Got to get a Giken - The ONLY LSD to have.
10-27-2009, 07:07 PM
#33
Race Car
I love interpretation, perception and how our own views of the world can cloud or block the views of others. (Funnily enough my lively hood depends on it.)
I think the best and fairest way to put something like this to bed is to complete a test (similar to that outlined in Paul’s post). Have an independent person/company install and test each type of differential in a car, use the same blind test driver (not while driving!) and do a comparison. Data log, driver comments taken and do a real world comparison. You could do in more than one location to allow for track differences etc.
I am sure we could even get magazine coverage for such a test, I for one would subscribe to that article, hell I would be more than happy to offer my car and driving skills to complete the test.
I think the best and fairest way to put something like this to bed is to complete a test (similar to that outlined in Paul’s post). Have an independent person/company install and test each type of differential in a car, use the same blind test driver (not while driving!) and do a comparison. Data log, driver comments taken and do a real world comparison. You could do in more than one location to allow for track differences etc.
I am sure we could even get magazine coverage for such a test, I for one would subscribe to that article, hell I would be more than happy to offer my car and driving skills to complete the test.
10-27-2009, 07:51 PM
#34
I have a friend doing a top end rebuild right now and he is considering his differential replacment options since the tranny is out of the car and he has 130k on it as it stands now.
I don't want to see people beat each other up / flame / defend their products. The most likely mistake that happened here was that the thread was called "the ONLY LSD to have". I, personally, can think of some LSD I had in college that was pretty good -- no friction material involved :-) If we had got this thread off on "hey we have a newer lower cost alternative that we think has advantages over existing units" we might have not gotten the tone of response from Paul (however I especially liked his additional info). I know that is not exactly how the thread started (so kudos to Erik for not starting off with the "down with Guards" thread that he easily could have), but we should all just have a group hug about now... right?
Doing a 'A/B' track comparision is not really all that meaningful to me as well -- I daily drive my 993 and I also track it. Clearly there will be some tradeoffs between the two extremes and lap times won't even begin to be the total story for me.
I have some more questions about the guards unit, but I'll start another thread as that is seemingly a fairly well known quantity being used by many on the list.
In any case, its always good to have a discussion. I was wondering what the expected wear interval for a OS Giken was? Erik, although these are new, can you put 80k street miles on one and still have it performing at the track? Perhaps its too early to really know (unless you have one hella commute and installed one right away), so I understand that certain eggs and chickens still need to be counted.
-reiner
I don't want to see people beat each other up / flame / defend their products. The most likely mistake that happened here was that the thread was called "the ONLY LSD to have". I, personally, can think of some LSD I had in college that was pretty good -- no friction material involved :-) If we had got this thread off on "hey we have a newer lower cost alternative that we think has advantages over existing units" we might have not gotten the tone of response from Paul (however I especially liked his additional info). I know that is not exactly how the thread started (so kudos to Erik for not starting off with the "down with Guards" thread that he easily could have), but we should all just have a group hug about now... right?
Doing a 'A/B' track comparision is not really all that meaningful to me as well -- I daily drive my 993 and I also track it. Clearly there will be some tradeoffs between the two extremes and lap times won't even begin to be the total story for me.
I have some more questions about the guards unit, but I'll start another thread as that is seemingly a fairly well known quantity being used by many on the list.
In any case, its always good to have a discussion. I was wondering what the expected wear interval for a OS Giken was? Erik, although these are new, can you put 80k street miles on one and still have it performing at the track? Perhaps its too early to really know (unless you have one hella commute and installed one right away), so I understand that certain eggs and chickens still need to be counted.
-reiner
10-27-2009, 09:29 PM
#35
Rennlist Member
Every product has its strengths and weaknesses, engineering is all about compromises. Especially in the diff world, these things have been around forever and from my limited knowledge I don’t think anyone has a “breakthrough” product. I would love for those in the know to elaborate on what tradeoffs/benefits were chosen for each product.
Here is what I think I have gleaned so far from this thread, please correct and elaborate where needed.
1) Carbon friction material is the least abrasive, provides for the longest transmission life at the expense of the diff itself. "Motorsports" plates provide much longer diff life at the expense of added wear to the rest of the transmission as the plates shed abrasive material.
2) There is no “right” answer as to how aggressive lockup is applied.
a. Drag cars want immediate 100% lockup
b. Drift car want immediate 100% lockup
c. Street car wants a very loose diff with low preload to accommodate sharper turns
d. Road race wants something in between, driving style, car setup would dictate how quickly lock comes on and let’s go. I’m guessing a 993 with low horsepower and rear engine would be on the slower end of the scale
3) More plates seem to be irrelevant at the horsepower levels these cars produce.
If anyone wants to fund a diff shootout, I am in need of a new diff right now and would happily donate my car and some $$ as a guinea pig….
What did I miss?
Here is what I think I have gleaned so far from this thread, please correct and elaborate where needed.
1) Carbon friction material is the least abrasive, provides for the longest transmission life at the expense of the diff itself. "Motorsports" plates provide much longer diff life at the expense of added wear to the rest of the transmission as the plates shed abrasive material.
2) There is no “right” answer as to how aggressive lockup is applied.
a. Drag cars want immediate 100% lockup
b. Drift car want immediate 100% lockup
c. Street car wants a very loose diff with low preload to accommodate sharper turns
d. Road race wants something in between, driving style, car setup would dictate how quickly lock comes on and let’s go. I’m guessing a 993 with low horsepower and rear engine would be on the slower end of the scale
3) More plates seem to be irrelevant at the horsepower levels these cars produce.
If anyone wants to fund a diff shootout, I am in need of a new diff right now and would happily donate my car and some $$ as a guinea pig….
What did I miss?
