Need forward traction...

[Wacker 2]

Yet more obstacles to overcome and problems with the back end of the X6...

I was all set to try the gearbox raising theory tomorrow at racing, but after preparing my car today for such testing have found that I cannot raise the gear box as the driveshaft plunge is enhanced and so the driveshaft fouls on the diff nut quite badly... I tried approx 1.5mm spacers (as I do not have the propper X6 shims - I think as stated above this is equivelant to 2 x 0.30" X6 spacers that you get with the kit)... I have approx 4mm of limitting on the outer shaft of the rear suspension to restrict the suspension travel and so restrict the driveshaft plunge I was getting before with BK2 axles (I say approx 4mm because I have used alittle fuel pipe cut to approx that size as this will act as a bit of damping when the limitters are hit rather than using 3-4mm washers as these will just stop dead).

With the 1.5mm raise of the gear box, the shocks get nowhere near the current limitters as the driveshaft fouled on the diff nut first. With everything bolted down, if you pushed the rear of the car down at the centre of the shock tower, the diff nut side (Spur gear side) doesn't even touch the ground... massive restriction on rear suspension - and this cannot be good for handling!!!

Getting so frustrated with this X6 back end... I know I have posted alot of negative comments about the car on oOple which some may find hipercritical as I race an X6, but all are related to the rear geometry of the car. I do currently run the X6 on a regular basis, and I want to get the car going well, and I want to adjust things to suit my racing style... but everytime I try and adjust anything, something else goes wrong - As with the handling of this car, everything seems to be giving with 1 hand but taking away with another.

Whats the point in providing all this adjustment if you cannot use it??????

Sorry to sound like I'm moaning all the time, beleive me I'd rather be posting threads on here about how great the car is but I cant.

Any suggestions or solutions to the above problem??? If not, its back to the drawing board to provide more forward drive!

Thanks, Jon

[Darren Boyle]

Jon, raising the gearbox will only serve to pull the drivehsaft further out of the outdrive on droop, not push it any further in. The plunge of the driveshaft at wishbones level (maximum plunge) will be less with a higher gearbox and not any more. You may want to just double check the sizes you are using of particular spacers (ie ones behind you CVD axles etc) to confirm that they are the same as everyone else and what is recomended, since this is NOT a problem for any one else that I know of.......

I will leave the other team lads to add any further help.

[bigred5765]

sounds to me like you have got the drive shaft spacing wrong badly some were,Matty's has the bk2 axles which space the drive shafts further in,lifting gearbox height does as Darren says reduce plunge,may be [ost some pictures to show us what you have done,??

[Wacker 2]

Will try and get a set of electronic calipers to measure the size of all spacers I'm using and get some pics posted as soon as I can... Prob tomorrow afternoon/evening after racing.

Really wanna get this sorted cos the frustration I'm constantly having with the car is starting to put me off buggy racing all together which is the last thing I want... and the season hasn't even really started yet!!!

Cheers for your help guys, Jon!

[dgriffin]

Raising the gearbox on the x-6 does actually increase plunge. If the diff is lower, the bones go into the drivecup to a certain point, and then "pull out" (for lack of a less sexual term). If you raise the diff, the point at which the dogbones begin to pull out is later and later in the shock travel.
Anyways, I have about 2mm of shims on the outside of the hub for my bk2 axles, maybe we can beg Ellis to post some pics of his car so you can get it sorted out.

[bigred5765]

raising the gearbox raises the diff also,

[Paul_Sinclair]

dgriffin is right, raising the gear box does increase the dog-bone plunge. What I would suggest, Jon, is moving the axle back out. You might try going back to the B4 axle, or with the longer axles you can adjust the spacers on the just inside of the hub. The Losi spacer that most people use is .100" wide - for raising the transmission I would suggest finding some axle spacers that are about .060" thick and using them inside. You'll have to add the difference (.040 or so) on the axle outside of the hub (between the bearing and the drive pin). Hope that helps some.

