The engineers nightmare: Increasing the diff oil weight can make it worse, make it better, or stay the same.
Increasing the diff fluid weight in my car made the back end slightly more lose.

Thanks for the replies guys. I have returned the car back to stock settings (still using the Exotek chassis). im going for a practice this arvo to see its changed and work from there.

Yeah, i went Exotek cause i liked the hinge pin block design. But the lack of support/testing makes me wish i had gone reflex, Christian is always doing this in his thread...


the rear is at its longest seting, i'll give the front ago

Im using 60wt, when i tried 35wt it made it worse. what are other people using?

You could try 70w and see how it feels.

A heavier front shock oil, and lighter rear shock oil could help too.

Not at all. There is no loss of forward drive, like there would be if you are diffing out. The car just has more of a tendency to rotate around the rear wheels. Some people may think of "steering" as breaking the rear end loose, but this is not always the case. You can also make the car rotate around the rear tires. Think about if you put a solid axle in the rear, what would happen if you tried to drive in a circle. It would have to be a very big circle, since the rear tires have to go the same speed. Ask anyone with a 12th scale about that :)

I agree, that, a lot of people confuse rotation with steering. Far too many.:rolleyes: There is a threshold that when crossed will result in a loss of or inability to apply power to the wheels. You can be too soft is what I'm saying. Would you agree that a modified car would typically have a softer rear diff setting? If so, then why is that? The more power you have, the harder it becomes to get the power transferred to the wheels to create traction needed for forward motion. If, your diff is tighter, you will have wheel spin and the car will be difficult to drive straight or through corners. Two-wheel drive 1/12 cars and four-wheel drive 1/10 scale touring cars are different animals. They're driven differently. Even still, the differentials work the same. If, you want to plant the car through corners, you diff will be on the looser / softer side. Only when the traction is high do you go with a heavier / stiffer rear diff to free the rear up with a controlled amount of wheel spin. I would think that you should be able to do the same thing at the other end of the spectrum.
Speaking of 1/12 scale cars, I just had a conversation with someone about his car appearing slow and not being able to get the car out of the corners. He did some research and found out that the diff was too loose. He tightened it and the power came back, he was faster in and out of the corners. He was racing on a high grip track and needed a tighter diff setting.
I'm using 2000 cst in my rear diff and my car isn't even close to "pushing". In fact, I've been working out a heavy oversteer / traction roll, which has to do with my shock set-up.

I had the same issue when I changed to the RSD chassis, to me its not the rear of the car but the front, due to the different dynamics of the dual bellcrank, I first had a gear diff in which was new and tight, so thought that it was the issue of the rear stepping out mid corner, the AE gear diffs by the way have to be the crappest I have ever experienced as far as tolerences are concerned, not an easy build at all, any way I moved back to my trusty ball diff and tweaked it back a bit and still had the same problem. I noticed that there was push at corner entry but only a little, but as soon as the grip returned to the front wheels the rear would snap around, it was like hitting a brick wall with the front of the car, the thing to try and do would be to try and make the front of the car more neutral through the entire corner.

I agree with your remedy. How would you achieve the more neutral feel? If, its definitely a front end issue, which it sounds like. I was thinking the ackerman and toe settings were the problem.

Tire compounds?

For the guys that run asphault. Do you usuallly run hard or soft compounds? I know hard tires wear longer and so have a longer life, but how many races do you typically get out of soft tires?

Curious what some of you guys prefer for carpet as well.

Actually, I would say that in general, mod cars will use a thicker rear oil, so it helps tame some of the rotation. What I was trying to get at with the 12th analogy, was think about a solid axle in that car, you would have absolutely no rotation at all.

You are thinking pure forward bite, and yes a softer diff can help with that, but there are many other options you can play with for forward bite, so I tend to leave the diff to control rotation, and use everything else to control that if I need it.

No, you missed it. It's cool. I was pointing out that you could and probably are achieving the desired effect by doing what would be considered the opposite of traditional diff adjustments ,if, you're able to utilize the area near the threshold. There's more than one way to skin a cat.:)

Tires...
 

I have not personally ran on Asphault but regarding carpet I personally like the Sweep QTS Tires:

Green 28s if the carpet is green with little to no groove
Blue 32s most of the time...
I have not tried the new Rug Racer Tire yet but hear good things if the carpet is really dirty or green...

Good Luck!

This depends on the temperature and the track surface/layout.
On an outside track you will prefer softer compounds (30 and 32) in the morning when temperature is around (15°C - 25°C) and the track is a little dusty. Higher temperatures (around 26°C - 35°C) and better asphalt conditions (no dust) need harder compounds (33 - 36) otherwise the tire will be used up very fast.

If you have a track with a fast banking curve (like Nascar) it will eat up your rubber tires ;) Testing it yourself is required! Some asphalt surfaces are good on tire wear and you can have a lot of fun out of one set and some asphalt will just destroy the rubber in one pack.

On carpet I always run soft compounds (28 or lower). Here the own test rule applies too. On most tracks a 28 compound will work very well. Only if you have a low grip carpet (or new carpet) it makes sense to look for 24 or 22 compunds.

I don't know what you mean. Can you please clarify?

Because racecar

Thanks i appreciate that. I have hard compounds on the car currently.