Modern vs. Vintage

[fred2000]

So I am sure there is a significant difference but I would be interested to hear peoples opinions. Just how different are the new cars vs. the vintage version (say '88 - '94). Is is just that a lot of the carbon and trick parts of the vintage era are standard on the new cars or is there a real big difference.

Also are newer cars about to handle the new batterys (lipos) and motors (brushless) better?

Any major challenges if I wanted to run my 870c with a brushless set up and lipos?

Interested to hear what people think,

Fred

[minichamps11]

Sticking with the racing class & brands I've raced the longest and know best, the older Yokomo & Schumacher 4WD buggies tended to have narrow section belts in order to maximise drivetrain efficiency. Back in the 80's & early 90's, club racers with 4WD cars struggled to race competitively for 5 minutes using commercially available batteries. By contrast, the latest CAT SX has deliberately sacrificed drivetrain efficiency (with 3 belts AND gear drive transmission!) to improve handling.... with today's brushless motors & LIPO cells 5 minute racing is no problem.

I wouldn't trust any buggy prior to 2002 to be reliable with hot brushless motors, but I reckon they'd cope fine with milder ones. Other issues I've heard about are older single plate slipper designs and vintage diffs with small diameter diff balls which destroy themselves with modern motors & cells. Also older buggies struggle to fit modern high capacity NiMH cells (they've grown in diameter over NiCd cells), and you're likely to need some major dremeling to fit LIPO.

On the subject of hot-ups, I agree that older cars generally used more fibreglass than today. For example Schumacher in the late 90's released all of their kits with fibreglass chassis & towers & steel turnbuckles, forcing the racer to buy titanium & carbon fibre parts as upgrades. Today's racers wouldn't buy a kit with this spec - the Lazer ZX5 had a moulded chassis & steel turnbuckles & it's never managed to get over it's "club racer / sport" image.

In my experience titanium turnbuckles are a necessity as steel will bend mid-race & screw your handling up. Fibreglass versus carbon fibre parts is a bit more complicated. Neil Cragg has said he prefers the slight flex offered by plastic, hence he uses the plastic tub on his RC10 B4 instead of the stiffer graphite option. In my experience the same thing works for fibreglass. The last car I upgraded completely from F/G to C/F was my CAT 3000. It made a big weight saving, (no longer needed with modern electronics - more weight equals easier to drive & more traction), but on the downside made the car more lively to drive (not what I need at my skill level) & the shock towers broke more often because the carbon fibre parts were stiffer & more brittle than the original "flexible" fibreglass parts...

I think the biggest improvements between vintage kits & their modern counterparts are due to:
a) better quality materials
b) design improvements brought about by competition & best practice
c) Cars now more user friendly i.e. "E"-clips now replaced with screws to hold pivot pins in, Allen key cap head screws instead of posi-drive screws
d) Designed for today's motors & cells i.e. CAT SX not only comes as a LIPO version but you can alter the internal gear ratio to suit brushed or brushless motors
e) extensive use of CAD software to analyse part stresses, tool access paths etc.

Be interested to hear what others think on this subject. I'm a real geek for this kind of discussion

[Bender]

Must admit, I too find these type of discussions facinating

Whilst I agree that the quality of competition cars has improved dramatically since the late 80's, I don't believe that the designs of the cars are getting much better - more just a slight evolution each year.

The best examples of this are the B4, which is still the dominant 2wd and has been around for 5 years, and then the Losi xx4, which is still competative (and probably still the best handling 4wd) and it is now 11 years old!

In many cases, newer cars are simply re-inventing previously tried ideas, but using better materials.

The major developments (in off road at least) has been tyres. The tyres we were using even in the early 90's were terrible compared to the losi red and proline m3 compounds of today.

What has also changed is the "design philosophy" of the manufacturers. In past decades, the car designers were always trying to make a "perfect" car - one that worked equally as well on all types of track conditions. If you look at the evolution of the electric 2&4 wheel buggy, you will notice from the late 90's onward that designers seemed to abandon this approach, because it really isn't possible, and instead they refined their designs to work better on certain types of tracks.

Of course eventually, everyone got the "latest" buggy, and so any disadvantage it might have had on some surfaces became irrelevant, because everyone was in the same situation.

Every now and again you can see on some race reports where someone has taken a relatively old buggy, and have been competative because the situations favoured the "old-style" cars.

[Bongo Fury]

Regarding brushless motors and lipos, I think designs for those are still in their infancy, especially for stock 17.5 brushless. The brand new Cat mentioned is the first attempt I am aware of to address the gearing needs of a 17.5. And given that so many are adding weight to cars to offset the lighter lipos, I suspect cars will change to better accommodate. Hopefully this will lead to improved durability.

A lot of the change is in the tires, bigger diameter (less scale) rims and much softer rubber. In many ways tires have replaced motors as the money pit, and thus probably a source of income for the industry. I used to hate the typical suggestion to someone just bashing, to use a Roar Stock motor. Especially in the non rebuildable (officially anyway!) days. The relatively high timing intended for racing is not good for general bashing. A somewhat lower turn motor with less timing is much better, less heat, better runtime, better motor life. I used to use such a set up as a practice motor, only switching to a race stocker for my last practice run. Not even that for a club race.

