Any X1/9 Guys lurking... say Hi., Now that we've got to know them Options

[tdgray]

After the unfortunate incident this past week... now that we've patched things up. I thought maybe the X19 guys would come over and check the site out.

Step up and say Hi guys.

Clay invited them to a "club" function. Would be neat if they showed up. (IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif)

[XHead]

QUOTE (Travis Neff @ Mar 4 2006, 12:22 PM)

Welcome XHead!  I see in your albums that you have a phantom grip installation?  Can you give us the dog and pony show on that setup?   Rich is working with Phantom grip right now to see if they can make a unit for our gearboxes.

Phantom Grip. Oh man....

A few notes: The guys at PG are like.... just too busy to.... like.... return a phone call... dude...

It was torture getting them to make me a unit. I build racing engines and transmissions for X1/9s (other cars too) as a sideline. But I do more X1/9 transmissions than anything else. I got a couple of PG units, one for me and one for a customer's car. The first one was custom made for the X1/9 diff. I had to really beat on the PG guys to get it done.

The unit is very simple. As you can see its an aluminum block with a hardened coating. The block is divided in two with a set of four preloaded springs that force the two halves apart. The back side of those two blocks push against the spider gears. You can see in the photo that the side gears are machined so that their flat, finished surface is what the PG block is pushing against.

The LSD function comes from the friction between the PG block and the machined side of the spider gear. Its not a locker that clicks or clunks. Instead its basically a very crude clutch type. That is, the "clutch" action is between the PG block and the spider gears.

As for how it works. I know 914s are like X1/9s in that once you start making power you spin the inside rear tire off the corner. Putting a locker or clutch type LSD in an X1/9 really screws up the car's handling.

I have learned to set the cars up with a lot of front roll stiffness and a low rear roll center. This solves most of the inside rear wheel spin problem. However, as you approach 1.4 g its really tough to keep that tire from spinning, especially if the car makes good power.

The PG unit doesn't work as well as a Torsen (of course a torsen has its own unique problems) or a clutch type LSD. But it does work enough so if you set the car up right, most of the problem goes away. After some intial testing I got a number of spring sets in different weights to test and found a combination that worked. I also found that much of what the PG people told me was wrong.

I now know alot about these units so if you have any questions let me know I will be glad to answer them.