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

Knurled. said:

This happened.

 

 

Then, last night, this happened.

 

 

Lookit the size of that trunk, you can fit four bodies in there!

 

That is an RX-8 trans, a series 1 RX-7 trans, a series 4 RX-7 trans, and an FB 12A trans (series 2 and 3 not really externally different).

 

i think the S1 was the "RX-3" unit - it bolts in to RX-3s, and was a not uncommon swap for a 4 speed unit.

I still have another RX7 trans that's yours if I end up not needing it.  Actually have two but will probably need at least one. 

This place is full of knowledgeable people, I am hoping you might know the answer.

I was reading the "Easy Replacement Miata" article and it talks about putting the Mazda L5-VE 2.5 litre engine in a Miata NC. Do you know if the bolt pattern would match an RX-8 transmission?

Yes I am considering a 4 banger for my RX-8, not seriously yet, but thinking about it.

Completely different species. of bellhousing pattern.

In fact, although the NC 6 speed and RX-8 6 speed are "the same unit", in reality the RX-8 has a larger input and output shaft as well as larger bearings, so it's more like they are the same general design but nothing actually interchanges.  So you can't even do a front housing swap like you could with smoothcase 5 speeds to put Miata gears in an RX-7 case.

In reply to Knurled. :

Bummer. Back to plan A, rebuild the spinning Doritos.

Good news, everyone!  I've created a device that makes you read this in Professor Farnsworth's voice.

Err,  I mean the two day rallycross that I didn't prepare for because it is berk-that degrees outside, has been cancelled on account of precipitation and it being berk-that degrees outside.

It snowed.  First drive in the AWD car on Blizzaks.

No tirespin possible in a straight line even from a stop.  Very good lateral grip although I don't feel much like testing that.  ABS still kicks in when braking but the brakes are very touchy when they are cold and dry, it is almost impossible to not engage ABS because of that.

"Do I want to continue with the 10v in the Quantum or go with a 20v?  Or do a 07K swap to make all the stupid power and RPM?  Or take a loss, sell the QSW, and be rid of all temptation?

(watches Audi rally videos on youTube)

...

(clicks Buy It Now on an ultrarare two-piece 10V exhaust manifold from an eBay seller in Latvia)

what about put the 10v in one of the RX-7's and a 20v in the quantum?

The last thing the RX-7 needs is an engine with turbo lag measurable on an astrological chart, that runs out of breath at 5500, for all sorts of reasons.  (And I do mean "lag" in the correct sense - the engine should be able to outaccelerate the turbo, at least in the lower gears)

Back to today, I decided to test out the ultra lightweight brake rotor option for the Volvo.

It did not work out all that well.

Either the picture is fuzzy or that is the ultra rare transparent, lightweight, brake rotor.

Today I learned that if I forget to turn the DSTC to "reduced", a full throttle kickdown to 4th gear at 60mph will cause the low traction warning light to flash angrily at me.  On dry yet salty asphalt.  I am going to blame how floppy the deeply-siped tread blocks are on the Blizzaks, because when I do this they scream like an air raid siren.

In reply to Knurled. :

What'd you get from my motherland?

In reply to artur1808 :

You're Latvian?  Neat.

The part, however, is German.  And it was wrapped in an innovative cocoon of shrink wrap and alternating layers of garbage bags and cardboard.  I guess I was expecting a crate or something.

Clearly Latvian packaging science is quite advanced, as despite it looking like people were playing football with the package (either type) it came here unscathed.

What this is, is a super rare two piece exhaust manifold for the Audi ten-valve turbo engine.  It is rare because Audi never installed it on the assembly line, it was only available as a service part extremely late in the 10vts' production run.  And they were flippin' expensive.  In short, you will only find them on cars where the owner took it to the dealer for an exhaust manifold replacement.

The flexible nature of the manifold means that they don't crack apart at cylinder 4 like all the other 10vt manifolds do.  They also have greatly enlarged passages!  Looking at this thing, the ports are much larger and better shaped than even the one I currently have on the car, which had about six hours of porting in it.  As well as about eight inches of crack repair.

All the studs are intact and not bent!  That is a miracle even for something that wasn't shipped in a bag halfway around the world.

All is not 100% perfect of course.  It is a thirty year old used part after all.  The Y is cracking.

And the crack is extending out of the manifold.

