Supper

See the crap i'm facing with trying to get this thing going?

Anyway... the update is I've finally got the interior most of the way stripped. I'll post some pics up tonight for all of you guys who are actually interested in this one.

Supper

this is what it looked like when i first got it.

and this is why it was chosen for the rally car project.

peejay

No.

You need SUSPENSION TRAVEL.

I don't have much time right now, need to go to bed so I can get to work early enough to make meaningful progress on my engine. But spacers on top of the strut don't give you suspension travel, they just give you ride height.

I played this game with hockey pucks shimming the front springs up. This gave me suspension travel. However the wimpy 100lb springs are just plain too weak, and it still bottomed out a lot, and after a thousand miles or so the springs collapsed from hypercompressing (the barrel shape was compressing into the rest of the spring).

I now have 200 pound-inch, 12" long springs. i now have suspension travel, and enough spring rate to keep from bottoming. That's the theory, anyway, since I bottom out STILL even on the street. What would be nicer would be some 250 or even 275 pound 10" springs, or better yet 250 or 275 pound 12" or 14" springs and relocating the lower perch on the strut tube. Longer springs are better because a given amount of suspension motion translates into less motion at a given point on the spring. Ride height should be set by having zero spring preload when topped out.

One rule of thumb I've read often is that the front spring rate should be the weight of the car divided by the amount of suspension travel in the front. So that if you land on one corner the suspension can support the weight of the car without bottoming. If your car weighs 2700lb total (including cage, driver, codriver) and you have 6" of suspension travel, that means about 450lb-in, which is a wee bit much. Most RX-7 guys run in the 200-300 pound range.

Next you need damping. Rally cars like to have not so much compression damping, to absorb bumps, and plenty of rebound damping, to properly control those stiff springs.

I don't compete in stage rally, but local roads are close enough, and I regularly rallycross. Given that, and I don't feel like spending $4000 on rally struts, I noted that the OEM wet struts are rich in rebound damping and light on compression damping. I drained the fluid, filled with ATF, and it works WONDERFULLY. However it's still weak OEM type junk and it's still fragile, so for stage rally, actual rally struts are a good idea.

Oh, and go to www.specialstage.com and search for "RX7" and "RX-7" in the Car Construction forum. (Also Maz-dog) Make sure you check "Also search archives" - after a few months of inactivity, posts are automatically archived and closed to replies, but there's still good info there.

For inspiration, visit www.havspeed.com and see how it's really done.

Anyway, bedtime.

peejay

Ah, I see you've already been to SpecialStage, and met Mr. VanLandingham.

He's a lot like me - we both seem to hate everything except some things which we fail to hate very much so we champion them like they're the best things in the world. (Even though it's not that they're the BEST it's that they minimize being crappy)

Come to think of it, I've seen that post, and replied to it...

Supper

well, the username over there is the same as over here.

more pics:

alien_rx7

I wonder why then, that so many rally FBs are still racing?

Anyway, it may not matter much longer. SCCA is dropping ProRally and ClubRally from their organization. Hopefully someone else will pick it up. Just do a search on SCCA for their press release. Sad, sad news for the rally enthusiasts out there. If we weren't such a litigation happy nation, this probably wouldn't be an issue (they're citing insurance costs).

peejay

It's already been picked up. Part of the dropping process is handing everything over to Rally America, which had been working with the SCCA in the past with respect to timing and other things.

The SCCA as an entity hated stage rally, and since they didn't care much for it, the sport has been foundering. SCCA dropping stage rally is probably the BEST thing that could happen for Rallying in the US.

In any event, NASA will still hold events, and Canada has a quite wonderful series with much more support. (Why? Because their stage rally was dropped and a new organization that was rally-based (CARS) was formed to fill the void)

Also, there's always Rallycross, which is cheaper and (IMO) more fun because you can run, *and* spectate, and did I mention that it's cheaper? (No it's not stage rally, but stage rally entrance fees are 10-20 times the cost of rallycross fees. Plus there's lots more driving involved)



edit: resized photo

alien_rx7

Thanks for the perspective Peejay. I forgot to mention that I had read that Rally America was looking into picking it up. I didn't know that in fact they already were in the process. Yes, it could be a much better thing that someone else run it. Canada's scene is nothing short of phenominal plus they have tarmac rallies up there too! Maybe this change will eventually convince the WRC people to move a race into the US too since the closest is now Mexico.

Rallycross is cheaper but in my opinion is not comparable to actual stage rallying. Sure, you're racing around a set course on dirt just like stage rallying (except without trees jumping out in the middle of the course ) but it is much closer to regular autocross. As a note, I do enjoy rallycrosses so please don't mistake what I am saying.

Terrh

iTrader: (7)

WOW! I had this idea first! I gave up when I saw the costs involved and my lack of funds.

