- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
Hydraulic Brake Build [V2] (G27 Based)
- Thread starter pilmat
- 154 comments
- 79,810 views
- 227
- Montreal
- SUPERNOVADAVE
- SUPERNOVADAVE
hope she does well in the new season.
my father in law used to be a aviation engineer at bombardier back in the 90`s.
and when it comes to stockcars i know them well as i used to own an engineering and manufacturing business back in the 80`s to 90`s dealing with Ford Motorsports.
my father in law used to be a aviation engineer at bombardier back in the 90`s.
and when it comes to stockcars i know them well as i used to own an engineering and manufacturing business back in the 80`s to 90`s dealing with Ford Motorsports.
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
Back to the build 
Here is my care package from DSD. A 12-Bit Controller Board w/Amp and a Pedal Pal:
The Pedal Pal is Derek's "easy connect" solution for wiring in G27 pedals to a controller board. I tend to like to do my own custom wiring, but this makes the project straight forward while still in the development stage. Cheers Derek 👍
Now I was scrounging around for a project box and came up with this
It works as advertised 
You will note the connectors are just inside the front edge:
The pedals are wired and all that is left to do is connect the sensor to the hydraulics and control board, bleed the system and test it
I have guests coming through the shop so the rigs have to stay as-is. But once they leave it's hydraulics time!!!!!!!
Here is my care package from DSD. A 12-Bit Controller Board w/Amp and a Pedal Pal:
The Pedal Pal is Derek's "easy connect" solution for wiring in G27 pedals to a controller board. I tend to like to do my own custom wiring, but this makes the project straight forward while still in the development stage. Cheers Derek 👍
Now I was scrounging around for a project box and came up with this
It works as advertised You will note the connectors are just inside the front edge:
The pedals are wired and all that is left to do is connect the sensor to the hydraulics and control board, bleed the system and test it
I have guests coming through the shop so the rigs have to stay as-is. But once they leave it's hydraulics time!!!!!!!
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
The Pedal Pal is a little device that Derek introduced to simplify connecting G27 pedals to a high resolution board. You can see it here on the DSD Components Page (It's the 7th item from the top). It comes with the jumper wires to connect it straight to his 12-Bit Controller board
- 797
- USA
I've been watching this project with much interest. It's creative and downright ingenious.
I'm looking forward to the report from the first race!
I'm looking forward to the report from the first race!
- 4,178
- Ottawa
First congratulation and thank you. Congratulation for this project it looks amazing
and thank you for sharing it with us, it is facinating to follow.👍
Being just a SIM enthousiast, not an enginier or SIM builder, and even if I read trough the thread again before writing this post, would it be possible for you to maybe recap on how does this modified set works, ie, pot, load cell, Hydraulic other, ??? and, when you have completed testing, what is it doing particularely well, in your point of view, compared to other device you have used.
Well done.
and thank you for sharing it with us, it is facinating to follow.👍Being just a SIM enthousiast, not an enginier or SIM builder, and even if I read trough the thread again before writing this post, would it be possible for you to maybe recap on how does this modified set works, ie, pot, load cell, Hydraulic other, ??? and, when you have completed testing, what is it doing particularely well, in your point of view, compared to other device you have used.
Well done.
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
@kikie
Yes, the Pedal Pal works to adapt the G27 pedals to a high resolution controller
@Cote Dazur
Thanks for the kind words 👍
Today's update: IT WORKS!!!!!!!!!
I did a quick trial run with it after our guests left the shop Here is what it looks like installed:
After a quick initial run, I found the elastomer stack was making the pedal feel notchy. I went to this config for a smoother feel:
Here is a bird's eye view (kind of a cockpit view from over the wheel looking down):
I have the gain set to around 3/4 (all the way counter clockwise is 100%). One of my friends was watching the gauge as I drove and I was achieving ~150psi in heavy braking:
How is it? Well there is a lot of potential in it, I haven't found a feel that I like yet, but the ability to modulate is nothing like a load cell. It is more natural, but at the same time it is quite heavy. So I will do more testing to see if I can reduce some of the heavy feel to achieve what I think is a better control harmony. I'll do some video of the set-up in action, as I would like to see what it looks like too
Yes, the Pedal Pal works to adapt the G27 pedals to a high resolution controller
@Cote Dazur
Thanks for the kind words 👍
Today's update: IT WORKS!!!!!!!!!
