JCH13 - Turbo Miata Rehab Thread

[manimal]

When your done all of AT should petition TOP gear to let the stig drive your car on the test track!!!

Now that would be something!

Looks sick man. Nobody will ever mistake your car for somebody elses. I wish it was in my showroom.

 

[jlee]

When your done all of AT should petition TOP gear to let the stig drive your car on the test track!!!

Now that would be something!

Looks sick man. Nobody will ever mistake your car for somebody elses. I wish it was in my showroom.

That'd be epic!

 

[JCH13]

When your done all of AT should petition TOP gear to let the stig drive your car on the test track!!!

Now that would be something!

Looks sick man. Nobody will ever mistake your car for somebody elses. I wish it was in my showroom.

Hehe, I would not be opposed to a petition... perhaps more likely is that youtube guy that goes around and test-drives peoples cars and does videos on them... can't recall his name/show off-hand... he did a nice video on an insane V8 RX7.

Also, thanks! I was going for the 'not mistaking it for anyone else' effect, among other things If you ever do that dyno day I might make the journey out... :awe:

 

[PseudoSport]

How about a petition to paint the whole thing red again…

 

[JCH13]

Having some Moog rod ends delivered next-day, hopefully they are less stupid than the Mevotech ones and I can get a sane alignment.

How about a petition to paint the whole thing red again…

This 'merica! Free speech for all! :biggrin:

 

[JCH13]

Gravity bled the brakes... one hose and one bottle on each bleeder screw. Cracked them all open, pumped the brakes twice (very gently) to 'prime' the hoses to siphon, waited ~1hr topping off fluid regularly, closed them up, and *poof* brakes are bled with good pedal feel. Too easy... I'm waiting for the other shoe to drop.

Also took off the front tow loops that were only being held on with 3 bolts between the two of them. My nitrocat impact gun worked like a champ, very impressed with it. Spent 2 hours just cleaning everything up and putting tools away... I got really lazy with clean-up the last few times I've wrenched.

Waiting on correctly sized rod-ends to arrive tomorrow...

 

[JCH13]

Went home for lunch. Saw the Moog steering rod ends had arrived. Saw the perfectly sunny 70F day.


So I installed the rod ends and drove my Miata back to work... :awe:

 

[jlee]

Went home for lunch. Saw the Moog steering rod ends had arrived. Saw the perfectly sunny 70F day.


So I installed the rod ends and drove my Miata back to work... :awe:

Hahah, ftw.

 

[Black2na]

Then he realized his brakes were still squishy and figured out he installed rear calipers on the wrong sides and the bleeders are on the bottom not the top so air bound!

 

[JCH13]

Then he realized his brakes were still squishy and figured out he installed rear calipers on the wrong sides and the bleeders are on the bottom not the top so air bound!

Sadly, trufax.

Got them swapped and bled, work a bit better now.

Might have a small leak in the thermostat housing...

 

[jlee]

Sadly, trufax.

Got them swapped and bled, work a bit better now.

Might have a small leak in the thermostat housing...

Didn't we replace that gasket on the old motor? At least it's easy to get to...

 

[JCH13]

Basking in the sun:

Confirmed that the thermostat housing is leaking. Lame, but cheap and easy (some comment about your mother goes here) to fix.

Secured the e-brake cables.

Found that there was a nut missing from one of 4 main front subframe studs. I cleaned up the threads and put a new nut on. Should help the front-end stiffness a bit.

Down to the smaller fixes now...

 

[JCH13]

Ordered a pair of wheel hubs from FM with their digital angle gauge and a set of 14mm 5-lug hub plates that I believe I can easily adapt to do 12mm 5-lug hubs as well.

The AMSoil transmission oil is starting to make a difference in shifting, most noticeably at lower temperatures where it's better than RedLine MTL. I think it's still making improvements though, will update again later. I am doing a longer drive this weekend, so everything should be up to temp for a long time, and I might learn more.

 

[JCH13]

FM hub stands are on back order already. Lame.

Still a little, tiny, itty-bitty bit of coolant leaking around the thermostat housing.... going to re-re-do the thermostat gasket and pay very close attention to getting an absurdly clean and smooth gasket surface.

In good news I found some rear sway bar brackets in my pile of Miata parts. Soaked them in evaporust over night, hit them with a wire wheel, and painted them red.