[Wacker 2]

Originally Posted by Paul_Sinclair

dgriffin is right, raising the gear box does increase the dog-bone plunge. What I would suggest, Jon, is moving the axle back out. You might try going back to the B4 axle, or with the longer axles you can adjust the spacers on the just inside of the hub. The Losi spacer that most people use is .100" wide - for raising the transmission I would suggest finding some axle spacers that are about .060" thick and using them inside. You'll have to add the difference (.040 or so) on the axle outside of the hub (between the bearing and the drive pin). Hope that helps some.

Going back to the B4 axles would again be something that would put a negative on the handling (give with 1 hand and take away with another!!!), and I had thought of trying that spacing thing... I currently am not running the Losi spacers, but instead am using some axle spacers that I had from running my 1/10th HB Cyclone Touring Car (you got a small axle spacer with every set of hubs that you bought that was designed to go between the inner and outer bearing of the hub) - not sure of the exact width of these spacers but I do have to use 2 of them each side to be the perfect size (will post size of spacers when I get my hands on some callipers). Therefore it would be easy for me to put one on the inside of the hub and one of the outside to reduce the plunge, but doing this would cause the driveshafts to pop out at full droop. To prevent this you would have to put the limitters inside the shocks or move the shocks into the middle hole on the wishbone - either way, reducing the droop to prevent the driveshafts popping out. On bumpy tracks that I usually run on this would be no good and so again "give with 1 hand and take away with another"!!!

So still need another solution to this problem... if there is no other solution then I'll need to find some other way of gaining forward drive.

Also rendering the raising of the gear box a pointless adjustment!!!!

I would like to also see pictures of other cars, Ellis' for example to see how his looks after raising the gearbox to see how he gets around the problem.

My presumption would be that he would adjust the driveshaft spacing or go back to the standard AE axles in order to raise the gearbox. And so he would run BK2 rear axles with the gearbox at its lowest (which I beleive is how he runs most of his set ups). So if he was running on a bumpy track which required the additional droop provided by the BK2 rear axles then the gearbox height would not be an adjustment available to him.

So on smooth tracks you would be able to use this as an adjustment to gain increased forward drive, but on a bumpy track this would not be an adjustment that you could take advantage of... Most off road tracks are bumpy and so I have to ask, if this is genuinly the case, then why have this adjustment???

Thanks again, keep ideas coming, Jon!

[Wacker 2]

Originally Posted by DMS Racing

Jon, raising the gearbox will only serve to pull the drivehsaft further out of the outdrive on droop, not push it any further in. The plunge of the driveshaft at wishbones level (maximum plunge) will be less with a higher gearbox and not any more. You may want to just double check the sizes you are using of particular spacers (ie ones behind you CVD axles etc) to confirm that they are the same as everyone else and what is recomended, since this is NOT a problem for any one else that I know of.......

I will leave the other team lads to add any further help.

Hi Darren, have re-read your reply and I would agree that on full droop the raised gearbox will pull the driveshaft out further. However, this will only mean that there is more chance of the driveshaft popping out at full droop - would you then have to start putting limitters inside the shocks???

The posts that others have put on following yours do support my findings that raising the gearbox causes more plunge at full suspension compression. The problems are found on full suspension compression and not at full droop... suspension is restricted massively as the driveshaft fouls on the diff nut!!

I would be very keen to see what others are running, so again I would ask that people post what spacers, washers etc that they are running with possible pics. I cannot currently see how this would be rectified without removing the E speed hangers and going back to the longer rear camber links -> There is obviously a handling benefit to using the E speed hangers otherwise people wouldn't use them on almost all UK tracks and so removing these would have a negative impact on the handling.

I have to say it again.. Give with 1 hand, take away with another!!!

Sooooo frustrating, and must summarise that this is a bad design!

Jon

[Paul_Sinclair]

Originally Posted by Wacker 2

Going back to the B4 axles would again be something that would put a negative on the handling (give with 1 hand and take away with another!!!), and I had thought of trying that spacing thing... I currently am not running the Losi spacers, but instead am using some axle spacers that I had from running my 1/10th HB Cyclone Touring Car (you got a small axle spacer with every set of hubs that you bought that was designed to go between the inner and outer bearing of the hub) - not sure of the exact width of these spacers but I do have to use 2 of them each side to be the perfect size (will post size of spacers when I get my hands on some callipers). Therefore it would be easy for me to put one on the inside of the hub and one of the outside to reduce the plunge, but doing this would cause the driveshafts to pop out at full droop.
...
Thanks again, keep ideas coming, Jon!

