Jim M.

All of you guys and gals with the older cars (pre 91) are correct about repairing the front wheel well liners and the two piece liners on the rear. But you don't know what your talking about when it comes to the 91 and later REAR liners. They are not a plastic, but more like a hard tar paper with the foam glued to the back side. Believe me, pop rivets will not hold. They will only cause more damage.

I've been researching this for about a year now and have found several American cars that have similiar W/W shapes and the sound proofing. My next step is to visit a scrap yard and take some actual measurments. I've also measured the noise level using a DB meter with and without the liners. I want the liners to reduce the tire noise, and they do make a big difference.

One other option Roger has mentioned is to use the rear liners from the 87-90 S4's. They only cover the B-pillar and the rear portion of the W/W. The center of the W/W is flat enough that dynamat could be installed to bridge the gap between the front and rear covers. That's not my first choice however. Exposure to the elements might compromise the adhesion of the dynamat. Finding another liner seems like the better solution.

Alan

Jim - did you consider & reject the front liners as a starting point? - I know its only a 2/3 - 3/4 liner anyway but that combined with the S4 splash shields maybe?

Alan

H2

[QUOTE=Jim M.;5943230] ...But you don't know what your talking about when it comes to the 91 and later REAR liners. They are not a plastic, but more like a hard tar paper with the foam glued to the back side. Believe me, pop rivets will not hold. They will only cause more damage."

Jim,

I agree with you...but only if...the plastic has deteoriated severely. I guarantee you that, done carefully, on the '85S and the '88S4, it' unbelievable what can be resurrected. When backed on both sides by metal, and cushioning glue in between, and the plastic is sandwiched between them, small aluminum pop rivits have worked every time for me. I don't have experience with the '91 and later liners but for my method to not work, they must be very poorly made. Not that the other liners are very strong. They suck too.

H2

dprantl

The front liners are 10 times stronger after 100k miles than the '91+ rear ones. You must understand that all I have to do is TOUCH it and it crumbles in my hand like Sara Lee pound cake. A pop-rivet anywhere on that panel will just make a nice hole slightly larger than the rivet and a pop-rivet on the floor.

Dan
'91 928GT S/C 475hp/460lb.ft

Alan

Indeed it is crappy material like rotted cardboard with a foam backing - it obviously deteriorated over time - but now you only have to breath on it to damage it. The foam is whats holding mine together - except for the parts that blew away in the wind...

I was looking at how bad mine were and just gently touched it and a part broke clean off - no pressure whatsover. Jim is correct there is absolutely no fixing these... you couldn't even get them off without damage.

They are officially worse at deteriorating than the GTS intake tubes!

Alan

Gary Knox

I too would like to replace the rear liners in my '94. They are perhaps the worst construction material ever to pass through a Porsche factory!!

I used the S4 rear wheel front and rear plastic parts on the left (driver's side), to reinforce and hold the OE lousy liners in place (had to do some cutting of the S4 pieces to get everything fitting in place). On the right side (passenger) I used the right rear front S4 plastic piece and reversed the orientation of a left side rear plastic piece (again with some cutting), to hold the right side OE liner in place. It is pretty decent now, except for that area directly above the wheel well opening. It appears to me that Porsche did NOT use a wider liner for the GTS rears, so there is that ~1.5" gap between the wheel and the inside of the outer fender well that is void. If I didn't have Louis Ott's rear sway bar stiffener and Koni shocks on the car, the 295/30 18 tires would be rubbing on that edge of the OE liner during any spirited cornering!!

Hope we can find a decently economical method to replace the whole kit and kaboodle. THANKS Nicole for stimulating this discussion. With all of us brainstorming and being additive, we SHOULD resolve the problem better than the designers at Weisach/Stuttgart did!!!
Guten Tag,

Gary Knox
West Chester, PA

H2

This helps me better understand why Porsche didn't incorporate the superior technology of the auto-adjusting T-belt tensioner they used in the 968 in years1992-1995. Saving money seemed to be very important to them during those years. Makes me wonder if the writing was already on the wall for the 928 by '91 or so.

PorKen finally did what Porsche could have done with relatively little engineering. In any case, the GT and GTS are still desirable cars.

