SLC 001 Build

[Mesa]

First week with the car - I spent last week taking a parts inventory, cleaning the car, getting the rear wheels pointing in the same general direction, measuring and re-measuring wheel offsets and brake caliper clearances. ''Measure 50 times - cut wheels once''. Now that I have something to look at I can contemplate the possibilities on wheel sizes/widths, centerlock? forged? three piece? one piece? John at CCW is a tremendous resource when it comes to knowing street tire to race tire dimensional and availability comparisons. I also made an appointment to see Jongbloed Racing Wheels since they are in my 'hood. Ryan at Jongbloed put together some wheels so I could get an idea what the measurement I gave him would look like. One possibility is to use really wide rims and tires in the back for visual 'impact'. The downside is the street tires available in this size are just 130mph speed rated and require 'coke bottling' the rear body panels to cover the extra width. On the up side the like sized race tires would be coming from a Lemans spec LMP1 car (Audi/Peugeot).

The more standard 11 inch front and 13 inch rear would be a no brainer by comparison, with Michelin offering every dimensional possibility imaginable! .... for a price.

See pics of the centerlock Jongbloeds made from unpolished and dust covered rough fitment pieces. (You can tell from these wheels I always wanted a Can-Am car! <big grin>)

[Mesa]

Another thing that has me thinking .... since the car will spend at least half of it's time on the street, .... how to keep the front end of the car from being busted up on driveways? After looking over the inner structures it seems this is a possible solution. Support the pivot point with a wide bracket the width of the flat area between the windscreen and the edge of the body. Bond the front splitter (which is fiberglass) to the nose for added rigidity and make plastic slide pucks the width of the underside of the splitter (or make from delron) too keep the splitter from hanging up on the ground. Use locating slides on the sides of the chassis located radiator side fences (there are corresponding fences bonded to the underside of the 'hood') to limit the upward sweep. To finish it off have a cockpit triggered lock down catch to keep it from pivoting under normal use. I don't like the fact the 'hood' will open the wrong way but don't see any other way to address this challenge without building a heavy reinforcing frame for the splitter. And making the whole splitter out of delron plastic too keep the pressure of a ground impact off the bodywork. Either this or build in a lift system for the front suspension that will be a whole lot more complex (and heavy) me thinks.

You gents have any ideas?

[Cillian]

Hi Rob, sorry for rudely making this my first post without introduction. However, I've been watching with great interest as you take delivery of your car.
I'll quickly say - I've been truly considering one of these for the last number of weeks (since I was first shown one by a fellow enthusiast), however the main difficulty which I would has is the point you've just made.
I'm in Dublin (Ireland that is) and we have a real problem with road quality. A spend most of my waking life in and/or around cars (particularly Lotus', Elise and so on) and can attest to the poor quality of our roads!

In an effort to find a solution for a car with as little ground clearance as the SL-C I researched a bit and I have to say I would lean towards the hydraulic front end.
This approach is used on all high-end, relatively 'streetable' cars, such as the Enzo, Carrera GT and Koenigsegg.
In fact in my travels I've found the manufacturer of the system that provides many components for the hydraulics fitted to the Porsche Carrera GT (and other porsches) - they may be of interest to you as you may be able to adapt something that appears quite light weight? Never used them personally, but appear very reputed in this area.
The company is KW Automotive and the system is called 'HLS'
The manufacturer is at:
KW automotive - dedicated to the automotive World

I wouldn't be that keen on your alternative solution and have so far found that eventually GRP (like many of the cars I already play with) will find that hinged pushing against the road surface pretty stressful over time - I certainly would be concerned personally, and aesthetically you're going to considerably affect the front end there.

Ok, enough rambling - please keep us posted, frankly I'm just dying to see more high resolution photos of the car as I've seen relatively few so far!

Best of luck.

Cillian.

[Will Campbell]

Hi Rob,

I agree with the idea that the front end needs to be liftable, and have spent considerable time thinking about it.

The GTM crowd is using the Delrin wear pads idea, but I really don't think it is a good fit for the SLCs with their even longer front overhang.

Fran mentioned to me that he thought he knew of a source of hydraulic spring perches. These look like thick bottom spring perches on a coilover, but expand in length on application of hydraulic pressure, neatly lifting the spring (and car) when needed. I hope to source such a perch and try it.

Another solution is to use a hydraulic ram to bear on a bracket that will lift the lower control arm. I haven't detailed the solution yet, just the idea.

I considered airbags but the apparent lack of a documented spring rate has made them look unattractive as a solution.

Good luck and let us all know what you decide to do!

[Mesa]

Hey Will,
I was going to call you earlier but it still would have been after 10 your time (too late). There isnt enough downward shock travel (droop) to use the hydro spring perch idea, you wouldnt get enough lift. A change of shock might fix this, I'll call Cillian's suggestion next week and see what that brings.

BTW: Your roller wheels don't have enough caliper clearance front OR rear to work on the SLC ! I guess that's the reason the calipers were not bolted in place for the trip out.

[Will Campbell]

Hey Rob,

Thanks for the update on the wheels. I may just fab up some quickie spacers to use while assembling the car just so I can avoid buying a "new" set of roller wheels. Anxious to see what you end up with with your car!

Lesson learned: C6 wheels don't work on the SLC! I knew the offsets were different, so it isn't too surprising, but I didn't anticipate caliper fouling problems.

