Tales from the Batcave (RX-7, rallycross, misc. stuff content)

Today's listening - uamee - TOWN CALLED CYKA BLYAT (Instrumental) 

I lavishly spent a whole can of brake cleaner to remove all the gear oil from everything, and since I do not have a fancy 9" adaptor for my engine stand, which is buried anyway, I laid it sideways on a chunk of wood.  Stuck a 27mm socket in my impact and spun it around.  Noticed that it has a clunking tooth on the coast side.  Oh well.  It also feels grindy on the drive side.  I marked the teeth and ran it back and forth a bunch.  This accidentally had the effect of making the pattern very easy to see, in the areas that I did NOT mark.

Coast side is low, drive side is way off the toe end.  That's not really what it looks like in the painted area!

Cool, we have a way forward.  At this point it was twenty after 8 and time to go home.

Today's epidose is brought to you by uamee - PERESTROIKA !  When you absolutely must have hardbass but also want to listen to Katyusha, attend uamee for your needs.

Anyway.  It may have been in the 90s today but the discontent in the Batcave is much wintery.  (see what I did there?) Everything says, to move the drive side towards the heel, move the pinion out.  So I did.  And I did.  And I did.  I eventually added .022" of shim (!) and got the drive side pattern centered.... but the drive and coast are now way off on the top of the tooth.  Even with backlash down to .004".

I didn't just jump to adding all the shim.  I worked my way up slowly, playing with backlash all along the way.

ARRRRRRRRRGH!

I checked eBay for something and noticed a bell thingy.  As it turns out, I won an auction for a set of 4.88 gears that I placed a low bid on and promptly forgot about.  Should see them next week.  Next rallycross is weekend after next week.

ARRRRRRRRRRGH!

No BatCave because my sister's car E36 M3 itself and I spent my time after work fixing it.

TIL that Versa Notes have a very, very strange battery size.  And that a 121R battery will technically fit, which is the best kind of fit when it is 7pm and you need to close the building up and her boyfriend has already left so she can't get a ride home.

Actually the best kind of fit is the Fit she should have bought, but oh well.

R&P shipped today.  Won't see until next week.

ARGH

I do not have the tools to press the middle (rear?, thrust) bearing off of a 9" pinion without destroying it.  So, I went to Summit to peruse scratch-n-dent and buy a bearing.

Daytona-specific bearing is only available as a bearing kit.  A $65 bearing kit.  OUCH.

Picked up a $15 pair of springs, because I am still fixated on rear spring rate when clearly I need to focus on the rear shocks.

If I embedded this right, video should start with the eventual class winner (and former national champion), then a Detroit local in his incorrectly-numbered Mustang, and then Sir Bounce-a-lot.

Car sounds good ( although it may be a bit loud for the street)

In reply to Indy-Guy :

That does annoy me, because I spent something like $900 in the past year or so replacing first the midpipe, and then the rear muffler.  The rear muffler was on backorder for a long time, and they apparently changed suppliers (they used to be made in Italy).  The old mufflers were made of thick steel, and had single inlets and small diameter tips.  New muffler is stainless (boo), is twin inlet (boo), and has much larger diameter tips.

You didn't used to be able to see into the old mufflers like this.  I wonder if the manufacturer made these backwards, putting the expansion chamber on the wrong end.  (The presilencers do have a roughly 8-10" expansion chamber at the front, which kills high frequency rasp) But doing that would require a brace on the other end, and that costs money.

It chaps my ass that the new muffler, while shiny, is as loud as the worn out 20+ year old one, which USED to be quiet.

I am seriously thinking of rebuilding the old muffler.  The inlet pipe would need to be completely remanufactured, of course, but I do have a 1.75-to-2.5 Y pipe on the shelf...

Here we go again...

Just realized that my bearing kit was missing the outer races.  Anyway, part numbers for the $65 bearing:

A thread about people's commute lengths got me wondering what mine was.

Not pictured because I forgot: Home to work, 17.2 miles.

Work to food and back: 1 mile

Work to garage: 25.3mi (the second most direct route)

Garage to home: 12.3mi

So roughly 56 miles a day, when I go to teh 'cave.

At least the stereo's nice.

And what did I do in the almost three hours today?  Lots. 

Berk this.  I entered a LOT of text and hit a wrong button or something and now all is lost.  I originally had this episode brought to you by Sabaton: Counterstrike (because I get the line "six days of fire, one day of rest" stuck in my head when thrashing to get the car together before the next rallycross) but because I am annoyed, I'm going to weeb out here and force upon you some Japanes video game music.  The less life-enabled will recognize this not as a guitar cover of a bullet hell BGM, but as something I listened to one of the times I drove home with a broken rearend

Pics now, text soon.

(Nope.  Still annoyed that I lost my entire post.)

Stuff:

Seal failure caught in the act, prevented.

Meaningless numbers.  There was two whole paragraphs here, let me Ciff's Notes it for you:  "Fark if I know"

Some torque wrench action.  You figure it out.  Offer not applicaple to open diffs or Torsens, which are open diffs that boost your self-esteem (despite them being made of failure and other things that suck)

Metal ripper.

Metal thread reinforcement

Pattern achieved.  There was a whole narrative here about zeroing in on the pinion depth, starting here, moving there, moving a third time, going back halfay, then playing with backlash... but this is all you get.

Berk it.  It's half past midnight, I want to wake up early enough tomorrow to eat breakfast, which will probably be stale bread and gray braunschwieger with a side of not-moldy-yet generic white cheese.  Six days of fire, one day of rest

Day Two.  No pictures.  Spent most of the day putting tools away, then realizing that I didn't put the lock tabs on the adjusters, then tore apart the rest of the area looking for them, wantonly cleaning and putting tools away in the process.  Then had a thought: Wouldn't it be funny if they were in the Richmond bearing kit box that I had been using as a staging area for gear setup?

