so i accidently bought a car and started a challenge team last night. have questions.

Dusterbd13-michael said:

In reply to Robbie :

You are making my day much better by continuing to build this. Im really happy about seing a different vision than mine and dallas.

The vision probably isn't all that different, at least this year. The main difference is mainly going to be polishing of the rough spots so this beast can be unleashed!  

As Robbie said, testing, data, testing, data, testing, data.  We plan on trying a bunch of tires at a 3 day autocross extravaganza here in northern MI where you get unlimited runs at an airport for 2 full days...testing out parts/settings.  Then drag strip work, trying a few different tires, launching techniques, etc.

We are also scheming on some fiberglass work, making a hooptdy hood (keeping the beautiful stocker/hardware, but ditch that weight).  Robbie and myself have always wanted to learn how to do fiberglass, and this is a great opportunity...

Sort clutch hydraulics.  We have a couple good ideas, so hopefully one will work out (remote reservoir kind of thing).

Make a Panhard bar?!  Dallas gave me a nice piece of square box metal stock left over from building his truck shelving.  I didn't even know what a Panhard bar design entailed, but now I'm confident we can add this for next to no cost.  Best I can tell the rear axle will not be over constrained from this, which is key.

I'm having a baby here in March, so that'll put the damper on any huge changes, but honestly, we need a good baseline more than anything.  Also, we plan on making it annually with the Holey Spirit, so this will be a great development car.  In fact, I was kind of scheming on us running 2 cars at the Challenge in the future...our Fiat and the Spirit.

If the Spirit turns out to be a capable HPDE/track car, I will stop driving my 240SX at track events, and instead, track the Spirit...its just born to do it...

We're just so incredibly lucky you guys (Mike/Dallas/Team) did such a good job of giving such an incredible base to start with!

Fantastic!  

It needs to be raced heavily after being sorted.

Robbie said:

listing these for my own memory later:

nissan pathfinder (2006) uses a 36.25 or 37.5 shaft with ford 1310 u-joints (same as mustang)

108 WB 4x4 s10 (2000) uses a 37.25 shaft with chevy u-joints

seeing this makes me want to Mustang 6spd swap a Pathfinder

My car in high school was a 1980 AMC Spirit 4 cylinder with a four speed manual transmission.

151 cubic inches of Iron Duke "power".

It was the same metallic copper/orange/red as this car was originally.

So you guys did to this car what I always daydreamed about doing to mine.

Great job!

So I found some time and decided to spend that time sorting the Holey Spirit.

To begin, an 'oddly satisfying' moment.  My username is my 240SX's license plate (real original huh?).  But I got the same plate, but with the digit swapped.  RACEC4R for the 240SX, and R4CECAR for the Holey Spirit.

The first item on the agenda was to diagnose and assess the condition of the 3 speed that currently is in the Spirit.  We plan on swapping in the T5 we acquired from Dallas, but would like a clean conscience in selling the 3 speed locally.

When we picked up the Spirit the clutch needed to be bled, and was described as a known issue to sort when combined with the shifter woes.  The clutch hydraulics system was described as...lacking a certain 'je ne sais quoi'.  The team was originally running an AOD that came with the 302.  The AOD met an early demise and needed to be replaced at the last minute with something else.  Turns out this 3 speed was the ticket.  The hydraulics system was created in last minute thrash mode, and to be fair, works great!  However, the serviceability...oh the servicibility...

1. Remove hood to access hood hinge (not kidding)
2. Remove drivers side hood hinge to access clutch master resevoir (not kidding)
3. Remove clutch master cylinder reservoir cap to discern fluid level
4. Reverse bleed or vacuum bleed hydraulic circuit due to clutch line being higher than reservoir level
5. You get the idea

Let us not disappoint:

See those 2 oil patches?  Yeah...those were the shocks.  Were.  The.  Shocks.  Turns out, jacking it up in sunny 60 deg Charlotte is perfectly ok, but the seals did not appreciate it here in ol' below freezing Michigan.  So that's fun.

See that white cap down there?  Neither do I.  That's the clutch reservoir cap.

I think I found it!

The angle adds a degree of difficulty unseen on other applications.

Bonus, that rubber pressure line?  That's the clutch line!  It's higher than the rest of the system...making it impossible to bleed the air out (for me).  Have no fear, new gear is here!

