SAAB was doing it without a sensor back in 2004ish.

Interesting.

That's because SAAB was friggin' BAUCE. :cry:

:giggle:

*depending on state and station

the station 2 miles from my house is e85, which is actually 85% most the time, at worst 80%, year round. It's some Valero.

Sadly, the shell/propel stations around here are all 70% for some reason.

That was in my head when I wrote it, but didn't make it to the fingers.

Yes, states, as those of us with CA experience know, have their own standards for fuel blending which sometimes deviate from industry and Fed specs.

https://www.miataturbo.net/attachmen...ine=1466115483

https://www.miataturbo.net/attachmen...ine=1466115483
https://www.miataturbo.net/attachmen...ine=1466115483

My evil plan . . .

1. 2018-19 Sport (give them a couple of years to fix the gearbox and whatever other issues come up);
2. Swap in LSD from a wrecked 2016 Club;
3. Add the ND XIDAs, 6ULs and recommended sways that will be out by then;
4. Add ND roll bar;
5. Add long-tube headers, exhaust and tune to add 40ft-lbs across entire rev range;
6. Profit!! :likecat: :party: :likecat: :party:

Modernized 95R project!

I'm starting to wonder if I should do the Sport the same way. Will have to play with lease figures again....

I am considering a Sport, as well. The stock LSD isn't very expensive, but it also isn't very good, so waiting for an OSGiken is probably a good thing. The stock one, however, could be installed at first, as a stop-gap measure, and then you would have an entire open OEM assembly to put a OSG in when it releases.

I think I would miss the stock better stereo in the Club or GT and the eventual display gauges that will come out for the dash screen, though.

Honestly this is about my plan for when I get a ND in a few years. Then after all that fun, I start on the ND MKTurbo setup.

Attachment 183718

Whoa!

"triples" Now what does the rebound adjuster look like?

Is it possible to have the rebound high speed blowoff slope much flatter?

Rebound side is same as the singles. See the single plot above to view the double digressive piston-ness.

Any reason we can't have separate high/low valving on rebound?

I dunno, it just seems kind of lazy. I'm sure they work ok, but I just don't know if they have enough knobs on them to really qualify as the sickest coilovers on the market. They need to be, like, 20% more dope.













(ducking)











j/k, man. Those plots look amazing.

I just inhaled coffee. D*** you!

Yup, that would be a 4 way adjustable shock.

Maybe the racetech suspension book I read is out of date or old school or something, but why would you want or need high and low speed rebound adjustment? With any given spring rate, doesn't the suspension always unload at the same rate? I understand why high and low compression, but rebound? I don't get it.

The wheel is both pulled down by gravity and pushed down by the spring, and the force that the spring applies depends on how far it's been compressed, right?

--Ian

Yes. F=k*d

Cars have mass, and things with mass have inertia.

For an uneven road surface, the rate of acceleration of the suspension in rebound increases as the rate at which the road is falling away from the vehicle increases.

But more specifically, it was just the setup for a joke.

High shaft speeds are road induced, low shaft speeds are driver induced. That is a generalization but the basic reason that being able to separate controls for low and high shaft speeds is desireable.

On the shock dyno, is the "OEM" line the standard damper or the suspension package Bilstein?

But any shaft speed on rebound is set by the spring right? I can see how deeper in the stroke the wheel will want to return faster. I totally get that how sharp or tall a bump is will cause compression speeds to change, but it can only return as fast as the spring pushes it back down. You only get a certain amount pushing down once you crest the bump.

Dont mean to derail too much here. This is obviously a very focused thread. Just more research on my end needed I suppose. Growing up riding dirt bikes I'm quite used to 3 ways. Now you got me thinking about 4 ways

I'm a software guy, not an ME, but here's my understanding. Think about what happens over the bump. The wheel moves up, some of that motion translates into compressing the spring, some into moving the body upwards. Since the body weighs a lot more than the wheel, most goes into the spring.

