Jump to content
gazza

Mjk Fly Truck Chassis

Recommended Posts

I tend to run the stock rubber singles on the outside of the rim, and MJK's on the inside.

Share this post


Link to post
Share on other sites

So got the truck and chassis, need pinion and crown. Not sure on which to get.(first slot car modification)

Have found slot it inline 9t pinion and 27t crown. is this the best option? would like it a little bit faster outta the corners.

Smaller pinion or smaller crown?

Share this post


Link to post
Share on other sites

Not familiar with these beasts so not sure on optimum gear ratio.

But, smaller pinion (less teeth), technically, will give it more punch and more brakes, alternatively, so would a larger crown (more teeth).

Best to grab a few crowns and pinions and play around with different ratios.


"Me Auntie's a Jack !!!"

Share this post


Link to post
Share on other sites

I find what makes 'faster out of the corners' for any chassis, is smoother acceleration rather than 'more punch'.

For faster motors (say 22k +) I gear for brakes - 2.7-3:1 for slower motors with good torque, I gear 2.4-2.8:1 (say Jack Rabbit). It does depend on the track too.

 

In 1:1 scale racing, a lot of drivers have said that if you are unsure what gear to use in a corner, change up and push harder...smooths the car out

Share this post


Link to post
Share on other sites

As pointed out by Phil, tyre diameter plays a major part in the gearing of these behemoths...

 

A 28mm tyre has a circumference of 80mm, and a more 'normal' 20mm tyre is only a 60mm circumference.

To put that in perspective, if both cars are running the 'standard' 3:1 gearing, the truck will move 30mm per motor revolution, whilst the standard car will only move 20mm.

That's a whopping 30% difference...

 

Now, as the trucks do run long can motors, they can pull quite 'high' gearing.

On the more open tracks, and the ovals that we have tended to run the trucks on here, I generally run the 'old' 15k trucks at 9/27, and the 'newer' 18k trucks, run much better at 9/30, or 8/27, all of which are quite tall gearing, but that assists in reducing the torquey tail slide that occurs at shorter more 'correct' gearing.

Edited by shadow_rusty

Share this post


Link to post
Share on other sites

I've bought a 2nd hand Mercedes off eBay and it has 11/27 gearing. Even with these tall gears it seems to have enough punch out of corners with it's standard Fly longcan. Has anyone else tried gearing like this?


May the downforce be with you.

Share this post


Link to post
Share on other sites

IMO the gearing needs to be changed unless it has very small tyres and no weight.

The Merc is the hardest of the trucks to get to handle, we run them with a big slab under the chassis.

Check out the Fly Truck Proxy pics over in SCI for all the info.


Phil

 

Hobart Miniature Car Club

 

Tassie Resins

 

Email

 

 

 

 

 

 

Logos%2016_17.small_zpswkcwjf0q.jpg

Share this post


Link to post
Share on other sites

I finally got round to running the truck on the local commercial 8 laner and it goes well, even with it's crazy gearing and no weight added. Very easy to drive and quick through the sweeping corners with it's quad MJK's on the back. I'm surprised how deep it goes into corners before you have to brake.

 

Laps bout 4/10 ths slower than a good Scaley GT, wouldn't win a GT race but it wouldn't come last.

 

It loses about a truck length per lap against Shadow Rusty but I'm happy with that considering how much work he's put into his trucks.

 

.

Edited by Sports Racer

May the downforce be with you.

Share this post


Link to post
Share on other sites

I've now got 3 trucks. The Mercedes, a lightweight Buggyra and a Sisu which is 2/10ths faster than the other 2.

 

It's faster than a lot of the cars in our Scalex GT class. :D

Edited by Sports Racer

May the downforce be with you.

Share this post


Link to post
Share on other sites

hi, would you mind sharing some pics of your truck setups?

interesting that the sisu is faster than a lightweight buggyra.


Cheers

G

 

"I am an expert at the top of my field when mowing the lawn".

Share this post


Link to post
Share on other sites

I'll take some pix but the Buggyra is setup for home tracks and the Sisu is quicker on the big 8 lane track at Way2fast in Canberra where we have a class for truck racing. The Buggyra sits so low I had to trim the bottom of the body so it doesn't scrape on the track.

 

We used to have demolition caravan racing and I put a slot car under my caravan facing backwards and took the motor out of the tow car so the caravan towed the car but backwards to all the other racers. Lots of fun (and carnage).

Edited by Sports Racer

May the downforce be with you.

Share this post


Link to post
Share on other sites

Those guys in Canberra are backwards....hehe

Reckon proxy racers might give truck racers a run for their money in the backwards stakes.Multiple leaps of faith missing the adrenaline of side by side contests, will forever remain a mystery to me. Understand though if there are no local racing options.

Each to their own I suppose....

Share this post


Link to post
Share on other sites

thanks. Looking forward to them.

by the way, the new scalex truck are really great for what they cost.

Out of the box they work absolutely fine (minus the stock motor)...even the original tyres are great after some trueing and a bit of oil.

Will post a review of how I did set up mine.


Cheers

G

 

"I am an expert at the top of my field when mowing the lawn".

Share this post


Link to post
Share on other sites

Here's the Bug, it's the lightweight race version from Fly. It's low because of the small wheels and it needs very little lead, feels like a Scalex GT to drive on home tracks.

 

b_222625.jpg

 

b_222517.jpg

 

b_222657.jpg

 

The Sisu is bigger and has more weight up top so needs a lot of lead to keep it planted. It's 2/10 ths faster on the 8 lane commercial track at Way2fast and needs a different driving style - brake early and coast into the corner and keep the speed constant so it's quick out of the corner.

 

b_222815.jpg

 

b_222838.jpg

 

I'm not happy with how easy it deslots on home tracks (tighter corners than the 8 lane track) so I'll move the lead in the middle to the front of the chassis to see if that helps.

 

b_222855.jpg

Edited by Sports Racer

May the downforce be with you.

Share this post


Link to post
Share on other sites

21mm, Yellowdogs off a Carrera CanAm. That's how it can get away with weighing only 142 g compared to the Sisu at 213 g.


May the downforce be with you.

Share this post


Link to post
Share on other sites

Paul it sounds like you don’t have enough guide in the slot on the Sisu have you thought about trying a different guide before moving weight?

Share this post


Link to post
Share on other sites

The Sisu has the Ninco sprung guide, the Bug has a Slot.it wood guide.

 

Interior of the Bug is standard but a lot of the plastic frame that holds the body to the chassis has been cut away to save weight.

 

Unlike the Tassie truck drivers ours only come with 1 head so no need to lighten the interior. ;)

Edited by Sports Racer

May the downforce be with you.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...