Sprocket's Competition

[clocker]

Proving myself nothing if not dogged, here are the latest deets about the project.

She's been a fairly reliable driver for some time now and Sigfrid and I were preparing for this season's warm weather attack on the interior when everything went pear shaped.
Idle/driveability began to deteriorate, she randomly refused to start and last and worst, the clutch went...AGAIN!

Our engine issues were finally traced to a bad Idle Air Control solenoid.
We had a spare already attached to the aftermarket (larger bore) throttle body (Holley) and decided to just throw the whole thing back on.
This throttle body was originally on the 383 stroker motor and was deemed too big for our new "stock" engine, so it's lanquished in a box for the past year.

Everything got a lot better.
Still needs tuning (we have a "new" tunable ECU already installed) but she idles steadily at 750 RPM ( and more importantly, returns to idle smoothly) and will pull past 5k RPM without hesitation.
Not a lot of power up there yet (@ 4K RPM seems to be the sweet spot right now) but we're getting closer to the theoretical peak of 6.5K RPM.
Figure we need a cam and rockers to make this happen.

The starting problem was traced to a bad connector on the fuel tank bulkhead plate.
This was the problem I planned on fixing this week...until the clutch decided to crap out.
Most inconveniently, I must add.
Sigrid's expanded work responsibilities require frequent trip/stays to Houston and during this one, I was to get the car and basically just drive and enjoy it. Tinker as necessary- the fuel pump wiring- but mainly try to reconnect with the reason I was involved...a fun car to drive.
I "enjoyed" four miles before the clutch pedal sank to floor, never to return.

Fortunately (in a relative sense) it was only the throwout bearing (our third failure of this component).
Unfortunately, the bearing is $230, only available from GM.
Many aftermarket companies sell clutch kits for the LT1 (which would include the bearing) but won't sell the bearing by itself.
No clue why...

Our Frankensteined clutch hydraulic system is apparently overextending the slave cylinder, which stresses the throwout bearing to failure.
The previous failures actually ripped the bearing out of the clutch plate (it's a "pull-style" clutch), this time the bearing flange distorted to the point that the fork slipped off the back of the bearing, leaving the clutch intact.
A silver lining, I guess.
Our last clutch cost over $700, so it's not a trivial expense...especially when labor gets added on.

Working on the clutch is beyond our physical capabilities (I'm far too old to lay on my back with a transmission on my ribcage), so the car was towed to Precision and our old friend Dan knocked it out for us.
Coincidentally, a few weeks ago Precision bought an alignment rack from a closing business.
The display didn't work and I miraculously was able to fix it.
So they kinda owe me a favor, which I'm cashing in tonight as Dan and I corner weight and align the beast.
Hopefully this will eliminate our handling quirks...I'm excited to find out.

Today I must address the clutch problem- how to prevent this overextension?
I have three approaches, ranging from the dead simple (a pedal stop) to the more elegant (smaller master cylinder).

We'll see how it goes...

[clocker]

Well, that was educational.

Spent five hours Friday night corner weighting and aligning the bitch and finally, for the first time ever, I think she rides/handles better than my RX.
Very sweet.

Surprisingly, Sigfrid and my method of measuring fender height to set the suspension resulted in a near perfect cross corner weight balance (with driver and 1/2 tank of gas, we were 7 lbs. off...too close to mess with).
Our loaded weight (driver & fuel) is 2988 lbs which puts us exactly at the stock car's stated weight (2740 lbs.).
The car is slightly tail heavy (which is not what one would intuitively expect) and we decided to leave it that way.
The thinking is the steering will be lighter and weight transfer under braking would bring us to 50/50 distribution.
We can dial this in later if necessary by slowly raising the rear spring perches (a two minute job).

If the corner weighting was perfect, the alignment was anything but...every adjustment on every wheel was FUBAR.
Dan set us up with an aggressive street setup- more negative camber (better grip but increased tire wear), slightly less front toe (less self-centering but more responsive steering) and "street" caster ( half degree more on the passenger front to compensate for the normal crown of the road -the extra caster helps reduce the tendency to dive at curbs on crowned pavement but is unnoticeable on flat roads).

I haven't done a lot of driving since then and what I have has all been low speed city driving.
I'll finally get on a highway when I return the car to Sigfrid this morning, so far she's been wonderfully docile and easy to live with.
I'm quite pleased.

[clocker]

Slight update.

When Dan removed/installed the transmission he did not first remove the center interior console.
As he pushed the gearshift back up through the rubber boot, it dislodged and ultimately started interfering with the shifter throw.
I thought the clutch needed adjusting but redoing the shift boot fixed the problem and she shifts cleanly again.

Just thought you'd like to know.

