Trouble shifting

[bnewport]

I believe the braking help, it's pretty easy to spin the car trail braking on the limit, I was practising that at a lapping day at MAM late last year, never spun a car as many times in an hour.

[944-Spec#94]

trail braking is an essential racing skill. Some tracks will punish you for not doing it well. Others not so much.

A good LSD will prvide extra stabilty in these corners and theory allow you to brake deeper and harder vs an open diff car. However this extra stability can also cause understeer. So like anything it is a balance. On paper a really good LSD like the Guard unit is a must have. On track however it much less clear as the benefits of the LSD are mixed with all the other factors that make a car fast that it is nearly impossible to fully strip out it is effects.

 

Personally have wanted one for years. Never been able to justify in my mind spending the $$$ for the unit and then the effort to install. Part of that stems from not really being able to determine what the actual lap time will be on my car at my home track. Some guys toss around 2 seconds, but I am not currently 2 seconds slower than the fast guys. At Miller with an open diff I held my own just fine. So would I really gain 2 seconds from an LSD after I set-up the car for it? I really don't think that will happen for me.

 

So in the end I just drive with open one and have learned to work and drive out its limitations and unknowingly have been able to use its advantages.

 

Bottomline for any one thinking about and LSD. Certainly a nice to have, but you can in fact run up front with an open diff so not by any means a "must have" if you want to race competitively.

[smlporsche]

Great info from all.

 

Charlie, wasn't sure which LSD you were using to make the pass three wide through the attitudes. Very open thinking

 

As for LSDs (the kind found inside transaxles), I was lucky to find a car with a guard LSD already installed. The only dilemma I have is deciding on a gear oil which is for good for both the transaxle and the LSD. Paul Guard recommended using Lubrication Engineers 9919 which is next to impossible to find in low quantities (I'm still searching). I flushed the gear oil with Mobil1 80-90w just to have something clean. Is the Mobil1 good enough? Or should I change to the Swepco 201 or any other recommendations?

 

Hi all.

Been lurking for a while gathering info for my supercup build and have a chance to give back...

 

I have a Gaurds LSD (50/80) and Paul reccomended thr LE 9920 but did not know of a small quantity source....until I found this...

http://www.mag-hytec.com/store/index.php?main_page=product_info&products_id=57" onclick="window.open(this.href);return false;

 

I've run this for 2 weekends so far and have had no problems.

Hope this helps

 

Eddie

[sagoston]

Thanks Eddie.

 

I found mag-hytec too (they happen to be very close to where I store my car) but they only have the LE 9920 in quarts. Paul said 9920 would be a bit too heavy for my application and that I should look for 9919 instead. It probably wouldn't hurt to run a heavier oil so I may still go with the 9920.

[schwank]

FWIw, I run a 924S box with a new Guard LSD unit. The shop that built it recommended Shell Spirax (only available in 55gal drums in the USA according to the distributor) or Porsche factory fluid, and very strongly said NO Redline, which is what I used to run in my oem box (MT90). That said, other racers in my region run Swepco 201 in LSD and non-LSD boxes, and that is actually what I put in mine as well. Drained it this weekend after about half a dozen races and it looks and smells just fine. No weird particles or anything like that. I refilled it with 201 again as well.