Dusterbd13
Dusterbd13 MegaDork
10/21/24 10:12 p.m.

So, i expect Keith will chime in tomorrow sometime, but we may be out of his wheelhouse. 

My challenge 1999 turbomiata build has a set of ohlins dfv coilovers. They have some issues id like to address.

The left front has a missing adjustment knob, assumed briken off in the wreck. Any ideas for an almost free knob replacement that aint vicegrips or other pliers?

None have boots or bumpstops i can find. I think i have some acura ones in a bin somewhere, but whats the bumpstops supposed to be like on these? Same with boots. 

The rear adjusters are almost impossible to access with the car assembled in street/show trim. Ohlins makes rear remote adjuters for $250, but no. How can i make my own to stick through the package tray?

The rear seems to have no travel. Whats involved in adding extended rear top hats to these? 

Planning tonrun hard s sway bars. Also have a 1.25 front bar i can use. Which bar?

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
10/21/24 10:28 p.m.

Only one thing in your list I can offer anything on. Run the big front bar and have the rear bar links readily removable. Way back when (2017 Challenge), I ran my supercharged NB with a 26MM Ranger front bar and no rear bar, 450/350 springs, and we came second in autocross. Look for Miata for sale listings of autocross CSP cars for an idea on setup.

Edit: I'll add a second comment. Good-Win sells extended tophats for NBs , so I would think you could fabricate/modify a set of stockers

.

Dusterbd13
Dusterbd13 MegaDork
10/22/24 8:27 a.m.

In reply to DeadSkunk (Warren) :

Ive never actually autocrossdd a stockish miata. Just the mutant v6 one. 

Ill plan on using the big bar thats modified from s10 application. 

As far as rear tophats, im not sure how the extended ones fit and work. Never held a pair, installed a pair, or anything else. But read a lot about how the significantly help the ride quality of lowered miatas and help the handling 

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
10/22/24 8:33 a.m.

Nothing special looking about these. I ASSume they're just deeper to allow the bump stop to be higher.  I just used stops with one third cut off.........

RoadsterSport Extended Travel Rear Shock Mounts for Miata 1999-2005

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
10/22/24 8:38 a.m.

I'll bet you're running higher springs rates than I did,too. It should be a little rocket.

stafford1500
stafford1500 GRM+ Memberand Dork
10/22/24 8:39 a.m.

pictures of existing tophats... Have machine tools and materials.

Ohlins USA is based in Hendersonville,NC and was hit pretty hard by the remnants of hurricane Helene. I think I saw that they are officially down until they can get the place cleaned up and running again.

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
10/22/24 8:45 a.m.

In reply to stafford1500 :

A stock tophat.

99-'05 NB Top Hats Set of Four (4)

Michael's Ohlins may have a pillow ball top mount, but all it requires is a taller tubular section to move the bump stop higher. They could be made from stock tophats and some thin wall tubing.

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
10/22/24 8:51 a.m.

If just the knob is gone and the shaft is still there, you could 3D-print a replacement knob, heat the shaft with a soldering iron and melt the knob into it.

DeadSkunk  (Warren)
DeadSkunk (Warren) MegaDork
10/22/24 9:01 a.m.

This what the Ohlins DFV "Long stroke" shocks look like. Note the rear top hat height. Michael could have this or the regular stroke length kit.

FPSpec Ohlins DFV "Long Stroke" Coilover Kit (NA/NB MIATA) – MiataSpeed

NickD
NickD MegaDork
10/22/24 9:03 a.m.
DeadSkunk (Warren) said:

Only one thing in your list I can offer anything on. Run the big front bar and have the rear bar links readily removable. Way back when (2017 Challenge), I ran my supercharged NB with a 26MM Ranger front bar and no rear bar, 450/350 springs, and we came second in autocross.

I can second that the Miata seems to be better off without a rear sway bar. I was running my NA (250whp supercharged 1.8L, Xida Race with 800/500 springs, 245/40R15 tires) with the huge front Racing Beat bar and no rear bar at all.

Dusterbd13
Dusterbd13 MegaDork
10/22/24 9:44 a.m.

I have the regular kit i fo believe. And that picture helps a LOT warren, thank you!

I need to stick my head in the parts car and look at the upper mount again. I think i remember it being a pillowball, but not positive 

GameboyRMH: genius on the knob!!

