exocet offroad

Miatas: More track time than most other makes/models and now trying for more off-road time than most SUV's

Keith Tanner wrote: We pulled the wing. There's no benefit in throwing high speed mud and rocks directly at a thousand dollar carbon fiber wing.

There sure isn't. I was just wondering if that occurred to you before or after something happened to it. Probably would have been after for me.

Fenders and a lot less air pressure for your off road exploits next time.

I have a feeling that those tires have enough sidewall strength to hold the car up when completely flat. They were at 15 psi in that video.

Mud's unusual around here, that's probably the last time we'll go bogging. Any future exploits will be on more typical hardpack dirt.

With beadlocks I'm sure they could. Since all you care about is keeping the tire on the wheel I'd say that 8-10 psi should be fine provided you keep jumps to less than 5' of vertical.

I ran 12 psi on my TJ when off roading and could have done less.

This vehicle will not be jumping on the current suspension.

I run 15 on my Land Rover and there's a whole lot more sidewall deflection!

Keith Tanner wrote: This vehicle will not be jumping on the current suspension. I run 15 on my Land Rover and there's a whole lot more sidewall deflection!

Some may read that as:

Keith Tanner wrote: This vehicle will not be jumping.

But I choose to read it as:

Keith Tanner wrote: This vehicle will soon be jumping on an amazing suspension!!!

Here's what an outsider had to say after driving our beast. I'm going to put "resident instigator" on my business card.

http://www.thedrive.com/article/2200/slinging-mud-in-the-lifted-turbo-miata-of-your-dreams

This could easily be the "tow behind my RV car." If I had an RV... or time to use it. It is light so easy towing. It will go anywhere any regular person would likely want to drive while on vacation. It will do basically anything any of us (not regular people) would want to do on vacation. I am thinking you take along two sets of wheels (One for dirt, the other with some DOT race type rubber), two sets of coilovers (one off road, the other on road), and enough tools to swap them. Then hit autocrosses and track days in between seeing the wilderness that would scare most Jeep owners off. Sounds lovely.

So....the Fox shocks have more travel. I assume they're valved stiff as all get out, but I also assume they can be valved softer for non-track car applications.
I can't quite get a lifted Miata out of my head now. I think I NEED one.

In reply to mazdeuce:

Also need much softer springs. Most off road vehicles are pretty softly sprung. That, plus the number of bumps is why the shocks are so very taxed and expensive for those kinds of vehicles.

alfadriver wrote: In reply to mazdeuce: Also need much softer springs. Most off road vehicles are pretty softly sprung. That, plus the number of bumps is why the shocks are so very taxed and expensive for those kinds of vehicles.

It depends on the terrain and shock valving. Crawler type use generally means soft springs, while faster stuff varies more. You can either run soft springs and have tons of suspension travel, or run stiffer springs and not need as much travel (although they'll still be softer than what you could get away with on a smooth racetrack).

When I put together the suspension on my Jeep (mostly used on the road, for rallycross and some mild trails, not heavy crawling), I ended up with a much, much stiffer setup than stock. The stock springs were 190 lb/in front, 160 rear. The current springs are 280 lb/in up front and the rears are progressive, sitting somewhere around 350 lb/in at ride height and getting to almost 600 at full compression. Combined with good shocks (Bilstein 7100s), it rides firmer than stock, but not much harsher. It's not stiff enough to sacrifice grip for rallycross on rough gravel and such, still flexes well enough for mild crawling (although not as squishy / flexy as stock) when you disconnect the front sway bar (rear bar is deleted) but works much better when larger bumps at higher speeds are involved, as it doesn't just blow through all the suspension travel and slam the stops, but can actually soak them up (it's not lifted, so it doesn't have tons of up-travel to work with, somewhere around 3.5 - 4 inches until full squish on the bumpstops at both ends).

