Skid Wheels to prevent scraping
 

Has anyone had any experience using something like these to prevent your lowered porsche from bottoming out?

http://forums.pelicanparts.com/uploa...1313095458.jpg

I dont think that would be a good idea at any kind of quicker speed.

Maybe im missing something but, that wheel thing looks like a bad thing all around. Figure if you mount it to the body somehow or somewhere, you are basically lowering that point of the car that much and when you hit something with it probably gonna do a good amount a damage (expecially at speed).

Skid Plates
 

PEL-SP7002 - skid plates work great on my car under the front spoiler area

We're way ahead of you!

Just make sure you've got a huge drill, a box of drill bits, and your Ace Hardware charge card ready to go. Oh, and a 6 pack or a quart of Tequila probably wouldn't hurt, either.

http://forums.pelicanparts.com/porsche-911-technical-forum/163512-training-wheels-my-porsche.html

oh wow :eek:

YIKES ....

Cheers !
Phil

You have at least three conditions to design for.

1. Low speed contact

2. High speed contact

3. Contact from weight shift under intense braking (nose dive)

...............................................

1. Low speed contact includes crawling up a steep drive with steps in it (like I once faced), you can get away with just about anything, for a little while.

2. High speed contact is unavoidable in some areas (ie; Michigan's potholes), it will rip off weak designs, stronger designs will transfer impact forces to what ever you tie them to (like front torsion bar mounts). Neither option sounds attractive to me.

3. JMPRO (I think) said an experimental set of neoprene rollers (with cross bar axle to distribute load to both front torsion bar mounting points) on a lowered 911 made the braking less effective under extreme braking conditions, because the rollers would roll or lift the front end. The result was longer braking distances, a bad thing (of course).

.................................................. ..

You can do what ever you want, it's your car.

However there is no long term or "safe win" solution which will address all three conditions - in my opinion.

.................................................. .........

Maybe you can invent a retractable system. One which can be deployed when needed, and tucked back up while underway.

The only people who don't make mistakes, are the people who do nothing.

My experiment did what it was designed to do, for as long as I needed it, and then self destructed with no damage to the pan. The few screw/bolt holes I had to make were easily filled with dabs of JB-Weld. I do not recommend anyone repeating my moment of desperation.

EDIT: Would a a retractable chin spoiler do more and be easier to make?

OMFG. That's some funny sheet!

Ah, why?:eek:

The design I have been using for several years now is shown below. I don't have a pic handy of the wheels installed on the car but I think you get the idea. The brackets replace the stock hooks and skid plates. The wheels are designed so that the wheel can not touch the ground in the event of a flat or blowout. I made a set for Jack Olsen that he used on his car he but found out the wheels did contact the ground in extreme cornering with a very low car, with the suspension severely compressed.. The brackets need to be very heavy duty. After testing several kinds of wheels I decided the hard urethane worked best and have lasted the longest. Steel wheels of coarse are heavy duty but make such a racket when they encounter a driveway that I decided that replacing the urethane wheels as needed was the best solution. I haven't had to replace the wheels yet after several years.http://forums.pelicanparts.com/uploa...1313128913.jpg

Thanks for the update JMPRO, your latest design reveals that it is a product of evolution and development after several false starts. Well thought out ahead of time and not installed in haste or desperation as a temporary fix. It seems like it would work under most conditions without self destructing as well.

To anyone reading, if you regularly use a drive which scrapes up full sized cars and just murders your 911 (my neighbor with said drive - ended up buying a full sized SUV to get around the problem), look into raising the front of your car. Avoidance is still your best option.

If you raise it too much you can throw the handling and balance off (to the point of dangerous). However on my car which was in storage for several years before I purchased it, had settled too low.

The adjustment screws up front were near or at the lowest point, creating a nose down, butt up stance. This lowered front end aggravated the driveway scraping condition, which no amount of angled approach could resolve.

