Sand rail autocross/skid pad build (or, why my wife hates me)

Andy, I will be moving to narrower stickier tires for the front but the balance between front and rear is not to be denied. I cant even put this thing on my lift without jackstands under the rear. The aero devices are now for autocross, so speeds will be higher.

Steve, Thank you very much for the advice. It sounds like you have experience in this area so I appreciate it. I will be getting it lower. I'm going with a much smaller sidewall for the front tires as well and really sidewall height is the only adjustment I have left but its about everything since the wheel without tire is about even with the bottom of the rail now. The rear I can drop much more too. But I will hold off on any ideas of undertrays or getting too fancy for now. I did order a sprint car nose wing with what they call "deep dish" or camber as you correctly stated. I think that and some adjustability for the angle and I can experiment and see what works best. Im not a good driver nor am I driven to be competitive but I like the building and experimentation to make things better :)

NOHOME wrote: Why add more weight? Steal a page out of the VW family and just borrow the control forward bits from a Microbus. Look where the driver and his weight is located.

Remember how I said I didn't like the idea of the battery being the first thing to hit something? I still like it better than my knees being the crumple zone.

so, who has the videos of this thing running?

Get that sprint car wing, but I think you should look for solutions to the handling balance problem that don't involve adding weight or going to narrower tires. Weight is the enemy of all aspects of performance (except top speed).

Sounds more like you need softer springs on the front, or harder ones on the rear to get a better balance.

There's only so much springs can do with that kind of weight imbalance.

Pat. Video is on the previous page.

Springs are the only reason it's as good as it is right now. Rear has 650 lb springs and the front has had the stock rate halved. Can't do anything more in front without switching to coil overs. Now accepting donations of front coilovers ;).

If you watch the video it stays flat. I think the spring rates are pretty good.

JThw8 wrote:

NOHOME wrote: Why add more weight? Steal a page out of the VW family and just borrow the control forward bits from a Microbus. Look where the driver and his weight is located.

Remember how I said I didn't like the idea of the battery being the first thing to hit something? I still like it better than my knees being the crumple zone.

Got ya covered!

Just think how easy it would be to keep an eye on those pesky cones.

NOHOME wrote: Just think how easy it would be to keep an eye on those pesky cones.

If I was quick I could just reset them on my own. ;)

JThw8 wrote: Pat. Video is on the previous page. Springs are the only reason it's as good as it is right now. Rear has 650 lb springs and the front has had the stock rate halved. Can't do anything more in front without switching to coil overs. Now accepting donations of front coilovers ;). If you watch the video it stays flat. I think the spring rates are pretty good.

What size do you need? I have a pair of circle track racing shocks that are too long for me to use on my 924, but I'd gladly send them to you if they would work for you.

turboswede wrote:

JThw8 wrote: Pat. Video is on the previous page. Springs are the only reason it's as good as it is right now. Rear has 650 lb springs and the front has had the stock rate halved. Can't do anything more in front without switching to coil overs. Now accepting donations of front coilovers ;). If you watch the video it stays flat. I think the spring rates are pretty good.

What size do you need? I have a pair of circle track racing shocks that are too long for me to use on my 924, but I'd gladly send them to you if they would work for you.

hmm, very nice offer thank you. I'm not sure of the size to be honest, I really don't know that I need it to be softer in the front. The shocks Im running right now are, if I recal, 19" fully extneded but should probably be shorter if I'm going to try to go lower (which I would with coil overs. If you dont mind measuring them I can do some measurements on my end to see if I could make them work.

And thank you for the offer!

In reply to turboswede:

How long are they? I might be interested if JThw8 isn't. The Midlana need shocks!

bgkast wrote: In reply to turboswede: How long are they? I might be interested if JThw8 isn't. The Midlana need shocks!

I don't remember how long they were so I'll check when I get home later.

If Jim can't use 'em maybe we can talk about those BMW wheels of yours?

JThw8 wrote:

NOHOME wrote: Just think how easy it would be to keep an eye on those pesky cones.

If I was quick I could just reset them on my own. ;)

ROTFLMAO! Beer on screen....

Great mental image.