Being too soft can also make it sloppy. It's much easier to drive hard in snow or on dirt with the stiffer suspension, as it's much better about just going where you point it right away, rather than wallowing around and not wanting to change direction (and that can also make it hard to catch the rear end if you get it loose at speed, while the stiffer setup will react much faster to corrective input).

Bascially, you don't want a track car suspension, but I wouldn't make it too soft. Soften it up enough to keep the tires from skipping around on rough surfaces and make sure it's well damped, but not over-damped on rebound (that'll hurt rough surface grip), but don't soften it more than necessary to hit that point if you want it to stay responsive and not need insane amounts of travel.

Springs is the easy part, but yes the whole thing would need to be softer for what I'm thinking. Nothing hard core, softer than stage rally. A competent gravel road sports car.

The big one that I forgot to mention is that, especially in the rear, you'll get better high speed performance in the dirt with more spring and less sway bar, as it'll let the suspension work more independently.

rslifkin wrote:

alfadriver wrote: In reply to mazdeuce: Also need much softer springs. Most off road vehicles are pretty softly sprung. That, plus the number of bumps is why the shocks are so very taxed and expensive for those kinds of vehicles.

It depends on the terrain and shock valving. Crawler type use generally means soft springs, while faster stuff varies more. You can either run soft springs and have tons of suspension travel, or run stiffer springs and not need as much travel (although they'll still be softer than what you could get away with on a smooth racetrack). When I put together the suspension on my Jeep (mostly used on the road, for rallycross and some mild trails, not heavy crawling), I ended up with a much, much stiffer setup than stock. The stock springs were 190 lb/in front, 160 rear. The current springs are 280 lb/in up front and the rears are progressive, sitting somewhere around 350 lb/in at ride height and getting to almost 600 at full compression. Combined with good shocks (Bilstein 7100s), it rides firmer than stock, but not much harsher. It's not stiff enough to sacrifice grip for rallycross on rough gravel and such, still flexes well enough for mild crawling (although not as squishy / flexy as stock) when you disconnect the front sway bar (rear bar is deleted) but works much better when larger bumps at higher speeds are involved, as it doesn't just blow through all the suspension travel and slam the stops, but can actually soak them up (it's not lifted, so it doesn't have tons of up-travel to work with, somewhere around 3.5 - 4 inches until full squish on the bumpstops at both ends). Being too soft can also make it sloppy. It's much easier to drive hard in snow or on dirt with the stiffer suspension, as it's much better about just going where you point it right away, rather than wallowing around and not wanting to change direction (and that can also make it hard to catch the rear end if you get it loose at speed, while the stiffer setup will react much faster to corrective input). Bascially, you don't want a track car suspension, but I wouldn't make it too soft. Soften it up enough to keep the tires from skipping around on rough surfaces and make sure it's well damped, but not over-damped on rebound (that'll hurt rough surface grip), but don't soften it more than necessary to hit that point if you want it to stay responsive and not need insane amounts of travel.

you have a good point but another thing to consider is that is is a very light vehicle compared to most offroad vehicles so it may actually be worth going softer because in those videos that thing looked like it had steel pipes in place of the springs

but i have little to no experience in this kind of stuff so im just rambling

edizzle89 wrote: you have a good point but another thing to consider is that is is a very light vehicle compared to most offroad vehicles so it may actually be worth going softer because in those videos that thing looked like it had steel pipes in place of the springs but i have little to no experience in this kind of stuff so im just rambling

Very true. Stiff is all relative to its weight. With how light an Exocet is, it might not need much more than stock Miata spring rates in the dirt...

Lots of potential for tuning, that's for sure. The big thing is the re-valveability of shocks. Off-road guys do a tremendous amount of tuning to make things work and it's not uncommon to read about garage revalves.

rslifkin wrote:

edizzle89 wrote: you have a good point but another thing to consider is that is is a very light vehicle compared to most offroad vehicles so it may actually be worth going softer because in those videos that thing looked like it had steel pipes in place of the springs but i have little to no experience in this kind of stuff so im just rambling

Very true. Stiff is all relative to its weight. With how light an Exocet is, it might not need much more than stock Miata spring rates in the dirt...

