Jerry Feather

Roger, would you mind doing something for me with your new liner? I wonder if you can lay it on a flat surface with the wheel opening down on the surface and then take a picture of it from an angle that shows what the plane of the opening actually is? Probably a low angle shooting from what is the underside of the liner. I kind of have the impression that the wheel opening may actually be on a nearly flat plane taken by itself. I haven't tested that idea yet on the S4s that I have, but I think the GTS might actually be flatter. Thanks.

Jerry Feather

ROG100

Like this Jerry?

Jerry Feather

Perfect. Thanks, Roger.

Jerry Feather

S4ordie

Roger, are you positive that is a GTS liner? You cannot trust the part number as I found out the hard way. The set I got had the GTS liner number on both but one of them was for a 91 S$/GT so too narrow. I'm not sure how to confirm that without slipping it up inside an empty GTS wheel well.

Jerry Feather

Roger, in your first set of pictures above, in the 5th, 6th, 7th, and 8th pictures with the liner laying flat as shown what is the height of the liner to the center of the wheel arch. Thanks.

Jerry Feather

cold_beer839

Correct, the liners I got 2 years ago, one was true GTS the other was S4/GT, but both part numbers were GTS.

Tom in Austin

Helsinki, Sydney, Grand Junction ... isn't it great to live in the internet era. I'm going to be in CO in a couple of weeks, wish I time to just drive to GTS up there instead of flying!

Jerry Feather

Tom, I don't quite get the message in this post, but if it means you are going to be anywhere near Grand Junction, CO, I will be very dissapointed if you don't have or make the time to come by here and let me show you some of my operation. You will, however, be required to keep confidential the basic secret to my creativity. I might even have you help blow one or two of the liner halves in the secret/proprietary blow oven/form set-up.

Send me a PM about any arrangements we might need to make to connect here.

Jerry Feather

Tom in Austin

Well, just enjoying the inputs of people from around the world on your liner project, that's all. And thinking how nice it would be if a GTS owner happened to be in your neck of woods to help pin down the exact shapes/dimensions.

I'd love to accept your invitation to stop by and see how you do your magic but I'll be in Avon which I think is quite a ways from Grand Junction. And of course, in a rental car and not my 928, sorry to say!

Jerry Feather

Well, Tom, Avon is about two hours east of Grand Junction on I 70. I can tell you about Avon from my own history when Avon was simply the name of the railroad passing track and there was no settlement there such as now. I guess that kind of ages me, doesn't it. I can show you scars from my history with Avon.

I guess it depends on your time and the cost of the rental car to drive over here. If those do not preclude the trip, you are welcome to come see me.

Jerry Feather

Jerry Feather

Sometime, often, material or avilability of material dictates design. This relates to the design of the overlap/joint of the inner and ourter halves of these new liners.

I had originally designed the overlap to be from 1 to 1 1/2 inch of overlap with a gap of about 3/32 inch to fill with some kind of seal. I hadn't looked for anything for the seal unti recently, and when I did, at the local hardware store, what I found was some closed cell weather strip that is 3/16 thick and 1 1/4 inch wide. It is gray. It is what is offered for sealing between a pickup truck bed and camper/topper.

Based on that, and I had already kind of finalized the overlap at 1 1/4 inch, I decided to go with that seal although I was really wanting something about an inch wide and eighth inch thick.

Fortunately I hadn't gotten too far along in the development process to have the outer half form designed for the thicker seal because today I found on eBay some black closed cell weather seal in just the right size that I had hoped for at the beginning. It is 1 inch wide and 1/8 inch thick. It is also much cheaper than what I got at the hardware store and comes in greater quantities.

The problem I was struggleing with with the 3/16 inch seal was to have to crush it down to about an eighth inch on installation and I am concerned that after I force it to the necessary crush in the jig I am making and drill the common holes for the connectors, that in the field an installer may not be able to crush it that much in order to connect the two halves, even working front to back one connector at a time.