Are you sure there isn't enough droop to allow the car to be raised up an inch or two? Even if the car only has 4" of total travel, it should have 2" of droop, right?

[Craig7L]

hiya messa, great to see a build log going for chassis 001.

any idea yet of anticipated total hours to build from the rolling kit? anyways will find out in a couple of weeks.

cheers mate

[Mesa]

Latest findings - If the car is set up with 4" of ground clearance in the front, the suspension has 2" of droop. If a hydraulic spring pad idea is employed IMO it will not render enough lift. Cillian's idea may prove of use but I have not had a chance to inquire, although one would think it would require at least a longer shock/ram to get more lift. I'm still partial to pivoting "hood" idea with one addition - have the hood be lifted and controlled through a 4 inch range by small electric rams. This way one could lift the front without it ever contacting the ground, thereby eliminating the possibility of the splitter getting wedged in a crack and transfering the load to the hood. Visually it isnt much uglier than a Maserati (MC12?) being lifted by it's hydraulic suspension to clear driveways is it?

I'm a little surprised the NZ contingent has not had a crack at this, they know how to do everything! (no joke I believe them blokes can do anything)

Sorry Craig7L ... have not thought that far ahead yet .... the major design stumbling block on the whole deal is this front end problem, after that it's pretty straight forward nuts, bolts and paint

[Russ Noble]

Originally Posted by Mesa

I'm a little surprised the NZ contingent has not had a crack at this, they know how to do everything! (no joke I believe them blokes can do anything)

Hi Rob,

Sorry we Kiwis are such a disappointment to you.....

I always go for the KISS principle. I think a permanently fixed rubbing strip that lets the pavement lift the body is the way to go. Light, simple, effective.

I am watching your build with interest. What size are those humongous wheels you are planning to run?

Good luck with it.

[Jac Mac]

Never had to do this Rob as the acceleration from a Ford engine is usually enough to lift the front end over most obstacles , however if I had to do something along those lines this is one possible solution. Make the top spring brackets along the lines of the link/bellcrank on a pushrod type single seater with a double acting ram to activate them.

[Mesa]

Thanks Russ and Jac,
I'm all for the KISS method.

My respect for Kiwi talent comes from John Britten's motorcycles and the movie "Fastest Indian" (I can't help it - I'm a brainwashed movie watching American).

Jac ...when Fran first showed his RCR-P version it had the front suspension set up something like your drawing, without the ram. I thought at the time it would be relatively easy to convert to what you have drawn here. On the SLC version there isn't enough room.

Russ, those wheels are the more extreme possibility - that rear is 17 inches wide <rubbing hands together>

[Howard Jones]

Here's a out of the box idea. Do you really need to lift both fronts? I nearly always "crab" my GT40 over speed bumps. I lead the bump with either the L or the R front. This really gives the front of the car quite a lot of effective height as the tire that approches the bump first does so from the center of the car out, with the tires turned towards the bump and the low body point following. By the time the bodywork reaches the bump the tire has begun to climb the hill and raise the car. It nearly always seams to be enough. I have about 4" of RH in the front of my GTD.

There may be something very simple to build using this concept that might work. Only one side to deal with.

Oh well..... thinking's free.

[Eric]

There is a company in Japan called Roberuta that makes a system that fits to the topside of coilovers for high end exotics. I believe it is a pneumatic system. It is now also being marketed for coil over kits for other types of cars. It isnt anywhere near cheap. But its exactly what you are talking about.

From their info:

"Imagine being able to raise or lower your vehicle's ride height at the touch of a button. Steep driveways, flatbed tow trucks, and jacking up your vehicle with a standard jack all become effortless. Lowering your vehicle to the absolute maximum for your next car show is possible without readjusting your coilover at the show. Life becomes simpler and you can spend more time enjoying your vehicle."

website is roberuta dot com

Dig on that-
eric

[Fran Hall RCR]

Eric,
I have been trying to work with these guys for a while....lead time is huge and but so is the pricetag....
Another option( better value) is also on the horizon...

[John Shand]

Hi

looking at that setup you would need some droop set up in the suspension to work well

if you like that option, give us some spec's and I will make you a set, I don't know what you call expensive but it does not look like it should be expensive,

John

[Mesa]

Since Fran has returned from vacation he has informed me that the "street" suspension will have more droop as apposed to the "race" suspension that is fitted to may car. So for now the heat is off and I can concentrate on other things. I will certainly keep an eye out for what he or others come up with.

[Eric]

Originally Posted by gt40fran

Eric,
I have been trying to work with these guys for a while....lead time is huge and but so is the pricetag....
Another option( better value) is also on the horizon...

Hi Fran-

I have heard the same, and i got a peek at some pricing, which might buy a SLR from what I saw. (CGT fittment)

Current Murcielagos have a lift system, I am not aware of what it is. But maybe simpler.

I am sure you will come up with something reasonable, check this out in the meantime for a D'OH moment.

Gumpert Apollo takes on America, foiled by speed bump - Autoblog

-eric

[Lance]

Fran,

I'm looking at a lift system for my GT40. Your enigmatic response gives me some hope, but no details. Is the alternative you're refering to suitable for a GT40? Is there any technical information avaiable? A timeframe for availability, maybe?

Any input would be appreciated.

Lance