My ST-RR EVO

iTrader: (5)

And what about pillow ball? For tight tracks?

30Tooth

iTrader: (1)

Ah forgot that. I want to hear JQ's opinion on it but here's my take:
Look at the front axle angle, it's even greater than the MP9. That means for the same wheel diameter the diff will sit lower and therefore the CG.
With the CG lower and RC height in the usual range the roll couple will be smaller, therefore the car is more responsive.
The MBX7 and other PBS cars are known to run low ride heights in the front, unlike the C hub designs.
Things I notice right away: long arm low RC height, stand up shocks, +1mm hub hexes. Was it stable without being lazy?

stanleyw808

Hello 30Tooth,

Just want to add up a bit about Your analysis regarding Rear Arm.

TLR and AE still have a bit longer rear pin to pin width compared to the Front Arm. And I would like to put a note that these 2 cars have a Wide Rear Inside Pivot Point configuration.

While the MP9 has a shorter Rear Arm compared to the Front and has a Narrow Inside Rear Pivot Point configuration.

And my analysis while I watch the TKI4 running on the track, the new front B Plate seems to make the Front of the car less bottoming compared to the TKI3 B Plate. I also notice that TKI4 seems to dive less coming into corner comparing with TKI3 with a same Front Suspension Package.

Cheers..

My ST-RR EVO

iTrader: (5)

A flatter front arm angle will dive less.

30Tooth

iTrader: (1)

Hey Stanley,
That's surprising, I really thought they had longer front arms.

It rolls less because of the flatter arm as EVO says, which enables tki4 drivers to run softer springs at the front which will require rear end setup changes, seems no one wants to devote time to that and slaps tki3 parts instead.

30Tooth

iTrader: (1)

I don't recall if I ever shared this pic before, it's a fine example of what we don't want to happen to our car's tires. This is the worse setup I've ever driven/seen. Controlled camber change is KEY to extract every molecular bit of grip the tire is capable. Which this thread is all about and beyond that...

BTW found a very good explanation of wide versus narrow inner pivot, credits go to Mr. Socket I couldn't explain this myself:

stanleyw808

Hello 30Tooth,

What/Which car did Mr. Socket's Analysis referred to?

Cheers..

JQ

Except for 1:10th scale. That's because of how the tyres are. The tyres are built to deform a lot and when you enter a corner and you stretch the tyre close to it's limit, that's when the car will be stable and corner steadily.

Remember when AKA and a few others then made those lower profile tyres and bigger wheels? That would be the way to go, except no one liked them, because the cars would need to be changed to actually work "correctly", and then the tyres would work. Ultimately they would be a lot fast in my opinion. But now running these "slow" tyres, we run strange car setups.

30Tooth

iTrader: (1)

The Xray XB2 but that applies to every car out there

Cheers

Absolutely right and a very good topic even if I used the pic as a bad camber angle situation. People were ripping the tire from the new LP wheels because they were making the car ride on it's sidewall and they didn't correct that, no one changed the setup when a major change occurred
I think I said this before, round carcass tires require less camber gain and square carcass tires more camber gain. Adding carcass height and the fact that in 1/10th the tires are very soft you can expect tire deformation to play a big part on overall performance. Same applies to 1/8th but I think tire deformation is rare, although I found marks on the sidewall when running normal setups which means the tire could have a little more dynamic camber.

Austin1031

iTrader: (1)

On the Tekno cars you can adjust the sweep angle with the pills. That being said I've never actually seen a setup where someone has played with this setting. It's for the front axle sweep. Over the weekend I'll fool around with that in different positions to see what effects it may have on the car. This thread is great by the way. I've read it twice now.

30Tooth

iTrader: (1)

It's sort of common in on-road electric sedan so give it a try. Try widening the B plate first as it is a normal sweep setup.

30Tooth

iTrader: (1)

Been a while huh?

After lurking here and there looking at walls of text, going to bed to think more about what I had read and theorizing changes I can surely add more info to this method.

I'm busy with projects that got off the ground but the plan is to revamp the tutorial and add handling fixes I've discovered ASAP. For example, the parallel lower arm fetish.

It should be parallel because of how the weight of the car is transferred to the tire during cornering and smaller RC height migration, also tire scrub (which also happens with high RC heights). Current F1 cars moved away from front lower arms parallel because of aero reasons but the rear arms are still parallel to ground.

Alright onto the next level.
There's two very valid setup strategies, one is the one in the original post and then there's the other option. Let's call them by name, High Roll-Low Travel (HR-LT) and Low Roll-High Travel (LR-HT).
As the name implies, one focus on less vertical suspension movement but having more roll motion and it's the most widely used in 1/10th electric cars (On and Off road) because those cars have generally lower CG height and weight. Has been used in 1/8th buggies "unsuccessfully" (TLR and similar buggies). The other, ah yes, think Kyosho/Mugen/HB D8XX and high powered 1/8th cars. Whenever there is a nitro engine this strategy works the best, particularly Off road. Why? Simple, the shocks have ample travel because the roll motion is far more contained and can be set softer overall while the roll couple is kept to a minimum, lessening roll motion. This is the most successful strategy, it works plain and simple in all major 1:1 racing leagues. Things to take into account if you follow this path:
-it needs less static and dynamic camber, so the tire is better aligned towards the track surface;
-you can get away with softer roll bars and springs;
-the car will bite back far less than a similar HR-LT;
-tends to put more heat into tyres.

