coupehdi

Hi guys, happy christmas and new year! Ive been thinking lately my local track is quite open and low traction and low temperatures almost always, i noticed the 1/8th scale cars are alot faster than the fastest 10th scale car by about 2 laps best 10th sclae lap being about 17 seconds, so i was wondering is the solid rear axles and front one way setup the 1/8th scale cars use beneficial and would it work well in a 200mm car, i havent seen any 200mms with a solid rear axle so perhaps not but just a thought.
Thanks for any discussion

bertrandsv87

iTrader: (2)

I thought so too at a certain point. I wanted to run two solid axles in my ntc3, but decided against it when I saw the difference in tire width in the 1/8scales compared to 1/10 scales. At only 30mm width, the rear 10scale tires would not last long. They might survive a five minute qualifier, but won't give you an advantage in a 30+minute main.....

bertrandsv87

iTrader: (2)

Also the 8scales have more power to weight ratio than 10scales that gives them a definite advantage.

coupehdi

Yeah, i know the 2 cars have other differences such as the bigger tyres and also more powerful engine, but you would think that what worked for one would work for the other but who knows, i still think i may try it at some time if i get a chance. cheeers for the reply anyway.

Teamgimpy72

iTrader: (29)

You should check your lap time's with the ball diff's, lock the diff then check your lap time. post your result's . id be interested in see what you come up with.

coupehdi

well my cars got gear diffs, but yeah i have locked the front one for the minute as a test but since i live in ireland i cant check anything right now cause its always lashing with rain this time of year lol but yeah if it makes it better ill let u guys know

kyosho malaysia

it will not stable when on power either out corner or straight line

coupehdi

Hi, yeah you may well be correct, but have you actually tried it?, just seems strange it works well for 8th scale but not for 10th but hey im doing this for over 10 years and learning every single day. Thanks for your input.

JamesHealey

iTrader: (1)

8th Scale have huge rear tires which have a much bigger contact point on the road, also the one way locks into a solid axle under power to as long as the car is aimed forwards you're going to go that way.

When you come off power the front wheels free wheel and you get the solid rear axle, hence the ability to turn very sharp with an 8th.

Also when you're cornering in an 8th on power only 3 tires have drive the outside front wheel is free wheeling around the corner.. this pulls the car around the corner.


The huge wedge shape body shell then creates down force into the rear hubs directly with the floating mount which tops the rear end whipping out around the corner.

It's a working relationship between many parts to get it to work, 10th touring cars are not setup to run solid rear and one-way front it's not a good combination for this class.

MrHistory

iTrader: (2)

I also wondered and am glad to see this discussion. As James Healey puts it, it is in fact these differences in the platform that define the physics and give us the answer the the question "why."

I recall speaking with Josh Cyrul about body design and how much it has changed, why certain things work and don't work. He pointed out that (as I remember it) the bodies are designed around a current chassis. And a given high force 1/8 scale body we see today would work very badly with an older chassis platform. To much down force etc. This idea is interesting because you realize it is all symbiosis. Not just making the best body design for all time toward perfection, but a body designed to bring out the characteristics of the chassis at hand. And Im sure this process occurs in reverse too.

It would be nice to hear from other knowledgeable folks who can discuss the physics and the other ways 1/10 and 1/8 are different. It seems that James hit on the main points.

Roelof

With the 1st Impact models they have mounted the rear end of the body the same way as the 1/8, directly on the wheel hubs. Due the 2wd there was a bad grip on the rear end and so people were experimenting with mounting the body on the chassis and from that moment on all 1/10 models from Serpent had the mounting on the chassis.

A friend mad his own 235mm car based on old Quatro, Sprint and BMT parts had made very good results after trying several things as also a solid shaft (2wd), the car had more steer and was better driveable in high speed corners bot it was a bit tricky in the low speed corners.

I have experimented with a suspension from DAX cars. It gives the car a huge amount of grip but also one huge side effect, with a solid axle on my 1/8 there is a huge wear on all rear shafts. Yes, there is a must to lift the wheel on the inside of the corner with the use of a solid rear axle.

JIM1

Interesting topic.

Could this be the reason (or at least a contribution) to why my rear dog bones sometimes twist ?

MrHistory

iTrader: (2)

What does it mean "lift the wheel"?

Roelof

Lift it from the ground so it will not give a friction.

blis

We had a 50cc kids Suzuki Quad bike with a solid rear axle and 2wd only. With an adult trying to ride it, the weight was all on the rear and it would not want to turn unless you almost climbed on top of the front and as Roelof said, let one of the rear wheels lift and slip.

I would assume that if one was Oval racing then perhaps a Locked rear and left right tyre diameter splits could perhaps be an advantage. The other is drifiting!