school me on rally raid/gravel cars

[piggdekk]

Hello,
I'm considering joining an historic rally raid in Spain (Home - Spain Classic Raid) and I would like to hear what would need to be done on my 911 (71T) to make it ready for it. The race isn't a full throttle kind of race, but the track is covering quite a long distance (2100 km) and the stages are +90% off road. It follows the rules of historic races here in Europe, so it's not about max speed but about keeping a certain average speed (usually 50km/hr). For what I read/heard, it's quite hard to maintain the average speed, so You need to push the throttle anyway. A few special stages are on auto cross tracks.

Conditions shouldn't be too hard, lots of semi standard cars join the race and You don't need a 4WD. Still it's important to gain a bit of ground clearance, and it's adviced to instal a plate to protect engine and fuel tank.
My car is mostly stock, has anyone got pictures of engine/fuel tank plates? How much can/should I raise the car? I still have stock T-bars, which I think should be fine for "off-road".
thanks
luca

[Quicksilver]

Raising the front is pretty easy because all you need to do is turn the hex torsion bar adjusters the same amount. (I'm not sure but I think I found that 2-1/2 turns was about an inch of lift.)
The rear is not as easy. You need to actually redo the alignment because you have to loosen up all of those settings to change it.
You can also put on a taller tire but that will mess with your speedometer and odometer accuracy. If the tire is narrow you can go a fair bit taller. I have a set of 205/75-15 Grabber AT2 off road tires I throw on my car for grins from time to time. (Anything to make the "car polisher" types angry!) They are a touch over 27" in diameter but I wouldn't use them for a real gravel rally. They BARELY fit in the front with the front fenders rolled, the front lifted an inch and a fair amount of front camber. They DO touch the inner fender at full lock. (The rears don't seem to be an issue.) If you got something 26" tall and lift the front you would probably have a much more usable level of clearance. You have a much better assortment of rally tires available in Europe so it should be better for you.

You will want mud flaps on all four fenders. From the pictures on the rally site I would have front and rear tow hooks in place so it is easy to get pulled out without diving into the mud to get under the car.
As far as a skid plate, I would just get some 1/8" aluminum and attach it with the inner front torsion bar mount bolts in the front and then extend it back to the floor of the body. You will need to look for where to mount the rear but you can always drill a couple holes in the gravel guard for the steering rack and fuel pump.

- - - - - - - - - - -
I do get a kick out of driving on the knobbies. The rock solid lateral stability of my Toyo R1s or Nitto NT01s goes away! The knobby tread makes it more like a "suggestion of lateral stability". The back end walks around when you do anything snappy and is very entertaining. (Yeah. I miss driving on ice and snow.)
Driving the knobbies on gravel and mud would be a major improvement though. Tread is king in limited traction situations!

Have fun. It sounds like an amazing run!

[piggdekk]

thanks Quicksilver,
I definitely need to lift the car and take come measurements for the slid plate, the idea . The race looks like fun, and me too I miss driving on mud and ice (I lived 7 years in Norway) and this is why I'd love to join this one. I haven't sent in my inscription yet because I would like to get my gearbox rebuild before the race, on Tuesday I will get an estimate and then I will decide if I pull the trigger. Getting it into first gear is a bit hard from time to time, and I get grinding in second gear, not ideal for a rally!
Mud flaps and hooks are mandatory to join the race, so they will be there.
thanks,
luca

[J-Mac]

This looks like a Regularity Rally or TSD Rally. Google both. You will need a navigator who is clued in on how to manage your average speed versus time allowed and read the stage notes. Notes are provided for each stage just before you depart that stage. Penalty points are added if you are early or late to checkpoints. I recommend you and your navigator practice this before embarking on the event. Mods to your car should also include adding a very precise distance measuring device. Google Halda. These events are fun. Enjoy.

[piggdekk]

thanks J-Mac,
You are correct, this is a regulartity rally. I already did a similar one a few years back, and it was fun. This should be funnier though because it is off road and therefore it will be a lot harder to keep the average speed.
For this rally the organizers supply a digital road book that basically runs in an app in your own tablet and uses sensors on the wheels to measure distance, so my understanding is that You don't need to use a halda, but I could be wrong.
Need to figure out how to mount the skid plate!
thanks
luca

[chris_seven]

We build Gravel Rally Cars. Front guards need to be substantial and we use 6mm thick Aluminium.

I would suggest you install a 'speed probe' for the trip meter on an un-driven wheel to make sure it remains accurate.

[piggdekk]

Thanks Chris,
for what I read the app they use connects to the speed probe, and You can actually have 2 just in case one breaks down.
Would you mind sharing a picture of the front guard? Do You use skid plates to protect the engine? Any hint for tires?
thanks
luca

[chris_seven]

I can take photographs tomorrow.

[piggdekk]

That is so unfair Chris, just when most of us are in a boring office you take pictures of race Cars!!
Thanks
Luca