Which LSD for a 993?
Discussion
Whilst my 993 has its engine out I'm considering maximising the, err, "opportunity" and fitting a LSD - what would be recommended for primarily road use but with some track?
Anyone have any experience of (the results of) fitting one to a 993 Carrera?
Whilst I'm at it is there anything else anyone would recommend - maybe a lightweight flywheel? - it had a new clutch aboput a year ago so no need to change that.
cheers
Tertius, sorry not an expert, but I have had the standard Porsche fit lsd on my last 2 993, the previous one was greatly improved by fitting motorsport plates when the others failed as they often do above 30k miles.
I was going to suggest you look over on rennlist, most of the posting on there is stateside and they do tend to modify their cars more and will no doubt be more aware of the available lsd options.
The standard fit lsd is ok, for road and track, i do know that some track spec lsd can make life interesting on the road, so be careful it suits your intended use of the car.
Lighweight flywheel,,,,helps the engine spin up a little better, downside is increase in noise from the transmission as the dual mass with it's gel insert does absorb some vibration which you would now hear/feel. There can be some slow running issues, which you can normally cure by re-setting ecu.....easy to do.
Again this is one of the more popular mods, well documented on rennlist.
By fitting these 2 components, you will make the car one step nearer to a track car...obviously you will gain on track but will lose some of the refinement.
Depends what you want from the car, but as someone with lsd, lightweight flywheel, no carpets or headlining, I am hardly in a position to offer any advice
I was going to suggest you look over on rennlist, most of the posting on there is stateside and they do tend to modify their cars more and will no doubt be more aware of the available lsd options.
The standard fit lsd is ok, for road and track, i do know that some track spec lsd can make life interesting on the road, so be careful it suits your intended use of the car.
Lighweight flywheel,,,,helps the engine spin up a little better, downside is increase in noise from the transmission as the dual mass with it's gel insert does absorb some vibration which you would now hear/feel. There can be some slow running issues, which you can normally cure by re-setting ecu.....easy to do.
Again this is one of the more popular mods, well documented on rennlist.
By fitting these 2 components, you will make the car one step nearer to a track car...obviously you will gain on track but will lose some of the refinement.
Depends what you want from the car, but as someone with lsd, lightweight flywheel, no carpets or headlining, I am hardly in a position to offer any advice
Re: the LSD, do you often find yourself spinning power away through an inside rear wheel when cornering hard? I can't say I've ever had this happen to me... unless you're talking RS or serious track use, I don't really see the need.
The lightweight flywheel, yes I can understand that - more noise but faster response. Most of the americans on rennlist reckon it improves acceleration just by reducing the rotational inertia in the engine. It probably reduces the 'sproinginess' of the standard clutch when in stop-start traffic, which would be a good thing - I've had 3 993s and still get caught out with the rubbers in the clutch bouncing back at me...
The lightweight flywheel, yes I can understand that - more noise but faster response. Most of the americans on rennlist reckon it improves acceleration just by reducing the rotational inertia in the engine. It probably reduces the 'sproinginess' of the standard clutch when in stop-start traffic, which would be a good thing - I've had 3 993s and still get caught out with the rubbers in the clutch bouncing back at me...
Thanks CS, a great help and I will ask on rennlist.
Cyberface, you are right I haven't actually seen this so I may be addressing a problem that doesn't actually exist, but there's part of me that says I have to get something out of this darn mess and anyway it might make me feel better ... ... even if its only value is bragging rights.
Cyberface, you are right I haven't actually seen this so I may be addressing a problem that doesn't actually exist, but there's part of me that says I have to get something out of this darn mess and anyway it might make me feel better ...
... even if its only value is bragging rights.
use a porsche factory lsd,if you intend to do track days.As clubsport says,more for traction/grip into and out of corners,and lift off stability.But only realy required if you push the car hard,or times are important to you.
Motorsport plates are a little more aggressive,but very good,not much more money than standard diff plates.
Best advice for best money spent,good tyres and a fast road set up.And still keep your creature comforts!
I have just fitted a gaurd diff to my early racer project,and will hopefully be on the road by the weekend,i can let you know what i think about the gaurd diff.
Motorsport plates are a little more aggressive,but very good,not much more money than standard diff plates.
Best advice for best money spent,good tyres and a fast road set up.And still keep your creature comforts!
I have just fitted a gaurd diff to my early racer project,and will hopefully be on the road by the weekend,i can let you know what i think about the gaurd diff.
bergmeister said:
use a porsche factory lsd,if you intend to do track days.As clubsport says,more for traction/grip into and out of corners,and lift off stability.But only realy required if you push the car hard,or times are important to you.
Motorsport plates are a little more aggressive,but very good,not much more money than standard diff plates.
Best advice for best money spent,good tyres and a fast road set up.And still keep your creature comforts!
I have just fitted a gaurd diff to my early racer project,and will hopefully be on the road by the weekend,i can let you know what i think about the gaurd diff.
Motorsport plates are a little more aggressive,but very good,not much more money than standard diff plates.
Best advice for best money spent,good tyres and a fast road set up.And still keep your creature comforts!
I have just fitted a gaurd diff to my early racer project,and will hopefully be on the road by the weekend,i can let you know what i think about the gaurd diff.