I had been planning on porting the manifold exit anyway.  Going to examine my options.  Given that antilag with external combustion has always been a bullet point for this project, I would prefer a weld repair rather than brazing.

Maintenance day.  Discovered a neat trick for removing and installing FU bolts, but it will only work on internal hex/Torx/etc fasteners.

Decided to change my AOC filter in the Volvo, since VW guys with gen 3 Haldex service it every 20k, and the car has 223k, I have had the car for close to 40k, and there is no record of it ever having been done in the stack of records that came with the car.

Can you see the cover up in there?

5/32 Allen wrench for scale.

There's enough room to fit a 1/4" hex drive bit in there, but not enough to back the screw out more than a couple turns, so once it is loose you kind of get in there with a fingertip and wiggle it out.  But then there's the top one, that you can't even touch unless you remove three fingers and half your hand first.  Because I will need those fingers later, I did not pursue this option.  Instead, I cracked it loose (using a prybar on the 1/4" hex ratchet against the pinion flange, to make SURE it didn't round out)

Yes, the visibility is poor.  The ratchet only works for a couple turns until it hits the pinion flange, and you can't touch it with your fingers.  Enter a really cool idea, illustrated on the bench.

Use two of the sharpest files you can to act as remote fingers.

IT WORKED AWESOME.  It will never work on external hex bolts or nuts, but that's okay since I don't like those anyway.

Remote fingers, brilliant!  You could probably make that work on an external hex if you could get a socket on it.  

FedEx delivered a small box from New Hampshire.

Less than thrilled with the 60-2 wheel I welded to the harmonic damper, and the craptacular bracket that came with it, and the fact that I had to cut away a lot of the lower timing cover for clearance, and needing to buy a very expensive crank sensor to make it work...  $320 off to Marc Swanson at EFI Express, and I got this crank trigger rear main seal in the mail.

Wanting to do this, but not wanting to spend the money, is most of why I haven't made much progress.  Didn't want to put the trans on in case I bought the seal, but didn't want to spend the money, but still MAYBE so let's leave the trans off for now, and so on for close to five years.

I have enough 10-valve spoor kicking about that sourcing another cover and damper should be a non issue.

I wish my camera was better.  These wheels had rust on them since 2010 or so.  Thoroughly scungy.  Thought they'd need to be repainted.

Nope.  Plastic scrubbies and the purple bottle Meguiar's wheel cleaner are taking care of it no problem.  Did the worst ones first.

Backsides need more work, but still.  Amazed.

2019 season in review!

April: Cancelled.

May: WOR at Ross County Fairgrounds.  Muffler fell off on the way to the site.  Ended up placing second by 2 tenths after a big mistake on one run.

June: GLDiv National Tour at Ross County Fairgrounds.  Drove like an idiot because I installed a steering quickener for this event and was trusting the steering to do what I should have known I needed weight transfer and throttle control to do.  Placed lolbad in class after one day, second day was cancelled.

July: missed event due to dipwad I work with, still kinda pissed off about it.  Showed up for afternoon session as a spectator, rode with a few people, fell in lust with an STi.

August: OVR at Bitzer's Farm.  1st in class, was almost 1st overall but for a run where I spun a bit and took out some cones while trying to avoid a corner worker.

September: Detroit at Thistle Hill.  1st in class at a mudfest on entirely the wrong tires, but so was everyone else so it didn't matter much.  Lots of fun.

October: NEOhio at Geauga County Fairgrounds.  1st in class by almost a run, but the event was literally over half noobs and casuals, so it was more of a get together and have fun and see how the site holds up thing than anything else.

There were two more October events in Ohio but they both got cancelled.

November: Car decided that the drive to the event was a fine time to plug the fuel filter.  After replacing the fuel filter the next day, it still feels off so I think the fuel pump has been hurt from processing whatever it was that plugged the filter.

End result:  2nd place in regional championship.  Some other guy got 1st, probably someone in a Miata, who managed to not only drive better but also not break his car.

Entered a post and lost it somehow.  Starting from the beginning, and this time it will be better, and with more betterness!

2020 goals, starting with the most important, the '81 RX-7.

Goal:  Fun anachronism to drive in the summer, compete in PR at out of region RallyCrosses.  Stretch goal: Make a good showing at RallyCross National Championship.