[clocker]

As he's pressed the 7 into daily service, Sigfrid has become obsessed with the "tune" of the engine and minor driveability glitches.
We have several possible problem areas and have begun addressing them...the trick is figuring out a priority tree to follow.

This weekend we'll be replacing all the engine sensors (MAP, IAT, TPS, IAC and VSS) with new parts.

Our current fuel injectors came straight off the intake I pulled from the junkyard last year and have never been tested/cleaned.
We have a set of bigger injectors from the original 383 engine, may put them in just to see what happens but they are untested as well, so I'm not sure what
info this would give us.
Ideally we would just get a new set and be sure they were good.

Our exhaust manifolds leak and in general pretty much suck.
Sigfrid bought a new set of Pacesetter headers (shitty brand but better than what we have) off Craigslist and I tried fitting them while the car was up on the rack,
but they were just not configured right for our application. Probably would have fit if the subframe was dropped but that would destroy our alignment every time the headers were removed, so I vetoed the idea.

Finally, there is the engine harness we built last year.
Since then we've learned a lot about how this could be improved (ground loop mitigation and twisted pair/shielded sensor wiring) and have been kicking around the idea of totally redoing it.
Sigfrid found a site that makes custom harnesses (and tunes ECUs as well) and began an email exchange.
Turns out, the guy is located in Golden, CO...about 5 miles from Sigfrid's office.
He's interested in seeing the car, Sigfrid is interested in getting the harness and I'm wanting to redo the entire body harness.
We should all be happy.
And busy.

[clocker]

Finally, there is the engine harness we built last year.
Since then we've learned a lot about how this could be improved (ground loop mitigation and twisted pair/shielded sensor wiring) and have been kicking around the idea of totally redoing it.

Well, we quit "kicking the idea around" and finally just did it.
Kind of.

Due to some recent personal upheavals the future of the Beast was in doubt and we went into "prepare for selling" mode.
The chassis wiring I did last year has performed without fault but the engine harness has suffered a lot of abuse as we (mistakenly) blamed it for driveability faults.
We had finally gotten everything in order but it looked terrible and did not reflect my current thinking on placement.
After completing the project last year, hindsight revealed much better ways to do it and I was eager to try.

It made sense to relocate the ECU and clean up the interior portion of the engine harness because that was a very low cost job that would significantly increase our curb appeal.
Selling a car like this is difficult because of the "shadetree" nature of the result. The buyer knows you've been all over the car and something as ugly and amateur as our ECU install would
frighten off many folks.
Rightly so.

Took us about 2 hours to strip the interior and begin the wiring.
The ECU fit into it's new location in the driver footwell almost as if it was factory designed.
One very simple bracket and two foam pads are all it took.
It's completely accessible with the dash in place and because we had extra length in the harness, the computer could be removed and set in the driver seat without disconnecting it.
Not sure if the last is a "feature" or a "bug".
Anyway, we were quite pleased that the project had gone so easily and quickly.

Of course, she then refused to start.

We adjourned for the day and began anew on Friday morning.

We decided- after no small amount of disagreement...I lost- to shorten the harness by a few feet and reverify all the connections.
(keep in mind that at this point we have not touched any of the harness forward of the firewall)
Ended up removing almost three feet of wire length and checking every single pin at the ECU (there are 49 altogether).
The harness was now nicely loomed, the grounds were all rationally laid out and in general, it was pretty fuckin nice.

Still didn't start.

Figured we had to get under the hood and start checking...out of sheer laziness I went for the easiest connector to get at, the coil.
Which did not have +12v where it was supposed to.
Neither did the ignition amplifier.
The solution struck us both simultaneously.

When we first built the harness last year, we had the exact same problem which turned out to be a flaw in our reading of the GM schematic.
The fix was a simple one wire relocate in the engine bay and a corresponding jury rig at the ECU side.
When we redid the computer to exactly match the GM layout, we "broke" the circuit we had jury rigged last year.
Undoing our previous fix at the coil connector was all it took and she fired right up.
Hallelujah.

I'm also happy to report that the plan- at least for now- is to KEEP the 7 and truly make it a daily driver, sole source of transport.
In light of this, I now consider the entire wiring layout to be at the end of beta stage.
Component layout is almost perfect and a very clean harness route has been established.
Next- and final- step would be a complete redo with all new wire and connectors.
We'll see.

So, we not only crossed another milestone, we also were finally able to get some info about our poor running issues (we have a constant Check Engine light).
Now that the diagnostic port was finally functional ( a long and involved story best left for later) we could finally pull codes and see what was up.

The "new" ECU (purchased from an online seller who flashes your desired tune and removes unneeded components) thinks it should have an auto transmission and is freaking out from lack of sensor data.
So it goes into limp mode to protect the "fatally damaged" transmission we don't even have.
We're getting no trouble codes from the engine itself.