HA! My rail is sitting on my lift right now.. It is PERFECTLY balanced with a full tank of gas at the Spring tube on the rear.. I ovbiously have to strap the front of it down.

My frame is a 90 in wheelbase with a Turbo Dodge VNT engine out back.

My solution.. 3x3 trailing arms in the rear... and 31 inch mud tires..

Seriously though.. You should consider extended length trailing arms front and rear... It would help quite a bit.

turboswede wrote:

bgkast wrote: In reply to turboswede: How long are they? I might be interested if JThw8 isn't. The Midlana need shocks!

I don't remember how long they were so I'll check when I get home later. If Jim can't use 'em maybe we can talk about those BMW wheels of yours?

About 19" extended and 14" compressed.

In reply to turboswede:

Sure. Send me a message or text. Jim has 1st dibs though.

Sorry for the hijack, back to your regularly scheduled sand rail of awesomeness thread.

Sent you a PM bgkast, please let me know if you didn't get it.

And now...Brown Santa arrived today. :) Yes it has sideboards, they still need to be installed and I have to figure out mounts. It will actually probably be a little more forward of that location unless anyone has reasons why it should be in one spot or another.

You got that for $50? Is that a price we can get?

MrJoshua wrote: You got that for $50? Is that a price we can get?

No the $50 one was a flat wing damaged unit, after discussion here and some research I realized I really should go with a cambered unit. The one above was right around $100 which is still a pretty good deal all things considered. It's nice quality and the leading edge is made of a heavier aluminum so it won't get destroyed the first time it picks up a cone. The sideboards are pre drilled and dimpled for the rivets and the rivets are included as well. Very happy with it overall.

Its a XXX brand model number SC-NW-0001. I got it for $109 shipped. You can find it as low as $89 but with shipping the $109 was still the best price (from www.PreciseRacing.com)

In reply to JThw8:

If you angle it right, it will help keep the bugs out of your face, too.

I feel like you need to extend it further, like a foot further, and it's hard to tell but maybe an inch or three lower? then widen it to go in front of the wheels...

Make new endplates that tie the ends of the wing to the torsion tubes. Mount it lower and forward enough that the back edge is even with the front of the torsion tubes.
The bottom should be just above the bottom of the floor (for when you get it lowered).
Build angle adjustment into the end plates by having the wing pivot near the leading edge (probably the lowest of the three rivet holes near the nose or in the center of that pattern).
The angle you have it mocked up at 'looks' about right, so set your adjustments up with +/-10degrees.
Make the end plates as long and low as you dare on the back side and shape the top to an angle that gives about 4" above top surface at the highest wing angle.

That is a nice score for the price, now I have to go look at them and see what I can do for making an active system for left/right independent actuation...
Speaking of actuation, would you be interested in tying the brake system into an actuator that lifts the angle when you get on the brakes???

stafford1500 wrote: Make new endplates that tie the ends of the wing to the torsion tubes. Mount it lower and forward enough that the back edge is even with the front of the torsion tubes. The bottom should be just above the bottom of the floor (for when you get it lowered). Build angle adjustment into the end plates by having the wing pivot near the leading edge (probably the lowest of the three rivet holes near the nose or in the center of that pattern). The angle you have it mocked up at 'looks' about right, so set your adjustments up with +/-10degrees. Make the end plates as long and low as you dare on the back side and shape the top to an angle that gives about 4" above top surface at the highest wing angle. That is a nice score for the price, now I have to go look at them and see what I can do for making an active system for left/right independent actuation... Speaking of actuation, would you be interested in tying the brake system into an actuator that lifts the angle when you get on the brakes???

It has existing bottom mounts, is there any reason I should mess with modifying the end plate design rather than just use the bottom mounts with adjustable posts?

I was thinking as far forward and low as possible, so than you for confirming that is the way to go.

I was thinking something like this where the red is a fixed support with a pivot at the wing end and the green is an adjustable support which can go up or down to change angle. Thoughts?

Tying it into brake actuation intrigues me from an engineering stand point if nothing else :)

That green bar would actually probably tie in to the top tube or behind the torsion tubes looking at the actual mock up photo and remembering where the mounts are.

In reply to JThw8:

I didn't get it. Try emailing username at Gmail