And of course batteries have changed just a little….. I still chuckle before every race at warm up laps. In the day we didn’t dare even turn our cars on until the very last second, at big races guys would use mechanics to do just that. The cars were set directly on the grid, no driving over to it even. Nowadays it's not unusual to run for a couple of minutes before the race even starts.

Now we have tons of battery and power available. Which destroys the soft tires at an amazing rate. The 1/8 electrics, which appear to be The Next Big Thing if not already, are stunning in this regard. Has prevented my little team from getting one, so far anyway.

[Mr. ED]

mmm, interesting
I don't intend on going heavy on brushless any time soon; still love driving the old stuff with 27turns.
But given the few classes and usual lack of stock 4wd: I'd love to hear about options to mount a contemporary double slipper on a 870C drive train...

[minichamps11]

Bender, your comment about the XX4 is a good one. The car is still up there at the top in the UK. It was ahead of it's time first time round, but the cells we were using back then meant it was hard to drive it fast for 5 minutes on grass and not dump. Interestingly enough, when Losi re-released it a few years back, the graphite material used was actually worse than that used originally. It wasn't unusual to see people break towers or front wishbones every race.....

Some cars are genuinely new & original, but I guess there's only so much you can do with a 1/10th scale buggy. They all need to take the same cells, motors, ESC, tyre sizes and have the same length/width restrictions. CAT SX is probably the most innovative 4WD out there at the moment. At least it's not a BJ4 clone.

I only recently realised that the X6 (which I thought was a new concept) is just based on an idea that's been around for a long time. A lot of RC companies bring out new cars (this is very evident in the touring car market) every year just to sell more kits. They change things for change's sake, and it's unlikely they offer much improvement in performance.

[RC10resto]

And of course batteries have changed just a little….. I still chuckle before every race at warm up laps. In the day we didn’t dare even turn our cars on until the very last second, at big races guys would use mechanics to do just that. The cars were set directly on the grid, no driving over to it even. Nowadays it's not unusual to run for a couple of minutes before the race even starts.

yes, I last raced in 1993 and when I went to check out the Nats this last summer in So Cal I was shocked to see guys doing a couple warm up laps - a different time.......I might actually like electric now.
Brian

[Bongo Fury]

In respect to 2wd off road buggies: Most of the changes are fine tuning in nature, not dramatic, but still there. Better weight distribution and lower center of gravity. More developed suspension geometry, in most cases longer arms, better control/tuning of roll centers.

The steering systems are more sophisticated and fine tuned. Better control and adjustability even of Ackerman, less bump steer.

As mentioned more capable diffs/trannies. More efficient with less gears and lower rotating mass/inertia. No more exposed diffs, metal out drives for more consistent & reliable diff setting. Included slippers. Diffs at the axle level instead of above, a major source of the lower center of gravity. No more flopping dog bones at both ends.

In terms of materials, in some cases less exotic, but most are more. More molded components, less woven graphite. But also more sophisticated design, shaped chassis that tie into the bulkheads instead of an essentially flat aluminum or graphite with parts just bolted to the flat. The materials have progressed beyond basic nylons, in many/most cases fibre loaded, various composites and such. And lower friction, such as in the gears.

Other electronics have improved, steering servos have certainly improved in speed and torque.

And yes, track dependent to some extent, as the tracks have changed probably at least as much, if not more, than the cars themselves.

Are the old cars capable of pretty good performance when properly tuned and expertly driven? Absolutely. But… take that same expertise in a new buggy, even with the same electronics, I know where my bet would be. If the old cars were better they would be ran.

Losi’s history, and my own to some extent, provides a great example: Back when many (me included) were running the top line graphite JR cars, kids with the budget Juniors with the molded chassis were doing quite well. Notice that all 3 of the top buggies now have molded chassis? I actually tried going back to graphite on my JRX Pro SE, tried for quite a while on many tracks, but it never worked as well as with the molded chassis. In fact it still sits in that condition, one of the restore tasks I need to tend to. I had gotten to the point where I was doing reasonably well with the molded SE, then came up with this brainstorm(?) and struggled for a while. Bought the molded XX when it came out and boom I was back to where I was.

Sorry for rambling on, a subject that I also enjoy. Ties into my day gig, I've worked with full scale suspension design & development for quite a while. Cheers!

[minichamps11]

Good post Bongo Fury, you eloquently described what I was trying to sum up.

Not all generations move a car design forward....XX4 - XXX4 on bumpy European tracks comes to mind, or the last two Yokomo generation. The Yokomo MR4-BC was a half-ars*d touring car conversion with using MX4 wishbones & the touring car moulded chassis, result = almost 1/11th scale size. However it always had loads of steering & was highly agile. In the hands of Mr Cragg it dominated the 2005 British National season. When the MR4-BX came out for the 2006 season, Neil went backwards through the field and remained at the back of the A-final grid /front of the B until he picked up the Yokomo B-Max at the end of 2008.

The problem? The MR4-BX was designed specifically for low grip tracks (Italy worlds) and has a reputation for being hard to tune for high grip without major modification. It also has exposed diff's just when shaft drive cars started offering entirely sealed drivetrains..duh. These need rebuilding every week in dusty conditions...great progress from the 870C heh?