I think I will install the RSB tomorrow methinks. I am not really liking the lack of front-end grip and the extra roll. I'm going to try 'stiff' on the FSB, and 'full soft' on the RSB. I still want a little more understeer than anything else right now as my fiancee is DDing it for the time being.

 

[JCH13]

Installed the RSB, feels a bit more balanced and less rolly. Fiance didn't complain about the ride either. Hooray!

Next on the agenda, in no particular order:

-fix as many rattles as possible (may be impossible considering how beat up the doorcards have become)
-recalibrate the LC1 wideband O2 sensor
-install an additional potentiometer in my KnockSense knock detector and use it to adjust out engine noise to stop false-knock events

Then it's off to futzing with the tune a little more. Now that I have real knock sensor I can safely adjust timing a bit more to get a few more horse-ponies out. A user on miataturbo.net saw 20+whp out of good ignition tuning... :awe:

 

[Zargon]

so jealous of the work you are doing

while my bike project sits

freakin wife baby and house

 

[JCH13]

so jealous of the work you are doing

while my bike project sits

freakin wife baby and house

Heh, know that feel. At least with the lady and house. I find it helps to pick one small thing to do every other night or so, and just slowly chew away at it until you have a bigger chunk of free time.

Tonight's activities:

Replaced the thermostat gasket, again, after block-sanding both sides of the thermostat housing. Might be a little leak, somewhere else, urg. Glad I ordered 4 new thermostat gaskets.

Did a free-air calibration on the wide band oxygen sensor.

Re-set base timing... it had apparently slipped 6 degrees advanced... not sure if I totally spaced on setting it in the first place (unlikely) or my friend's skeevy timing gun borked out (considerably more likely). Anyway, runs way moar smooth and strong.

Added a 100kOhm 'threshold' potentiometer to the knocksense unit, readjusted everything to be happy, worked perfectly this time!

Did some VE Analyze Live auto-tuning with my friend driving, added a big of fuel almost everywhere, felt like it was making small improvements in smoothness and maybe a little in power. Several wastegate-pressure boost runs were quite strong with nary a hint of knock anywhere!

I found myself grabbing the o-shit handle more than once, but everything felt solid: engine, suspension, brakes.

:wub:

 

[JCH13]

I took the Miata in to work today, taking the really long and un-traveled way to get a little more tuning in after tweaking my spark map to closely match the Flyin' Miata Link ECU map. I made small and reasonable changes, largely smoothing things over.

So I setup VE Analyze Live for another 'spirited' tuning drive :awe:

VE Analyze Live tuning screen:

It's a program that automatically tunes the fuel table based on a target AFR table. On the left I've got gauges for main engine information, RPM, MAP (manifold absolute pressure), and AFR, for reference. In the middle is my fueling map, axes are MAP and RPM and the cell value is essentially a % of an 'ideal fuel' value that's entered elsewhere in the program. As I drive around VE-AL looks at RPM, MAP, AFR, and a few other variables (the company doesn't actually say what they are, no doubt part of their secret sauce) including an AFR delay table (takes time for exhaust gases to reach the WB sensor) and makes incremental adjustments to the fuel table to try and reach the AFR targets.

It works pretty well I think.

The mini-tables on the right-hand side show you where in the map you've been driving and what is being changed. The yellow/green map shows a 'weighted average' of where in the map you've been operating, white = not at all, light yellow transitioning to dark green = a little to a lot. The red/blue/white map shows how much cells have been changed, white - not at all, light red to dark red = a little to the most fuel removed, light blue to dark blue = a little to the most fuel added. The red/blue/white plot only shows small tweaks, which means I'm homing in on a tune that will be very faithful to my AFR table.

The bottom of the screen is a 'history plot' of RPM, MAP, EGOcorrection, and AFR. EGOcorrection, exhaust gas oxygen correction, is a feature that allows the MS to make small fueling adjustments on the fly to better match the target AFR table, it is disabled during tuning so VE-AL and the EGOcorrection algorithms don't chase each others' tails.

To round out my early morning drive I may or may not have bumped the rev limiter and may or may not have blown off an IC pipe :sneaky: ... it was a good morning :awe: :wub:

 

[JCH13]

For any who may be interested, this is the FM Link spark map converted to 12x12 MegaSquirt format, very close to the spark map I'm running now.

I'm comparing it to most other turbo Miata owners' maps and they all have considerably more aggressive timing in the 'cruise' region, i.e. 2,000-3,5000rpm, 26-55(ish)kPa MAP. Most are up around 35-39deg, which would help with fuel economy, especially if I lean out fuel there a little bit.

