Boomerang, Final Tips Topic.

[kontemax 1725]

Hi all,

with the re-releasing of the Boomerang I would like to share with you all my experiences with this car. How to increase its performances but overall how increase the strenght of the chassis.

In the truth the Boomerang never had the bump steer. It was my first car when I was young and these are the problems and the solutions I've found:

1) The steering linkage becomes slow and hard to move with the use cause the wearing. You must grease it anyway to avoid plastic wearing but also you MUST CLEAN IT often as you can because sand and debris became like sandpaper. I think with a modern +4.5 Kg/m servo will be no more problem with the linkage movements.

In my Boomerang I machined a new alloy steering bar that moves on 4 little ball bearings and between two slices of self lubricant white teflon slices.

http://www.tamiyaclub.com/showroom_model.a...0820&sid=24

This allows a perfect smooth movement without flexions and without the need of grease.

2) Sloppy front suspension. Original 8 mm brass balls were a big problem due the wearing. I suppose that Tamiya now will use steel ball connectors. You can use some piece of extra lexan from the body to make washers to reduce slop in the front arms. Front damper is 5mm shorter than necessary so you can do two things:

1 - You can reverse the front damper stays, left with right and right with left.

2 - You can change the lower damper part (the lower ball mount) with a longer one to obtain the lost travel and avoid sloppy front end. I prefer this solution.

3) Rubbish hard propeller shaft probably will be changed with Rere Hot Shot one so no more problems. Same thing with shafts and cups. Thunder Shot UJs will work. Modern similar CVDs will be the light.

4) Rear suspension needs some tips. Rear dampers are too long (3/5 mm). To avoid rear upper arms breakage you must add some spacers inside the dampers (a couple of o-ring or a 4 mm tube is good). Then you must cut the rear arm stoppers on the rear gearbox. With this tip you can roll over everytime you want without the breakage of upper arms.

Then drill a 3.5 mm hole in every rear arm holes where the long pin screws are screwed. Fix the screws with a drop of loctite or some liquid treadlock. Not needed on front arms.

In alternative you can use some stainless e-clipped arm shafts (like Top Force for example) so no 3.5mm hole is needed. I prefer this.

5) Rear suspension tower. If you make a very giant jumps probably you will break the gearbox where the shock tower is locked. Make a brace using the Hot Shot rear damper mount onto the rear gearbox (see my Manta Ray/Top Force picts for example of brace in my showroom) and fix it to the shock tower.

http://www.tamiyaclub.com/showroom_model.a...36245&id=24

6) Steel antenna. Simply don't use it. It will destroy the antenna hole in your body leaving the car upside down. Use a plastic tube type.

7) make two big washers with some lexan sheet and put them onto the body columns. They will help to preserve the body holes.

8) Cut away the driver if you want but leave the blue roll bar in place. It will save your body.

9) Always ALWAYS ALWAYS use steel pinion gears, specially if you like 13T and 14T.

10) Battery door. This is the bigger problem. It will break. Really don't know if Tamiya changed it but I don't think it. It's the bigger problem of the car.

I made this:

I locked forever the battery door to the rear gearbox and the chassis. Now the car is 1000 times more rigid and stronger but you have two ways with the battery. You can lock the battery inside the car or you can slide it from one side like Thunder Shot. I used this solution so please check my showroom, its too long to explain.

http://www.tamiyaclub.com/showroom_model.a...3734&sid=24

http://www.tamiyaclub.com/showroom_model.a...3735&sid=24

Sorry for my low english skill.

Hope this tread will help you future owners of the best Tamiya buggy ever (in my opinon obviosly).

Cheers

Kontemax

[loaded 4]

The Boomerang was my first car and this post takes me back to my enjoyment and learning about limitations and upgrading the car.

One thing I would say you forgot is the bumper, which is a big weakpoint also, the little corner pieces which attach to the chassis breaking off. I made one out of aluminium, but there are some aftermarket ones available, I believe I have seen them in Jason's store, although I never used one myself. They will continue to use the steel antenne.

