LSD. Do I have one in my race car? Of course but I'd never worry about one in a street-track car. There really aren't that many corners where, when driven properly, you generate meaningful wheel spin. T7 at Sebring and T7 at Putnam come to mind but even then a little spinning can help get the car headed in the right direction. BTW, I've been told the factory LSD is pretty weak and won't last long on the track so if you find one it probably isn't working anyway.
Jim
Jim
03-29-2007, 10:26 AM
#22
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Originally Posted by SleepRM3
Jim, based on your experience as an expert 996 racer, would a Quaife torque-biasing (1-way) LSD be good enough for my needs? My 996 would see very little track time (3 to 4 DEs per season?). My local Porsche expert (Terry Heath of EuroMotorworks http://www.euromotorworks.com/ ) can install a Quaife LSD in my prospective 996 purchase for $3216--parts and labor (the GT LSD would be $4036; and the GT3 LSD would be $4339--parts and labor). Thanks!
An expert 996 driver I am not but thanks anyway. I really can't speak to the difference between the different LSDs. I think you'd really have to drive them back to back on a tight track to decide. You don't want too much lockup or you'll be heading for the weeds so I'd guess the Quaife might be a very good alternative. I would say that if I has $3K to spend on making a 996 a better car this is not where I would spend it.
Jim
03-29-2007, 10:27 AM
#23
Rennlist Member
SleepRM3,
I can understand where you are coming from having previously owned an e36 M3. But in all honesty I think you are making a bigger deal about this than you need to.
My recommendations is to buy the nicest 911 you can afford. Note that some options are easier to add later than others... 3 spoke steering wheel, different wheels, even an aero kit if you wanted. I had a list in my mind that would make the car special to me and set about looking for that combo but was willing to make some trade offs based on what I knew to be reasonable.
Now as far as the LSD goes, I think you have done a ton of research already and know that there are viable ways to add one should you determine that you need it. Key point here.. Buy the car, do a few DE's and then decide.
Some advice for you. Buy a car with either a US M030 or ROW MO30 suspension otherwise coming from the M3 you won't be too happy with the base 996s handling. The rest will be outstanding... much better brakes, much more top end than you are accustomed to and with the M030 suspensions (note that there are even better options available but M030 is a great starting point) much better handling as well (provided you run the big rubber on 18s like these cars like and not the puny 17s with 7s and 9s).
After driving one for a bit and learning the thing around the track you may come to the decision that the LSD is not needed after all. I wouldn't run out and add it right away without having a baseline.
But if in the end you are hell bent on getting an LSD go for it .... it is your cash
I can understand where you are coming from having previously owned an e36 M3. But in all honesty I think you are making a bigger deal about this than you need to.
My recommendations is to buy the nicest 911 you can afford. Note that some options are easier to add later than others... 3 spoke steering wheel, different wheels, even an aero kit if you wanted. I had a list in my mind that would make the car special to me and set about looking for that combo but was willing to make some trade offs based on what I knew to be reasonable.
Now as far as the LSD goes, I think you have done a ton of research already and know that there are viable ways to add one should you determine that you need it. Key point here.. Buy the car, do a few DE's and then decide.
Some advice for you. Buy a car with either a US M030 or ROW MO30 suspension otherwise coming from the M3 you won't be too happy with the base 996s handling. The rest will be outstanding... much better brakes, much more top end than you are accustomed to and with the M030 suspensions (note that there are even better options available but M030 is a great starting point) much better handling as well (provided you run the big rubber on 18s like these cars like and not the puny 17s with 7s and 9s).
After driving one for a bit and learning the thing around the track you may come to the decision that the LSD is not needed after all. I wouldn't run out and add it right away without having a baseline.
But if in the end you are hell bent on getting an LSD go for it .... it is your cash
03-29-2007, 10:33 AM
#24
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Thread Starter
Great advice, fellas. I appreciate it very much.
-Manny
-Manny
Originally Posted by JimB
Sleep,
An expert 996 driver I am not but thanks anyway. I really can't speak to the difference between the different LSDs. I think you'd really have to drive them back to back on a tight track to decide. You don't want too much lockup or you'll be heading for the weeds so I'd guess the Quaife might be a very good alternative. I would say that if I had $3K to spend on making a 996 a better car this is not where I would spend it.
