Lonestar's RC10 OIN - turned B1M Racing chronicles (Race #3 on P.7)

[Lonestar]

What does the width of the motor slot need to be to run a silvercan?

The silvercan went back into the brushed motor box... I have to check

More work on the car the past couple of evenings... Fiddling with electronics placement, which is always a PITA as one wants to optimize while not spending tons of time seeking perfection, at least not on a suboptimal vintage-ish pseudo-racecar

So, I started with a well known hack

I want to play with different motor placement via spur/pinion changes, so a bit of buffer is needed:

Of course, the neat, tidy and short cables I had resoldered to my controller were too small... needed to pull out the soldering iron, and fit new wires to the speedo, which I abso-freaking-lutely HATE to do... I have an old pack of dubious quality to hold the bullet plugs while I solder the wires so I don't heat up a racepack. Joints look good (and even better in the flesh than on this pic), nice and shiny, homogeneous. Thanks to my 100W Weller

One more countersinking, still, for the antenna holder. I've drilled so many in that bitza's tub already, I thought, what the heck

At last, all done now. I fitted the shocks as they were after last race to get some reference point, and the damping is an absolute disaster (as expected). Gonna go back to #2 pistons and 35WT oil all over, and start back from there.

Over the next couple of evenings I will fiddle with shocks to get something acceptable on the bench, I won't have time to mount that new body, which is a shame. But bodies don't make racecars fast (at least not offroad bodies...), shocks do. Priorizing 3ds before raceday is key

Till next time...

[scr8p]

Well, so much for the discussion a couple pages back.

What it needs, which it would probably never get, is have 6-10 guys build a car in the form of the original idea. And, keep them all very similar....... almost like a kit. Then go out and test, share info, etc. That's the only way to help it evolve.

Looks good though.

[Lonestar]

Last update before after raceday

(which looks like it might not happen as I'm on waiting list... grr... screw these guys who sign up and don't show up...)

Spent the whole evening fiddling with shock setups yesterday, playing with mounting points (towers and arms), shock eyelets, collars, bottom retainers, springs, oils, pistons...

I even ran out of inner shims

The front buggy shock springs (silvers) are too short, even with the shock collar screwed to the bottom... and I didn't want to use split collars, not reliable enough esp. on the "conical" part of the shock body. So I had to revert back to front truck ("blue") springs as the closest thing in the range, stiffness-wise. I did tell you I fiddled with stuff, right?

B4 Shock retainers were too long... had to pillage parts off another one of my runners

I still can't get the suspension where like I'd like it to be. In the end I have #2 and 37.5 all around. Static is good although not plush, but dynamic feels wrong, the chassis slaps a bit when dropped from one foot, both front and rear. It's stiff while not having enough pack I know #3's in the rear pack too much, the plushness is gone and when one drops the car you can see it "rebound", likely on the tire inserts and possibly even on the suspension plastics. Maybe a #2.5 would be the way too go but I have to admit I'm fed up with this now. I'll drive it as is, hopefully the MM aspect will help me overcome some of the crappy suspension setup.

aaaaaand the icing on the cake is, the body doesn't fit anymore... so more work tonight, still... sigh.

Honestly, I'm at the point where if I don't get a slot for saturday's race, screw it, I'll go skiing with the kids instead!!!

[Lonestar]

And, we're back for the second to last installment of our "how to race a vintage-ish car in a modern race" series

One last couple of mods friday evening, BHS at the bottom to not damage the track, as well as new-but-dull black nylon nuts for the steering to take some off the slop off (the old ones' threads appeared stripped, actually!)

In the end, I was able to race, thanks to other drivers cancelling their registration

It's very important to have the right T-shirt during raceday - here I settled on a AE/Reedy "80's-pink" Tee (the pic was taken after the race, one point if you tell me how you figured it out!)

Here's what the track looked like at 7:30am saturday morning (picture taken during briefing). Very technical, not fast, no big jumps, the usual "8" jump in the middle that has become a staple of the SIORC. 50 guys signed up in 2wd, including a couple of continental hotshots who really really wanted to race that day and did hundreds of miles to be with us(a regular B-Mainer at the EOS, and a full factory Kyosho guy that usually ends up in the top 20 at the Nitro Euros), plus all the fast locals.