Given what you're saying, perhaps just using the crumbling "tar paper" as a mold for a fiberglass coating would help? However, Gary's approach may be the best approach for the time being...if you can find used pieces.

H2

Jim M.

Alan, when I did my rear brake upgrade I removed the liner on the LH side and took photos and measurments of the W/W. I did try the front liner in the rear, but only the LH front on the LH rear. The fit was not to my satisfaction (I can be pretty **** about detail things.) and I wanted to find a better fit. I was also concerned with the lack of noise canceling foam. There are several 90 and newer Cady W/W liners that look close, also a Lexus that might work. Again a visit to a scrap yard is my next step.

You owners of Mercedes/Audi/BMW's etc. or other high end cars what do you have? Why not take an hour and remove the one from your Mercedes and see how the fit is and of course the quality of the material. The W/W's of the S4's and the OB's is so close to the GTS that it shouldn't make any difference. Together we can find a solution to this POS that Porsche used.

Fogey1

Judging from the experiences described here, if it were my problem I think I'd be at the point of "Lemme cruise hardware stores and Home Depot and office supply store floor protectors to see if I can make a Franken-liner."

Amazing what can be accomplished with L-brackets, heavy rubber/plastic, goop, washers and nuts and bolts. The doc's monster might have been ugly but he was high functioning.

Alan

I am about to embark on a project to fix my GTS rear fender liners. My drivers side is partly gone and the forward part is now occasionally rubbing on the wheel... not good (depends on wind direction )

I just got in the S4 splash shields from Roger: stock rear-fronts on both sides and 2 of the rear-rear LHS so I can flop one over (with mods) for the RHS.

I also plan to glue on some thick closed cell foam on the rears of these splash shields and find a way to build a top ~flat liner to go over these also with foam on the rear of it. I haven't exactly figured out all the steps yet. I have the foam on order - 3/4" closed cell nitrile (like for the hood liners but much thicker...) it should be very effective at noise reduction if i can figure out how to get it in the right place and fitted well. I do also plan to address the B-Pillar noise insulation while I am in there and am toying with various ideas on that topic.

Has anyone already successully made a top arch cover like this? - I'm thinking to shorten the splash shields at the top & top sides by ~3/4" and have the top foam enclosed above these front & rear. The top cover/liner in flexible PVC sheet (any sources - still looking...) would have the foam glued to it in the center section above the wheel and would attach to the top of the front & rear splash shields via speed nuts/self tappers (rather like on the front splash shields)...

Any thoughts on this idea from anyone who has done similar?

I'm also looking at spray-on bed liner materials (wary of this) and also self adhesive bed liner sheeting as a possibly more rugged cover for the PVC.

I also have on hand some noise reduction sheeting (FatMat) that I may consider using on the underside of the arches directly.

I feel the front & rear splash shield target approach is quite clear and pretty well proven - the top area less so.

Another possibility is to just glue the 3/4" foam up across the arch tops & spray the bed liner material over it for better protection from the elements & road debris...

Comments?

Alan

Larry Velk

I adapted a US liner to a German car - better plastic, newer car (Taurus to Merkur). While at the junkyard I surveyed many wheel liners. Any liner will have the approximate shape and they can be easily made smaller - harder to make larger. They come in every possible shape and usually remove easily. I optimised the side fit using hardware store neoprene (plumbing dept.) riveted on. You can cut this quite prcisely and do a Porsche quality job, not butchered at all. The key is getting a ready made liner that is close to what you want. Ford contor (sp?) liners, for instance, have a narrow top and are quite wide, they remove easily.

worf928

Don't forget to make a covered access hole for the PSD.

Alan

Dave - actually using the S4 splash shields the PSD access should be significantly easier... rear-rear splash shield just unscrews & off...

Alan

worf928

Hmmm... I need to go look at my '91. My memory is cloudy.

ROG100

What ever you do not use "fatmat".
Thats what I used and after a month or so it started dripping the black gue backing everywhere.
It would leave puddles of a tar like substance on the suspension and the floor.
Very very messey.
When I took the liners out all that was left was the silver part of the FatMat.
I used the bed liner to seal what was left on there after cleaning as much off as possible.