 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
10/22/24 10:01 a.m.

Miata Ohlins are short on travel. You can try to make an extended upper mount but watch you don't run out of droop as well. Also, remember that they're an adjustable length body which means it's possible to adjust them wrong. Set the length to get maximum bump travel (probably as short as they go) and then use the spring perch to set your ride height. Again, watch for a lack of droop. You will likely have to compromise.

For knobs, there may be an off the shelf option at McMaster if you don't trust the strength of a printed one. 

As for rear sway bars, it depends on the rest of your setup. Power level, spring choice, alignment and sway bars all interact. 

SV reX
SV reX MegaDork
10/22/24 10:24 a.m.

Is it worth considering swapping the Ohlins for something else?

They should have quite a bit of value on the used market- perhaps a more conventional setup?

(I wasn't ever a fan of the Ohlins)

Slippery
Slippery GRM+ Memberand UltimaDork
10/22/24 10:48 a.m.

Not sure this is what you are looking for, but these is what the extended Ohlins knobs look for the rear of an M3. 

They are just a piece of sturdy material that gets held on by the setscrew instead of the little yellow knob. 

Dusterbd13
Dusterbd13 MegaDork
10/22/24 11:14 a.m.

In reply to Slippery :

Sweet! I know im capable of making something similar. Or maybe theres a generic off tge shelf?

Keith: can you explain the setup more? Im not sure im following properly. 

Paul: why didn't you like them?

SV reX
SV reX MegaDork
10/22/24 11:24 a.m.

In reply to Dusterbd13 :

Not enough travel. Perhaps a contributing factor to me wrecking the car. 

rkammerer
rkammerer New Reader
10/22/24 11:55 a.m.
SV reX said:

Is it worth considering swapping the Ohlins for something else?

Well, there's *cough* the Fox/Flyin' Miata coil overs.  Have a set on my STR NC Miata, great!  Track springs for fun, Sport springs when I was winter driving it on snows...

Goodwin likes the Ohlins stuff.  949 has their Xidas.  That's the usual suspects to me.  Miata.net loves them the MeisterRs, a more value-priced option.

Then there is the pricey stuff, Penske 8300s or MCS (have a set on the C5, like these too).

Challenge pricing, wonder what you could get if you sell the Ohlins, then find used FM/Xida, or one of FM's non-Fox setups?  I'd wager someone on M.net or similar would like the bling of the gold bodies and swap / swap with some cash to you for their current setup.

SV reX
SV reX MegaDork
10/22/24 12:04 p.m.

In reply to rkammerer :

The Fox/Flyin' Miata coil overs are what I was going to put on the car.  But they are not too Challenge budget friendly. 

I'm sure the budget won't cover much at this point, but maybe they could be swapped with someone who wants the Ohlins?

Im just thinking out loud...

The Ohlins are desirable by many, and rebuilding them is more in keeping with the spirit of the event.  I just didn't like them, and the short travel distance was a surprise to me.

 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
10/22/24 1:09 p.m.

Ohlins aren't exactly budget friendly either unless they come on the car :) They have a great reputation in the Miata world because they feel really good on a low speed test drive, but they struggle when you start to push them hard because whoever engineered the application didn't think wheels had to move. You can feel it going over railway tracks or over the top of the Corkscrew. I'm amazed it took them so long to fix it with the "long stroke" variation.

For setup, you have the ability to adjust the length of the shock body - that's the result of using a generic off-the-shelf shock cartridge with an adapter screwed on the end. Same thing MaxPeeDingRods does :) It's usually marketed as a feature and not a bug, but basically it means that there is one correct length and you have many opportunities to set them to something else. In the rear of the Miata, the correct length is probably "as short as you can make it go".

Procedure:

  • put the car on jackstands and pull the springs. Disconnect sway bar. Install a wheels.
  • use a jack under the control arm and fully compress the suspension. Make sure nothing is making contact - wheel on body, control arm on subframe, etc. Adjust shock body length to get maximum compression before contact. In the rear, this will probably be "as short as it will go". In the front, it will likely be longer than that.
  • reinstall spring and put the car back on the ground. Adjust spring perch location to reach desired ride height.
  • check to make sure you have droop travel, that the wheels can still drop down when you lift it from your static ride height. You want roughly 1/2 as much droop as you have compression travel. Since the shocks are short on travel, you may have to sacrifice some compression travel to get that droop travel.

