Hotshot Rere Toe In

[yamita]

I assembled the rere hotshot exactly as in the manual and noticed it has quite a bit of toe in. Does everybody run it this way? Is this much toe in required to counter bump steer? Thanks.

[secretasianman]

I've never had any severe-toe-in problems with this kit. You probably just need to tighten up the links a bit.

If anything, it should toe out slightly at rest and correct itself to parallel when the front end lifts during acceleration. Since the stock suspension settings are quite soft the nose will sag at rest.

[94eg!]

Most older Tamiya kits have lots of toe-in per the instructions. Running it that way is great for straight line stability, but it reduce top speed and cornering ability. Fortunately you can mess with it all you want. Unfortunately the Hotshot has such bump-steer issues, that you'll be redoing the toe every time you change ride height (if it matters to you that is)...

[yamita]

I wont be running this car too often and I just built it per the instruction. Still a fun car tho, considering the design is almost 20 years old.

[Mad Ax]

I've noticed the re-re is supplied with two different types of front uprights, and I couldn't understand why. The modified type seem to make the track wider and give more pronounced toe-in with stock rod lengths; also due to the wider track the front driveshafts are quite loose.

After building, I swapped my front uprights for the original parts from the tree and found the driveshafts and steering settings were much better that way.

Anyone shed any light on this..?

[007al]

The new uprights are from the TA01 and they correct the bump steer problem.Use about one degree toe out with these uprights and it should handle corners better.

[madaz75]

The new uprights are from the TA01 and they correct the bump steer problem.Use about one degree toe out with these uprights and it should handle corners better.

They also have better Ackermann Effect, improving Mid-Corner Grip, and slightly reducing understeer.

[94eg!]

The new uprights are from the TA01 and they correct the bump steer problem...

How do they fix the bump-steer? The Parma bump-steer eliminator kit I'm using (for the original uprights) moves the tie-rod ball connector WAY down to point that the tie rods run directly behind, and parallel to, the lower control arms?

According this step of the re-re manual, the uprights are still reversible like the original (centered lever arm), and still use the same ball-studs as well. I can't see how only moving the connecting hole in-or out with a new upright would help with bump-steer that much...

I really gotta take a pic of the Parma kit installed so you guys can see what's going on. It really makes the front suspension near perfect. It can never be TRULY perfect as long as the left & right tie-rods are different lengths, but what are you gonna do...

[terry.sc]

Standard issue bump steer with the Hotshot. Lots of toe in when you pick it up, lots of toe out when the suspension is compressed. The Hotshot has to have lots of toe in to control the huge amount of bump steer and to make the steering as consistent and stable as possible, especially as the Hotshot has different amounts of bump steer on either side of the car.

I've noticed the re-re is supplied with two different types of front uprights, and I couldn't understand why.

Anyone shed any light on this..?

The original ones included on the sprue were only used on the Hotshot and Supershot kits. The ones supplied separately were used in all other models in the Hotshot range as they give a much better steering geometry to reduce the huge amounts of understeer. They don't affect the bump steer at all. The separate front uprights are also a better material.

The rerelease Hotshot has longer front driveshafts than the original to go with the wider track of the new front uprights.

[007al]

My original Hotshot has wheels pointing forward and my rere has 1degree toe out.If i stand them side by side and push the front ends down,they end up with the wheels pointing at the same angle.I have a Parma bump steer kit,havent tried it yet,its still in the packet.I have GRP chassis plates for another Hotshot i plan to build with period hopups,i`ll try them on that.

[94eg!]

My original Hotshot has wheels pointing forward and my rere has 1degree toe out.If i stand them side by side and push the front ends down,they end up with the wheels pointing at the same angle.I have a Parma bump steer kit,havent tried it yet,its still in the packet.I have GRP chassis plates for another Hotshot i plan to build with period hopups,i`ll try them on that.

If you install the Parma kit you will notice a huge difference in bump steer. Toe change through the suspension stroke is pretty much eliminated. Of course it will never be "prefect" since both tie-rods are different lengths causing one side to be slightly different from the other. The only issue I've noticed with this kit, is that the new angle of the tie-rods (downwards) causes the longer tie-rod to bottom out on skid plate when the suspension is at full droop. This causes one side to have more droop than the other. It could easily be fixed by cutting a notch into the skid plate, but I didn't bother with that. I have noticed NO issues from the uneven droop while driving on a track.

The bump-steer kit makes the car WAY more predictable when accelerating and braking...

[Savage03]

I really gotta take a pic of the Parma kit installed so you guys can see what's going on. It really makes the front suspension near perfect. It can never be TRULY perfect as long as the left & right tie-rods are different lengths, but what are you gonna do...

the parma kit does help alot, theirs a guy on ebay selling them. I notice tho they sure stick down far and fear they will break the knuckle cause of it, time will tell I guess.

[94eg!]

I've raced my Hotshot dozens of times around a hard-paked clay track with big jumps and had no problems with the knuckles breaking or the adjuster popping off (using the original uprights too). The only thing I've noticed is that the long ball-studs can start to loosen from their screw after a couple runs. It might be a good idea to add a dab of lock tight to them...

[markbt73]

So that's all the bump-steer kit is, is just longer ball studs? The idea is to make the angle of the tie-rods as close to the angle of the suspension arms as possible, and that makes the bump-steer go away?

[94eg!]

Well yeah. The problem with the stock setup is that the lower control arm and upper control arm are at completely different angles to the tie rods. If the control arms were pointing downward, the tie rods were laying flat or pointing upwards. This meant that as the suspension was compressed, the effective length of the control arms would widen, while the tie rods would shorten. this causes the wheels to severely toe-out as the suspension was compressed. By relocating the mount point downward behind the lower control arm, you could get both tie rods to move with the suspension. It isn't perfect because the right tie rod is longer than the left one, but it's as close as it's gonna get without going to a bell-crank or rack & pinion steering system...