I also seem to remember making an upgrade to the front shocks by using parts from the Hotshot upgrade kit (the Supershot shocks). I will have a look to see if I still have this car in my collection somewhere. Also, weren't the 8mm connectors aluminium?

I can't wait for this one, the Hotshot re issue didn't excite me as much as this one.

[94eg! 834]

9) Always ALWAYS ALWAYS use steel pinion, specially if you like 13T and 14T.

Where do I get steel pinions for my Hotshot. I am sick of replacing the 13T alloy junk...

[kontemax 1725]

I didn't forgot the bumper. Simply I never had problems with it, never broke.

You surelly could make the double dampers front upgrade from Super Shot but I didn't like it for these reasons:

1) Extremelly ugly on the Boomerang body.

2) You lost the front swaybar

3) Damper lenght was too short and fully compressed the front bottom of the car didn't touch the ground cutting greatly away a lot of the suspension movement. If you compress the front single damper of the Boomerang with two fingers you'll see the car touching the ground and the wheels rising up 5mm each. A lot of suspension movement.

Steel pinion gears. You can buy them to Tower Hobby, they are produced by RRP and are 32 pitch module (0.8 metric).

Ciao

Max

[Toonz 1]

got any links to the pinions? thanks

[Mr. ED 5]

The bigwig front suspension will work on the boomerang also and looks more assorted with the blue plastic uprights. But you need the bigwig arms for it and they're harder to arrange than the uprights of the supershot

[Lonestar 1]

I didn't forgot the bumper. Simply I never had problems with it, never broke.

you didn't try hard enough, then... this was the first thing that would go! None of the boomy's or super sabre's I ever had in my hands had this part intact. And my runner broke a few these past years.

You surelly could make the double dampers front upgrade from Super Shot but I didn't like it for these reasons:

...

2) You lost the front swaybar

The front bar is a joke on this car anyway... one just needs to look at the "swing" movement of the front suspension with the monoshock as well as the plastic the swaybar mounts are made of to convince oneself that front swaybar is utterly pointless (if only for looks, I agree)!

The rest of your post is great - thanks for sharing. I WILL get another boomy which I will run a bit harder than the other ones I currently own, so that is a welcome set of tips.

Thanks!

Paul

[richard.tufty 20]

The front bar is a joke on this car anyway... one just needs to look at the "swing" movement of the front suspension with the monoshock as well as the plastic the swaybar mounts are made of to convince oneself that front swaybar is utterly pointless (if only for looks, I agree)!

Thanks!

Paul

The front sway bar does perform one very useful action on the Boomerang, it holds the front of the body down! I upgraded my Boomerang to the dual front shock system and the first time I drove it the wind got under the nose and flipped the shell up at about a 45 degree angle, nice wind brake!

We used self adhesive velcro to overcome that one.

I've never broken a bumper either, perhaps I don't drive it hard enough... I had a Boomerang and a Sabre back in the day and never broke one, I have a Boomerang (the upgraded one) now and I haven't broken that either.

[Mr. ED 5]

The front sway bar does perform one very useful action on the Boomerang, it holds the front of the body down! I upgraded my Boomerang to the dual front shock system and the first time I drove it the wind got under the nose and flipped the shell up at about a 45 degree angle, nice wind brake!

We used self adhesive velcro to overcome that one.

There's a little part on one of the part trees that's not used. it fits between the 2 gearbocxhalves on the top and acts as a bodymount. A hole in the body and a bodypin later you will never see that body flip up again.

The swaybar just makes it hard to mount the body

[richard.tufty 20]

There's a little part on one of the part trees that's not used. it fits between the 2 gearbocxhalves on the top and acts as a bodymount. A hole in the body and a bodypin later you will never see that body flip up again.

