LSD for street use...yes/no

Allright, too many threads on this subject I know (flame suit on), but I need to know from the experts if buying the aftermarket LSD kit (group buy) is really worth it for me or not. Plain and simple question is, will it make my slightly modded car any faster, corner better, etc for street and "spirited" driving? I am not planning to track or autoX my croc. And I am not Juan P Montoya either. Thanks for the input .. Happy Valentine everyone ! Saludos :beer:

If you are taking tight corners and losing grip due to lack of LSD then yes it will help you. If you are just punching it from stop light to stop light then much less so.

I think most people will tell you that for street use, adding LSD would be a pretty big waste of money.

Totally agree. brad

I think an LSD (or Quaffe style dif) is a good buy. I plan to do this mod. I have been frustrated by the wheel spin on accel and agressive cornering. Likely down side is that the car will push (under steer) in really tight corners with the LSD . If you are not experiencing excessive wheel spin currently, then you will probably not notice much improvement with an LSD , but you may experience the push in tight turns.

For street uses, would an lsd not assist with bad weather (ice, rain, etc)? (Assuming that PSM is off or disabled)

To get the best out of anything, you need to know how to use it, and more to the point have experience. (Like driving the car for the first time) I don’t at the moment pretend to know how a diff, be it plated or torque biased will affect the car. As I haven’t got it in yet. But I do know how it changed a 944 for me in the 80’s. In that instance it made it into a complete car. For normal road driving, it felt as original, but as soon as you wanted either to have , shall we say, a ‘spirited ‘drive, or even to ‘play’ it gave you 100% confidence that the car would do exactly what you wanted it to do. As far as understeer was concerned, it had none, as you tended to drive the car on oversteer. How it will affect the working of the PSM computer, again as yet I don’t know. The standard car with PSM ‘on’, is very good and safe, for example when you hit lets say a patch of ice mid corner, it almost does the job of bringing the car back for you. Suppose if you try and drive it with the throttle nailed, and PSM off, you’ll just finish up spinning, like the Stig did when driving the Carrera GT …..Time will tell, ………….and I hope this will be a short time before we find out, as the people that have already ordered the Quaife version, hopefully, will be fitting it within the next month. So watch this space. To say it’s a waste of money, even for road use, is a little harsh., in my opinion. Lets wait and see. But to go back to the original Question asked at the start of the post. If Cocodrilo is running 400+bhp with a supercharged Cayman, Trust me, it’ll be as big a transformation as your supercharger was.!!!!

Hey Tess, Don't misunderstand me. I am a big fan of LSD and think it's ridiculous that the car didn't come with one in the first place. I for one am sitting on the edge of my seat waiting to see the reaction of the folks you have lined up to try one, and I am EXTREMELY happy that you are working so hard to make this mod a reality. Thank you for that. My point was, that since we see very few complaints here about wheel slip, and the few that we do see are happening during aggressive track driving, I am thinking that your basic street driven Cayman will see very little benefit from an LSD . I had forgotten that Cocodrilo was going supercharged and that added torque can turn the whole equation around. In retrospect, to answer Cocodrilo's question, I would say, "Are you experiencing rear wheel slip? If so, yes your street car will benefit." Personally, I LOVE controllable over steer. It's fun. I also love powering out of turns and using the throttle to fine tune my line. So I am very likely a future customer for an LSD . You need to get one of these things into K-Man S' car so we can all go crazy discussing it and see just how deep the rabbit hole goes.

In tight corners, yes. By the way, I dont have the supercharger yet :argue: But I can imagine the additional benefits of LSD with the extra torque, so once I have my S/C or whatever in, then I'll join the GB Thanks all !

Gator Bite, Didn’t mean to rant, so please don’t misunderstand. Quote from Andy Lee back in November in a run called ‘Cat And Fiddle’ in the UK “The road was very tricky to master! I can see why so many bikers died here!! Blind bend, steep gradient..... some corners were very slippery (The traction control was lighting like a christmas tree-however only mild adjustment to correct oversteer!!!)” Traction Control Lights, were caused because of road conditions, not lifting a wheel. I’m sure you agree, on some occasions you need ‘drive’ to get out of trouble, even on the road. In these circumstances the last thing you need is loss of power and/or brakes being applied to straighten the car up via the TC. because one wheel has more traction than the other You also say, the car should have been built with some sort of LSD !! in the first place, I agree completely As Ken is number 2 on the List, I’m sure that there will be an un-biased view as soon as it’s fitted in his Yellow Bullet.!!!

I recommend that someone ask Hurley Haywood, as to whether or not LSD would be a value for the $$ for the Cayman as a street machine. My gut feeling is nope.

