Honda City Turbo front suspension bump stops

[AJB123 107]

My recently-built Honda City Turbo is great, but if it's wheelying and then you lift off the throttle, then as it drops down from the wheelie the front suspension compresses to the point that the front bumper/splitter crashes into the ground with a horrible noise. (This impact also revealed that my gluing of the bonnet vents wasn't up to scratch the other day...!!)

I was wondering whether there's any point in adding a bit more rubber tubing to the front suspension bump stops to try to get it to stop compressing before it hits the ground? Or is that a lost cause, and tyre squish etc will mean it bottoms out until the front hits the ground anyway? I get why most chassis bottom out on the ground rather than the suspension, to avoid over-stressing the suspension on landings from jumps, but this isn't a solid bit of chassis taking the impact.

If it's a good idea, has anyone tried it, and how much extra length did they add? I don't really want to trial-and-error it given it'll involve taking the ball end off the shock shaft each time!

Thanks!

[max69vk 708]

I'm hazarding a guess you are still using the original kit supplied pogo-stick dampers?

A set of oil filled dampers would make a massive difference to the way front is cushioned when it lands back down, adding more rubber tube to the damper will just limit the damper stroke to the point of them not doing anything at all. 

Most cheapo damper sets come with quite hard springs as standard so this will also add a bit of resistance to bottoming out.

[AJB123 107]

1 hour ago, max69vk said:

I'm hazarding a guess you are still using the original kit supplied pogo-stick dampers?

A set of oil filled dampers would make a massive difference to the way front is cushioned when it lands back down, adding more rubber tube to the damper will just limit the damper stroke to the point of them not doing anything at all. 

Most cheapo damper sets come with quite hard springs as standard so this will also add a bit of resistance to bottoming out.

Thanks for the reply! Yes I am - the Honda City Turbo didn't exactly feel like it was designed for the ultimate in handling anyway! But yes oil filled shocks would make a big difference as their resistance goes up with speed of compression rather than being fixed. It's just that I'm not really looking to spend any money on it right now, and it's the one kit I felt I could get away with leaving the friction shocks on (the greased rubber tube sort, rather than the even-more-horrible all plastic ones they use now).

There's actually quite a lot of travel, so limiting the stroke to stop a bit earlier wouldn't necessarily mean they then did nothing at all, as long as it kind of stopped when it hit the bump stops. The unknown in my mind is whether I'd actually have to limit it way too much in order to keep it from bottoming out once tyres compress, suspension arms flex, etc..

And yes, harder springs would help, but I love the fact that this is one of the very few kits Tamiya make with nice soft springs from the factory - most are just way too stiff in normal driving in my experience. I hate seeing the car bounce around on a fairly smooth surface, and I like seeing the suspension working. So I'd rather put up with having to drop down from wheelies carefully than have to make it super-stiff when the wheels are on the ground.

[AJB123 107]

To answer my own question, I don't think it'll work. I've added about 1mm of extra rubber tubing, which means that pushing the front down by hand now causes the shocks to stop the travel on their bump stops with the bumper 1 or 2mm off the ground rather than touching it (as it did with the specified length). But... it still bangs into the ground coming down from a wheelie - tyre compression and suspension flex lets it take up that extra clearance.

The screws mounting the shocks to the lower arms were very slightly bent when I took them out (not really noticeable, except that the metal collar was catching on them rather than sliding straight off). It's not had any jumps or driven over any large bumps, so I think that must be from dropping down from wheelies even with the standard bump-stop length. So, if I added enough extra spacing to stop the bumper from hitting the ground at all, then I think it'd just end up bending or breaking something from the impacts - I think I'm just going to have to learn not to lift off when the front's up in the air (and therefore not get it into the air whilst heading towards any solid objects!!)

I'll leave the extra mm of tubing in, though, as I don't think it'll put much more stress through the suspension, it might slightly lessen the ground impacts, but mostly because it annoyed me that the bumper hit the ground when just pushing it down by hand - it's much more satisfying when it stops just clear of the ground.

[AJB123 107]

On 9/24/2019 at 1:55 PM, max69vk said:

A set of oil filled dampers would make a massive difference to the way front is cushioned when it lands back down

If I did get oil filled dampers for it, which Tamiya CVA sets (if any) fit the WR02C?

(Just realised I've put this thread in the re-release forum, but it maybe ought to be general really... Sorry!)

[max69vk 708]

If you want to stick with Tamiya then CVA mini shocks are the ones to go for, there are plenty of cheaper options out there though.

[taffer 948]

Set 53619, use kit springs to start

[AJB123 107]

Thanks both!