You don't need more that stock Miata spring rates in the dirt on a normal Miata.

mazdeuce wrote: Lots of potential for tuning, that's for sure. The big thing is the re-valveability of shocks. Off-road guys do a tremendous amount of tuning to make things work and it's not uncommon to read about garage revalves.

That's why I really want to fit off-road Bilsteins (or other user-rebuildable shocks) on my Miata so I can play with the valving at home.

In reply to rslifkin:

It very much depends on how it will be used. Running on prepared surfaces vs. not and how fast you intend to travel on said surface matters a lot. Your jeep is more like a rally car, and the surfaces are pretty nice- and the need of precision is more important than not getting beaten to hell. But watching cars run really off road racing, they favor softer springs to be able to glide over terrible surfaces vs guessing a rate that may cause really bad results over bad surfaces.

When I worked with a Trophy Truck team for a weekend, it could go over 3 ft. washout pretty fast and the truck would be pretty even over the surface even going 60mph. It also landed nice and softly off a 15ft jump. Those things are very softly sprung, and is well illustrated when those cars are on pavement going around a corner.

Either way, an off road spring set would be quite different than an autocross set up.

Which brings me to a question for Keith- given the right rates, do you think the suspension would work well on track/autocross given the long travel set up? (of course, lowering it appropriately).

Which is another way of saying- could this car be a good track/autocross/off road vehicle just by changing tires and spring/shock set?

If so, that sure seems to increase the appeal of the exocet a lot.

for those wanting to start such a project in need of a donor, your enabler awaits:

http://washingtondc.craigslist.org/nva/cto/5451940572.html (NMNA, and you all should be damn glad that I can't move, otherwise I'd be claiming it for a future exocet build with the intent of offroad. Now someone on here het the damn thing).

alfadriver wrote: Which brings me to a question for Keith- given the right rates, do you think the suspension would work well on track/autocross given the long travel set up? (of course, lowering it appropriately). Which is another way of saying- could this car be a good track/autocross/off road vehicle just by changing tires and spring/shock set?

In the video, we simply swapped out the tires and threw on the lift kit brackets. The suspension was as used on Mazda Raceway Laguna Seca. Yes, it was too stiff. It was still fun though, and I could have it back in racetrack mode in an hour

Could the long travel setup work well on the pavement given the right shocks? Probably. As long as the roll centers didn't get screwed up and the wheel rate doesn't change due to shock angle at the extremes of travel (specifically the compression end of travel, where it could possibly go into falling rate), it should work. That setup is currently designed around a set of inexpensive dual shocks, I think they would be the weak point. Remember, it doesn't yet exist in the physical world.

I don't think the long travel setup is necessary to make it work well off-road, which makes life much simpler. A set of stock springs and shocks would be a good first start. The AFCOs would be even better, as they are user-revalveable and have more total travel than any other Miata shock due to a long rear body. An interesting thought would be to bolt on a set of stock ND springs and shocks - they're similar in dimensions to the NC units that have been bolted to a couple of NA cars, but have 7" of shaft travel in the rear and very soft spring rates.

I will probably try the Fox. You can revalve them at home if you have a nitrogen bottle.

Next time I get this thing on video, it will be running an easy-to-swap setup you can actually buy. I get tired of the internet commenters assuming that anything they see is the final, tested and perfect version. Not here so much, just in general.

Keith, I for one am glad that you posted the video that you did and shared the working prototype information. During a time that very little manages to lift my spirits or make me smile, you had me grinning ear to ear, gave me a laugh and best yet, gave me something to want and look forward to. There will always be internet detractors, most of whom aren't in the target market or have the means or desire to be potential future owners anyways.

Illegitimi non carborundum, right? Glad you enjoyed it. It was fun.

I declare this the " Offcet Exocet"