The swaybar just makes it hard to mount the body

Hmmm, I have to look into that! Presumably it's like the rear shock tower mount, fits into the slots in the gearbox?

Thanks for the tip!

[Mr. ED 5]

Hmmm, I have to look into that! Presumably it's like the rear shock tower mount, fits into the slots in the gearbox?

Thanks for the tip!

it slides inbetween the 2 slots on top , yes.

the colour is black and I had multiple spares at some point. The only other parts I had spares of were the rear bumpers, and It think the drive triangles, so maybe they are from the same tree?

[loaded 4]

Part B8

Paul

[Mr. ED 5]

Part B8

Paul

It's a bigwig part isn't it? If I'm right that shows how they already had palns for the bigwig when they designed the boomer more or less. It's a shame they neve made a conversion kit for the 2-damper front kind of like they were blind for the revenues of hop-ups back then

[loaded 4]

Hi,

Yes, the Super Sabre, Boomerang and Bigwig all have the parts laid out like this. The Hotshot, Hotshot II and Supershot do not. Models are designed in batches, not necessarily released all at the same time. The part can be used on the Boomerang, but it lifts up the front of the body about 5mm.

Paul.

[richard.tufty 20]

It's a shame they neve made a conversion kit for the 2-damper front kind of like they were blind for the revenues of hop-ups back then

But they did make a conversion kit, it's what my Boomerang has on it:

http://www.tamiyaclub.com/showroom_model.a...13&id=21086

I will try to find the Tamiya part number, I got mine off the bay a few months back for about $30 I seem to recall.

[loaded 4]

Your wing is on the wrong way round.

That is a Hotshot H.P. suspension set (front only) which was not a Boomerang exclusive upgrade. Your rear is a standard one, but you can use the Hotshot H.P. one as well.

Paul.

[richard.tufty 20]

Your wing is on the wrong way round.

That is a Hotshot H.P. suspension set (front only) which was not a Boomerang exclusive upgrade. Your rear is a standard one, but you can use the Hotshot H.P. one as well.

Paul.

I never realised the wing was backwards, thanks for that.

What advantages does the Hotshot HP rear setup bring?

[loaded 4]

I can't remember off hand, I imagine it is only marginally lighter than the Boomerang one. It was designed for the Hotshot not the Boomerang, as the Boomerang already had a pair of rear shocks.

All the best, Paul.

[kontemax 1725]

HP Hot Shot/Super Shot suspension set up is rubbish.

It was a real upgrade in front of Hot Shot 1 set up but Boomerang is far away better than HP suspension set up for these reasons:

1) Longer suspension travel than HP set up, in rear end but expecially also on front end.

2) Greater softness of front suspension in front of HP one. The HP front springs are too stiff.

3) Lighter than HP, expecially on front.

4) False common idea that front HP elimenates the slop on front arms (that it is due the ball connectors)

5) Extreme ugliness with Boomerang body.

In the Boomerang rear shocks are the longer ones mounted in Hot Shot serie. The bottom of the car can touch the ground and the wheels can still rise up 4/5 millimeters each. This is very usefull if the car get an hole in the ground in the middle of its width and a stone, or more stones, under the rear wheels. With HP setup the rear bottom of the car can't touch the ground.

Same thing, or worse, with front end as I wrote in my previous post.

The problem with slop in front end in the Boomerang is due the 4/5 mm shorter than necessary front damper. You can solve this increasing damper lenght with a longer spring retainer. You will rise up a little bit the car eliminating some rolling movements and saving the suspension lenght.

Front sway bar is absolutelly needed with mono shock. Try the car with mono shock without the bar and let me know how many times you will roll.

Front sway bar can be easly increased with Hot Shot alluminium ball ends (or similars) and Hot Shot FRP bar stays. The HS stays are more rigid than Boomerang plastic ones and the bar works better. Don't mount Hot Shot bar because is too thick and too hard. You need only to cut the treaded ends on Boomerang one to fit Hot Shot ball ends.