I may be picking up a cheap FB shortly and will renew the idea. Do you have MSN or something? lets talk rally lol

frode

Here is one of the factory 1st gen rallycars being raced in Hillclimbing in Norway! We have two of them!

Terrh

iTrader: (7)

where? I don't see anything :P

alien_rx7

Here are four examples of rally FBs from the 2k2 and 2k4 100 Acre Woods ClubRally.

Terrh

iTrader: (7)

those are some nice cars!

Definatly good examples of cheap fun rally cars.

Supper

Thanks for the photos. Those are looking damn good. Gave me a few ideas for my own project too.

As it stands right now I can't find a pipe bender to purchase/borrow/rent so the roll cage is still being delayed on the start. Sometime in the next couple weeks i'm pulling one of the engines and giving her a rebuild. Haven't decided yet if it is going to get streetported yet or just leave it with stock porting.

So if any of you know of a good hydraulic or mandrel pipe bender for sale, I need one.

Terrh

iTrader: (7)

Go to an exhaust shop and bend the pipe there, it will cost you $40 at most to do everything. Don't mandrel bend, it's $$$$$$$$$$$$$ and not necessary. You're not trying to flow stuff through the pipe, are you?

I'm going to do a 4 point cage in mine.. maybe 6.

Keep the motor BONE STOCK for your first season. It's difficult enough to control a car with 120HP, never mind 200HP...

alien_rx7

Just make sure your cage meets the rules specifications in attachment points and pipe wall thickness.

You're right about porting. Race first with a stock port engine and learn your techniques. You'll be better off learning the basics first. Then the next season, have the engine or a engine ported and installed. The 609 car from my pictures is ported. I even have video clips with it taking off from the start line and buzzing by on another stage I was on. Sounds sweet and the guy took second I think in nationals for his class if I recall correctly.

Terrh

iTrader: (7)

Is there anyone on the forum that's rallied? I've always wondered about the strut towers holding up to the pounding the car takes..

How about using an FC front springs/struts? They're a bolt in replacement, aren't they? Even the base n/a should have stiffer springs and a bit higher height/more travel than any FB unit.

As for the rears.. just a beefier shock that bolts up should work.. and I guess you could add a leaf to the spring?

alien_rx7

From what I could see, three out of the four in the pictures I posted were stock suspension setup meaning they didn't modify the strut tower or rear. They put in stiffer springs, shocks and struts. One did modify his to use coilovers which would be the way to go.

Terrh

iTrader: (7)

pics:

Terrh

iTrader: (7)

Terrh

iTrader: (7)

Used gravel rally tires are apparently very abundant in my area. Cheap, too.
I picked up a set of spare wheels for free a few days ago. Yay. I might have found a parts car with a PERFECT body but siezed motor for a few hundred $$$. Gotta go have a better look. It's even another SA, too.


I'm having a hard time finding cheap used rally shocks (for that matter, rally shocks at all!). I haven't looked for springs yet, I think I'm going to go with coilovers.

Will (street) snow tires stand up to rally use? I can get a set of 13" snows for $80...

Does anyone know where I can find rally shocks? The car has aftermarket shocks allready installed, do you think that they'll stand up at all to rally abuse? I'm not on the west coast, most of the gravel roads that I've seen around here are in pretty reasonable shape.


There are a ton of weld in (and bolt in) rollcages for cheap (under $700 US) Most of them are 6 point. I don't think that I'm putting a rollcage into the car until I have the rest sorted out. Hopefully I'll have pics in the next few weeks, I might have enough cash to buy a camera sometime soon.

85rotarypower

Well, I don't know if the snow tires will stand up to rally abuse, but I sure as hell know that they grip VERY well on gravel surfaces. I would suggest them for rally use.

Oh yeah, if your looking for stiffer, longer rear springs, the front springs from a Fiat 128 are almost exactly the same diameter as the stock springs but have about twice the amount of coils for reletive length and are quite a bit longer. They are probably stiffer too, but I'm not sure yet. I'm putting them on the rear of my car to stiffen if up hopefully.

Terrh

iTrader: (7)

cool!

Where the hell did you find a fiat 128?

85rotarypower

Surprisingly enough, there was one in the junkyard near me. Its quite possibly the oldest car they have there. Its not in too bad of shape either. But another alternative to stock rear springs is the rears from a Geo Metro!! They are even closer to the same diameter as the stock rear springs on an FB. Only thing is though that they might be weaker than the stock springs. They are after all only holding up a very light car. Me and a friend were almost able to flip one while we were searching the junkyard for stiffer springs for my car. But it was gutted and was a convertable.

Terrh

iTrader: (7)

I've got a set of metro springs at my house, I'll pull them off next week and find out!.

The back of metros don't weigh much. my (gutted, but still) '89 turbo firefly is light enough in the rear that I lifted a corner up while my dad pulled an extention cord out from underneath one of the tires... now that's light!