I did a quick trial run with it after our guests left the shop Here is what it looks like installed:
After a quick initial run, I found the elastomer stack was making the pedal feel notchy. I went to this config for a smoother feel:
Here is a bird's eye view (kind of a cockpit view from over the wheel looking down):
I have the gain set to around 3/4 (all the way counter clockwise is 100%). One of my friends was watching the gauge as I drove and I was achieving ~150psi in heavy braking:
How is it? Well there is a lot of potential in it, I haven't found a feel that I like yet, but the ability to modulate is nothing like a load cell. It is more natural, but at the same time it is quite heavy. So I will do more testing to see if I can reduce some of the heavy feel to achieve what I think is a better control harmony. I'll do some video of the set-up in action, as I would like to see what it looks like too
- 797
- USA
The purpose of the Gain Knob is to allow one to adjust their own Relative Maximum braking pressure. Some want to use a "gorilla leg" and others like less effort. The knob will allow one to set the level at which they want to reach maximum resolution and do it at a level comfortable for them.
You can see this in action if you press the brake pedal and hold it steady. Then adjust the knob and you'll see the output rise and fall as you turn the knob both ways (having a friend help makes it easier.
Welcome to the world of true-to-life sim braking.
d
You can see this in action if you press the brake pedal and hold it steady. Then adjust the knob and you'll see the output rise and fall as you turn the knob both ways (having a friend help makes it easier.
Welcome to the world of true-to-life sim braking.
d
That's the reason why I was talking about the brake booster!@kikie
Yes, the Pedal Pal works to adapt the G27 pedals to a high resolution controller
@Cote Dazur
Thanks for the kind words 👍
Today's update: IT WORKS!!!!!!!!!
How is it? Well there is a lot of potential in it, I haven't found a feel that I like yet, but the ability to modulate is nothing like a load cell. It is more natural, but at the same time it is quite heavy. So I will do more testing to see if I can reduce some of the heavy feel to achieve what I think is a better control harmony. I'll do some video of the set-up in action, as I would like to see what it looks like too
I now know that you can reduce the heavy feeling by adding softer rubbers to the slave cylinder.
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- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
As I move along with the testing phase, is there any aspect of this project that I've missed or not provided enough details of? There has been a request to provide detailed explanation of how the hydraulic system functions, and I'll do this gladly. Any more that you would like to know?
Through the testing phase, is there anything you would like me to try/show? I'll do some video work of the whole thing functioning, showing the pressure rise and fall, and try to sync it with driving footage so you can see the effect yourselves.
Let me know what you would like and I'll see if its possible
As I get more mileage and data, I'll be going back to the Sim Bake Thoughts thread to develop the discussion some more. I've learned a lot in this project and will be discussing comparisons in the other thread.
Cheers folks, it's been fun doing this
Through the testing phase, is there anything you would like me to try/show? I'll do some video work of the whole thing functioning, showing the pressure rise and fall, and try to sync it with driving footage so you can see the effect yourselves.
Let me know what you would like and I'll see if its possible
As I get more mileage and data, I'll be going back to the Sim Bake Thoughts thread to develop the discussion some more. I've learned a lot in this project and will be discussing comparisons in the other thread.
Cheers folks, it's been fun doing this
- 1,934
- Nazareth/Israel
- GTClub_Wajdi
As I move along with the testing phase, is there any aspect of this project that I've missed or not provided enough details of? There has been a request to provide detailed explanation of how the hydraulic system functions, and I'll do this gladly. Any more that you would like to know?
Through the testing phase, is there anything you would like me to try/show? I'll do some video work of the whole thing functioning, showing the pressure rise and fall, and try to sync it with driving footage so you can see the effect yourselves.
Let me know what you would like and I'll see if its possible
As I get more mileage and data, I'll be going back to the Sim Bake Thoughts thread to develop the discussion some more. I've learned a lot in this project and will be discussing comparisons in the other thread.
Cheers folks, it's been fun doing this
Hi mate, are you an ingeniere ?