 

[JCH13]

After a week or so of driving I noticed that the brake fluid level had dropped a tiny bit. To find the leak, I jacked the car up, took the wheels off, put clean cardboard under each corner, started the car, and pumped/held the brakes for a few minutes. A few drops of brake fluid on the cardboard quickly identified the soft-to-hard line connection on the passenger front to be the culprit.

I figured it could be one of three issues:
-fitting isn't tight
-piece of crap in the flare seal
-broken tube/flare/fitting

I tried tightening down the fitting to stop it, but couldn't.

I then loosened the fitting 1-2 turns and pumped the brakes to blow brake fluid through the flare and threads to clean out any crap that may be preventing a good seal. I re-tightened the fitting and bled that brake line and, magic, no more leak!

On a different front:

So, after blowing some IC piping apart I started looking into options for putting a bead on all of the pipes. JLee (I think, maybe Black2NA) had sent me an link on how to make a tube crimper out of some vise grips, a washer, and an exhaust clamp several months ago. So, I went ahead and made one.

What I started with after grinding down the vise grips a bit.

Cheep HF 90deg clamp FTW!

I braze-welded everything together to avoid burning off the zinc plating on stuff and inhaling those toxic fumes.

Instead of what most of the articles suggested, welding the washer directly to the vise grips, I brazed two nuts onto the vise grips, so I could potentially used different size washer for different tubes, or make adjustments if I had to.

To use the crimper I put the vise grips in a bench vise so I could focus on manipulating the tube with one hand and operating the crimper with my other hand. I could do a bead in <1min after a practice run or two. I always kept the outside edge of the tube even with the exhaust clamp, this ensured the bead lined up with itself when it was finished.

The particular exhaust clamp I used didn't allow me to make very tall beads, but it still worked pretty well. The beads are nice and smooth and very uniform if you take small steps around the tube.

I uninstalled, crimped, and then reinstalled the 3 cold-side pipes in 20 minutes or so, very useful tool to make. Hopefully no more blown apart IC piping.

 

[manimal]

bad ass man!

 

[FuzzyDunlop]

no way. That is brilliant.

 

[phucheneh]

So amateur. Let me know when you're a master fabricator like me.

:awe:

Obviously you put a little more effort into yours...i'd weld the washers, though. I thought about doing the same thing, making a little axle for mine to spin on, but I figured it would just end up wallowing out the center. Then the washer wiggles and makes shakier beads.

One thing that I CAN say is that mine does both 3" and 2.5" pipe. I used a 2.5" saddle and ground down the one side so that anything vaguely round will fit in there well enough to crimp a bead.

Yep, you crimp, not roll. Unless JCH's shit is fancy enough that he can actually spin it, but you really can't get leverage. I don't think you're gonna actually roll a pipe without the real (hundreds of dollars) tool. But this works pretty damn excellent, and is a lot less caveman that just flaring the end of the pipe [by bashing it with a hammer].

 

[JCH13]

Thanks guys. If someone wants one, I'm sure we could come to an arrangement

The washers shouldn't 'wallow' or get shaky. They're only being loaded from one direction, so as long as the bolt is snug enough to keep the washer(s) from tilting, it'll be fine. Weld brazing the nuts on also offered a stiffer, stronger, support for the washers.

Mine can't spin, to do that effectively one needs to be able to drive the rollers, and every contacting surface needs to be a roller. Some people have tried non-driven rollers (where they grab the tube and spin it) but I've never seen pictures of good results.

 

[PseudoSport]

VE Analyze Live is awesome. Within 20 minutes of driving we had a decent base tune for our Turbo Jeep. Even after a few hours we still had to hand smooth a few spots of the map due to a 10 hp dip on the dyno since it was too rich. Still its way better then doing it all by hand. I&#8217;m curious to see how KnockSense works out for you and how much timing you can dial in under 3000 RPMS when its spooling. I&#8217;ve always been too conservative down low which made things feel laggy.

How is your idle? Its helpful have to keep the 4 cells around idle the same values for fuel and spark depending on how you map is scaled so otherwise it would fluctuate. VE Analyze Live likes to mess those up unless you fix the settings so it ignores those cells.

Nice to see it on the road again. Do you autocross at Fort Devens in Ayer MA at all?