My T500RS "Even Stiffer" Brake Mod

  • Thread starter mrbasher
  • 305 comments
  • 64,751 views
Hello,
I am new on this forum and I have some questions regarding this mod.
I'm gonna buy a new wheel, fanatec or thrustmaster, and i hope this mod gonna help me decide.
For now i am only racing on ps3 (GT5 & F12012), I read it works fine with GT5, but did someone try other games? WRC3, F1 2012,...
Do you have to callibrate the pedals every time?
How much Travel will you loose?
 
I will have a set of 73a's coming from basher soon so I will post my opinions on them versus the 78a's once I get some time to use them.
 
Mr. Basher, are you an iRacing member? Would you mind if I shared and linked back to this thread at the iRacing forum?

It's a great idea and I would like to spread the word.

Cheers!
 
SpecMiata-JSW
Mr. Basher, are you an iRacing member? Would you mind if I shared and linked back to this thread at the iRacing forum?

It's a great idea and I would like to spread the word.

Cheers!
Click to expand...

Sure man, that's no prob at all. I am a member there though I don't post too much. :) (or get to race nearly as much as I'd like too!)
 
Just wanted to post and show what you get if I send you the bushings and plate:

bushings.jpg


(The plate shown here is a little different than the one I was sending out. I liked this thickness of metal better, it was easier to machine.)
 
I think I been through about all configurations. I tried the short travel without spring. Surprisingly it gave me full range of the pot if the raw data of diview is to be trusted. But awful feel. It was not really a progressive resistance just a mushy feel from start to finish.

Spring is going back in until I get the bushings.
 
I think you will like these. You can always just use one if two is too much as well. They are pretty soft. I can squish the bushing between my finger and thumb and almost close the hole. Though my hand strength is probably on the upper side of normal... However, they are nothing compared to a leg acting on a lever :)
 
I'm using one 73a khiro bushing and I think its perfect. It gives me just enough stiffness and a good amount of travel.

Your hand stength is def up there, I can't do that :D
 
rekki
I'm using one 73a khiro bushing and I think its perfect. It gives me just enough stiffness and a good amount of travel.
Click to expand...

pondering...

My guess would be that initial travel would not be affected too much by using one or two but the last bit would be more affected... I think I'm thinking about that correctly... Maybe not.

So if one bushings takes say 20 pounds of pressure before the hole is closed, two would take 40. However, if the last .5" of travel takes 50 pounds with one, two would be 100?

I dunno. I'd have to try it, I've only ever used two. I also keep forgetting to give those green ones the squish test. I'm almost certain they are the same as the white Khiro bushings though.
 
I tried this last night with two and then one 83a bush and found it way to stiff for my liking.

Today i picked up some 73a bushings and put one in and its perfect!! Thanks for sharing this.

I managed to build a ghetto retainer, as i use mine in GT style, by punching two holes with a sharp kitchen utensil through an old credit card. Holding up so far.

Is there any way you would be able to make me up a neat metal retainer like in your photos and post it to England? Cheeky for asking, but just let me know how many beer tokens you'd like and I'll sort it out :)

Rob
 
Springs in series versus parallel matters here…just calculate the net spring rate accordingly. Note that plastic has hysteresis effects to consider.
 
These "springs" would be parallel unless my grade school science is lacking... So, additive.

Hysteresis as it is applied to urethane (in this case) has the added benefit of the "return energy" being slightly less than what was necessary to compress the bushing or bushings. This decrease, while slight, helps in brake modulation as you lift. This is a critical portion of the braking cycle.

Another great thing about the urethane is that unlike rubber, it's "springiness" doesn't degrade nearly as quick with repeated cycles.
 
mrbasher
These "springs" would be parallel unless my grade school science is lacking... So, additive.

Hysteresis as it is applied to urethane (in this case) has the added benefit of the "return energy" being slightly less than what was necessary to compress the bushing or bushings. This decrease, while slight, helps in brake modulation as you lift. This is a critical portion of the braking cycle.

Another great thing about the urethane is that unlike rubber, it's "springiness" doesn't degrade nearly as quick with repeated cycles.
Click to expand...

You can adjust the hysteresis via trimming.

From the late, great Carroll Smith's seminal Tune To Win, in which he examined the hysteresis of the ubiquitous Koni bump stop.

