Chump Car Project! Thelma, the Chumpster - First race under her belt!

[NigelStu]

She's Back!!!! Cage is done. But bare....

In conjunction with a very busy race weekend (that included a trans swap Saturday night - damn 3rd gear syncro on Miatas...), I was able to pick Thelma up from the cage shop. She is getting closer and closer to being track worthy!

So, here's a few shots of the cage. My buddy Chris and Angry Sheep Motorsports did an awesome job and cut me a deal (partially since I did most of the prep, and will finish the cage up - hence the naked tubes...). If anyone in the Midwest needs a cage, go to this guy!

From the passenger side -



And the driver side -



Dash shot - not sure if you can tell, but there is a dash bar tucked up under there. The 1.5" bar fits snug, but perfect. DEF ducting and meter/dash fit with no interference!


And lastly, the roof - also showing of my superb body werk skillz () with the sunroof.....




Now, as you can see - NO paint on the cage yet. Part of the deal, I'm doing it myself. Our team name is "Bavarian Mustache Werks" and the theme is "Art Car". So with that in mind, I ask you R3V, how should I paint the cage??????? PM me, post here, photoshop some crap and put it up, whatever - the cage shall be painted as the R3V community desires!

[NigelStu]

With EXACTLY 1 month to go to the chump race, and another good work weekend, Thelma's a bit closer to becoming a real race car!

I ended up having an extra, extra day this past weekend when the diff in my Spec Miata decided to give up the ghost during the 1-hour enduro race at Mid-Ohio on Saturday - so we packed up and headed home. Sucks for the racing, but it also gave me all day Sunday to work on the BMWs. First step was getting the new DD driving, so basic maintenance was done (did that on Sunday). Second step was to work on Thelma (horray for labor day!).

First thing I tackled was to mount up the window net - had to weld on the tabs and shorten the rod a bit. I have some tubing scraps, so I did a few practice welds to get back on my game. I think they turned out all-right, so I moved on the the cage. 2 tabs welded in easy. Shortening the rod, easy. Removing the nice rounded plug end from the rod and putting it back in the shorter rod, not so easy, but its done! Window net is in, just need to add straps to the bottom.



Next up was painting the cage to protect it a bit and give it a nicer look (sure its a chump car, but I still want a professional looking cage). I had some "aluminum" 'professional' rustoleum enamel left over, so I used that. Nice silver color with a bit of shine to it.



Once the paint was dry, I remounted the seat and 6-point harness. Also stuck the window net in its top mount and mounted up the (rather huge) 5-panel wink mirror. The mirror barely fits between the front down-tubes, but give a TON of visibility. Also mocked up the fit for roll-bar padding. I'll tape/zip-tie those in place once I can confirm our tall drivers are properly protected).





A few more things have been complete this week as well.
-all new seals in the 3.7 LSD rear end. Inside of the case was CLEAN when I pulled it apart, no signs of wear on the gear teeth either :)
-Dash is out, Oil pressure / water temp gauge pod has been mounted. Kill switch mounted on dash (dumb place, but its per Chump rules....).
-Fire extinguisher mounted to floor - ended up using one of the passenger seat mounts and 1 drilled hole.
-new captured hood pins mounted
-RR quarter glass removed
-New 80 degree fan temp switch (previous one was INOP)
-The bright red Kosei K1s have the Dunlop Star Specs mounted. And I came home last night to a full set of TRM C1s with the same tires mounted sitting next to the garage :) Pics are definitely in order for these guys - I'll post those up this weekend.

Upcoming project list (to be done by end of this weekend)
-mount IGN switch and start button (removing key cyl completely on this beast) - its going in the vent opening left of steering wheel.
-reinstall dash
-finish lightening hood
-test fit wheels
-mount new spring perches to rear arms (fabbing up reverse-cups for the engineered rear stock springs)
-new brake hard-lines on rear amrs (rust SUCKS!!!!)
-new bushing into rear cross-member, mount arms and diff to cross-member
-install CHMSL (per rules, and not a bad idea to have a 3rd brake light)
-replace my good rear lamps with my cracked/broken ones (no sense in ruining something good!)
-Drive the DD (BeBe, the beaten bronzit) around for shits and giggles. just cuz I'm a :pimp:

[NigelStu]

I'm gettin' all studly in here! Box from Turner Motorsports was sitting on my front porch when I got home - containing the 75mm studs that will be used for the race. I then unpacked and checked over the TR-Motorsport C1 15x7 wheels with 205/50R15 Dunlop Direzza Star Specs. These will be the back-up wheels/tires for the Chump car,and the DD set if they make it through the race.