No free practice (not enough time, there were 100+ registrations with 4wd, SC, and Juniors). First 3mn run - reseeding, in a top-tier series (the second fastest I think), where your fastest three consecutive laps determine which qualifier you will end up with. . Only the club members who assembled the track till 1am have actually practiced the night before (which is fair - everyone can help build up the track, the reward is you get to drive it). I couldn't drive it before, So I basically have to learn the track in 3mns tops. The car actually feels pretty good, very, VERY different from the rear-motor from before. It drives almost neutrally, but still on eggs. In the non-bumpy sections it's very fine, on the jumps it's still below average, but I can do three semi-decent laps, and I end up with a 49.8s, which puts me in the second qualifier at the 18th position. The top-reseed runs a 45.2 (he built the track the evening before PLUS is immensely talented), most fast guys run hi-45's to mid-46's.

(TBC)

[Lonestar]

Net - I'm not fast, but I'm not shamingly off-pace either. Some of my fellow racers who were there the race before comme and tell me "this is definitely a different-driving car than last time" (when it was pushing like a pig). And I have to agree, I know I'm not "competitive" but the car is not a pile-o like last time... so time to pull out the B5's BB I had taken out from the "Blue Is Better" TRX-1 at the last minute the night before when packing up the car and thinking, what the heck...

This takes a bit of adaptation, and I'm well helped by the fact that the reseeding takes ages, I'm not in the bottom qualifer (that would start first) and qualifiers now last 5mn.

So, after a bit of work, that's what we have:

I had to pull out the dremel to remove some delrin on Jake's (Dynotechs? No idea...) lovely arms to clear up the spring retainers (didn't take the plastic set), oh well. This is a runner after all. I also had to re-use the STRC alloy mount I had on the TRX-1 as well as space these away from the front tower, what you see here are conical washers, this was not to be refined, and I still had to wrench somewhat fast (and prep my son's car and marshall it, as he was again running in the junior class)

And off to the first qualifier I go. OMG what a change... the car now has a proper suspension! Not perfect, but it's beginning to feel like a racecar. There's still too much roll, and it slaps a bit when landing, but I can actually start driving the thing on throttle instead of just clenching my buttocks all the time! I'm beginning to have fun, and to hope I can land a mid-to-top of the B slot... I am 13th for now with an 18L 5mn04, BL 16s0. Again, people are stopping by to look at the car and compliment it TQ is a 20 lapper, BL 15S3.

Second qualifier, even better as I'm finally racing now, but then again everyone improves their times, I do 19L 5:13, BL 15.7. That's 7th in that round (but some of the guys were faster in the first one, so I'm probably like 12th or so). I was even in the lead of my qualifier for quite a while, not being that fast but running very consistently, I just had an 18s lap and the rest was all in the high 15's - lo 16's. This was all good. TQ is now a (faster) 20L, BL 14s9.

Third qualifier - I borrowed a pair of Schumacher Cactus's which are the replacement for the no-more produced minipins which we used to run till the beginning of the season. My minipins were washed out (didn't want to dump more cash in a substandard racecar), and I could feel they were slowing me down now. So here I go with the new tires. The car has a LOT more side grip now, but this means I rolled it a couple of times too... but I was still doing good. And then disaster struck after 1mn30 or so, the car whines and doesn't move any more... I'm thinking "oh no... the diff..."... but it turns out it's the spur. That round was not going to be faster anyway as I had screwed up the first few laps due to the significant handling change, but I would have liked to do more laps just to learn this more! Oh well

Now... changing the spur on this baby means taking pretty much everything but the bulkhead off the car, including the battery box, everything... it's a PITA to be honest, and not a quick job. But a man's gotta do what a man's gotta do, and I change that spur as fast as I can. I run to the board and I can see I'm 6th in the B with my second qualifier, as I could DNF'ed the third. Everyone's going faster, TQ is with the EOS B-main guy (what a surprise) as his yokomo ran a fast 20 lapper so in the lo 5mns with his BL being a 14s4

(TBC)

[Lonestar]

Time for the mains, still with the used rear cactus loaners

First main starts ok as I can work my way through the first corner's pileup, and I'm running third or so for the first 3.5mns or so, then I roll it a first time as it's still not a "relaxing " car to drive, you know you're on eggs somewhat, and then at the last lap a few corners before the line when I'm 5th or so, WIIIZZZZZZZ and I'm thinking "OH NO!!!"... and I can just pass the line, then the car stops... YEp, you guessed it, a chewed spur (take same picture as above ). I'm 5th (so 1-up vs. qualifier, which is always a bonus) with 18L 5mn07, BL 16.0s. The B-main winner does a 19L 5mn02 with a 14s9 BL.