If memory serves I adjusted up just a little bit maybe 1/2", and gained another 1/2" by taking the weight of the spare out. This resulted in still a slightly nose down stance, but good handling.

EDIT: I also had 50 series tires on 15" wheels/rims which made the car sit another 1/2" lower. Nothing but trouble sitting that low in Michigan.

Jubilation!!!!!!!!!!!!!!
 

retractable? hard urethane?

My mind is a raging torrent, flooded with rivulets of thought cascading into a waterfall of creative alternatives...................................... .................

OK, OK, I get it!!!!!!!!!!! This is starting to be funnier'n hell!!!!!!!!!!!!!!!!

...........come to think of it, a pub, Guiness, and a lousy parking lot entrance caused the last scrape................

OK, so here's the fix..............................

http://forums.pelicanparts.com/uploa...1313161799.jpg

Alternatively, hard urethane spinny round thingies of small diameter seem to be the best alternative for us luddites who live in places other than Flatland and want low cars but undamaged a/c condensers............

Your sense of humor survived intact, well done.

Short of turning your Porsche into a Citroën DS with hydropneumatic suspension, your options are limited.

JMPRO's on to something.................
 

JMPro,
Actually, that looks like a good way to go, rather than steel.
Guys, remember, this setup is designed to do what JMPRO did above: to take the hit in an unusually bumpy situation, instead of softer, more costly things. Looks like they will actually ride a bit higher (certainlly no lower)than the plates I now have on the car.
I might weld up a set and try them.

JMPRO,where did you find the wheels?

[QUOTE=Brorag;6192716]JMPro,
Actually, that looks like a good way to go, rather than steel.
Guys, remember, this setup is designed to do what JMPRO did above: to take the hit in an unusually bumpy situation, instead of softer, more costly things. Looks like they will actually ride a bit higher (certainlly no lower)than the plates I now have on the car.
I might weld up a set and try them.

JMPRO,where did you find the wheels?[/QUOTE


Found them in a boat shop. It is one keel roller cut into two pieces then drilled for a larger axel.

I was thinking of a wide skid plate

A skid plate is fine but I wanted to get away from that scraping noise from metal dragging on pavement that makes everyone look at you and wonder what kind of a dingbat does that to a Porsche.

Maybe we just all need really dark tinted windows.:cool:

Yo ron!!!!!
 

what do you have in mind?

Any solid object between the chassis and the road won't reduce any impact force - just transmit it. The wheel and skid plate solutions allow the chassis to glide over a bump without any chassis or bumper material rubbing off. The only difference is in the sound frequency and Db levels they produce while doing so.

Urethane wheels do a better job in that regard, but they should be smallish in diameter to increase road clearance. They should also swivel when the vehicle rolls and isn't pointed straight - otherwise the wheels drag and create flat spots (next thing you know, I'll be discussing the slip angle of urethane Porsche skate wheels :) )

A true impact absorber would feature some sort of dampening device that gives upon impact. There's nothing on this thread thus far that accomplishes that.

Sometimes backing out of a driveway at an angle produces fewer interference zones. Try that.

Gasoline weighs about 8lbs/gallon. Consider the fuel load. I create better front end clearance because I hate filling up at $60 a tank. YMMV (literally).

Sherwood

ordered rollers
 

decided to go with these:
Code Item Qty Price Grand Total
94-8777 Weld-On Steel Mini Roller 2 $21.37 $42.74

Subtotal: $42.74
Tax: $0.00
Shipping Cost: $11.59
Grand Total: $54.33


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.................and attach to the front steering arm cover in either of 2 ways.


Plan A:
http://forums.pelicanparts.com/uploa...1313258305.jpg

http://forums.pelicanparts.com/uploa...1313258377.jpg

Ground clearance should be greater than current setup.

