ok... so what are the DISADVANTAGES of fiberglass GT flares as opposed to steel fender flares? this would be for primarily a fun track car (non-competative, just HPDE) maybe occasional street use very seldom.

Should I avoid something with fiberglass? or is it not really a big deal ?

For a track car I would use fiberglass - you can get bigger flares and if you rivet them on they are a whole lot easier to replace if you break one. If I do a track car it will have FG flares - the street car is going to be steel.
Steve

I think the fiberglass is more prone to pitting and other wear damage over time. Might not seem to make sense because both steel and fg get painted, but the paint holds up better over steel because the material under it is so much harder and doesn't give when hit with dirt/debris from the road.

Street car needs steel, so you can pick the car up by the fender still to fit the floor jack under it when it goes on jackstands.

I'm replacing my FG flares with steel (street and track car).

FWIW - I thought I had the flares epoxied on really well. It took about 20 minutes with a heat gun and putty knife to get the first on off. The others will probably be faster.

Steel takes road debris way better. The FG ones will star crack on you from rock hits. You also can't butt weld fiberglass on. You'll have more filler if you bond FG on. I have seen FG flares bolted on very clean.

Here's Retrotech's car w/ FG:

COST.

Coming from someone who has fiberglass flares I would have to say I really have no clue if one is better than the other . After learning how easy the glass is to repair and work with it is really not an issue to fix. Sure the metal "should" be better for a street car I guess. I would say if you have a real 6 and you are making a GT clone out of true factory flares it would matter for the return$. For a track car... dunno if it really makes a big difference one way or the other.

FWIW, my car has fiberglas flares. They were installed in 1977, the car was repainted in 1982. They're still perfect, no cracks, no issues.

Fiberglass, Light weight!!! The gift that keeps on giving. The cheapest HP you will ever get is less weight.

I've put on a number of FG flares and they all seemed to have lasted years, one set over a decade now. If you do FG right, they are fine for street use. But if I had a choice, it'd be steel for street and probably removable FG for track use.

It's mostly about cost I wager. It was for me when I did FG flares. Just didn't have the funds at the time for steel flares.

steel also reinforces the body and makes the car much more valuable (no I am not tooting my own horn!!!!)

I've got steel flares and the car is a street/DE car. One advantage is it seems is FG flares let you use 9" rear wheels where it seems like the steel ones can only get 8" wheels. I've got three sets of wheels, 2 sets Fuchs/1set BBS and there is no way I can get any wider rears on. Maybe a differend inside offset in a 9" would work. A friend had a 914 with FG flares and the rocks from the track/slicks began spider cracking the OUTSIDE of his paint on the rears...A dedicated track car would be better off with FG...Have another friend who has FG flares and his 9" BBS fit just fine. We're going to try his 9's on my rear and see if they will go, but I'm betting they won't....

On fiberglass when you paint stick to light colors. The use of great stuff expanding foam on the inside of the flares will eliminate star cracks from damage caused by rocks and stones.

No? Well of course you are!

So here you are, Doc. I assumed you'd be absent until the website thing got all straightened out. You commenting yet?

Edit: Oops, he was there when I posted, not there now. He'll be back....

I'm nearly finished with the install of fiberglass flare, but also have a set of steel flares I recently bought. My 255/40/17 on 9" just barely fit the rear fiberglass flare and was wondering if those would fit under the steel flares. Let us know if the 9" fit.
Andys

I've had fiberglass for 16 years with no worries. The only thing, which most know is for any rivets used during the installation to be drilled out and filled before painting.

They expand at a different rate from the surrounding fiberglass/filler and eventually bubble up the paint. But fiberglass is a cinch to repair.

Good Luck

There is a simple way to avoid that. It adds ounces to the weight and won't absorb water.

Care to share with us what that would be?

Andys

Ron, wondering minds want to know......We have to see if your 9's fit under my steel flares....

I'm thinking the great stuff expanding foam.....

Insulating foam in a can...the stuff you shoot around pipes, doors, & whatnot in the home...messy, but effective. You want the stuff that dries hard. I have zero stars after 5-6 years of rocks from slicks.
The paint around the wheel opening is hurtin' tho, but so are the metal fronts.

Recommendations on how to apply? How thick a layer? Spray it on and scrape off the excess before it dries?

-Josh2

I can't really tell you the "best" way. As I said, it's messy. Wear long rubber gloves....like your wife uses, not the surgical type.
The surfaces need to be clean of loose dirt so the stuff will stick......it seems to stick to everything else. You gotta kinda feel your way for the best way to spread it. It's been a while since I did it but as I recall, my fingers were involved. Cut off excess after it hardens. I had a large area to cover & it took around 2 cans per side and came out around an inch thick....with lumps.
Clean up with lacquer thinner...before it dries. God knows what after.......