I'm out of spurs now... I had one backup, not two Fortunately, this is the same spur the B6 is using it seems, and there are plenty of B6 drivers around that are willing to help (at least one of them does ), and I can do the switch faster. I try to set up the gear mesh on the low spot now instead of not thinking about it last time... It IS still a PITA and I'm getting tired of wrenching all the time on this car with zero buffer between my runs, my marshalling, my son running, marshalling my son, and fixing the darn thing! But I'm still ready for the last main.

The start of the second B-main is a bit less lucky for me this time... I can squeeze past a few guys but at like the third corner, I get taken out, it happens... but I'm starting dead last. I climb my way all the way back to third again as the others do mistakes too, plus I'm racing with zero pressure so that makes me faster! And at ca. 4mn30... no more throttle, but no WIZZZ this time, no clue what's happening... but I'm gutted. When the race is over, I pick up my car... and the pinion had come lose and free inside the black tub. Which is a shame, really, as this was my very best run, I was clocking 15s4's and 15'6's consistently. Oh well. The winner in the B does a 19L 5mn08 runinng low 15's consistently. The A-main winner Mr EOS did a 20L 5mn04, with BL 14.4's (and he did a few).

That gives me the final ranking of 18th, which, with a DNF towards the end of the last main, is kind of expected.

(TBC, conclusions)

[Lonestar]

Here are my key takeouts.

1- Big Bores are a must. I still think the suspension cinematics are not "right" on this car, a B4 or C4 and C4.1 with stock small bores was plush, this isn't. This could also come from the arms mount / bullkhead which are made of nylon and could be too elastic, compared to the modern graphite-loaded, stiff-as-hell (as losi called their plastics bitd) plastics. The "smaller" arms aren't probably helping either. The way the front tower flexes back and forth is (honestly) appalling.

2- When looking at the car, it's much narrower than its modern counterparts at the front, and wider at the rear. This means a darty front end, and possibly explains the permanent "roll" I think i could feel/see all day long.

3- The steering is wobbly, all the time. There is slop everywhere, but also the trigonometrics of the steering make the whole assembly "floaty" when loaded. This is striking visually with the inside front wheel moving all over the place when the outside wheel is loaded. Not sure how to remedy this, but again, using B4 c-hubs, SC10 spindles, custom arms, on a 10T bulkhead is probably not what the AE engineers had in mind

4- Still, overall, the car was not totally off-pace. I would have loved to put it in the A, but I don't think this was possible, even with a better driver. The other cars do everything right - jumping (landing, especially), steering, they are both agressive and stable, on- and off-throttle. The OIN B1M still has a bit of a mind of his own, which the driver has to cope with. Then again the modern cars are 30yrs younger

5- I am not sure where my transmission problems come from. I am leaning towards the cheap motor I'm using, maybe the shaft is off-spec, maybe the bearing is blown, I don't know... I have a hard time thinking the motor plate is flexing, but you never know I will triple check everything for the next race, and use another 8.5T with a "normal" price tag that time

6- Accessibility on that MM setup is a PITA. Maintenance is a PITA. But then again, that's the case of most MM cars, it's inherent to the design, the motor is in the middle (duh) of everything. But still, this is worse, because this setup is afterthought (for instance you can't access the slipper locknut with the shock mounted, unless using pliers). BUT BUT BUT, that kit is worth every penny, because...