Plan B:
attach to piece of 1/4" plate and mount to rear bolts of front steering arm cover, using bolts that are 3.5 cm longer. The same compensation would have to be made for the mounting angle:
http://forums.pelicanparts.com/uploa...1313258992.jpg

The wheels don't need to pivot since at low speed crawling over a driveway, the vehicle heading and vehicle velocity are in the same direction, so no slip angle. It might help if they were rounded like motorcycle tires or roller blade wheels so that if you go at an angle it will follow the cambers better.

no swivel action
 

right--welded to front steering arm cover. I'm figuring that the shim will bring wheel ~parallel to ground.

Yes, I was responding to the post before yours that said there should be a caster action.

type of bumps around here
 

can you eat that thing ?

I believe cannibalism is still illegal, but I bet the snake tastes like chicken.

This thread is retarded.....

retarded? retarded?
 

yes, Davy, it is; what's your point!:D
Yes, Ron, it's good eat'n, especially with hot BBQ, or if used in a good hot vindaloo....................
now, back to the more serious silly stuff: can the front a-arm protective bracket be removed and replaced without affecting the front alignment?
If so, what precautions must I use?

Why not just install a curb ramp at $300 it is a fix for all your cars.

Bridjit Curb Ramps - The No Jar To Your Car Curb Solution

curb ramp
 

Yo super!,
The issue isn't entering or exiting the driveway. If it were the case, your suggestion would be a good fix.
Often the roads and parking lots in our area are not as well maintained as they should be, and could cause the car to bottom out............

I wonder if just bolting on a nylon (plastic) rub strip or pads might do the trick?

When I used to road race that type of material seems to do just fine when dragging a knee.

A plastic shop should be able to sell you a chunk cut to size, and if you do it well it will be easy to replace when it wears out. You could even put a less dense material behind it to give you some bump absorption.

P.S.

Glad to see you were smart enough to wear high boots. I'd hate to see that thing nibble at your ankles ;)

here's the wheel
 

Wayner, that's not me--local news pic--I'm a little put-offish re: friends if the slithery pursuation. Sounds like a good alternative re: bum material.

The wheels are heavy--shipping at 6.7 pounds, but beefy enough to take any tap:

http://forums.pelicanparts.com/uploa...1313774836.jpg

If I go with plan A, they will be less likely to drag than the current setup:

http://forums.pelicanparts.com/uploa...1313774910.jpg


I'm now checking around to see if the front a-arm protective cover can be removed without affecting the front alignment--Pelican says OK. I've also asked on 911 tech forum, and will sort it out before removal. If removal will mess up the alignment, I'll go to plan B

The protective cap can come off without affecting alignment, just don't mess with the two bolts that hold the front bushing housing onto the chassis.

You mean HDPE?

Old thread on that topic:
http://forums.pelicanparts.com/off-topic-discussions/440870-hdpe-plastic-uses.html

I think that even if you replaced the aluminum teardrops with a thicker, lets say 1/2" HDPE it would crack or shatter eventually. Just would never have the shear and impact strength required.

It is an idea worth testing, just to see how long it lasts.

Na, not HDPE.

Titanium!

<iframe width="640" height="390" src="http://www.youtube.com/embed/O0oy5Ex9RnY" frameborder="0" allowfullscreen></iframe>

This thread is hilarious. Funny car wheelie bars in the front. Do we use swivel casters or rounded wheels? LMAO.

If you can't anticipate a problem with transition, your card to drive a super exotic is hereby revoked. If you have to do this for your wife, I have a suggestion.

Mount a significant amount of rubber or urethane footed by a skid plate. Better to ski over the obstacle than try to use a furniture dolly.

Why is that better?

It's better because it will shear from the surface, prevent the pan from hitting the ground, and won't rip a hole in the bottom of the car. And when the plastic or rubber is worn out remove it and put on a fresh piece. Something with the consistency of a hockey puck would likely be good material for this purpose.

If you bottom out the car with the current design and simultaneously hit anything taller than half the diameter of the wheel you will see some significant bending force applied to the mounting point as the wheel and mount will act as a lever.