Since I wanted to check fitment, I threw them on BeBe for a bit. Plus this is a good way to breakt he tires in and get all the mold release agent off the tread. They fit nicely, but REALLY show that a stock ride-height car is too high...




I did manage to get a few things done - re-mounted the dash, mounted the battery-cutoff, did a bit of clean-up, mounted the fire extinguisher.

And I fabbed up some mock-ups of the new rear spring perches so I know what I need to do for the real part. Since I modified the stock springs (read "I cut* them"), the lower pig-tail is gone and we need a suitable way of locating the spring. Some research showed that the circle track guys use weld-on perches, in a cup form, to locate the spring. So that is the plan.

Here is the assembly mocked-up - Spring held in place for now with a vise-grip.



I used some old folders from work, rough cut, trimmed, taped together until I had the size and basic shape I was looking for that would hold the spring in place while still allowing suspension movement without the spring catching or binding.


The mock-up part -



I'll be adding a tab to prevent spring rotation right where it says "end" (the end of the spring). The spring will have a tendency to rotate into that tab, based on suspension movement and the new bottom coil shape. RH side will be a little different due to coil direction vs. suspension swing direction. And the wall height will be an even 1.75 inches around, curved inward for the top 1.25 inches. The real part will be 16 gauge steel, and welded to the stock arm. Stock spring perch nub will remain so that the stock UPR spring pad / bumpstop can still be used. We will be able to make minor adjustments in ride-height / corner weights by inserting stock spring pads.



* before everyone gets in a tizzy about the fact I cut the springs, let me just point out 2 things.
1 - Its chump car, and the E30 is at the top of the value chart. This means no extra expenses without penalty laps, so buying some H&R sport springs are a no-no - likewise, I didn't want to run stock spring rates.
2 - I didn't just cut these. I'm an engineer in the auto industry. I sat down with my suspension design books, equations, measuring devices, springs and a list of all the common aftermarket spring rates / ride heights for the E30. Based on how much spring I had to work with (still need to keep some ride-height for suspension stroke), the target is the H&R sport springs for spring rate. Fronts were an easy calculation and should be within 2-3%. The rears are a bit trickier and took some estimations but I'm confident they are within 10% of H&R sport springs - on the low side. Ride height will be a bit higher than H&R Sport, but I'm not as concerned about that. Once calculations were done a few times (ok, 5...) and some more very careful measurements, I took the cut-off wheel to both the fronts and rears. The spring in the above pic is the outcome. Once I can locate a spring rate checker for free, I'll get the actuals. Dampers are a different story that will be handled when the time comes.

[NigelStu]

I
HATE
RUST!!!!!!


I have managed to get a LOT of work done this week, and Themla is getting ever closer to being track ready. I'd say she would be good to go already, but DAMN that rust!!!!! I'm estimating that at least 50% of my time spent for the entire build so far has been dealing with rust. Spraying, heating, wrenching, swearing, beating, breaking, more swearing... buying replacement parts, more swearing...

This past week I dropped the entire suspension. Front was easy. Rear, well, rust sucks.

At the end of the day on Tuesday, here she is. Ready for different suspension (I'd say 'new', but its really not. just parts pilfered from Louise)



Fronts came apart and now have shorter springs and new front hubs with 75 mm wheel studs from Turner installed. New tie-rods put on and the fronts re-installed in their new 'max camber' position. Fancy.

Rears sub-frame came out, but not without a lot of cursing and persuasion. In the end, one axle nut appears to be welded in place (thanks mother nature!) and both of the sub-frame bushings broke the tip off in the body... How the F do you get those out????

