I'm planning to install front brake cooling ducting on my track-focused Porsche 968, and the plastic wheel well liners are right in the path from the duct scoops in the bumper cover and the brakes. So, I either need to cut holes in the liners to allow the ducting to pass through, or get rid of the liners altogether. Is there any harm in getting rid of them? It seems that all they do is trap heat from the brakes, and they get in the way of enough projects to be an annoyance. I only drive the car on the street to and from the track, and I never drive it in the rain. Am I overlooking some vital function of these things? Thanks.
they keep things clean, which doesn't matter on a race car
May also be some aero effect. I know that the back of the wheel well on a miata is parachute shaped under the liner.....
It depends on the car. When I bought my 1993 Cobra R Mustang back in 1995 it came without the front liners because Ford didn't install them because "race car". But when you have such a car and want to keep it that way, getting rock chips in the top of the fenders from rocks hitting the underside of the fender, well you then have to consider installing them. Which I did.
I wish I had liners on my racecar because rocks and bits of rubber get flung up into all sorts of bad places and I have to keep vacuuming them out. I would leave them in if you could
In reply to loosecannon :
I’m just enough of a weight conscience guy that I want them out . As far as getting debris like rubber in places, It’s just part of my maintenance that I vacuum everything out because looking for dirt and debris forces me to look everywhere and at everything. Looking carefully helps me to see things that I might have missed.
Finally with regard stone dings and chips in the tops of fenders is just another way of telling me to keep it on the track. I’m going slower when I’m driving through the gravel pit.
Uh, just so I don’t sound too sanctimonious, I prefer to race with fiberglass or carbon fiber fenders which seem to absorb gravel/ stone chipping better than steel or aluminum.
I have no idea on a 968 but they can have a pretty significant effect on aerodynamics on some cars, creating lift and/or drag. Personally in your situation, I'd cut holes.
I would rather rub on the liners then on a part of the car that might have an edge and kill a tire at speed. But that is just me.
I like to know if things are rubbing as I change to new tires as they all seem to have a different shoulder profile.
I bought my Miata this spring, there's no Fender Liners in it. Now I'm wondering if I should install them.
It's mostly used for autocross, with some Street driving. I guess the previous owner took them out when he put in the 9 inch wheels, it's possible that they rubbed.
They are important for all sorts of reasons related to airflow control. Remember if you are going 100mph, you have a poorly shaped fan moving air up, down, and forwards at 100mph in the wheelwell. I would leave them in if at all humanly possible.
Ever have a car overheat on the street because one of the fender liners was missing? The tire was pushing air from the underside of the car back up in front of the radiator, making a kind of radiator air recirculation effect.
The fenders would definitely catch a lot of air on an SN95 Mustang without liners. So those are staying.
I pulled them out of my truck because all the clips holding them in were broken, I'll put them back in if I see a problem other than my headers getting dirty.
Knurled. said:
They are important for all sorts of reasons related to airflow control. Remember if you are going 100mph, you have a poorly shaped fan moving air up, down, and forwards at 100mph in the wheelwell. I would leave them in if at all humanly possible.
Ever have a car overheat on the street because one of the fender liners was missing? The tire was pushing air from the underside of the car back up in front of the radiator, making a kind of radiator air recirculation effect.
My Black Jack had the body shell and no fender liners. It also didn’t have a fan
It did have a shroud from the grill opening to the radiator so all the air that entered the grill went through the radiator. Full tilt racing never overheated that ancient long stroke Six cylinder. In fact water temp stayed right about 180. Even on 90 + degree days.
I could draft right up to inches from the back bumper and stay there at 150+ mph. Never ran hot.
Real race cars don't have liners.
I doubt there is much aerodynamic effect.
My FD was so low my front driver's tire was rubbing the wheel well through and in to the wiring loom causing some interesting issues. Glad I had them but besides that just keeping water and debris deflected is enough for me to keep them.
Thanks for all the responses. All things considered (especially the potential dents from underneath), I think I'm going to keep them for now, as their weight is insignificant.
