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-   -   Which layout are you using for your B44.3? (http://www.oople.com/forums/showthread.php?t=159088)

cutting42 30-10-2014 12:08 PM
Which layout are you using for your B44.3?
 
I am curious as to how you are setting up your B44.3, Shorty or Saddle layout? Please add comments as to what surface do you race on.

richm 30-10-2014 01:30 PM
Shorty with the centre ballast weight.
Indoors and out on astro and carpet as well.
Tracks were stotfold,herts, silverstone, maritime and faversham.

Like the car much better than my 44.2 running saddles.

Noob 30-10-2014 01:40 PM
running saddles with the center weight and 7k front when the oils arrive,60,000 center and 5 rear for now till I have tested it, then may go for a lighter front spring.

sheddy 30-10-2014 08:36 PM
Shorty for me at Maritime. As kit set up except oils, 10k, 100k, 7k. 50/40 oil. At last off road wars meeting the car was flying.

milesallen 31-10-2014 09:25 AM
just bought mine, and as i only have shorty packs then the decision was simple, nearly finished the build shocks to complete then the body and i'm done. any base level setup setup data from anyone? i'll use the kit info to start with seems a decent piece of kit, instructions not bad could be better.

Timee80 31-10-2014 09:30 AM
Why is everyone using really thick oil in the centre diff? Surely at 100k you aren't getting any proper diff action anyway

cutting42 31-10-2014 12:27 PM
Quote:
Originally Posted by Timee80 (Post 883734)
Why is everyone using really thick oil in the centre diff? Surely at 100k you aren't getting any proper diff action anyway
Its a great question. Partially the answer is people are familiar with a slipper (locked diff equiv) so a tight centre diff gives an expected behaviour.

For a more detailed answer you need to appreciate what a diff does (forgive me if you know this already)

Diffs on one axle are there to allow the wheels to rotate at different speeds to allow them to track different radius curves without locking /skipping. In a 1:1 car these are set quite loose so you don't wear your tyres out. The downside is that if you are in low grip or accelerating very hard a loose diff sends the drive to the wheel with the least resistance (grip) meaning you spin that wheel and the wheel with grip gets no drive. This is often known as diffing out.

Racing cars (and therefore our RC cars) are not bothered by tyre wear so much and prefer traction so we can increase the tightness of the diff so the wheels are more locked together and resist diffing out. The downside is that the wheels are less keen to rotate at different speeds and the whole car resists turning corners. This is why a rear diff often has a thinner oil so it still turns the corners well. The front has the steering to force the turning so can have a thicker oil or in the case of on-road cars a spool - or locked diff.

With a centre diff, under acceleration, the least traction is on the front axle because the front lifts so if you had a loose diff, all the power would go to the front, spinning up the front axle and not driving the rear wheels. This is a bad thing for fast acceleration so most centre diffs are run close to lockup to maintain the drive to the rear wheels but loose enough to put a little bit more drive to the fronts to pull the car out of corners. A bit like the overdrive pulleys that you can/could get from belt drive cars.

I have not driven the centre diff yet but on mega grip I would expect it to be run almost locked. I have heard in the states, some are using a million weight oil for high grip! On lower grip or a bumpy track, more front drive makes the car easier to drive so a lighter oil such as the 60k would be a good starting point

Timee80 31-10-2014 01:30 PM
Maybe the ideal setup then might be to have a belt driven buggy with option to overdrive the front by various amounts with different toothed pulleys and still retain a central slipper. If the pulleys / belts were really fine pitched then you could have lots of tuning potential

cutting42 31-10-2014 04:18 PM
Quote:
Originally Posted by Timee80 (Post 883764)
Maybe the ideal setup then might be to have a belt driven buggy with option to overdrive the front by various amounts with different toothed pulleys and still retain a central slipper. If the pulleys / belts were really fine pitched then you could have lots of tuning potential
Trouble is, they always overdrive and tyre wear is high. With a centre diff the overdrive only happens on the weight shift of acceleration which is when you want it.

gazhillAE 31-10-2014 04:27 PM
1 Attachment(s)
Quote:
Originally Posted by cutting42 (Post 883754)
Its a great question. Partially the answer is people are familiar with a slipper (locked diff equiv) so a tight centre diff gives an expected behaviour.

For a more detailed answer you need to appreciate what a diff does (forgive me if you know this already)

Diffs on one axle are there to allow the wheels to rotate at different speeds to allow them to track different radius curves without locking /skipping. In a 1:1 car these are set quite loose so you don't wear your tyres out. The downside is that if you are in low grip or accelerating very hard a loose diff sends the drive to the wheel with the least resistance (grip) meaning you spin that wheel and the wheel with grip gets no drive. This is often known as diffing out.

Racing cars (and therefore our RC cars) are not bothered by tyre wear so much and prefer traction so we can increase the tightness of the diff so the wheels are more locked together and resist diffing out. The downside is that the wheels are less keen to rotate at different speeds and the whole car resists turning corners. This is why a rear diff often has a thinner oil so it still turns the corners well. The front has the steering to force the turning so can have a thicker oil or in the case of on-road cars a spool - or locked diff.

With a centre diff, under acceleration, the least traction is on the front axle because the front lifts so if you had a loose diff, all the power would go to the front, spinning up the front axle and not driving the rear wheels. This is a bad thing for fast acceleration so most centre diffs are run close to lockup to maintain the drive to the rear wheels but loose enough to put a little bit more drive to the fronts to pull the car out of corners. A bit like the overdrive pulleys that you can/could get from belt drive cars.

I have not driven the centre diff yet but on mega grip I would expect it to be run almost locked. I have heard in the states, some are using a million weight oil for high grip! On lower grip or a bumpy track, more front drive makes the car easier to drive so a lighter oil such as the 60k would be a good starting point
Or just run a vts :thumbsup:

Noob 31-10-2014 05:22 PM
All you need to do is look at what ppl are doing and choose ONE thing to start changing.
I noticed out the box the front has high tyre wear so im upping the oil there to push power rear on acceleration and see what happens, i think you should be racing it standard for a few races and on different surfaces if you can before you start pulling it to bits.

cutting42 31-10-2014 05:35 PM
Quote:
Originally Posted by gazhillAE (Post 883785)
Or just run a vts :thumbsup:
Personally I am on Avid :lol:

gazhillAE 31-10-2014 07:33 PM
Quote:
Originally Posted by cutting42 (Post 883797)
Personally I am on Avid :lol:
Rather you than me :thumbsup:


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