You have to hold the can upside down when it's about half empty. Start at the bottom & work your way up on as the can gets into the goop you've applied....even more.
I made an extension nozzle out of flexible plastic tubing for some areas.

I use a hacksaw blade to shape it first - less messy, then finished with some sort of sanding could of been a flapper wheel, then finished over it with spray in a can truck bed liner. It may be covered in my build thread because i had posted how i did it back when. DONT GET IT IN YOUR HAIR!

Acetone is how you clean up the spray foam...lacquer thinner will just make it wet and smelly.

JP,
Are you saying to basically covered the entire inside of the fiberglass panel with an inch or so of foam?

Rich

Acetone and lauquer thinner. Ahh. Explains everything.

So when you trim that stuff isn't there the risk of it taking in moisture? I've never really worked with it but thought the reason some people didn't like to use it was due to the risk of causing rust I know if it isn't anywhere near the metal this would not be an issue but isn't where you would put the stuff right in the middle of the joint?

Lacquer thinner has acetone in it and is WAY less volitle.
Just covered the areas that might take a rock shot......that means all. Hot slicks can pick up fairly large rocks, almost a good throwin' size.......then they bounce around in there.

I think my rear flares are lapped on the inside to but this picture shows different maybe the fronts are or there not, but i didn't spray it up into the metal area, i did seal it though, as it looks much better that way. I remember using a wire wheel and a disc sander very carefully to finish shaping and smoothing out the foam after the initial hack saw blade shave.
I had to reapply a few times as you can see the gaps, and sometimes it dont stick and flops off on you. Wear throw away everything clothes.



"DONT GET IT IN YOUR HAIR"!

OK, I'll be the bad guy here!

Other than destroying the value of the few 914's left - why would you do this? Steel or plastic - if it wasn't an available option on your 914 - why?

Just curious, and sorry for the hijack.
Pat

ps: my thanks to all who've sliced up thier 914's to fit flares for no reason than whatever - you've increased the value of mine.

Why do this? To get more tire underneath the car.

The Porsche family, more often than not, was all about producing a car already good from the factory and providing a platform for privateers to make them faster and handle better. We have been doing that for a very long time. I love to look at and drive factory original cars, but I also get a thrill when designing and building, or riding in, or looking at competently modified 914's.

It's also important to me to have a good test-bed to try out ideas. Some are good, some I leave behind, but in it all, I have a bunch of folks to bounce thoughts against.

I think it's really cool that the 914 supports all of our efforts in all directions. I don't understand all of them, but I don't have to.

Just because, and IMO they look cool just like the 914's that did have them. 914's go really fast if you put a big flat six engine in them like the factory should have.
Because the factory was to wimpy to offer all the stuff on the 911's on our cars, forgive us Pat, some of us had to do it ourself.

I love the stock 914's as they are also, and someday if i can find one that isn't all hacked up with flares, a flat six, and 5 lug Fuchs with big sticky tires on it, i hope to buy it.........

Oh on another thought, helps the economy.

Instead of spray foam I did the under car spray liner and topped it off with dynamat... It works good for my uses, but I think if I were running real slicks (have dot-r's now) I'd probably glue some foam padding in there... (I have heard that works well)

My flares look totally different underneath from the picture above. The metal is expanded out to meet the flares in the same shape and the glass is lapped to it with FG-cloth strips. If I were near the car I'd post a pic. The point is that there is no gap to fill. Surely I'm not the only one.

I thought you guys were talking about filling cracks on the outside with this stuff.

I did, periodically, have to dig rocks out that embedded themselves in the foam.....ecxess weight, ya know.

Will rubberized spray undercoating do basically the same thing ? I know it won't be as thick but the foam in my opinion after being cut,sanded,shaped will be open cell. Won't that trap moisture ?

The insulating foam is a closed cell coat as long as you have 2 or more layers of bubbles.....I got maybe 20-50 layers, me thinks. I was shootin' for an inch thick...did that or better.....controling that while applying is a challenge.

NO, don't get it in your hair/beard/stash.

jt914-6,

Any new info on the fit of the 9" on the rear steel flares?

Thanks,

Andys

Because when it comes to classic car guys there are two types. Show car guys and drivers. 914's are sports cars meant for sporting, great entry level race cars. Plus they aren't THAT rare. Just sayinisall.