Like Tree194Likes

Tamiya TB Evo 8

Old 04-21-2023, 10:38 AM
  #181  
Tech Fanatic
iTrader: (32)
 
hotdognobun's Avatar
 
Join Date: Sep 2009
Location: San Diego
Posts: 871
Trader Rating: 32 (100%+)
Default

Originally Posted by hipwell
When you say central spur setup do you mean motor on the front left?

If so I just run the servo cable under the motor, it goes nowhere near the spur gear as my servo sits in front of the motor and the cable exits on the left and then i just tuck it under the motor with a bit of douvle sided tape

I just noticed the opening under the motor mount. Applied some body reinforced tape over it and its good to go.
hotdognobun is offline  
Old 04-27-2023, 05:26 AM
  #182  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

Turns out my grip roll problems weren't solved, it was only solved because I've been glueing the sidewalls.

First run out last week without glueing, and the rolling has returned.

Anybody found a setup that doesnt roll yet without having to glue the tyres?
hipwell is offline  
Old 04-28-2023, 08:52 PM
  #183  
Tech Fanatic
iTrader: (32)
 
hotdognobun's Avatar
 
Join Date: Sep 2009
Location: San Diego
Posts: 871
Trader Rating: 32 (100%+)
Default

Originally Posted by hipwell
Turns out my grip roll problems weren't solved, it was only solved because I've been glueing the sidewalls.

First run out last week without glueing, and the rolling has returned.

Anybody found a setup that doesnt roll yet without having to glue the tyres?

I'm playing around with tire foam inserts and even changing out the super short shocks to standard big bore (42354)
hotdognobun is offline  
Old 04-29-2023, 05:48 AM
  #184  
Tech Apprentice
 
Join Date: Feb 2017
Posts: 85
Default

A few updates. I too find the front being sensitive. I found increasing droop, proportionally more at the rear tamed the steering and got rid of the off throttling oversteer. Further more I used 2mm shims at the steering bridge to decrease the Ackerman, this seems to have reduced some of the initial steering and did not take away very little if any on throttle steering. I replaced the inner front drive shafts pins with 11mm pins as the longer pins give the C bushes better support as the pin now actually sit flush with the bush. Hopefully this will extend the life of those clips.

This weeks damage report, I managed to bend one of the front shock mount when I slammed into a pole along the main straight at our track… I did managed to bend it back to 90 degree however on hindsight I should have heated it up a little before attempting to bend it as it now has a tiny crack around the 90 degree bend.
200sxr is offline  
Old 04-29-2023, 07:35 AM
  #185  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

Interesting. I tried a few things last night, I increased the roll centre all around by 1 notch on the wishbones, which in terms of laptimes, I did improve slightly, but it was very difficult to drive I was having to be very careful not to roll it, I could see it wanting to lift and on 2 occasions she rolled.

I too have been playing with the ackerman, I added a 2mm shim on the steering bridge, but when checking on my setup station i found that adding shims actually made the outside wheel turn in even more, which i found odd as usually when you move the arms straighter and less of an angle you get less ackerman effect and a bigger difference between the inside and outside wheel. I can only assume this is different on the evo as the entire steering bridge moves further forward when at full lock as it pivots from the bulkhead rather than from further back like on a traditional tc, so I'm thinking there is reasoning for the very strange steering link angle on the evo compared to for example a 420 who's steering arms are dead straight and adding shims makes it more agreesive.

Next week I'm going to try the complete opposite woth roll centres and go all the way down on the front wishbones and 1 notch up on the rear to see if giving the car a bit more overall roll will reduce the traction rolling problems.

But overall this car is still flying and finished 3rd in the A last night amongst some pretty decent drivers using mugens, xrays etc.
hipwell is offline  
Old 04-29-2023, 09:18 AM
  #186  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

Interesting. I tried a few things last night, I increased the roll centre all around by 1 notch on the wishbones, which in terms of laptimes, I did improve slightly, but it was very difficult to drive I was having to be very careful not to roll it, I could see it wanting to lift and on 2 occasions she rolled.

I too have been playing with the ackerman, I added a 2mm shim on the steering bridge, but when checking on my setup station i found that adding shims actually made the outside wheel turn in even more, which i found odd as usually when you move the arms straighter and less of an angle you get less ackerman effect and a bigger difference between the inside and outside wheel. I can only assume this is different on the evo as the entire steering bridge moves further forward when at full lock as it pivots from the bulkhead rather than from further back like on a traditional tc, so I'm thinking there is reasoning for the very strange steering link angle on the evo compared to for example a 420 who's steering arms are dead straight and adding shims makes it more agreesive.

Next week I'm going to try the complete opposite woth roll centres and go all the way down on the front wishbones and 1 notch up on the rear to see if giving the car a bit more overall roll will reduce the traction rolling problems.

