41LikesI'd like an understanding of why 1/8th cars work
09-29-2019, 07:58 PM
#1
I'd like an understanding of why 1/8th cars work
and how in the world did somebody think that far out of the box to develop them. I'm sure it wasn't a single individual.
But in my head, I feel I can make a more graceful (?) exit from 2wd Pancars into 4wd, if I understood why they are what they are. and I've tried internet searches to no avail.
If this is making you laugh a bit, fine. But I have asked this question to a few veteran drivers and the answer has pretty much been "it's just the way they are".
But in my head, I feel I can make a more graceful (?) exit from 2wd Pancars into 4wd, if I understood why they are what they are. and I've tried internet searches to no avail.
If this is making you laugh a bit, fine. But I have asked this question to a few veteran drivers and the answer has pretty much been "it's just the way they are".
09-29-2019, 09:41 PM
#2
Tech Apprentice
What I haven't figured out is how a 4 wheel drive car with a spool in the front turn
09-29-2019, 10:13 PM
#4
And the jacked up roll center in the rear? How does the car NOT snap roll anytime it turns hard!
09-29-2019, 11:17 PM
#5
In the front we run a oneway. most people choose to run an overdrive to the front so they are locked for the most part. Others choose a neutral drive or a bit underdrive which gives no or less drive to the front so when the rear wheels spins the front will step by and correct the car. Because there is no diff in the car the overdrive to the front is set by 2 choices of a side pulley and you can play with the tire diameter.
The rear works as a gokart in the corners, the wheel on the inside of the corner is lifted up.
Due the front oneway the brake will only work on the rear axle.
The rear works as a gokart in the corners, the wheel on the inside of the corner is lifted up.
Due the front oneway the brake will only work on the rear axle.
09-30-2019, 07:55 AM
#6
Well lets see.......if you go back to the mid late 60's and the founding of the sport by people like George Siposs, Norb Meyer, Roy Moody, Gene Husting.... they scratch built cars by hand patterned after Indy, Sports, and Can Am cars of the day. Their budget would not allow them race 1:1 race cars but their scratch built mini replicas where well within their means. The cars started out as 2wd cars and racers being racers, everyone started looking for a new innovation or edge to put them ahead of the guy in front of them. As more people came in to the sport with them came new ideas on being faster. A lot of the ideas failed miserably but many of them didn't and soon where adopted by other racers as well. Somewhere down the line someone came up with the idea of having all four wheels drive the car. Pretty much from the get go, 4WD was significantly better than 2WD such that the classes where separated. 4WD drew in even more people to the sport and as a result more innovation to go faster than the guy in front of you. Bottom line is this....today's modern 1/8 4WD car is not the result of any one persons design and manufacture but rather the result over 50 years of evolution design by a substantial group of racer innovators too numerous to list here
Last edited by P2gee; 09-30-2019 at 12:52 PM.
09-30-2019, 01:09 PM
#7
Not to mention a perfect set of rules that haven't significantly changed since the modern era of rc.
No stock or mod. No multiple class of bodies. Touring cars have six different damn classes now, and the popular one changes randomly every month.
You can box up your nitro onroad car, or nitrobuggy, and be ready to race anywhere in the world. In electric, nearly every darn track has different rules. 1/8th nitro is a perfect example of a class, that actually works well, and has survived the test of time.
Only downside is needing to team up with someone else for pit stops, and hopefully they travel reliably.
No stock or mod. No multiple class of bodies. Touring cars have six different damn classes now, and the popular one changes randomly every month.
You can box up your nitro onroad car, or nitrobuggy, and be ready to race anywhere in the world. In electric, nearly every darn track has different rules. 1/8th nitro is a perfect example of a class, that actually works well, and has survived the test of time.
Only downside is needing to team up with someone else for pit stops, and hopefully they travel reliably.