I took some time to clean up the spare sub-frame, diff (new seals) and arms. Since I had to knock a bunch of rust off the sub-frame, I decided to throw some paint on it - in an attempt to still make it look not so great for Chump, I used gray primer...

The old (2.9 LSD out of a ES) and new (3.7 out of the IS).




To get this bad-boy mounted up, I just need to finish up the spring perches on the rear arms and figure out how to get the old bushing material out of the car. Side-note, rear arms have new bearings, brake lines (I'll get to that in a minute...) and the same 75 mm studs. Keeping the trailing arm bushings since they seem to be OK.


Now, rust issues. SO much rust on the underside of this car. I discovered that not only are the brake lines on the trailing arms shot (um... OK, they were fine until I attempted to separate the hard-line from the soft line, at which point the hard-lines twisted and broke....), but also there was NO way I'm swapping the inner soft-lines for the fancy UUC stainless Steel lines without replacing the short hard-lines there. I figured I could take the main rear line (minimal rust) off of the distribution block and just replace everything past that.... HA! main line is rusted solid to the dist. block, the dist block is rusted solid to the body, and the other lines of course are rusted solid to everything else..... looks like its time to buy myself some tubing and a flaring tool! Horray installing a 10ft long piece of brake tubing with crazy bends all over the place.....


On the positive side, all this extra work has freed up probably 5 lbs worth of dirt and rust...



Soon. Soon. The car will be drivable!

[NigelStu]

Running new brake lines to the rear ended up being a very good thing.... A pain in the arse, but a good thing!

The majority of that line looked good, with the only rust I could see at the distribution block at the back. Apparently not so - since while removing the line, it snapped near the front, just before it bends upward to go the the master. That likely would have failed at some point in the race, leaving us with no rear brakes and probably off the track somewhere, in the middle of the night on the back side of the track where there are no lights.....

Pain in the arse, well worth it! I now have full confidence in the braking system on the car.

I ended up just buying a 25ft roll of tubing, a little cutter and a flaring tool. So... If anyone in the Detroit area needs some brake lines made up, I'm getting pretty good at it!


And, since I managed to beat out the broken pieces of the rear sub-frame bushings, the new rear sub-frame can go back in. I spent some time searching on best way to remove the stuck bushings - and came across the 5/8" lag bolt idea. Awesome idea I thought, only my bushings were so frozen to the car (even with lots of PB Blaster and FreezeOff) that it didn't work. I ended up taking a big drill bit to it, and some dremmel work to basically slot the sleeve enough to break the sleeve apart and have them drop out. Once again, corrosion turned a 10 min job into an hour.... At least its ready!

The best part of being at this stage. All the dirty work is DONE!!!!!! Everything that is coming off the car has been removed, dirt and grime have been knocked off. Clean parts are going back on. Ah!


Pics coming soon once I get the girl back on the ground.

[NigelStu]

Break time - aka, the calm before the storm!

This past week has included a TON of work, late nights, and finally, a car that can be rolled around and even driven all under its own power!

• Front suspension modified, reinstalled - check
• Rear brake lines run - check
• Diff cleaned and re-sealed - check
• Rear half-shafts cleaned, re-greased - check (F'n rust... ended up stealing one off of the Zinno for time being - only other fricken half-shaft I could get un-bolted from a stub-axle and/or hub....)
• rear sub-frame removed, cleaned up, re-assembled - check
• Fuel-tank dropped, checked for holes/rust, sealed in potential leak areas and lines replaced - check.
• little bits and pieces of old sub-frame metal bushing drilled, beat, chissled and cursed out of the car - check.
• Assembled rear sub-frame reinstalled in car, complete with new spring perches, brake lines - check.
  
• Wheels back on the car, tires touching the ground - check!!!!

Woo Hoo! the car even fired right back up, goes through the gears, everything seems to work!

And I dropped it down on the scales - a bit heavier than I was hoping for, but 2300 lbs (w/o driver) is not so bad! Cross weights even came out to 49.4% - hell of a lot closer than I was expecting and well within adjustable range to get the (hopefully) ~51-52% I want for Nelson's ledges! BONUS!