Jim
An expert 996 driver I am not but thanks anyway. I really can't speak to the difference between the different LSDs. I think you'd really have to drive them back to back on a tight track to decide. You don't want too much lockup or you'll be heading for the weeds so I'd guess the Quaife might be a very good alternative. I would say that if I had $3K to spend on making a 996 a better car this is not where I would spend it.
Jim
Originally Posted by Paul 996
SleepRM3,
I can understand where you are coming from having previously owned an e36 M3. But in all honesty I think you are making a bigger deal about this than you need to.
My recommendations is to buy the nicest 911 you can afford. Note that some options are easier to add later than others... 3 spoke steering wheel, different wheels, even an aero kit if you wanted. I had a list in my mind that would make the car special to me and set about looking for that combo but was willing to make some trade offs based on what I knew to be reasonable.
Now as far as the LSD goes, I think you have done a ton of research already and know that there are viable ways to add one should you determine that you need it. Key point here.. Buy the car, do a few DE's and then decide.
Some advice for you. Buy a car with either a US M030 or ROW MO30 suspension otherwise coming from the M3 you won't be too happy with the base 996s handling. The rest will be outstanding... much better brakes, much more top end than you are accustomed to and with the M030 suspensions (note that there are even better options available but M030 is a great starting point) much better handling as well (provided you run the big rubber on 18s like these cars like and not the puny 17s with 7s and 9s).
After driving one for a bit and learning the thing around the track you may come to the decision that the LSD is not needed after all. I wouldn't run out and add it right away without having a baseline.
But if in the end you are hell bent on getting an LSD go for it .... it is your cash
I can understand where you are coming from having previously owned an e36 M3. But in all honesty I think you are making a bigger deal about this than you need to.
My recommendations is to buy the nicest 911 you can afford. Note that some options are easier to add later than others... 3 spoke steering wheel, different wheels, even an aero kit if you wanted. I had a list in my mind that would make the car special to me and set about looking for that combo but was willing to make some trade offs based on what I knew to be reasonable.
Now as far as the LSD goes, I think you have done a ton of research already and know that there are viable ways to add one should you determine that you need it. Key point here.. Buy the car, do a few DE's and then decide.
Some advice for you. Buy a car with either a US M030 or ROW MO30 suspension otherwise coming from the M3 you won't be too happy with the base 996s handling. The rest will be outstanding... much better brakes, much more top end than you are accustomed to and with the M030 suspensions (note that there are even better options available but M030 is a great starting point) much better handling as well (provided you run the big rubber on 18s like these cars like and not the puny 17s with 7s and 9s).
After driving one for a bit and learning the thing around the track you may come to the decision that the LSD is not needed after all. I wouldn't run out and add it right away without having a baseline.
But if in the end you are hell bent on getting an LSD go for it .... it is your cash
03-29-2007, 11:10 AM
#25
Rennlist Member
Hey ! I look forward to seeing that avatar change to a Pcar. All it does if remind me of my Black E36 M3 that I still miss... but the Pcar helps makes up for it.
03-29-2007, 11:33 AM
#26
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Thread Starter
Originally Posted by Paul 996
Hey ! I look forward to seeing that avatar change to a Pcar. All it does if remind me of my Black E36 M3 that I still miss... but the Pcar helps makes up for it.
Last edited by SleepRM3; 03-29-2007 at 11:49 AM.
03-29-2007, 02:57 PM
#27
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Manny,
One thing that came to mind since we pm'ed. Since you have an M3 currently you will relate to this. Let's say it is raining outside, you hop in your M3 and turn off the ASC/TC. Now put it in 1st and take off nice and easy and then stomp on it.... hmmm not going anywhere..shift 2nd quick.... hmm same as 1st. How fast are you moving...? not much huh. Pretty much just standing still
Try the same thing in the rain in a 996 C2 with tires with reasonable thread and see how little if any wheel spin you get. Surprised the crap out of me the 1st time I did it.
One thing that came to mind since we pm'ed. Since you have an M3 currently you will relate to this. Let's say it is raining outside, you hop in your M3 and turn off the ASC/TC. Now put it in 1st and take off nice and easy and then stomp on it.... hmmm not going anywhere..shift 2nd quick.... hmm same as 1st. How fast are you moving...? not much huh. Pretty much just standing still
Try the same thing in the rain in a 996 C2 with tires with reasonable thread and see how little if any wheel spin you get. Surprised the crap out of me the 1st time I did it.