I'm not HH. but... I do have 10yrs racing experience with podium finish at Rolex24 in a PorscheRSR (2000) and numerous top 10s in World Challenge GT series in a Porsche GT3. I have had 8 Porsche's and currently have 3, including the CS. This is the first sportscar I have owned w/o LSD . I have driven Lotus Elise and Exige on the track w/o LSD ... but there is no question that CS should have come with LSD . I would bet $100 that HH would agree.

in terms of "value for the $$s" that is an individual call for each CS owner... I didnt buy my CS as a compromise for $$s... I actually optioned it out beyond the cost of a base 997S. I bought the CS it because I felt the 911 has gotten too big and has lost the spirit of a true sports car. I like the mid-engine packaging and looks of the CS. I feel the lack of LSD was part of a compromise by Porsche to satisfy the marketing position of CS below the 911.

Greg, I have to agree since I had a conversation with Hurley last year about the Cayman S at Barber and how it faired against the 997 and 997 S. His comments at the time were that he was currently faster than the 997 around Barber and within a fractions of a second to a second behind the 997 S all without LSD . I asked him "What if you had LSD " and his response was something to the effect that he would be sure he would be faster than the 997 S as well and "Porsche wouldn't like it". So yes, I concur HH would be a fan of LSD , at least on the track, can't speak to his "street" opinion.

Help is on the way-- Greg-- Couldn't agree more. Hang on until June, there will be a very nice chromoly GT diff for the car and I believe it will be a more reasonable than the gold-plated Farnbacher Loles unit. BTW, I would not put an off-the-shelf Quaife in the car unless it was for autocross only -- I realize a lot of folks are entranced by the $1,300 price tag, but I'd rather wait for a LSD that's designed for road racing. Rgds, Lee '06 Cayman RS Stg III

Lee, Can you expand upon why you think the Quaife unit will not be good for road racing / DE use?

Cocodrilo...... You don't want that supercharged CS with out an LSD , even if it is just for straight ahead drag racing. With the supercharger, you are going to have enough torque to spin the tire that has the least grip. There was a thread posted here recently that linked to a video of some British reporter flogging a stock CS around a track and lighting up the inside wheel. That video says everything that you need to know. As for the street with a NA car, I have one on order for my car because I agree with everything that Greg posted (wish I had his driving creds). From my personal experience, I would always prefer a Quaife (torsen type) to a clutch unit. I think that if you look at what is being used in serious race cars you will see that is the common choice. Greg.....me too on the too big 911. That is why i got rid of my Z06. It's not the money......Just too much car.

Thought the question at the start of this thread was ‘LSD for street use….yes/no’ Correct me if I’m wrong but Road Racing isn’t street use and you would use a plated LSD for that, with all it’s advantages. But then you would also expect to replace the clutch plates or at least re-shim them periodically change the LSD oil and generally service it after 2 or 3 races. Which I would call a dis-advantage of a fit and forget unit like the Quaife. If I was racing my car as a Pro then yes I’d probably fit a spool diff or at least a plate diff, and the constant clanging/clicking of the diff as you went slowly round a corner wouldn’t bother me. But in a road car that’s occasionally used on the track, I don’t think so….Only my 2 cents

K-Man S-- I knew someone was going to ask this. I've had both kinds of diffs on various PCA track cars and people whose judgement I respect (uber-tuner Chris Cervelli, Paul Guard) counseled that on the late-model cars that clutch-and-ramp type LSD was preferable in terms of handling characteristics. I'm not an engineer or a pro racer, so forgive me if I omit a technical discussion in which I'll invariably make mistakes. I have been very happy with Guard's GT units and find that an occasional rebuild is no big deal, either in terms of the time or expense involved. Re Tess Tickle and the the original tread Q, LSD for street -- just my opinion, but I don't see why anyone would need a Quaife or any type of LSD for the street. BTW, a competition LSD that's fitted for club use does not make noise (it's not a locker), does not require periodic oiling, and can go a long time before a rebuild since 25-minute sprints or run groups are the order of the day. Lee in D.C.

Thanks for your view Lee, suppose price is one of the determining factors. I, like you, can’t get too technical but when I’ve used plate type LSD ’s in the past that have been quite tight. In slow turns I thought that I’d left the whole back end of the car on the road it was that noisy. The Guard diff is a proven winner, so I’m not anti that, or even, as you say the Gold Plated F-L unit but at 2500 or 4500 they are much more expensive, slightly more difficult to fit and do need maintenance. As I previously said What I was looking for was a unit that would suit the following criteria: Predominantly Road Car with Occasional track use and cost considerations. There’s only one choice for me, which may well be different for the next guy.

You'll notice it in corners for sure. More power, more grip, less wheel hop.