Cheers.
When you say "Best advice for best money spent,good tyres and a fast road set up.And still keep your creature comforts!" do you mean don't bother with the LSD or the lightweight flywheel?
At the moment I've asked RGA to price up the Motorsport diff and the lightweight flywheel but no decision yet.
The difference in feel between the two extremes of tyres on a 993 is enormous - I run winter tyres in the winter (Pirelli Snow Sports) and now have (courtesy of clubsport, cheeers mate!) Dunlop SSRs for summer. The SSRs on warm dry tarmac are so far unstickable, the stiff sidewalls give instant turn-in and you can really lean on the tyres. They also show up suspension inadequacies!
On the other hand, the winter tyres are soft and very progressive, allowing you to drift the 993 around like it was a V8 TVR. Really friendly and easy to slide around.
Seriously, it's like driving two completely different cars - just from a change of tyre.
I'm sure the more committed trackday dawgs here with the super-special rubber experience this even more.
On the other hand, the winter tyres are soft and very progressive, allowing you to drift the 993 around like it was a V8 TVR. Really friendly and easy to slide around.
Seriously, it's like driving two completely different cars - just from a change of tyre.
I'm sure the more committed trackday dawgs here with the super-special rubber experience this even more.
Cyber, glad you are enjoying the tyres...you will feel the difference at Brands, particularly how you need to work on brakes and shocks
I was happy to let you have them as it was so obvious I would find a car soon after
Tertius, with respect to lsd / flywheel decisions...it is all down to your intended use of the car...as simple as that!
I am 95% sure to be at Goodwood on sunday morning, more than happy to show you what the standard 993 lsd & lightweight flywheel sound like if that is any help?
I was happy to let you have them as it was so obvious I would find a car soon after
Tertius, with respect to lsd / flywheel decisions...it is all down to your intended use of the car...as simple as that!
I am 95% sure to be at Goodwood on sunday morning, more than happy to show you what the standard 993 lsd & lightweight flywheel sound like if that is any help?
clubsport said:
I was happy to let you have them as it was so obvious I would find a car soon after
I felt a little guilty about that - I guess the right car turned up for you faster than expected... if you can get a couple of fronts then you can have my spare set of rears if it helps? Or are you going to go for even stickier stuff (Pilot cups / corsas / Toyo 888s)?
clubsport said:
Tertius, with respect to lsd / flywheel decisions...it is all down to your intended use of the car...as simple as that!
I am 95% sure to be at Goodwood on sunday morning, more than happy to show you what the standard 993 lsd & lightweight flywheel sound like if that is any help?
Thanks for the offer. Unfortunately I can't make it to Goodwood on Sunday.
I guess my intended use is as a "civilised" track car, that is equally at home taking the family out as running on the track.
Civilised is in quotes as I don't mind a bit of noise but I would not, for example, take out rear seats or carpets ...
Is the additional noise of the lightweight flywheel, present all the time or only under certain conditions, accelerating say?
cheers
Basically, there is a noise up to about 2000-2500rpm.....this is from the lsd and gearbox meshing, the single mass flywheel transfers more noise and vibration than the gel filling in the dual mass flywheel sandwich.
There is also rumble noise at tickover from the gearbox, this stops if you dip the clutch....I fitted a single mass to my previous RS comfort, the first time I drove it I wasn't sure, but soon began to feel it enhanced the car....so, not too bad with carpet...noise goes after 2500 rpm,,,dip the clutch if noise annoys you or passenger at tickover......over to you!
There is also rumble noise at tickover from the gearbox, this stops if you dip the clutch....I fitted a single mass to my previous RS comfort, the first time I drove it I wasn't sure, but soon began to feel it enhanced the car....so, not too bad with carpet...noise goes after 2500 rpm,,,dip the clutch if noise annoys you or passenger at tickover......over to you!
Cheers.
So prices were: LSD 1050; flywheel (incl. clutch) 900 (both plus VAT and labour of course)
Since I don't need a clutch at the moment - new less than 5K miles ago - I'm thinking I'll do just the LSD for now and save the flywheel for when I really need a clutch.
It'll also mean that the impact/feel of the rebuild won't be impacted by the change in flywheel.
THe LSD seems to come with two different locking ratios, IIRC 65%/35% and 40%/25% - any views?
So prices were: LSD 1050; flywheel (incl. clutch) 900 (both plus VAT and labour of course)
Since I don't need a clutch at the moment - new less than 5K miles ago - I'm thinking I'll do just the LSD for now and save the flywheel for when I really need a clutch.
It'll also mean that the impact/feel of the rebuild won't be impacted by the change in flywheel.
THe LSD seems to come with two different locking ratios, IIRC 65%/35% and 40%/25% - any views?
Some comments on LSD's in general: Without an LSD one wheel will break traction and spin; this can cause mild oversteer. With an LSD that one wheel won't spin but at a higher torque level both wheels will spin and you'll tend to get significant oversteer. Nothing that can't be corrected, particularly in the dry when you know full well you're pushing on and you're fully alert. But in the wet or a suddenly greasy surface it can result in snap oversteer that needs very quick reactions. So tread carefully in the wet!
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