03-29-2007, 03:25 PM
#28
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Thread Starter
Yes, in the pouring down rain, I was hounded by a fellow instructor driving stock a 996 C4 aero around Mid Ohio--damn, that thing stuck in the wet. Good to know the C2 has good wet stick too! I'm looking forward to owning one of these fine machines (the '99 996).
M
M
Originally Posted by Paul 996
Manny,
One thing that came to mind since we pm'ed. Since you have an M3 currently you will relate to this. Let's say it is raining outside, you hop in your M3 and turn off the ASC/TC. Now put it in 1st and take off nice and easy and then stomp on it.... hmmm not going anywhere..shift 2nd quick.... hmm same as 1st. How fast are you moving...? not much huh. Pretty much just standing still
Try the same thing in the rain in a 996 C2 with tires with reasonable thread and see how little if any wheel spin you get. Surprised the crap out of me the 1st time I did it.
One thing that came to mind since we pm'ed. Since you have an M3 currently you will relate to this. Let's say it is raining outside, you hop in your M3 and turn off the ASC/TC. Now put it in 1st and take off nice and easy and then stomp on it.... hmmm not going anywhere..shift 2nd quick.... hmm same as 1st. How fast are you moving...? not much huh. Pretty much just standing still
Try the same thing in the rain in a 996 C2 with tires with reasonable thread and see how little if any wheel spin you get. Surprised the crap out of me the 1st time I did it.
03-30-2007, 12:03 PM
#29
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Sleep RM3, I was in almost the exact same boat about 2 months ago, and ended up buying an '02 C2. For background, I tracked my e46 330ci for 7 years, and instructed for 2.
The decision basically came down to this - do I want to wait for a 99 car with factory LSD option, or do I want the relatively more reliable '02+ cars? I am sure through your research you had read about the potential issues with the 99 - 01 cars. Do I want a LSD? Am I absolutely amazed when I found out that LSD is not even an option for 99+ car (40th anniversiary not withstanding)? Yes and Yes! However, I figure that I will already be getting a huge upgrade from what I had, and it will take time for me to learn and connect with it. My learning curve starts again and I will throughly enjoy the process. I am also the type of person who values stability and predictibility. Therefore, in the end, I decided to look for an '02+ car, and gave up looking for the right 99 with factory LSD.
There is also the thesis that the factory LSD may break down easily. That kinda make sense. Afterall, this will be a LSD on a ~8 year old car, and the originaly driver may be a relatively aggressive driver (loosely defined here) if the LSD option was chosen. I'd hate to have to spend the money to replace a broken factory LSD, when I could have gotten an 02+ car and do the same thing on a later date of my choosing.
Just my 0.02. I hope that was helpful.
The decision basically came down to this - do I want to wait for a 99 car with factory LSD option, or do I want the relatively more reliable '02+ cars? I am sure through your research you had read about the potential issues with the 99 - 01 cars. Do I want a LSD? Am I absolutely amazed when I found out that LSD is not even an option for 99+ car (40th anniversiary not withstanding)? Yes and Yes! However, I figure that I will already be getting a huge upgrade from what I had, and it will take time for me to learn and connect with it. My learning curve starts again and I will throughly enjoy the process. I am also the type of person who values stability and predictibility. Therefore, in the end, I decided to look for an '02+ car, and gave up looking for the right 99 with factory LSD.
There is also the thesis that the factory LSD may break down easily. That kinda make sense. Afterall, this will be a LSD on a ~8 year old car, and the originaly driver may be a relatively aggressive driver (loosely defined here) if the LSD option was chosen. I'd hate to have to spend the money to replace a broken factory LSD, when I could have gotten an 02+ car and do the same thing on a later date of my choosing.
Just my 0.02. I hope that was helpful.
03-30-2007, 01:34 PM
#30
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Thread Starter
Helpful post. Thanks. Actually I'm not clear on some of the MkI 996 reliabiilty issues, except for the smaller (3.4-L) motor, oil seepages from rear main seal or crankcase metal housing, and engine failures--which appears to be possible with any 996 regardless of mileage. Do tell...!
Originally Posted by Galun
I am sure through your research you had read about the potential issues with the 99 - 01 cars...snip...Just my 0.02. I hope that was helpful.