7- ... I had the abso-freaking-lutely COOLEST CAR ever at the track that day Last time it was cool, but still a bit of a joke. This time it was just as cool with the body on, but with the body off it drew crowds, and on the track people couldn't believe it. Mr. EOS came to chat (in English, as he was only german-speaker and my german is crap) to enquire what it was, had a look, asked questions. All my racing buddies stopped by at some point or another to try to understand what the heck it was that I was running that day and why it ran so much better than last time, and heck, semi-competitively, even. I had people literally coming to shake my hand and congratulate me at the end of the day for having raced with it and not been ridiculous. Honestly, I think this is how the Beatles felt as they drew crowds at their heyday in the 60's (except there are no promiscuous girls at the racetrack, unfortunately) - I was a rock star And for this alone, this car is fantastic

Voila... this is the end of Race #2. Race #3 is in March, till I need to fix that steering wobbliness (how?!?), I bought a whole set of tires to be better off right away, I need to buy a pallet of spurs, I will have to check if I can lengthen the camber links to free up the suspension a bit (protect track width under compression), I need to change the motor, etc... I have a few more ideas to try.

Stay tuned for next time

[XLR8]

So what's causing the spurs to fail?

EDIT: Sorry I just read your latest post. Curious to learn what you find.

[Lonestar]

So what's causing the spurs to fail?

you need to read it all, not just look at the pictures

(hint - #5 in the last post )

Edit - read your last post too... will keep you guys updated about what I find out (if I do find anything other than a faulty motor... I will tear down the transmission anyway, I can do it with my eyes closed and one hand behind my back now )

[XLR8]

I read every word. I was typing while you were posting.

[Lonestar]

I read every word. I was typing while you were posting.

I know - I edited mine, too

[XLR8]

Unless you installed new ones, wobbly steering could be worn/undersized hinge pins. I'm guessing your ball studs and cups are new so they're probably not the cause. The plastics tend not to wear so wear is usually at the pin. You might pull the pins and check with an accurate digital caliper.

[Lonestar]

Unless you installed new ones, wobbly steering could be worn/undersized hinge pins. I'm guessing your ball studs and cups are new so they're probably not the cause. The plastics tend not to wear so wear is usually at the pin. You might pull the pins and check with an accurate digital caliper.

Can you please clarify which hinge pins you are thinking about? The C-hub-to-spindle ones?

[XLR8]

Well, I guess all of them but mainly the arm pins since they see the most movement. I say this because I recently had to replace all of the pins on my RC10 runner (it's got a ton of miles). The steering wobble got so bad that, in a turn, the inside front wheel looked like it was coming off. When I replaced the pins, everything tightened-up almost like new and the handling suddenly became incredibly precise. A pin that is few thou under-size can result in many degrees of movement at the wheel. And, it may not even be due to normal wear. I wouldn't put it past AE and their questionable QC to have sent out new pins that are out of spec. The pins are made from 1/8" diameter steel rod stock and, depending upon where the material is sourced, the OD can vary quite a bit.

[Lonestar]

Well, I guess all of them but mainly the arm pins since they see the most movement. I say this because I recently had to replace all of the pins on my RC10 runner (it's got a ton of miles). The steering wobble got so bad that, in a turn, the inside front wheel looked like it was coming off. When I replaced the pins, everything tightened-up almost like new and the handling suddenly became incredibly precise. A pin that is few thou under-size can result in many degrees of movement at the wheel. And, it may not even be due to normal wear. I wouldn't put it past AE and their questionable QC to have sent out new pins that are out of spec. The pins are made from 1/8" diameter steel rod stock and, depending upon where the material is sourced, the OD can vary quite a bit.

Ha. I see what you're saying, that's slop in the suspension you're talking about, that's creating slop in the steering knuckle (slop doesn't add, it multiplies). No, not an issue on this car, it isn't any sloppier than a modern car, if only because the suspension was actually very tight when I started working on it a few weeks ago and I had to enable the pins to move at all in the delrin

The steering geometry is the issue I think, because the inside wheel's (i) spindle pivot point (ii) spindle ballstud (iii) steering rack ballstud are pretty much all aligned at max lock, this plus the insane ackermann rate (the differential rate if you want).

Again, that's why modern cars have the steering system pointing "backwards", so the steering rack arms move parallel to the spindle to avoid this effect. It was probably of lesser importance on RM cars (even the B4) but as MM architecture started taking push out of the equation and load the front wheels more, this becomes an issue.

Maybe I could flip the steering rack by drilling the nose plate... but then again the ackermann tuning would be a lengthy quest... I won't do it