Now the wheel crests the bump, and the wheel is no longer moving up. The energy in the spring pushes the body and wheel away from each other, with the wheel moving a lot faster because it's lighter.

So yes, the wheel will only go down at fast as the spring and gravity will pull it, but that's plenty fast enough to make a difference in driver vs road induced rebound because it is light compared to the body.

--Ian

OEM Showa, not Bilstein.

Study what Emilio said. Make sense out of it. Then you will understand.

Mazda put a belly pan and an 8mm Allen key for the oil drain plug.

They've ruined the Miata forever.

high speed rebound adjustments are pretty much useless in my opinion. Maybe an F1 team can find gains using them, but for the average consumer it just adds confusion, cost and another hole for the damper fluid to leak out of.

I played with some of these (4 way adjustable mountain bike shocks) for days and couldn't really tell wtf the high-speed rebound was doing. Smart to leave it off the shock IMO.

https://www.miataturbo.net/attachmen...ine=1466521881

Yup. Very rare situation when you need more high speed rebound in a sports car. At higher shaft speeds, the bulk of the energy acting on the damper is just the stored spring energy and unsprung mass.As those remain effectively constant (inertial effects notwithstanding) the damper can be valved
to deal with them without requiring further adjustments. Driver input and road surface are out of the picture. In off road suspensions, high speed rebound can be tuned to change how the vehicle performs near full droop. I see that high speed rebound adjustment employed in rally cars and off road trucks/buggies.

NA/NB and also ND Xidas for example, have digressive pistons that bleed off most of the high speed rebound. This allows an adjustable low speed segment where driver input, roll moment (grip) and vehicle weight are highly variable and
often require tuning. The high speed portion is tuned by yours truly with a range of wheel assemblies. On a vehicle with much heavier wheels/tires, less or no digression is needed. On the NA/NB at least (low unspuing mass), the only way to get the suspension to work without digression is to have too little low speed rebound so that the entire rebound side is weak. This has the added benefit of being able to pressure balance more easily and also reduces hysteresis. Problem is handling ultimately suffers with race tires when there is inadequate low speed rebound so we don't do it. Typically, we'll focus on a typical track setup but also test a super light and also heavier wheel setup just to make sure we don't uncover any anomalous behavior. The Tecna's for example, have been carefully dialed to work with OEM weight wheels/tires but still cope with the now standard 225/45/15 EHP on 15x9 6UL. At the relatively low price point they're targeted for, that has proven a challenge. Many prototype valving sets rejected.

So yeah, decisions made for function reasons, not cost or bling factor.

So what you are saying is Tecna's are still being worked on slowly and might one day become a reality for the consumer?

I sure hope so. Please don't let them go the way of the rev9 or whatever it was you were going to name those wheels.

:yippee: take my money meow? :likecat:

That has always been the case, never stated otherwise. We just don't publish ETA, price, spec or anything else. We'll announce them when they are in stock and ready to ship. I only mentioned here to illustrate how that particular area of the damping curve receives specific attention in relation to it's intended usage.

After this statement I am surely going to wait and give my moneys to you when the time comes.

Just give me 2 weeks advance notice on the Tecna's so I can sell my budget Bilsteins.

No problem. Consider this thread your 2 year notice :giggle:

I'll be sure to backorder your set.

:laugh: well played

Anyone have reliable lap times that ND's are running? Actually being driven to the limit on 200tw tires? I'm curious how they stack up, and haven't seen any at our tracks around here yet. If so, mods list would be helpful.

Has the ECU intrusion/limitations during constant track use been permanently dealt with? I've been following this thread pretty close for the last year and don't recall updates on these items.

The car is still new enough that there are very few that are both well prepared, tuned properly and driven by an advanced level pilot. That said and given the same level of mods, the ND is quicker than any other year Miata, the FRS and close to an S2000.