The big thing to remember when adjusting shock body length is that you are not adjusting total travel, despite what some marketing says. You're adjusting the travel RANGE, how much of it is compression and how much of it is droop. Offroaders like a lot of droop but for performance Miatas, we usually want as much compression as we can get.

Dusterbd13
Dusterbd13 MegaDork
10/22/24 2:00 p.m.

In reply to Keith Tanner :

They were on the parts car i bought from svrex, so no additional challenge budget cost. Just trying to optimize what i have, and im hoping they are way better than my previous high mile hard s bilstein and ebay coilover sleeve kits. 

Thank you so mu h for the dial in procedure. That really made sense to my drain bamaged self. 

jwagner (Forum Supporter)
jwagner (Forum Supporter) HalfDork
10/23/24 6:11 p.m.

In reply to NickD :

I have the big RB bar on my NA too.  Initially had the RB rear bar on and that was way too much, the back end was way too happy.  I unbolted the rear bar at a track event and zip tied the end links up and immediately gained a second/lap.  In the end, I think the small 11mm stock rear sway gives better balance and more neutral sustained cornering.  The car is on Koni yellows and FM springs.  YMMV.

z31maniac
z31maniac MegaDork
10/24/24 4:04 p.m.
rkammerer said:
SV reX said:

Is it worth considering swapping the Ohlins for something else?

Well, there's *cough* the Fox/Flyin' Miata coil overs.  Have a set on my STR NC Miata, great!  Track springs for fun, Sport springs when I was winter driving it on snows...

Goodwin likes the Ohlins stuff.  949 has their Xidas.  That's the usual suspects to me.  Miata.net loves them the MeisterRs, a more value-priced option.

Then there is the pricey stuff, Penske 8300s or MCS (have a set on the C5, like these too).

Challenge pricing, wonder what you could get if you sell the Ohlins, then find used FM/Xida, or one of FM's non-Fox setups?  I'd wager someone on M.net or similar would like the bling of the gold bodies and swap / swap with some cash to you for their current setup.

There is also FCM (Fat Cat Motorsports), I wasn't as much of a fan of those when I drove my friends car up in Iowa at Raceway Park at the Midlands. But that could have been down to the used up R1Rs the car was on at the time vs the shocks not being good. 

I really liked the FM VMaxx on my NA, and really liked the 949 Racing BGK (Big Grip Kit). I ran that one 800/500 with their recommended sway bars on R888s (this was like 12 years ago), -3.5 camber in the front around 2.8 in the rear. 0 toe up front, tiny bit of toe in, in the rear. 

But I like a slightly understeery car because of how I drive. Which I think stems from my first track experience being on a sport bike, I very much like to be back on the power a bit before apex and let the car be a little loose. Probably not the fastest way around the track, but it was fun and I wasn't trying to win anything at track days. 

Slippery
Slippery GRM+ Memberand UltimaDork
10/24/24 4:39 p.m.
z31maniac said:
 

...

I really liked the FM VMaxx on my NA, and really liked the 949 Racing BGK (Big Grip Kit). I ran that one 800/500 with their recommended sway bars on R888s (this was like 12 years ago), ...

Those are still alive and kicking on my NA ;) ... along with your brakes.

AMiataCalledSteve
AMiataCalledSteve HalfDork
10/24/24 5:23 p.m.
DeadSkunk (Warren) said:

 Look for Miata for sale listings of autocross CSP cars for an idea on setup.

Duster, if you're looking for CSP car info my NA is CSP prepped pretty tightly to the class rules and was pretty quick in the local autoX club. I can look at my suspension setup if you're curious.

z31maniac
z31maniac MegaDork
10/24/24 6:41 p.m.
Slippery said:
z31maniac said:
 

...

I really liked the FM VMaxx on my NA, and really liked the 949 Racing BGK (Big Grip Kit). I ran that one 800/500 with their recommended sway bars on R888s (this was like 12 years ago), ...

Those are still alive and kicking on my NA ;) ... along with your brakes.

That is fantastic! Car is looking great! Hope the parts are still treating you well. 

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