Hey Jon - it sounds like you'd thought about the axle spacer idea but not tried it? I'd recommend taking a close look at it because I know you can get all these settings to work together: I'm currently running my car with the transmission raised up .060" (1.52 mm) and can run the inside hole on the rear arm with as little as .060" internal shock limiting. I have my CVD axles (the longer ones, part #5660) with .065" of spacing between the axle head and the hub carrier bearing. The standard set-up I'm running currently is with the rear shocks mounted 1/2, but I moved it to the inside hole on the arm for these pictures. I broke the toe-in bar trying to do a front flip by running a jump backwards ; the car only made it about 2/3rds of the way around and landed on the right rear wheel .

See the transmission spacer (I use shock spacers usually):


Here's at full droop:


Its hidden in there but you can see there's plenty of engagement at full droop. This is with .120" (2mm) of internal limiting, and I would feel pretty comfortable going down to .060" (1 mm) before I think the dog bone would start popping out.


And here's at compression - sorry about the blurry quality of the top-down pic; its close to hitting the diff nut carrier but doesn't:





------------------
For general comments, here's the track I've been running on:


(bigger version: http://www.xfactoryrc.com/paul/WHTrack4-15-09.jpg)

My car is dirty as it rained the day before we raced. I've actually cleaned it up some; here's how it came off after the first practice run:

[Big E]

Originally Posted by Wacker 2

Hi Darren, have re-read your reply and I would agree that on full droop the raised gearbox will pull the driveshaft out further. However, this will only mean that there is more chance of the driveshaft popping out at full droop - would you then have to start putting limitters inside the shocks???

The posts that others have put on following yours do support my findings that raising the gearbox causes more plunge at full suspension compression. The problems are found on full suspension compression and not at full droop... suspension is restricted massively as the driveshaft fouls on the diff nut!!

I would be very keen to see what others are running, so again I would ask that people post what spacers, washers etc that they are running with possible pics. I cannot currently see how this would be rectified without removing the E speed hangers and going back to the longer rear camber links -> There is obviously a handling benefit to using the E speed hangers otherwise people wouldn't use them on almost all UK tracks and so removing these would have a negative impact on the handling.

I have to say it again.. Give with 1 hand, take away with another!!!

Sooooo frustrating, and must summarise that this is a bad design!

Jon

I think you are being a little harsh with the statement "and must summarise that this is a bad design"

Absolutly anything you do on a model car, no mater what, has positive effects and negative effects!! It is always a case though of if the positives out weight the negeatives to decide if you run it or not. Also the adjustment makes a big difference to the drive, sure it is hard to get away from the plunge issue, but at least it can be done.

When you raise the gearbox the driveshafts do start to hit the diff nut if you don't have many up limiters fitted. But what I would say is the whole of last year my shocks bottomed before the chassis, didn't seem to hurt too much and to be fair if you are hitting the the chassis on the deck then either it is set up wrong or you are hitting jumps big bumps!! Also, I don't really care if my chassis hits the floor all the time, it is only what it does when it hits the deck, if it carries on fine..great, if not then I will tweak it.

What do I do when I jack the gearbox, nothing!!! If the raising does what I want it to do then I leave it. If I was then going to run the tranny high all the time then I would possible adjust the shims like Paul suggests.

One thing I would say though, is raising the gearbox does give a lot more drive..however, and heres the taking away with the other hand bit, it does make the car a fair amount worse on the bumps.

Highest you also want to raise it is 0.06", don't go any higher or it really will be shocking on the bumps, I would try the 0.03" one to start with and see how it feels.

Like I say I do think you are being a little harsh with some of your statements, raising a transmission is always going to cause something else to be tweaked. Also look out for when it is high you still have enough engagement of the driveshaft at full droop, otherwise you will be moaning again that the driveshaft fell out and it is such a shocking design

Can I ask are you still running the car with the saddles?? From my experience with the car I very rarely suffer from a lack of straight line traction it is only when exiting the turns, especially for tracks over here. Normally what you will find is the car is actually hanging on to the turn too much and then the rear breaks away. How can you sort that, well maybe move some ballast weight to the rear, lower the front inner link, take off the rear Espeed hanger and run one of the stock positions!! Lots of other ways to get traction.