But overall this car is still flying and finished 3rd in the A last night amongst some pretty decent drivers using mugens, xrays etc.
hipwell is offline  
Old 04-30-2023, 03:31 PM
  #187  
Tech Initiate
 
JSHuiting's Avatar
 
Join Date: Apr 2023
Posts: 23
Default

Originally Posted by zuqbu
I was very happy with the "bridge" modification the car handled great and responded better to setup changes as well. High grip indoor carpet, mind you. I have now gone from 3D printing to a carbon CNC version:


I have an AutoCAD file I used for the carbon modification, I can send it to you. I ordered it cut from 2mm carbon sheets.
I'm not able to send PM's yet, could you please send me a PM with the file aswell?
The flex between my spurholder is just bonkers, eventhough it handles like a dream.
JSHuiting is offline  
Old 05-01-2023, 12:18 AM
  #188  
Tech Fanatic
iTrader: (32)
 
hotdognobun's Avatar
 
Join Date: Sep 2009
Location: San Diego
Posts: 871
Trader Rating: 32 (100%+)
Default

Originally Posted by JSHuiting
I'm not able to send PM's yet, could you please send me a PM with the file aswell?
The flex between my spurholder is just bonkers, eventhough it handles like a dream.
If you sell it I will buy it
hotdognobun is offline  
Old 05-01-2023, 02:09 AM
  #189  
Tech Initiate
 
JSHuiting's Avatar
 
Join Date: Apr 2023
Posts: 23
Default

Originally Posted by hotdognobun
If you sell it I will buy it
I'm surprised sellers like T-Works aren't selling them yet tbh
JSHuiting is offline  
Old 05-01-2023, 03:03 AM
  #190  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

I'm not sure a brace is actually required, I know there's a tonne of flex, but even with a bridge piece there's still a load of left to right flex, I think the only way to eliminate it fully would be flat top decks.

I've tested with and without the brace and get similar lap times and grip roll if i push too hard.

I'll be trying really low roll centres on Friday so I'll let you know how it goes.
hipwell is offline  
Old 05-01-2023, 07:26 AM
  #191  
Tech Initiate
 
JSHuiting's Avatar
 
Join Date: Apr 2023
Posts: 23
Default

It's for the flex lenghtwise, not so much sidewise.
Just lift it up by the front and rear and bend the chassis ever so slightly.
If you'll look at the spur you'll see what the issue is, you can almost make the spur touch the bulkheads(?)/spur holders.

The forces that are put on the bearings this way can't be good for performance or reliability.
JSHuiting is offline  
Old 05-01-2023, 12:30 PM
  #192  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

Originally Posted by JSHuiting
It's for the flex lenghtwise, not so much sidewise.
Just lift it up by the front and rear and bend the chassis ever so slightly.
If you'll look at the spur you'll see what the issue is, you can almost make the spur touch the bulkheads(?)/spur holders.

The forces that are put on the bearings this way can't be good for performance or reliability.
yeh I agree, I do have to change those bearings quite regular, but I think thYs usually if I have a bad front end knock and it flexes that area, but when I've run with that brace I don't think there's that much difference after lots of testing, gives a little bit more initial turn in, which this car really does not need any more of due to the dodgy ackerman angle!
hipwell is offline  
Old 05-01-2023, 02:00 PM
  #193  
Tech Initiate
 
JSHuiting's Avatar
 
Join Date: Apr 2023
Posts: 23
Default

Haven't even checked the ackerman setup yet, is it that bad?

Also i'm making my own protoype atm, 3D printed at first first but if it works i'll have some carbon variants made.
Only forseeable issue is that they won't fit all spurs, so perhaps 2 versions later on.
JSHuiting is offline  
Old 05-02-2023, 03:45 AM
  #194  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

Yeh the ackerman is insane, the links aren't straight, they point rearward, but because the steering pivots on 2 arms from the bulkhead, as the steering turns, the links move forward.

When testing on my setup station I've found on full lock if I set up to 24 degrees of steering on the inside wheel, the outside wheel has just over 20 degrees which is alot compared to on a regular tc which might have a 7-8 degree difference between inner and outer wheels.

I've tried changing the angle with shims to get them more regular, but because of the way the steering is setup it's just not possible.
hipwell is offline  
Old 05-05-2023, 03:33 PM
  #195  
Tech Regular
 
Join Date: Nov 2014
Posts: 293
Default

Well she's sorted!
New setup tonight, no glue on the tyres and no traction roll even if I tried, and the car was absolutely rapid.

I'll fill in a setup sheet at some point but for anbody interested

In a nutshell

Front wishbones on the lowest setting, 1 notch out (F)
rear wishbones one notch up from the bottom, set to 2.5 degrees toe on the blocks and 0.5 degrees of toe on the tie rods giving 3 degrees total.

No shims under the top inner links, kit shims outer, 2mm I belive.

Xray 2.6 rear, 2.5 front.

5 droop rear 5.5 front.

Kit ackerman and bump steer

450 lil in shocks 5k in diff

Volante 28 tyres

I didn't try with the brace last night, but I dont think it's required
Captain Howdy and h2e like this.

Last edited by hipwell; 05-06-2023 at 02:54 AM.
hipwell is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.