Anyway, obligatory teaser pic. Not the greatest shot, but since I'm in Mexico again, its the best there will be until this weekend.


Yup, that's right! Thelma's grand track debut will be this Sunday out at Waterford hills. Testing, tuning, familiarization and economy calculations to be done. And of course, more pics - and real pics, or the girl in action and not sittin' in the garage! WOoootttt!!!

(If anyone in SE MI area want to come out and check the car out in person, head on up to Waterford for the OTD on Sunday!!!!

[Keith M]

Good job! Heck of a lot of work you have done. What is going on with the rear of the trunk lid? Looks like it has duct tape on it and it's purple.

[NigelStu]

Thanks Keith - its been a fun project so far.

If you take a look back at some of the other pics, a few body panels came off of 'Louise' - a former bronzit car painted gold/purple. So yes indeed there is purple on the trunk lid. and hood.... That trunk used to have a spoiler, but I removed it (and sold it to help fund the build), and put clear duct tape on it just to cover the holes. Chump is not necessarily about good looks, and I've had a few people mention the car looks to nice for Chump... so I've picked and chosen a few select body panels to better fit the race.


Those nice panels are making their way onto the '89 I picked up - that car almost looks good on both sides now.

[NigelStu]

Fab work

We had the car on track over the weekend, and the suspension worked well. Here's a few shots of the fab work done for the rear spring perches.

I could use some more cool tools, like a bandsaw, drill press, etc....

First step - cut, bend, weld


Step 2 - paint and attach (weld) to arms


And what it looks like all together

[CabrioPunk]

Good work. Looks like a lot of fun. You aren't married? Jealous of the time.

Shot in the dark, but do you still have the fogs from that original valence? I am trying hard to find a good condition one to replace my cracked one.

[NigelStu]

Thelma on track!!!! and then off....

Thelma's first track experience has come and gone. There was good (she start! runs! moves! yay!!!!!) and bad (oh boy - slow down the back straight...), followed by good (it's only the CPS connector, phew!) followed by B. A. D!!!! (I thought this was a 6 cylinder car? what's that noise? why is there a puddle???)


Overall, it was a good, but busy and somewhat painful day. I ran a relay trail race on Saturday and decided to fubar my left ankle (severe sprain - its purdy colors right now...). Clutch was an uncomfortable thing to use, but for the 1 session I was out it didn't bother me. Sunday morning started with waking up early and finishing the last few things before heading to the track - like filling the diff with oil, setting front toe, zip-tying a few loose wires, removing ABS computer (no abs anyway...), filling the tank and trying to fix the trailer.

We got up to Waterford Hills about 10:15, missing the first on-track session but not a big deal. I wanted to check things out one more time before heading out on track. Plus it gave me a chance to check out the Lambo Diablo and Ferrari (new) that were actually running on track! woot!. Oh, and the very nice E30 that was also participating. :)

So, here she is, in basic race trim. Ready to rock before her first ever track session! (guy in red suit is my dad, next to him John, one of our other drivers)




Things were going well, as my dad took the honors of putting the first laps under Thelma's belt. Its been a while since he has been at Waterford, and the was Thelma's first ever shake-down (not to mention first time she's really moved under her own power in a long time), so he started out easy.


Car looked good out there, and pace was steadily increasing. The gap to a Porsche Caymen was not changing... and then.... coming out of turn 5, she slowed, and my dad puller her off at turn 6 station and hoped out. NOT how I wanted the first session to end...



Dead, no power. electrical OK. Turned out, after a quick look, that the CPS connector (broken) had come unplugged. a few zip ties later, and Thelma is back up and running. And my turn behind the wheel.

I headed out on track and eased into it. Thelma handles surprisingly good, better than I had hoped - A bit of a push and I can tell she is under-damped, but definitely controllable and pretty easy to drive. I quickly got into a rythem and brought her up to about 80% speed, shifting at 6k RPM. Never really pushing the issue, and found myself running 1:26 second laps. Not bad considering I wasn't pushing it, on street tires with street pads. For reference, I run 1:18-1:19 in my spec Miata at full-tilt.