Always wanted one of these bad boys!  Works bad-berkeleying-ass! Bled that bitch in 6 mins start to finish! So...lets drive this bitch!  Snow be damned!

Backing it out on Hoosiers/ice was hilarious to say the least.  I let the clutch out, and the wheels just turned...they were hard as plastic wheels on your grocery cart.

It runs and drives great!  Shifts buttery smooth, but would agree with Mike/Dallas, the shifter is just...ehh...confused?  Easy to find Reverse, 1st, and 2nd, but 3rd is in no mans land, and Nuetral, forget Nuetral.  Nuetral just disappears.  Ok, I'm being dramatic, but it's not fun or easy to shift.  The gates seem to change position every time you move the levers.  But thank god every gear is super smooth and with a freshly reverse/vacuum bled hydraulic system, the clutch disengages/engages well.  I can now sleep well knowing when we sell the trans, it will have been in excellent condition on my end.

Few take-aways:

1. No wipers.  It was trying to snow.  So thats a thing.
2. No turn signals.  I signaled out of my window like a bike rider.  Not kidding.
3. No gas gauge.  Stop early and often?  Took 9 gallons when I stopped.
4. No rearview mirror, only drivers sideview.  So that's a thing as well.
5. Michigan roads+wide Hoosiers = wandering like no other.  Never take your hands off the wheel.  Ever.  You will go into oncoming traffic.
6. Needs a wheel hook for the steering wheel.  
7. Starts instantly when hot.  First revolution.  That's nice.
8. No speedo, so hope traffic is present to help keep you in line?  Can use phone I suppose.
9. Garners unbelievable amount of attention.  4 people approached me while filling up.  Best I can discern, I think everyone in MI has owned an AMC of some sort at some point in time.
10. Sucks to park.  2 widebody/flared cars fit like E36 M3 in my garage.  Does not help there is no passenger side mirror.  Lulz.

Next stop, swapping in the T5.  Making/using a remote clutch master cylinder reservoir system, hydraulics update.  Making our own driveshaft(s), 1x $25 carbon fiber (hopefully for challenge), 1x all aluminum 1 piece (my LS/T56 shaft), 1x professionally made (not for the challenge, but known good quantity). Can't wait to wash it and give it a concours level detail.  Needs to be above freezing for that...bring on Spring!

Wait till you see the clutch master butchery i did to the pedal. 

Not proud of the hydraulic clutch setup. Not at all. But it got the job done. Usually. 

Before you sell the 3 speed, can you grab the metal flake shift knob? Only part of the car i wish didn't go with it.....

Also front shocks were 4x4 s10 shocks.

Gas gauge: sending unit is garbage. Go aftermarket street rod stuff. 

Column has been gutted of all turn signal parts, but its an 78ish gm column. Gid bless amc parts bin.

We'll get the knob for ya.

Ian and I did marvel at your linkage. Be proud that it works! 

Before Ian got that mittyvac however, I was getting some texts...

In reply to Robbie :

It was not some of my better work. But it worked well enough. 

It can be filled and bled with the hood on, and without a mityvac in the pits at the challenge. However, thats a blood sacrifice and requires 3 guys.

Dusterbd13-michael said:

Wait till you see the clutch master butchery i did to the pedal. 

• Haha, I was trying not to call out specifics, as it shouldn't be a measure of our ability...but that angle iron works...so fuggit!

Not proud of the hydraulic clutch setup. Not at all. But it got the job done. Usually. 

• Yeah!  I mean, it works great!  I think I actually solved the leaking cap thing as well.  So honestly...it's probably good to go forever.  We plan on eliminating that 45 degree tilt on the master though, cause it can't hold much fluid!  (I bet you are all too familiar with this).

Before you sell the 3 speed, can you grab the metal flake shift knob? Only part of the car i wish didn't go with it.....

• Yep!  I will be sure to mail it to you.  Either Robbie or myself will make sure that wish is honored!   That knob is baller.  I would want it back as well.  PM either of us your address when you get a chance.

Also front shocks were 4x4 s10 shocks.

• Any idea on year?  Just off the top of your head.  The part number on the shock itself will give it away.

Gas gauge: sending unit is garbage. Go aftermarket street rod stuff. 

• Yeah, I think I want at least a light for low fuel?  Maybe a readout if we are feeling saucy...

Column has been gutted of all turn signal parts, but its an 78ish gm column. Gid bless amc parts bin.

