Jaynen
Jaynen SuperDork
12/21/17 3:34 p.m.

So I happened to be showing my buddy the off-roadster and stuff on Paco's site and this lead to watching Keiths review of the 3" lift kit. Now I know suspension wheel rate wise if you were building suspension for rallycross that you probably would want something softer but is it a completely ridiculous idea to buy a skid plate/lift kit and throw tires on the stock wheels for when I feel like doing a rallyX vs a HPDE?

Car would normally be setup on coil overs with 15x9s and RS4s for now swaybars/rollbar/hartop/seat.

I am not expecting that this would necessarily be a rallycross winning setup but it might be fun to have the flexibility? What sort of tires would you run for this?

irish44j
irish44j UltimaDork
12/21/17 5:08 p.m.

The fastest Miata rallycrossers are stock height or close to it, from what I've seen. Hell, the fastest one on the east coast is Shawn (moxnix here) and if I recall correctly, his is actually on the R springs, or was at one point.

Bee Thao came out to our last event with the Paco suspension on his. I think he said after the event that he would go back to stock springs, or something to that effect. Also, it looked idiotic in addition to being slower, since he was running regular-size rally tires.

I'm sure those guys will chime in with more detailed informtion, though. There's really no reason to be much higher than stock height for rallycross in any car,..maybe an inch...IMO.

EvanB
EvanB GRM+ Memberand UltimaDork
12/21/17 5:24 p.m.

You can lift it if you want, it will look cool. It will definitely be slower though. You would be better off cranking the coilovers up to stock height and running it like that. 

Jaynen
Jaynen SuperDork
12/21/17 5:47 p.m.

I guess my thought was, my HPDE coil over setup is likely to be 1.5-2" lower than stock at 4.5" pinchweld? so if I just put the 3" lift on it will only be a little bit higher than stock?

I think it would take less time to install the lift kit and not mess up alignment/ride height/cornerweighting than messing with the coil over adjustments?

rslifkin
rslifkin SuperDork
12/21/17 5:56 p.m.

If you can find a way to mark the current position on the coilovers well enough, it shouldn't be too hard to put things back the same after and not mess up the corner weights.  Maybe put a dual rate slider stop below the perch, adjusted so you just move the perch to the stop to return to non-rallycross height? 

bluej
bluej GRM+ Memberand UltraDork
12/21/17 6:00 p.m.
irish44j said:

The fastest Miata rallycrossers are stock height or close to it, from what I've seen. Hell, the fastest one on the east coast is Shawn (moxnix here) and if I recall correctly, his is actually on the R springs, or was at one point.

Bee Thao came out to our last event with the Paco suspension on his. I think he said after the event that he would go back to stock springs, or something to that effect. Also, it looked idiotic in addition to being slower, since he was running regular-size rally tires.

I'm sure those guys will chime in with more detailed informtion, though. There's really no reason to be much higher than stock height for rallycross in any car,..maybe an inch...IMO.

I talked to Bee about it briefly,  and recall him saying words to the effect of he planned to drop it back to stockish height via the coilovers but keep the lift kit hardware. Something about the kit helping w/ full travel clearance.

Jaynen
Jaynen SuperDork
12/21/17 6:31 p.m.

The lift would only be for dual purpose laziness, I used to swap back and forth from supermoto wheels and dirt wheels on my WR250R, and it was annoying having to adjust the chain and bleed the brakes everytime because of the different calipers etc

Knurled.
Knurled. GRM+ Memberand MegaDork
12/21/17 7:24 p.m.

High is slow at rallycross.  If you need the added weight transfer from ride height, grow a pair of brass ones and drive faster.

 

I would NOT want softer suspension than stock, ever, on any vehicle.  Just because it's dirt doesn't mean you aren't able to build significant lateral forces, and you need to be able to soak up bumps besides.  I used to be a fan of jacking up the spring rates and removing the sway bars, but now my paradigm is only increasing the spring rates by 50% or so and keeping the sway bars.

 

Not a Miata, but my S40 was perfect with spring rates in the front 100% stiffer than stock, with stock type dampers, and keeping the bars.  (Stock wheel wate was stupid low like 80lb-in or so.  The springs I mostly ran were 200lb-in) Suspension must be limber with loose damping but it must have enough spring to keep from bottoming out.

Jaynen
Jaynen SuperDork
12/21/17 9:10 p.m.

While I agree, I don't think people run rallycross at HPDE ride heights of 4.5" or so to the pinch weld. Measured my NB at stock height its right at 6". So figure 1.5" drop for HPDE setup. So if i wanted to get to stock ride height the coil over adjustment would be the way to go, the lift would put me 1.5" above stock unless you could also compensate with a shorter tire which would also shorten gearing

Kylini
Kylini Dork
12/21/17 9:59 p.m.

I’ve rallycrossed my car on 700/400 springs and it was competitive. I’m currently on a softer setup, but still stiffer than most. I think your plan of lift kit on otherwise HPDE will work, as around an inch above stock is good if you want rally tires (try to get 14s to avoid fender liner surgery, but 185/65-15 is awesome otherwise). Remember to adjust your sway bar end links and consider removing the rear.

If you go this route, buy shock bags (velcro nylon bags to keep dirt out). They’ll help your shocks last longer. 

rslifkin
rslifkin SuperDork
12/22/17 7:59 a.m.

Depending on the car and course, stiff suspension isn't necessarily a problem for rallycross.  I've seen cars (all with very good drivers) turn in very similar times despite one being on stiff-ish coilovers, one on pretty stock 2.5RS suspension and the other being a Forrester with weak shocks, stock marshmallow springs and no sway bars rolling all over the place. 

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