SleeperX

Does the LSD really make a difference at the track?
Will it increase MPH or reduce 1/4 mile times..

I realize that the best way to get traction off the line is for me to just get some DRs, but it seems like a hassle to change tires...

Right now I am running PS2s, and might swap them for the Toyo RA1s.
For a modded car thoug, does he LSD really make that big of a difference?

housclass

for the street i would get a good set of tires in place of the lsd...

i was going to get a set of the toyo ra1's and couldn't find them anywhere in stock...i called up luke at tire rack and told him i wanted the softest tire i could get besides the dr and he recommended a set of bridgestone potenza re01R's.

i've always run the goodyear dsg3s...the bridgestone’s blow away the gsd3! i can turn off esp, keep the car in first at 10mph and nail it...the car hooks without spinning a tire!!! even from a stop the new tires are much, much better!

it rained on the way to work today and the tires did great...the only drawback is the tires have a tread wear rating of 140...they won't last a real long time but it's better than losing a drag race!

john

GTA23109a

The car is a completely different animal with the LSD. I would absolutely do it again. Improved straight-line traction is only a very small part of the benefit. The car is much more stable through on-throttle corners and no longer requires the ESP every time you try to leave a driveway to pull into traffic or make a simple right turn. Basically, the car behaves like it SHOULD after the LSD.

JLP

Kleeman literature claims a drop of 0.3 seconds to 60 mph!

SleeperX

???
Is that really credible.. So on street tires you will drop 0.3 seconds to 60mph. So that must imply that you could reduce your 1/4 mile times by about 0.5 seconds with LSD alone. Hence with the same street tires 1/4 mile time will reduce by 0.3 to 0.5 seconds. I assume DR would drop your time even more.. This just doesn't sound plausible to me....Anyone?

JLP

http://www.kleemann.dk/site/9E507DFA...BF8849E063.htm

SleeperX

JLP,
I am not questioning whether or Kleemann actually stated that their LSD will result in a 0.3 drop in 0-62mph. I am simply questioning whether or not it is realistic. Has anyone on this site experienced a 0.3 drop in their 1/4 mile times from Kleemann's LSD..

Rock

Steve,

This has been discussed numerous times. NO BOARD MEMBER (including me) has ever shown an improved 0-60ft with the addition of LSD. As a matter of fact, I have seen some of the best 0-60ft times from those with no LSD. I have no doubt that this modification is helpful in driving transitions (like coming out of a corner) but I doubt that it helps in 1/4 mile runs.

JLP

I think its probable, years ago I owned a Porsche turbo that didn't come with a LSD, once I installed it the car was literally transformed and put the power down much better.
I'm sure others who have LSD can chime in.

SleeperX

Rock,

Thanks! I am getting the mod bug and trying to decide what to put on my beast next..Since LSD won't improve my 1/4 mile times I think I will change my tires. Noticed that you have Green filters..Have you noticed a difference with them...

GTA23109a

The street is a COMPLETELY different environment than the track and THAT is where the LSD will make the most noticable difference. At a nice, smooth, flat track, the open diff actually has a chance of not being upset by changing conditions. On the street, it's not even close to smooth OR flat, and that's whn the open diff gets all out of wack. Just think about how many contour changes there are in a basic intersection. The crown changes twice and there are usually 2 solid bumps. The open diff can't tolerate these at all and the car will come unglued. With the LSD, instead of one tire losing traction and all acceleration being lost (from either wheel-spin or ESP intervention), the worst that happens is the car steps a little to one side or the other, then takes a new set and keeps on pulling. And that's just in a straight line!! Once we start talking about corners, the LSD stands out more and more and the mod to have.

I hear lots of people naysaying LSDs and I don't know if it's the price that has them wound up or what, but the FACT of the matter is that a LSD will completely transform the way the E55s chassis behaves. If you want dragstrip-only performance, by all means go buy a set of DRs (I have a set on spare wheels and they work great). but on the street, since the addition of the LSD, my regular BFG G-force KDs hook and transition *almost* as well as the DRs whereas this was not the case before.

Quit with the excuses and just go buy one. Then you'll know what those of us who have them are talking about.

Edit: All of my opinions/observations apply to the QUAIFE limited slip. I don't have any experience with the Kleemann piece, but judging by pics of it, it looks like a knockoff Phantom Grip unit, not an actual gear-type, torque-biasing differential like the Quaife. BIG DIFFERENCE in the way those two work.

Rock

All true........................ but the question was, "Does the LSD really make a difference at the track? Will it increase MPH or reduce 1/4 mile times.."
My response was directed at this question.

BTW, I have LSD and would purchase it again. Unfortunately, it has not made a "difference at the track."