• My hand signals are adequate for Michigan...Michigan is a lawless place when it comes to vehicles...I'll risk it.  If the po-po were to pull everyone over for no signal, nearly every single driver would be pulled over.  Shiz is NASCAR round these parts...no idea why...people just don't care (Motor City?!).

First test weekend in the books!

Ian and I spent some time Friday buttoning things up and doing some light testing.

-checked and/or tightened all suspension fasteners

-bled brakes

-checked for major leaks (Ian did replace the tailshaft seal last week, seems not to be leaking for now).

Then we put the phone in the car with gps extender and I took it to a nearby empty parking lot:

Just drove some circles while slowly accelerating and not moving the steering wheel. I let off when I started to significantly slide. 1G is pretty good on the junky and gravel-covered lot!

This was on the big f40 tires that were on the car when we bought it. We decided to swap on some tires isn had that would be hopefully more representative of the tires we want to run at the challenge.

(Yes we put on smaller tires). They made the flares look a bit goofy.

We had planned to run both sets of wheels at the autox (swapping between heats) but there was a huge turn out so we only got 4 runs in one heat. And with double drivers we didn't really even have time to adjust tire pressure between runs!

Ian was literally the first car off for the entire event:

We tried to take good notes (also, Ian is normally a better driver than me, but Saturday he crushed my 51.5 with a 50.0). I brought a laser temp gauge to check tire temps, but didn't check the battery before. Of course it was dead. Lesson learned. So instead I used my hands to check for cold, warm, or hot after each run.

Now, to address some leaks, do an alignment, tune up the ignition advance and check the carb tuning, lower tire pressure a bit, find out why there is no fluid pressure at the rear brakes, and maybe try the other shifter we got from Patrick.

Almost forgot, data on Ian's best run. 1.3 g is really impressive!!

It was triggering the finish too early, I think we set the finish point a little too close to that point of the course.

Check the brake bias valve on the transmission tunnel. I remember we had to do something funny while bleeding the brakes to get their ears to bleed and actuate properly by using the adjustment knob. We then readjusted it for proper brake bias but it wouldn't do both at the same time. The smaller wheels and tires do look Goofy. How did it run though?

Oh, and this is page 42. So i guess amc IS the answer to the question of life, the universe, and everything. 

In reply to Dusterbd13-michael :

42, awesome. 

The car ran really well. It always starts right up, so even though the battery is crappy it still doesn't leave you stranded. No overheating, good oil pressure, good power. Shifting is like stirring a bucket of mud, but if you just jam the lever in the general direction and push HARD it will go into the requested gear. Finding neutral can be a task but that isn't a problem DURING the race. haha. Steering is good if a little slow in ratio. Suspension is noisy but seems to work - we didn't find the car to be overly prone to understeer or oversteer - the driver could easily select which he prefers ;)

We did have a couple of carb hiccups, as it seems in sustained turns the engine would either stumble (if on the throttle) or stall (if on the brakes). No stalling completely since the car is in gear and the clutch engaged, but still I think we can work this out. May be able to just lower the fuel float level a hair as I've read that fuel spilling down the vents and into the motor during high g maneuvers can cause this behavior. Maybe also extend the vent tubes up a bit with some fuel line? I'm still in the learning phase on this one. 

We tried to mess around a little with the prop valve on the brakes. But turning it all the way one way and then all the way the other didn't seem to let pressure/fluid through in either direction. Maybe the valve crapped the bed. Or maybe we can take it apart and clean it. Or maybe there is somewhere in the 'sweep' of the valve that it does let fluid through and we just didn't spend enough time finding it. Since the car was stopping and not leaking brake fluid we didn't want to create an unsolvable problem the night before an event so we didn't dig too hard. 

Thought I'd drop this link to the GRM article on the "Racing Spirit" here.  Good article about a great car and even better team.  Congrats.

So it's been awhile since we've updated the build, but we have been working diligently on identifying the shortcomings of the car, and developing those areas.

The big deal as seen above, was tires, and establishing a baseline.  After the above event, I somehow broke the LF shock...I think the suspension travel ran out over a large obstacle on the way to/from the event, or to the gas station...and the shock became the spring as the spring compressed further.  As evidenced in the previous photos, the shocks actually blew out when I lifted it back in December because it was so cold.  When we lifted it in NC, the shocks were fine and did not leak.  However, I think the seals shrank and lifting it when it was -7 degrees out was a bad idea...  So the blown shock breaking in half was just motivation to fix it pronto.