Yup.

Diff in, right side axle in.  Don't have left side in yet because I need to re-tack a caliper spacer into place.  No fluid because I am out of 1/8 pipe plugs to fill the drain hole I put in the housing.  And I didn't feel like digging out the welder at 8pm, so I stopped there.

I also took some measurements of some things.  I got an Idea, which is usually where I go wrong, but sometimes it works out okay.

If I had a dollar for every time I wrote the preverbal novel and then hit the wrong key...

Your post made me laugh.  Thanks!

Day three.  Jack left side of axle high enough to pour 3 quarts of gear oil in.  (Photo missing, it was horribly out of focus despite the preview looking good)

Get out welder, replace spacer that fell off.  Delete that photo as well because there are catacombs with better lighting.

While welder is out, install two 1" washers.

I previously had success with a 1 7/8" restrictor in the tip of a 2.5" exhaust system.  So, I found the area of a 1.75" hole, divided that in half, un-found the area of that, and came up with 1.25".  So a little die grinder work and we have this:

Finished assembling the car, and given that it was still light out (barely) I took it for a drive.

The rearend is still noisy.  It's not screaming OMG noisy, but given that the pinion gear only has seven teeth, and the rear is booted through metal to the floor under my head, it will probably never be silent.  I need to come to terms with this but I still think it could be better.

Engine is running pig rich all the time according to the wideband.  All the time.  I don't think this is due to the restrictors, that should only have an effect at high RPM.  All the same, if you follow my math, you'll see the mistake that I made that I didn't even notice until writing this post.  It is at least noticably quieter exhaust wise.

For starters 1 7/8 is 1.875 not 1.75

In reply to Patrick :

Yup.  The correct figure is 1.325.  I'll open them up more than that and re-evaluate what the wideband claims the engine is running at.

Day four.  Tuning day.

Reset my injector deadtime from 1.2ms to .950 (a figure that is still wrong, but at least consistent with other large Bosch injectors), reset my IAT curve back to the correct ideal gas law curve, re-enabled the rev limiter to 9500rpm, made a couple minor detail changes, and went tuning.

The details of the tuning episode are boring, but I did note that with the correct(ish) deadtime, the VE table looks a lot more consistent with what I'd expect from this kind of engine.  Also spent a good deal of time nailing down the low RPM/high KPa region to make the engine less easy to stall. Seems good so far.

The car had some wicked rear end steering, so I backed it back into its bay, yanked the wheels, and verified that the UMI joint in the left link had loosened again.  I readjusted it this time with a hefty dose of preload.  We'll see how it drives tomorrow... err, today.  

I'm looking, but I don't see you here!  Yallright?

In reply to wae :

No.

Day five.  At work, mounted a pair of ancient 195/65-15 tires I have packratted away on some extra wheels.  4.86 gears are a bit much with 195/55s, but they should theoretically be faster than 3.86 gears.

Ahem.

Had a rush job at the end of the day, had to thrash in order to cash a check that a [redacted] service writer wrote with a promise because he's a [rant deleted]

Aaaanyway.  This was on the road after leaving work.

(yeah, teh R needs a cat.  RX-7 needs attention first)

It was hot as fark at work, in other words.

The Plan was to go home, shower, go to Batcave, finish assembling rear suspension, mount new wheels, hookup trailer, and haul ass to Evan's Volvo Farm. 

What happened was I showered, realized that I left dinner (gyros) in the fridge at work in my haste to leave, fell asleep, woke up at midnight, couldn't sleep, fell asleep, woke up at 8am exactly four hours after I would have needed to go put the car together to make it to Bitzer's by 8am, got pissed off, went to garage, put car together, grabbed helmet, and left in teh R to try to at least make it to the afternoon session to ride along with people.

I think I had more fun than driving the RX-7.  That says something, not sure what.

so what you are saying is that you need a back up stock miata for SR.

In reply to MrChaos :

Hell no.  If I was to have an SR car it would probably be an S2000.  Miatas are too cramped unless all the interior is removed.  Besides, I already do have a backup car, if only I could find a fuel tank for an '81 RX-7 or at least a shop that can boil this one out.

..

Thinking about the rearend thing some more.  The carrier bearings' races have a lot of crush in the caps.  I had been just 'snugging' the caps when making adjustments, and only doing a final torque once I had the adjustments made.   I am wondering if the ring gear was getting closer to the pinion as a result.

Easy enough to test - I can drain the fluid, pop the pinion support out, and make the shim .001-.002" thicker, and see how quiet it is or isn't.  If it's quiet, the mesh is good.

The exhaust still has me pissed off.  Makes me think long and hard about 2 liter Ecoboosts.

Knurled. said:

In reply to MrChaos :

Hell no.

I’m not sensing any hesitation in that answer  

In reply to paranoid_android :

I'm "helping" Evan un-break his Miata, which coincidentally has rearend troubles as well.  And it doesn't look like it was power's fault this time.

Went to teh R to get a hot Gatorade and it was like a blast furnace inside.  Got the key to roll the windows down, and HAL said 111F.  We were staring at the bushing conundrum and I stood up and started to pass out, so I opted to go inside for a bit since getting heatstroke once in my life is enough.

Now we're cooling off on the front porch, "researching".  Yeah, that's it.  It's totally not just procrastinating because working on the car has you literally forming pools of your own sweat on the ground.

Many parts ordered for the Volvo.  It's maintenance time.  Going to have a very busy Saturday.

Aaand I just realized that I forgot to order a replacement right side seal for the angle gear.

Timing components, and gear seal, and Class II receiver have arrived.

One more box to come.