Steve, I am not sure if green filters make a difference. I will say that they are very pretty.

GTA23109a

I read the original question, but I have to wonder how much time one of these cars spends at the track . . . even a guy who lives nextdoor to a dragstrip and goes twic a week would be hard pressed to put 1% of his car's mileage on "at the track". The real world is where it's at. After you get chopped off by some dork in a new vette are you gonna roll down the window at the next light and go "let's go to the track and try it again after I go put on my drag radials and pull out the back seat and spare tire and ice my intake and blah blah blah." Don't be that guy. That guy's a hack. For me, if my car's not a monster as it sits, right now in my garage, then none of that other crap matters. That's part of the reason I never take my daily-drivers to the track. They are what they are. I have race cars for the track.

Sorry about the semi off-topic rant, but I felt like a slight reality-check might help. Everyone build your cars how YOU want. Don't kill yourself trying to chase a number at the track. Tracks are ****-poor representations of the street which is where these cars LIVE.

Rock

Wow!! you are pretty serious about this stuff.

I guess we (Steve included) like to see numbers attached to the modifications because it is then easier to justify the money we spend. If others have shown that LSD reduces 1/4 mile times I would be more likely to make this purchase. I also would assume that if the improved numbers are reproducible on a track they would also translate to better street performance.

I know we both agree that LSD is a big help on the streets. I only question whether it makes any difference at the track.

jangy

If all you want is drag racing, save the $$ or do it later. For all around driving, INCLUDING track laps, The LSD is nearly a necessity. I will be getting it soon. My buddy has one and he can put the power daown WAAY before me when exiting a turn. I could push sooner, But the lean makes the inside rear tire spin, where the LSD would put it down.

jangy

Can anyone chime in on the "best" one and why?

Quaife, Kleeman, AMG, etc.

GTA23109a

I haven't seen the AMG unit, but I know the technology behind the Quaife has been tested and refined in tons of applications from street to racetrack. Their rep. is the main reason I chose Quaife over the other offerings. As far as Kleemann's unit, I haven't driven a car with one, but I have seen the units themselves and it's operating principles are very different from the Quaife. I don't want to bash on anyone's products, but I will say that my personal opinion, based on both technologies (again, without having driven the Kleemann unit) is that the Quaife is the superior piece of technology.

stevebez

GTA23109a What model Quaife did you have installed , and what was the cost if I may ask ? Also did you change the diff ratio at all ?

I am checking them up now for my beast ... I just cannot handle the slipping/ESP when the car's weight is marginally off centre....

Also does the ECU/ESP need to be reprogrammed when you fit an LSD?

vrus

Like GTA said, the LSD will show its best on the street.

I wasnt going to bother with one, but, I am going to order the Quaiffe unit for my car. I am sick and tired of coming out of a driveway and trying to pull out onto the street.. As soon as you try to accelerate, the ESP light blinks for 2 or 3 secs and takes ALL POWER away from the car.. It's almost like stalling in the middle of the road; very dangerous behaviour!! The LSD will get rid of this annoying behaviour and make the car much more responsive.

The Quaiffe unit can be had for $1,300. That's pretty reasonable compared to the alternatives.

2QUIK4U

Vrus,

Please tell me where the Quaife unit can be purchased for that price.

vrus

Let me make a small revision to that previous statement... Those diffs are around $1300 based on some conversations I've had with 2 different people. The price *I* was given was $1650 SHIPPED to my door because it has to come from California and I am in Canada.

Contact VividRacing (Forum sponsor).. He can provide you with a quote based on your location.

If there are a few people interested, maybe we can get a "group" price?

GTA23109a

I'm not sure which "model" it is . . . I think they only make one for the E55. It cost me are out $1400 I think. (don't remember exactly) AFAIK, it's the same design they use on all their diffs. No reprogramming of anything is required when installing a LSD as long as you don't make a gear ratio change. I kept the stock gears.

stevebez

Would a 2.82 ratio not be better than the stock 2.65 ? If one is already changing the diff why not go for a more agressive gearing ...?

catalystkid

EVOSPORT sells Quaife maybe they would be interested in a group buy?

GTA23109a

There are a couple reasons to keep the stock gear ratio:

1) The programming involved in getting the car to understand and deal with the new gears is a headaceh, as I understand it. It's not just speedometer recalibration, but ABS and ESP as well. I'm sure it can be done (and has been) but it's no small task.

2) These cars already have traction issues in 1st (and even 2nd) gear. Unless you plan on driving around with custom 16" wheels and ET Street slicks (al la DerekFSU) going to a more agressive rear end ratio will do you more harm than good. These engines make more than enough torque to move the mass of our cars with the gears they have.