Our older ECU (replaced because of burned connector pins) only complains of VSS (Vehicle Speed Sensor) signal failure (rectified during the harness repair) but doesn't have as good a tune for our setup.
We need the guys who sold us this last computer to replace it with one for a manual trans (which is what we ordered dammit!) and we should be good to go.
If it runs like this in limp mode, I can't wait to see her unleashed.

Money will probably be very tight for a while, as will time since we'll now have to concentrate on keeping her on the road instead of torn down in the garage.
Nevertheless, I'm pretty happy with how things are going.

[clocker]

Two pics from yesterday:


Only the compulsive will see any changes here and that's actually kind of the point.
The Beast is due for an emissions test this month (required to register/tag the car) and, well...we really don't have much of the original emissions stuff installed.
So, we decided to install these Corvette intake valley covers to cover up the area where most of the stuff is supposed to be.
They look very nice, I think.



Also installed a Miata gauge cluster bezel which is a big step towards integrating the Miata gauges into the FD dash.
This shows the driver's view and how well the whole setup fits the steering wheel, all that remains is to transition from the new bezel to the dash, and we're exploring options for doing that.

[clocker]

So, here's what happened yesterday...
As previously mentioned, we need to emission test the car.
The first- and so far, only- time we got "tested", money exchanged hands and a pass was slipped to us through the backdoor, as it were.
Since then the state has tightened up procedures and our "free market" approach is no longer possible, so into the belly of the beast we rode, having decided that a full frontal approach was best.
Figured we'd just present her as a normal car and see the response.

The first check uses a mirror on a broomstick to verify presence of catalytic converters and evap system...we have both and they're fully functional.
(The cats play a part later in the story, so get ready...)
Next, the VIN gets entered into a computer and a picture of the engine bay appears with arrows pointing to systems/parts that must be present...the hood is then opened and a comparison made.
This is where things got a bit weird since the Corvette engine looks nothing like the Mazda rotary.
At one point there were six techs huddled around the car (one of whom kept insisting the car was actually a Viper...go figure) and I was pretty sure the test would be halted right then due to the obvious and massive discrepancy.
But it wasn't, and she proceeded to the rollers for the sniff test.

Passed with flying colors, the tailpipe emissions were barely a blip on the screen (and we hadn't tweaked a thing, she ran just as she normally does).
I was dumbfounded as it looked like we were home free.

But no, they failed us on the "visual" inspection, specifically citing the lack of an airpump.
We showed them documentation from our new (very expensive) catalytic converter (Random Technology, if you care) that specifically and emphatically states that air pumps must NOT be used because new design cats are so efficient they don't need extra oxygen to work properly and the extra air just overheats and destroys them.
This swayed them not at all...the computer says an airpump should be there and they had no leeway to excuse it's absence.
They also entered into the system that there appeared to be "non-standard" engine modifications- no shit Sherlocks, we changed the whole damn thing- which now forces us to visit a state referee.

Once we get by him, he'll amend the system to reflect the changes and excuse the car from further visual inspections.
I hope.
Tomorrow morning (Thurs.) we're going to bolt in an electric airpump and fake wire/ hose it, so it looks functional.
We have an appointment with the ref at 3pm.
It will be a major milestone if we can get her absolutely legal and smogable...fingers are crossed.

[clocker]

Met with the referee yesterday.
It did not go well.

Our "fake" airpump install did not impress him- he actually followed the airline down and discovered it does not connect to the cat (to be fair, it kind of does blow air at the cat...or it would if it was actually wired to anything and ran).
And he wants an EGR system installed...preferably where he can see the valve/solenoid (which means even the stock GM parts, which are hidden behind the intake manifold, would not do).

The irony of the situation was not lost on any of us*...our car sails through the sniff test, yet we're being penalized on technicalities and must spend time and money adding parts that in all likelihood will make the car run worse and will be removed again immediately following the inspection.
Sigfrid and I agreed after the meeting that the ref (who was a nice enough guy) was willing to work with us and we'll probably get through this OK.

So, it's off to the junkyard, which will be a total morass after days of massive thunder/hail storms.
Ah, good times.


*I asked what would happen if we installed an electric motor- would we still be required to have an airpump and EGR system?
No answer was forthcoming.

[j2k4]

Nice car continues to 'nicen'.

As to the other, this popped into my head -

[clocker]

Behold the glory of our emissions and despair!




We now have air injection for the cat and EGR for the intake.
None of it functional of course*, but results are not the issue...being present is all that apparently matters (since the car passes-easily!- the tailpipe test without any of this nonsense).
With a 1/2" open end wrench, a 10mm socket and a Phillips head screwdriver, the entire mess can be removed in under ten minutes.
Which it will be, immediately following the date with the inspector.
Hopefully, Monday.


*The air pump is actually wired and comes on with the ignition key but doesn't really send any air into the exhaust.