I've been trying to fit the LR-HT strategy onto 1/10th buggies and sedans with mixed success. For one, the suspension design on some cars favours one type of strategy and on others I can't seem to get balance. The pinnacle is however THE Car, I am confident that moving that suspension setup towards the LR-HT would present a killer track car.

IOP_Racer

iTrader: (14)

Is there any special process to setting up a car in the LR-HT manner? Or are 1/8 nitro buggies designed like this? I want to revamp the set up on my nitro buggy and I was going to use the process in the first post. My ebuggy ended up with a set up similar to the process in the first post and it drives well anywhere I go.

My ST-RR EVO

iTrader: (5)

30- regarding set up for the different cars that made the finals at the Worlds, what do you think they needed? For example, what could TLR have done to be more competative? That car looked like it was a handful to drive. I've seen the AE cars looking better on different tracks. The K-cars went from great early in the week to so so in the main. I don't think any X-Rays or JQ cars made the final. What could everyone have done? Ongaro's Mugen looked super dialed in.

30Tooth

iTrader: (1)

Yes there is, basically we deviate from the zero dog bone bind I talked in the first posts (while it still provides a good all-rounder base it's old school setup strategy and the new one is better) to a new process where dog bone bind and most wheel alignment parameters are lower priority. The major blowback is our cars aren't really designed to take this new approach, except the Kyosho MP series (explains their success) and now the other C-hub designs, THE Car OG and the XB9'13. Current PBS cars are a tick off than others but no major re-design needed.

The big difference between one way and the other is the High Roll-Low Travel prefers lower roll centre heights and stiff shock springs (control roll with shocks, contrary of what I've been advocating) and LR-HT prefers higher roll centre heights and softer shock springs. Everything else is close, except with lower roll you will need less camber gain, I would bundle lower ride height with this manner provided you still run same droop between setups. For example in your SRX you would run the rear hubs with the high roll centre insert for a start and IMPORTANT!!! go down one or two rates on the end you changed roll centre height. This is where most get mad at me, the changes made the car more responsive but they still use same springs as before! In electric TC I need the softest springs available and could go lower. This is paramount to the LR-HT way, the springs have to be softer. Pistons and shock oil doesn't need to change and you can start with the previous base regarding wheel alignment. Almost forgot, as the car is softer it will pitch and squat more, a change in anti-squat and front kick up is to be expected.

The one I have seen was Ronnefalk's from the main, isn't much different from this year's Euros, only more camber gain in the rear and up a size in shock pistons (still staggered front-rear), small changes in toe and camber. The LB Kyosho springs are a touch softer than the Blue-Yellow he used. Lowest holes used in both shock towers for RC height and now the particular bit, he used the rear hub in the lowest height with the #5 plates, which angled inwards the rear arms while keeping the RC height above ground level. I would need his car to measure RC height but with all things going on he was surely into roll control and trying to avoid jacking forces inherent of higher than ground RC height. He could push more than most(Ty included! Ongaro excepted).
TLR cars are headed in the right direction with the 4.0, the HR-LT of the 8ight platform is a hindrance and each version is further from the oldschool way of setting a car, would advice to use the same method described to IOP, high roll centres and softer springs. Would ditch the stock LRC plates as they are the main culprit of the TLR team looking bad.
The K cars suffer the same-ish issue, using the LRC bushing presents a car that as IOP drives very good on lower traction and as grip goes up the car will roll more and more until the movement is too much to what the geometry likes. By not using the HRC bushing when grip goes up the K team is more likely to get caught and surpassed (2012, 2014 and 2016 WC K start good and then they loose steam as grip goes up). That change would help a great deal in keeping the pace/improve drivability.
Almost sure Ongaro's MBX was similar in concept to David's HB, softer springs and higher roll centre height. Quite possibly more rear camber gain, as Mugen traditionally go for super long rear links. Would love to take a look at the rear setup he had there.
It was quiet in the Xray camp, I think the XB8'14 was a step in the correct direction but every year the car looks more like the competition instead of wanting to be ahead of the competition.
AE, they are heading to the right direction, slowly...

Once PBS designs mimics the Losi style and the C-hub (0 KPI, longer front arms than rear, straighter shock angle, less caster would be the best possible geometry) we might see them as threats in every track, currently they have some tracks which they work worse than others. Still, it's on the drivers shoulders to strive to achieve the best setup possible