But of course with all of these changes above you will be giving with one hand and taking something else with the other

E.

[ttboyy2k]

Does any aftermarket companies make a motor plate that allows the motor to sit on the chassis while using the .120" tranny height?

[super__dan]

Ignoring fit issues at the back for a second, just to check are you running the light saddles packs forward? Assuming so it must mean your car is Much lighter than anyone else and have significantly different weight transfer even if static balance is the same. I think this is why you might have less drive than anyone else? The stock layout isn't broken

Also, I used to have a perception that in lower grip conditions I had less drive, but actually when I tried others cars at the ends of meetings I found this wasn't the case and I was psyching myself out. I did however have better, safer on turn in.

Ref the fit issue, I have mine with low gearbox and not external limiters and it JUST touches the angled driveshaft pin if I push the suspension up by hand. I have run a little tranny height and not changed anything though with no sign of any ill effect. I would just swap the Losi bearing spacer out and shim the driveshafts across if I could ever be concerned by it.

[Kopite]

I tried raising the gearbox today. just added the spacers under the gearbox, didn't do anything else at all (!!!!)

Made quite a significant difference actually. I think i raised it too much, as the side bite was a bit too low, however the drive was immense.

Excellent setup option!!

[Richard Lowe]

Originally Posted by Paul_Sinclair

I broke the toe-in bar trying to do a front flip by running a jump backwards

Only BJ4's can do front flips Paul!

[Paul_Sinclair]

Originally Posted by Richard Lowe

Only BJ4's can do front flips Paul!

I was thinking about that . I could have made it though, with a little more... commitment... on the approach. Live and learn I guess. I'll get it next time, and maybe my youtube video can be as famous

[Richard Lowe]

Originally Posted by Paul_Sinclair

I was thinking about that . I could have made it though, with a little more... commitment... on the approach. Live and learn I guess. I'll get it next time, and maybe my youtube video can be as famous

Haha

[discostu]

Originally Posted by Big E

I think you are being a little harsh with the statement "and must summarise that this is a bad design"

Absolutly anything you do on a model car, no mater what, has positive effects and negative effects!! It is always a case though of if the positives out weight the negeatives to decide if you run it or not. Also the adjustment makes a big difference to the drive, sure it is hard to get away from the plunge issue, but at least it can be done.

When you raise the gearbox the driveshafts do start to hit the diff nut if you don't have many up limiters fitted. But what I would say is the whole of last year my shocks bottomed before the chassis, didn't seem to hurt too much and to be fair if you are hitting the the chassis on the deck then either it is set up wrong or you are hitting jumps big bumps!! Also, I don't really care if my chassis hits the floor all the time, it is only what it does when it hits the deck, if it carries on fine..great, if not then I will tweak it.

What do I do when I jack the gearbox, nothing!!! If the raising does what I want it to do then I leave it. If I was then going to run the tranny high all the time then I would possible adjust the shims like Paul suggests.

One thing I would say though, is raising the gearbox does give a lot more drive..however, and heres the taking away with the other hand bit, it does make the car a fair amount worse on the bumps.

Highest you also want to raise it is 0.06", don't go any higher or it really will be shocking on the bumps, I would try the 0.03" one to start with and see how it feels.

Like I say I do think you are being a little harsh with some of your statements, raising a transmission is always going to cause something else to be tweaked. Also look out for when it is high you still have enough engagement of the driveshaft at full droop, otherwise you will be moaning again that the driveshaft fell out and it is such a shocking design

Can I ask are you still running the car with the saddles?? From my experience with the car I very rarely suffer from a lack of straight line traction it is only when exiting the turns, especially for tracks over here. Normally what you will find is the car is actually hanging on to the turn too much and then the rear breaks away. How can you sort that, well maybe move some ballast weight to the rear, lower the front inner link, take off the rear Espeed hanger and run one of the stock positions!! Lots of other ways to get traction.

But of course with all of these changes above you will be giving with one hand and taking something else with the other

E.

hey ellis

how does raising the gear box give more drive and why would this cause the car to be bad over.

cheers

stu