With this later discovered seal the crush will only need to be about less than half as much and will, I think, still give a good seal. I am more comfortable now about the ability of the final user to connect these halves upon istallation in the field.

Now, out of here and out to the shop for some more progress.

Jerry Feather

Jerry Feather

Well, it is not a big deal, or maybe it is, but I finished one of the branches I have fouund I need to deal with in this development. I completed a little secondary forming machine I needed to make to form the hem or slot needed to have the inner lower edge of the inner half of the liners grab onto the lower flange of the frame just aft of the mounting point for the rear suspension cross member. It works great.

I also got the outer perimeter of the stand/jig/form to hold the liners while both the doubler on the inner half is curing and while the two halves are held together for common drilling as previously mentioned. I need more work on that jig to get it complete for both of it's purposes.

I have the fifth blow of the inner liner now trimmed and fit to the S4 version of the cars on the left side and it fits great. I see that I am going to have to add some kind of form devise to the basic form for the right side to clear the gas line or gas vent--whatever. I'll work on that tomorrow and then perhaps blow what I hope will be my last prototype of the inner half.

I have made a check list of about 20 items that need to be done before I can go into production, and I have completee about 5 or 6 of them. I'll keep working on the list and checking off the items until I get this project ready to go. There are some items that will need to go on the list before it is complete, but at least I can see what my progress is.

Jerry Feather

Jerry Feather

Roger's pictures really help and the drawing that Gary Knox made for me many months ago of the GTS wheel well opening is invaluable. I finally got around to making a similar drawing of the S4 opening and compared them the other day and see that there is really a significant difference in the shapes. I'll take a picture later and show you.

Right now I am getting ready to try to fit the last blow of the innner half to the right side of the S4 wheel well. Right off I see the possibility of the need for some kind of form devise in the basic form so that I can form around the fuel line or whatever it is that looks like it will interfere with the liner in the right side. I'll work on that tomorrow.

In addition, I still need to know just what ever else might be interfering with these liners in the right wheel wells of the GTS cars. The left too I suppose. I mentioned before the need for some input on that and have not got any reply. If you look at the liner that Roger posted for the right side of the GTS cars it has a significant indent or recess in the top that must be needed to form around something that in not in the earlier cars. What is it????????

I have almost all of the perameters needed to make the form for the outer halves of these liners, both the GTS and all the earlier cars. That basic form is going to take some shape this weekend. It will be a sort of transformer form because it will have to have components that can be interchanged to make both versions of the outer half of these liners, Stay tuned for progress on that part of this project.

Jerry Feather

Jerry Feather

I just reviewed this thread quickly and see form some of the pictures that Rob has posted that there is really not much in the top of the right wheel well that needs an indent like the original liner seems to have. I hope that is right.

I also notice, again, the concern about my physical condition. I am rehabbing well and walk one or two miles a day and I am doing it without a limp. The Dr call that "symetrical." I feel great and am actually considering getting back to a little bit of running. Actually I had to run a little today to get to the middle of the street to tell a lady in a motor home that she was dragging a bicycle behind her motor home. Felt pretty good. Then I put in my one mile walk for the day.

At this point I think my new liners are taller than the originals by a little bit, maybe about an inch or inch and a half. It does not appear that there is anything in the GTS wheel well that needs to be formed around except perhaps the fuel line or fuel vent line that I mentioned before. I have to form around it for the S4 and perhaps earlier cars, and I suppose the GTS also. I'll be working on that this weekend.

Jerry Feather

Hilton

That cube-shaped indent on the GTS liners is interesting - wonder why Porsche put it there; its definitely not an accident.

Possible NVH improvement? Or a higher strength area where road debris like gravel or small stones is most likely to contact the liner?

Thinking about it for a few seconds, it may be a combination of both.

With a smooth inner surface, small stones thrown up by the wheels would follow the complete arc of the liner's interior, giving more abrasion, and also making more noise (longer distance over which the scraping sound would occur). Adding that shape would interrupt the parabola and the debris would become airborne before a single bounce off the front half of the liner.