If you absolutelly want the double front shock set up go with Big Wig ones, you'll have dual shocks and will save the suspension lenght.

Max

[kontemax 1725]

And at the end I drove my Boomerang with hot motors when I was young and crashed it hard a lot of times but never broke the front bumper.

Max

[richard.tufty 20]

4) False common idea that front HP elimenates the slop on front arms (It is due the ball connectors)

I disagree with this point, the slop completely disappeared form my Boomerang when I put the HP front shocks on, it was terrible before, even with a brand new sway bar.

I totally agree with you that they are too stiff as stock though, I put softer springs on mine and used the pistons with the 3 biggest holes to avoid it being too bouncy.

[Splended 4]

Bought a Boomerang 6 months ago. Replaced 90 % of the chassis. I think the old Boomerang was a big dissapointment and just ****. Slow, noizy, sloppy and fragile. My boomer was placed on the shelf after just one run. I actually have it for ONE reason only: the nice design lines. Maybe the re-re is better?

[highflyer 73]

And at the end I drove my Boomerang with hot motors when I was young and crashed it hard a lot of times but never broke the front bumper.

Max

Never broke? Try the Lunar Jump and see what happens..

Richard, did you fix the rear wing yet?

[kontemax 1725]

Bought a Boomerang 6 months ago. Replaced 90 % of the chassis. I think the old Boomerang was a big dissapointment and just ****. Slow, noizy, sloppy and fragile. My boomer was placed on the shelf after just one run. I actually have it for ONE reason only: the nice design lines. Maybe the re-re is better?

Yes but you probably don't think about the fact you bought a 22 years old plastic and rubber. Probably your car was old, used and worn.

A new one will be different.

Max

[kontemax 1725]

I disagree with this point, the slop completely disappeared form my Boomerang when I put the HP front shocks on, it was terrible before, even with a brand new sway bar.

I totally agree with you that they are too stiff as stock though, I put softer springs on mine and used the pistons with the 3 biggest holes to avoid it being too bouncy.

Ok. Please disassemble the front gearbox leaving all suspension and arms mounted (single damper set up). Disassemble also the front wheels.

POINT 1

Take the part and observe it very very well. You must watch the gearbox from its rear end, the side where the propeller shaft joint is located.

With this point of view watch the front lower arms near the pin screws. You can see the triangular shape of the lower arms. And you can also see the stoppers on the gearbox.

You will also see that, with all extended front damper, the arms don't touch the stoppers leaving a couple of millimeters of free space each side.

Now, holding the gearbox in your hand, move a little bit up the right knuckle.

You will see the damper will not compress but the right arm will go up, increasing the free space between the arm and the stopper of 2 mm more, and the left arm will go down decreasing the free space to 0 mm. Repeat this operation with left arm and you will obtain the same result.

This is the reason you find the slop on the front suspension. If you put a longer damper the arms will touch the stoppers and you will eliminate the slop.

The front sway bar doesn't eliminate the slop because it works against the roll, no more.

POINT 2

Keep one front lower arm with your fingers.

Then move up and down the wheel axle. It will move all together with the upper arm.

Then keep the lower arm and the upper arm with your hands and move them in opposite directions. They will increase the distance between themself.

This is the real slop of the front suspension of Hot Shot serie and it is due the rubbish 8 mm ball ends, expecially if they are worn out.

With double or single dampers the situation will not change.

The only difference from HP and stock set up is that HP set up eliminates the 2 mm of free space between the lower arms and the stoppers. You will also notice that with HP set up the front end of the car is raised up.

You can obtain the same result with a slightly longer single front damper keeping a better geometry and a better suspension set up (sway bar is needed).

Hope I did explain well now the problem and sorry for my low skill english.

All you don't observe and don't study your cars. Please before study the cars, study the problems and only then speak about them. I'm 22 years old experienced with this car so please let me say that I know what I'm speaking about.

That's all.

Max