Needless to say, we had to fix the shock before any more testing could take place.  We opted to just put in new Bilsteins at this point because locating a set of used Bilsteins was next to impossible because they are worthless.  Will need to go pick them from the yard, or install the $7 Gabriels from RockAuto.  Which, can we just all agree, that is hilariously cheap for BRAND NEW shocks?!  How is there even room for any profit?!  But I digress.

Fixing the shock made a world of difference, and also made it readily apparent how important it was to the handling and overall drivability of the vehicle.

We decided a great way to establish a baseline would be a test and tune up with DRSCCA in Oscoda, MI at Wurtsmith Air Force Base.  It's a 3 day event with unlimited autocross runs as well as additional areas for skidpad testing and full throttle straight runs. 

As mentioned above, tires were the first major shortcoming, but we can't use my 275/35/18 Toyo RR's from my 240SX as the wheels are not budget friendly.  But we had the fantastic 15x10 steel wheels that the car came with, so sourcing a budget friendly 15x10 tire was paramount.  We of course could go and buy the widest A7's money could buy (295's at over $400 each), ORRRRRRRRR we could keep in the "Spirit" of the competition and build and get some used race tires that fit the build and our wallets.

We did some pretty extensive research and established our requirements. 

1)  The selected tire had to be shorter than the 27" diameter that the F40's and 275 RR's.  This would serve as a huge multiplier for our gear ratio.  We actually WANT to keep the 3 speed.  Believe it or not, it'll be faster than a 5 speed in any scenario due to less shifting.  For autocross specifically, 2nd gear is quasi close to topping out on big courses.  This is huge.  Launch in 1st, bang 2nd, done.  Also, hitting the rev limiter means we are using the most aggressive gear ratio and highest torque possible from the rear wheels.  This translates into best acceleration possible, which is also huge as acceleration and corresponding speed are used throughout the entire course.

2)  The selected tire needs to be at least 10" wide.  We have the wheels.  Use every inch.

3)  The tire has to be cheap and nearly disposable.  We want to do extensive testing.  We are not committing big $$$ to this car.  It is a fun hobby and competition, not "who can spend the most money and win" competition.

4)  Compound needs to be the stickiest possible.  Is A7 rubber available in other race series?  (The answer is yes!)

5)  The tire needs to have stiff sidewalls.  This was the shortcoming of the F40's at the Challenge.  The marshmellow sidewalls look badass, but give zero feedback or dynamic/transitional stiffness/reaction force necessary for something like autocross.

6)  Tire has to be as lightweight as possible.  This is a largely underrated 'want' item.  Unsprung mass and rotational mass at the farthest location radially outward from the hub.  A double bonus in each area if you can decrease tire mass.

Extensive requirements list one might say...however, we made a bunch of phone calls, looked at spec sheets, and found the secret sauce!  Disclaimer:  I am not going to divulge the tire make/model or source.  I consider that proprietary at this point because we did all the research and testing, which cost us significant time and money.  Pro-tip, its not that hard, and any GRM'r can repeat what we did with a little effort.  The pictures will give plenty away as it is, but we don't want to make it TOOOO easy.

Above image shows the stark difference between the tires we've been evaluating.  Left to Right (Mystery short badass tire, 275/35/18 Toyo RR's, 27-10-15 Hoosier F40).

I think I literally have about ~30ish tires on my property that are all race derived.  Can't wait to start burning through some of these to I can get them out of my garage and basement.  Needless to say, lots of mounting and balancing had to be done.  I would just toss out the inferior tires...but...the...frugalness...in...me...cannot...allow...it...must...use...them...in...some...capacity...

Giggity!

Looking forward to seeing you guys with a well sorted amc.

The event itself was awesome!  Unlimited runs, fairly wide open 50 sec course, 90 ft skid pad for more static condition testing, and mega bonus of only have to work the course with a friend for 1 hour per run day.

First things first.  Establish a baseline.  We knew the RR's were great tires, I run them in HPDE/autocross with the LS13.  What we need now, is to establish HOW much better each tire was with data.   So before we went out on the autocross course to thrash the car at length, we decided it was best to go to the skid pad and figure out which tire pressures were best, what the car did at the limit (does it understeer/oversteer), and get a good feel for what the cars limiting factors were while taking the driver and the course out of the equation.

Robbie getting all suited up for a session.