Thanks. Close to S2000 times sounds right. New cup cars looking to be running towards the pointy end of TTD times, maybe into C times. I'd expect a tuned h/e car on some Xidas and R7s to be even faster. I like the idea of having a car that's faster than my VVT swapped NA, with all the modern comfort of a new car.

Our shop car is already quite a bit faster than than the GCC and that was with just 150whp and 235 RC1's before we had the suspenion or brakes fully dialed. This from two drivers involved in the GCC program after having driven our car. With 180whp and 245 RE71R's, suspension and brakes dialed, it's quite a bit faster. So 100% stock engine other than header, exhaust and reflash on pump gas, coilovers, sway bars, wheels/tires and a small Wilwood front kit. With that, about 4s under SM Hoosier lap records on a 2:00 course.

Yesterday I had the opportunity to go for a ride with Brian in the GWR shop car. Holy smokes, was I impressed.

The tuning did not give the car the top end pull I would really like, but that's not surprising given the dyno results (and sharp power drop above 6500 rpm). But the torque was truly impressive.

That being said, the drive did far more to sell me on the Ohlins than it did on the tune/exhaust. Yes the 40+ whp was noticeable and impressive, but the way that car cornered even with bumps as absolutely astonishing. It was also still comfortable.

Shopping list has begun, and I think it's mostly from the GWR catalog this time round... though may still end up with 6ULs.

Thanks a million Brian.

Also got to check out the LFX swap project and chat with Ryan, but that's a post for another thread :) very cool project though. Solid group!

I still want to see the 40whp header/tune verified by a 3rd party.

And STILL, STILL I can't get a damn answer about headroom in the stock fuel system for E85 with that header.

If the header/tune is really doing that AND there is still headroom for E85.........I will seriously consider taking the hit on the BRZ and picking up an ND. Then XIDAs and 6ULs would be on order before I left the parking lot.

So question: most of the talk here about suspension is people saying they'll buy Xidas. Why would you guys be picking the Xidas over the Ohlins for the ND?

I trust Emilio for suspension design more then I trust Ohlins when it comes to the miata. I am doubtful anyone has spend as much R&D specifically on the miata as he has, and then has national wins using the suspension parts.

This.

Plus I already owned a set of XIDAs for my track rat NA, that occasionally saw the street on Rcomps. They were awesome.

Also, the Ohlins solutions have been significantly more expensive than Xidas, different price point shocks. The ND Ohlins offering looks to be closer in price, though.

^thats what I've been thinking. On my NB I went with the Xidas because it's a proven solution at $1k ish less than MCS. But Ohlins are fantastic quality, and they're only $20 more when comparably equipped (no helper springs). Adding helpers to the Xidas and then subtracting club orange makes it only $120 more than the Ohlins without helpers.

Decisions, decisions. I love my Xidas but was suuuuper impressed with the Ohlins on the GWR shop car.

looks like Ohlins come with spherical front mounts and use stock rears. Xidas doesn't specify but talks about the different spring perch... more research to be done.

The ND Xida are specific length and stroke, slightly different than OEM. During development we discovered some potential tire/wheel interference issues both front and rear with our biggest combination during that we were able to compenste for. This is done with OEM ND mounts.

We have Billet coaxial mounts for the ND Xidas in the works. They should be ready in a week or two.

I should have saved my money for an ND.... already can pick them up for mid 20s. :(

Ouch!!!

One of them appear lighter :)

I wonder if they results would have been different on the driver side of the MX-5. I was talking to a friend who works at a Nissan plant in the "body shop" where shells are actually built and he said that all their cars have more material on the driver side than the passenger side to pass insurance tests.

I dunno'. At least on older Miatas, driver vs. passenger side impact protection seems really similar -- and Mazda's home market is RHD. It's interesting watching the side airbags work though. I'm actually amazed at how both cars protect the occupants, those are hard hits.

It is on the driver's side. The NDs in the tests are RHD.

--Ian

dat ceramic color on the Miata doe :party:

Doh! I see that now.