Current status:  Verified drivability for a few weeks, has hurt 13B in engine bay, and a horrendous drivetrain shake due to a broken trans mount.  Rebult 12A on engine stand.

Need to accomplish:  Tear down 12A that was rebuilt in the mid-1990s and verify that it was rebuilt to my standards and not just an "amazing pile of junk" race engine.  Have two mint 12A rotor housings, will send side housings off for machining if necessary.  Sandblast paint off of engine housings because painted rotaries are fugly and raise too many questions.  Reassemble and reinstall with modified '79-80 intake manifold (legal per Prepared rules, carbureted may use any intake manifold) and rebuilt Nikki carb.  Will schedule dyno time to get maximum midrange torque with various carburetor and exhaust options within the scope of the RXR.

Install new headliner, sunvisors, and sunroof hinges.

Remove and diagnose/repair turn signal flasher unit.

Mock up Wilwood calipers on spare uprights/rotors to verify that they can be made to fit under stock 13" wheels.

Locate another pair of Lucas aluminum calipers, locate a small axle drum brake rearend housing, make them work together.

Locate a pair of rear stabilizer bushing brackets and reinstall rear stabilizer bar.  (It is necessary with the stock 4 link, IMO, unless you are a fan of ripping the links out of the chassis)

Stretch goal: Keep scouring eBay for a Mazda Motorsports 7.5 or 5.5" clutch setup

2020 goals, VW Quantum:

After the RX-7's 12A is no longer powering the engine stand, remove Quantum engine, install on stand, and pull cylinder head to verify that things didn't rust up in the last five years. (If they did, al of the following is moot.  If not, then Install new head studs, since the current set is half one type of 4cyl stud and half the other type.  Remove oil pan, remove rear main seal, install crank trigger type rear main seal.  Button everything up.

Disassemble the K26 turbo on the engine and the K24-7400 (S60R) turbo powering a box and meld the two, bolt up to 2 piece exhaust manifold, install on engine.

Machine as much metal as possible from heavy as berk "MC1" turbo flywheel, install along with the "Stage 1" (whatever the hell that is supposed to mean) stock-looking clutch purchased six years ago for $100 with the flywheel.

Attach 400k mile old Quantum transmission, insert drivetrain into car, purchase equipment for MIG welding aluminum, cut apart heavily-modified intake manifold because it wasn't modified the way I would like it it to be, splice in large diameter plenum chamber and rear-facing throttle body.

Figure out what the heck I'm going to do for an intercooler.

Modify cheap scratch and dent Griffin radiator to be mounted 90 degrees out of phase with newfound aluminum welding abilities.

Acquire some form of engine management.  Still not sure if P38, M4.4, or MS3Pro.  If you know what those TLAs are, congratulations.  If not, ask your momma when you're old enough.  P38 and M4.4 offer way-high geek cred, MS3Pro is more expensive but is the lazy button, also offers the option of poppitybang turbo melting antilag.

More things I am forgetting.  There's a lot to do.

Finally, '84 RX-7.  To be honest, I have no idea.  I mostly hang onto it because it's what I got, and I have a lot of R&D effort tied into it.

Immediate requirements::  Remove fuel tank and descunge.  Replace fuel pump.  Patch floor where rear lower control arms are supposed to attach, but largely don't.

Like-to-dos, minor:  Reinstall the "storage bin" sheetmetal to cover up the echo chamber behind the seats.  Find out and repair the cause of the Autometer tach bouncing uncontrollably over 7k RPM.  Cut and splice exhaust system for more rear axle clearance.  Fix floor by using the lower of the two link mounting points on the rear axle, and bolt/weld new rearend pickup points much more forward, so the lower links are a good three feet long or so.   Have a chat with Terry at Henderson about hat it will take to have a driveshaft live at 6000rpm on the highway without harmonics issues.

Like to dos, major:  Pull engine and subframe, install subframe Mk2, add engine mounts to use front cover mount instead of side mounts, send bridge ported side housings off to Chips for remanufacture, fabricate airbox so dual DCOE intake manifold and 45mm thottle bodies can be used, which will negate the need for the GSL-SE center housing, so a 12A "tallport" housing can be used instead, allowing for much more horsepower.

If you don't care to purchase a spool gun for aluminum mig welding i have a tig here and you're welcome to use it