10-01-2019, 09:19 AM
#8
I haven't measured any of the current crop of cars but the last couple I did (MRX-4 and early Shepherd, like 09 or 10) had the rear roll center somewhere right around ground level or just a couple mm above depending on settings. That might be higher than a diff car would have but not what I would call jacked up. As for why you might want it to be higher, because of the rear spool. It's like a kart or the old 917/30 Can Am car. You need the inside rear tire to unload to get the car to turn in.
10-01-2019, 03:04 PM
#9
Not to mention a perfect set of rules that haven't significantly changed since the modern era of rc.
No stock or mod. No multiple class of bodies. Touring cars have six different damn classes now, and the popular one changes randomly every month.
You can box up your nitro onroad car, or nitrobuggy, and be ready to race anywhere in the world. In electric, nearly every darn track has different rules. 1/8th nitro is a perfect example of a class, that actually works well, and has survived the test of time.
Only downside is needing to team up with someone else for pit stops, and hopefully they travel reliably.
No stock or mod. No multiple class of bodies. Touring cars have six different damn classes now, and the popular one changes randomly every month.
You can box up your nitro onroad car, or nitrobuggy, and be ready to race anywhere in the world. In electric, nearly every darn track has different rules. 1/8th nitro is a perfect example of a class, that actually works well, and has survived the test of time.
Only downside is needing to team up with someone else for pit stops, and hopefully they travel reliably.
ThIs is spot on, and to tag along what Zerodefect stated, the racers in 1:8 IC are mature enough not the whine about changes to rules and such. I would also say its the most hospitable class and supportive regardless of what chassis or how long you have raced!
10-01-2019, 07:52 PM
#10
I haven't measured any of the current crop of cars but the last couple I did (MRX-4 and early Shepherd, like 09 or 10) had the rear roll center somewhere right around ground level or just a couple mm above depending on settings. That might be higher than a diff car would have but not what I would call jacked up. As for why you might want it to be higher, because of the rear spool. It's like a kart or the old 917/30 Can Am car. You need the inside rear tire to unload to get the car to turn in.
10-04-2019, 06:55 AM
#12
Of course. The higher the grip and the lower the ride height, the more roll resistance you need. Thus stiffer springs, sway bars and higher roll centers for paved onroad cars compared to dirt cars. If you tried to run an offroad car with a standard offroad setup except for grippy foam tires and only 7mm of ride height you would be dragging the chassis all the way through the corner. 1/8th onroad cars (again I haven't measured any of the current cars but I doubt they are much different) actually have suspension geometry very close to what you would find on low to medium downforce sports racing cars or pre-ground effect F1 cars. The MRX-4 I first measured and graphed out was actually very similar to the info I had for Lauda's 1977 Ferrari. There are some differences of course due to the unusual drive train we have and there is one other big difference all RC cars share having to do with natural frequencies but that is a whole different topic of discussion.
10-04-2019, 08:59 AM
#13
I have some questions; why a front one-way? Instead of a spool/diff.
And why are the rear tires so insanely and deliciously wide?
And why are the shocks so leaned over, like a Tamiya Avante?
And why are the rear tires so insanely and deliciously wide?
And why are the shocks so leaned over, like a Tamiya Avante?
10-04-2019, 10:44 AM
#14
I have some questions; why a front one-way? Instead of a spool/diff.
A spool makes the car 4wd all the time which makes the car push. A oneway only works when throttle is applied, so when the car is off throttle and going through a corner its only 2wd which gives it more steering.
And why are the rear tires so insanely and deliciously wide?
And why are the shocks so leaned over, like a Tamiya Avante?
A spool makes the car 4wd all the time which makes the car push. A oneway only works when throttle is applied, so when the car is off throttle and going through a corner its only 2wd which gives it more steering.
And why are the rear tires so insanely and deliciously wide?
And why are the shocks so leaned over, like a Tamiya Avante?
10-04-2019, 11:13 AM
#15
^A fair point, I was thinking along the lines of 10th scale touring cars, and if as Roelof says 1/8th scale cars lift their inside rear would mean the car would sort of go around corners...