Good shot of the front.  The foglights had to go as they had no real function for our current use case except disrupting flow to the radiator.  We would need all the cooling possible from hotlapping the absolute E36 M3 out of it this weekend.

Robbie is currently in posession of the data, so I can't quote figures, but the RR's were good, and the new tires were REALLY good.  After spending about half the day at the skid pad, we found the optimal tire pressures and characteristics of the car.  We discovered to our NOT surprise, the rear end of the car has WAY more grip than the front.  This causes a slight understeer condition at the limit on the skid pad.  

I'll be honest though (and Robbie will agree), at no point on the autocross course was the understeer condition present.  In fact, we can't even turn the wheel fast enough to get through the cones.  We picked up about ~2 seconds on the course with the new tires over the RR's!  A bit of this can be attributed to drivers getting more seat time in the car and learning the course, but the new tires are flat out faster in every way!  I think they were about half a second faster on the 90ft skid pad, which is crazy considering how small a 90ft circle is (8.3 vs 8.8 sec).  Another big thing to note, was since they tires were so much smaller, they created a much better ratio which caused us to hit the limiter perfectly in 2nd gear on the big sections of the course!  Also, we were able to launch the car with deadly effectiveness.  We'll have to go to Milan Drag strip and see if any of my drag slicks make any difference.  But that is a discussion for another time.

It looks a little funny compared with the F40's, but thus the price for speed and efficiency.  We may even trim the flares back, but who knows, not really important at this point in time.

What is important is that we also tuned the carb with all this new found time and space.  We fixed the bog issue at WOT launch/shift, adjusted the idle, adjusted the secondary cam ramp rate, and adjusted the float bowls.  And by we, I mean Robbie.  Robbie did this.  I watched and started the vehicle per his instructions.

So flat, even at the limit!

They do look funny. But the car looks way better without the wing and fog lights. Definitely dig it.

And suprised about the rear having more grip. I always felt it wat really, really neutral.

Steering is definitely slow, even with the jgc quick box.

Takeaways:

1)  Car pushes.  We theoretically need to add more front grip, but not take away rear grip at the expense of balance.  Because as I said above, I don't think I ever got the car the understeer out on course.  Possible actions include upping front spring rate, stiffer front sway bar, additional front sway bar, increased camber, wider front tires.

2)  Steering rate.  The car is so berkeleying fast, we can't steer the damn thing fast enough!  I know the fastest Jeep steering rate box is already in the car, but damn, we need even faster!  You are all elbows at speed and the thing grips so well, it does exactly as you tell it.  So if you fail to give it the right input, it won't go that direction.

3)  Tire size is perfect.  The new smaller diameter tires make it top out in 2nd perfectly on this big course.  Couldn't ask for better.

4)  Tire compound.  Perfect.  Don't think A7's would make us any faster to be honest.  A7's weigh more anyways...  Lateral grip is not our problem now (which is a weird thing to say as a racer).

5)  berkeley carbs.  Plain and simple.  Bae needs LS power and fuel injection.  She gets a little heartburn being flung so hard left/right etc.  She also has a propensity to flood herself when she gets into transient state trying to catch idle speed when off WOT (for example, at the end of a run/course).

6)  Aero.  Don't want to steal Robbies thunder here, but I think the car could benefit considerably from some aero treatment in certain areas.

Conclusion:  with a few tweaks, the existing build and platform are great!  Just wish it fit into a class a little better than all of the "unlimited-anything-goes" classes for SCCA and other sanctioning bodies...

I'm sure Robbie will chime in and fix anything I forgot or quoted wrong.  Onto the next!

Dusterbd13-michael said:

They do look funny. But the car looks way better without the wing and fog lights. Definitely dig it.

And suprised about the rear having more grip. I always felt it wat really, really neutral.

Steering is definitely slow, even with the jgc quick box.

Dude, you're not wrong, it is neutral on the course at speed.  I cannot get it to understeer.  Period.  We just got it to understeer on the skid pad...so if anything, it will understeer before it oversteers...which is just a thing?  I don't think anything is wrong.  But we couldn't get the front tires to roll over any farther despite lowering the pressures to very low states and losing time in the skid pad.

The car definitely had more grip than the steering speed would allow for. Our initial testing was eye-opening on the grip level, and that was on tires that needed way more heat.

Glad you are getting it sorted AND having fun.

So:  quicker steering box, dual element ply front, and single element ply rear?