But then, with the checkered flag waving for the session, there is a significant change in exhaust note, and a loss of power... damn. Are we down a cyl? car feels like its being choked off.... I make it back into the pits and we do some diagnosis. First thought, plugged exhaust (still has the cat on it). We start it up to see if we can locate the noise, and I notice a puddle under the car. Oil is spraying out of the filter/cooler adapter housing... oh shit. So, we pack her up and head home for a full diagnosis.

We decide that since Oct should be cool, no more oil cooler - we don't know if the cooler/lines are plugged/blocked or what, but something created more pressure... so back to the ETA oil filter setup. Next, removed the valve cover and found the reason for the noise and loss of power...

this...




So, I know what I'm doing this week! Since we broke a rocker at reasonable engine speeds, I figure the rest of the rockers are suspect at best. All new parts = reliability and confidence. 1.5 weeks to go to race, its gonna be tight!

[NigelStu]

Cabrio - I think I do have them. I'll check tonight to see what kind of condition they are in. I could use the sale of those to offset a few rockers.... lol. And no, not married (the GF has been somewhat understanding but not so willing to help.) - and I still don't have enough time!

[kts]

Looking at this, you might want to send some photos of this to 'Evil Genius' (john@evilgeniusracing.com is his email) on the Lemons forums to see what he says about the backstays.

http://forums.24hoursoflemons.com/viewtopic.php?id=3334 11th photo down, the backstays look similar to yours where they connect to the car floor vs the rear shock towers. They really seem to like having the backstays hit the shock towers instead of the floor.

I'd also get him to look over the hoop diagonal. Usually I've seen that bar end right at the main hoop bend and not a foot or so over like on your cage design.

Having wrote all that and looking over it again, I see that you are mostly doing this for Chump Car and maybe some Lemons. Chump Car's rules for the diagonal support bar state they want the diagonal bar "with one end terminating in general proximity to the main hoop bend above the driver's head and the other end terminating in general proximity to the lower end of the opposite side of main hoop."

I'd see if you can get contact the Chump Car people and send them photos of the cage design before your first event.

Sorry to be a pain with pointing some of this stuff out but I know a few folks who have sat out races or scrambled the day before a race to fix all of this stuff after their cage didn't pass Lemons tech inspection. They are pretty serious when it comes to the cage and other safety gear.

Other than that looks pretty good (minus the broken rocker) good luck replacing all of them and much better to have one go at a shakedown track day then during the event!

[NigelStu]

Thanks for the words of caution - its always good to have another set of eyes looking at something like this. Although, I am in no way concerned about the cage passing Chump tech. We spend a lot of time with the design and where the attachments should be to maximize safety. Cage was actually built with SCCA in mind - All aspects will pass SCCA safety inspection (and over-built in regards to tubing size). My cage builder is well known in my area for making excellent/safe cages and he recently completed a similar cage in another E30 for SCCA use that has its logbook.

Main diagonal is legal, and its attachment point is located there to provide adequate helmet clearance when the seat is moved all the way back for taller drivers. May be the angle the pic is taken at, but the diagonal attaches only about 6 inches from the rear-down-tube node.

Down-tubes touch down right on top of the spring perches/rear frame rail, where all the suspension load is transmitted - A stronger, smarter design than the strut towers that are more likely to crush/deform in a roll-over condition. Unlike that picture 11, the tubes have adequate space between them and are attached at (not between) load-bearing areas.

[CabrioPunk]

Cabrio - I think I do have them. I'll check tonight to see what kind of condition they are in. I could use the sale of those to offset a few rockers.... lol. And no, not married (the GF has been somewhat understanding but not so willing to help.) - and I still don't have enough time!

Good man. Not knocking. Just jealous!

Looks like fun times at the track... A typical day it seems. Go fast. Break a part. Pit fix. Go fast. Prepare for next time.

Id be glad to have the fogs. Just need one, but if you have both in working and unbroken finish is take both in a package deal. Help offset some cost of that race car.