TTW-SmithA_zpsabf96bce.png
 
Received my 73's and plate from mrbasher today. I'm going to spend some time switching back and forth between the 78's and 73's and see which I like best. First impression of 73's are that using one feels just a tad bit softer than I prefer but it's easier to make minor brake inputs versus the 78's. The overall firmness of the 78's is good but I wish it was a little softer for the first 33% of brake inputs. Either way I like both and could definitely use either for the long run. When I was using the 'real brake mod' I was never satisfied with the feeling and constantly looking for other options and looking to spend money for a quality mod. I got what I was looking for and have spent $12 total and have two levels of resistance. Can't beat that deal.:)
 
mrbasher
Nice! :) Thanks for the feedback. Did you try two of the 73's to see how that felt?
Click to expand...

I did, but actually before I started up the PS3. Obviously not a good test so I will give it a try tomorrow.
 
mcfizzle
I did, but actually before I started up the PS3. Obviously not a good test so I will give it a try tomorrow.
Click to expand...

Ah.. Gotcha.. You gotta run some laps and see how it feels :) Keep us posted. I'm curious as about 9 other people will have these in the near future
 
mrbasher
wimps...

jk ;) My friends did call me Popeye in high school...
Click to expand...

Having got the Khiro in the mail today I can see why. I need both hands and push really hard to achieve that :) Installed and did a race with them. Work as advertized. Did a race and work really well. One bushing up next.

Okay haven´t even tested it on track but I dare to say one Khiro 73 is IT for me and the T500RS pedals. Get a more positive feel when I am at 100 % and don´t have to think about mashing like an idiot to get to full brake or even be uncertain if I am going heavy enough on the pedal of if I am being lazy. I can still feel the pedal through the entire travel from the beginning and it shouldn´t be so heavy as to numb my leg to much over time which is an issue with the stiff brake mod on the T500RS and dual Khiros. I am no body builder :)

Very fluid movement and progressive resistance regarding both but the end travel somehow feels more solid with just one. I much preferr the rubber feel of this over only the rubber on the stiff brake mod that come with the pedals which really seemed to need the spring despite the noices and quirky feel it bringed to the mix.

CSP V2s in on monday. Regarding performance I suspect it will be a very tough fight actually now that I believe I found the sweetspot with my T500RS pedals regarding smoothness and progressive resistance :)
 
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Tried out it with one Khiro 73 and yes no doubt this is the best T500RS brake I used. I did have problem with braking in the stock car V8 interlagos Race. Particularly T1 I got quite embarrassed where I at one time had a guy coming from behind at higher speed. Taking the inner line of course and outbraking me while I thought I did a decent effort and probably was lighter on fuel... Humiliating.

I beat my personal best within the first warmup lap when I didn´t even thought I was pushing. Obviously getting the braking better which was very evident in T1 at Interlagos but particularly all high speed corners where I probably had problem keeping enough pressure up previously or not being able to soften up smoothly.
 
After trying the 70a bushings I can say that they provide more than enough resistance for my liking, I also made a retaining plate from an old plastic card. Since replacing the stock clutch and throttle springs with some stiffer ones and using the bushings for brake resistance my T500 pedals are now a joy to race with....
 
Day one with the CSP V2 and to my shock it´s not even a contest. Preferr the brake of the T500RS a lot.Spent the night tweaking the CSP best I could will see if the CSPs fair better tomorrow. Sadly they where not quite as configurable as I remembered the V1s?
 
oqvist
Sadly they where not quite as configurable as I remembered the V1s?
Click to expand...

My sentiments exactly, and I own both. Although, in all fairness, this is partially because my V.1s have the tuning kit installed, whereas the V.2s have no counterpart from Fanatec yet.

Also, The brake pedal travel is a less configurable on the V.2s because the brake arm pivot is mounted one notch higher by default than the V.1s due to the RC shock. The V.1 tuning kit also provided alternate length/hardness foam inserts and metal rods for the brake.

Some V.2 owners have stated that the feel is improved by substituting the spring in the RC shock with a stiffer one, I have yet to try that.
 
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Have you made some objective measurements yet? I mean anecdotes and polls can be fun but can only go so far…

In the plot below, some bump stops (bushings which fit over the shaft of a automobile damper) are compared. They are modified bushings. Plotted on the X axis is the distance the bushing is compressed. The Y axis shows how much total force it took to obtain any given amount of compression. Notice the knee in the curve and how the different stops behave. Some measurements might help you further prove and develop your product.

For bushings/bump stops used in brake pedal devices, the leverage factors need to be considered of course.

HTH.

ScreenShot2013-01-15at123631AM_zps2e4015ad.png
 

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