I don't think to have your knowledge and capacity to do some thing like this! I will go for the Perfect pedals soon!Congratulation m8, great job!👍
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
Hi mate, are you an ingeniere ?
Congratulation m8, great job!👍
Thanks
Yes, I do happen to be an engineer. But a degree is not what makes you ingenious, there are some really gifted folks around this forum that I learn from every day! 👍 And asking questions get me to think about things a little differently too
- 797
- USA
As I move along with the testing phase, is there any aspect of this project that I've missed or not provided enough details of? There has been a request to provide detailed explanation of how the hydraulic system functions, and I'll do this gladly. Any more that you would like to know?
Through the testing phase, is there anything you would like me to try/show? I'll do some video work of the whole thing functioning, showing the pressure rise and fall, and try to sync it with driving footage so you can see the effect yourselves.
Let me know what you would like and I'll see if its possible
As I get more mileage and data, I'll be going back to the Sim Bake Thoughts thread to develop the discussion some more. I've learned a lot in this project and will be discussing comparisons in the other thread.
Cheers folks, it's been fun doing this
I think some may find it interesting your observations why hydraulic pedals give a better feel, control and modulation than a load cell version.
Of course, I am biased
However, it's instructive to those who want to have an objective and informed point of view as to why using race car parts to simulate race car input is the ideal manner. A hydraulic brake is more than a spring. The fluid moving through the system gives the pedal a dampening effect unlike anything else. It's my option that this is the distinction as to why a hydraulic pedal offers the advantage it does.
It's a great project you have! 👍👍
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
@derekspeare
Thanks for the question, it is an important one. I'll get to it
Today's progress: CHANGES!!
My boss (a NASCAR driver himself) was excited to try the pedal this morning. After a few laps he seemed to have the same feeling I did yesterday, that it has potential and is close, but not quite there yet. His biggest issue was that the pedal becomes too stiff (short travel) in the area he would like to modulate. He said the initial feel is good, but that the pedal goes "too hard" where he felt his real race car offered more pedal "give" through the modulation zone (he motioned about 1-1.5inches of "give" zone.
This got me to thinking about the notchy-ness and too short "give zone". I need to increase pedal travel a bit. The best way I know to do that is install a smaller master cylinder. The CNC kit comes witha 3/4in bore, so I rummaged through our stock and found a 5/8in (the smallest standard size master I know of). The feel is much smoother now, requiring a stiffer elastomer set up (to also compensate for longer pedal travel).
So without further ado, here is Rev 1.1:
Also note the really nice aluminum plate our fabricator made to overcome the butchered G27 cover Thanks Francis!
The reservoir is actually quite stable like that (I was surprised) Again the Gain is still the same and I'm only using about 2000 steps of the brake resolution (will use more as I get deeper in).
How is it? It is now at a point where I can claim a serious WOW! The feel under heavy breaking is the best I have felt in any sim brake. The ability to modulate is fantastic, and the brake release characteristic is phenomenal. I turned my fastest laps ever, and with a remarkable consistency. There are hardly words to describe how good it felt while driving, I kept saying "wow" for 15 minutes!
This is the short answer to Derek's request. I'll get into a longer description of my findings, with video, over the weekend. And duplicate it over in the Sim Brake Thoughts thread.
Thanks for the question, it is an important one. I'll get to it
Today's progress: CHANGES!!
My boss (a NASCAR driver himself) was excited to try the pedal this morning. After a few laps he seemed to have the same feeling I did yesterday, that it has potential and is close, but not quite there yet. His biggest issue was that the pedal becomes too stiff (short travel) in the area he would like to modulate. He said the initial feel is good, but that the pedal goes "too hard" where he felt his real race car offered more pedal "give" through the modulation zone (he motioned about 1-1.5inches of "give" zone.
This got me to thinking about the notchy-ness and too short "give zone". I need to increase pedal travel a bit. The best way I know to do that is install a smaller master cylinder. The CNC kit comes witha 3/4in bore, so I rummaged through our stock and found a 5/8in (the smallest standard size master I know of). The feel is much smoother now, requiring a stiffer elastomer set up (to also compensate for longer pedal travel).
So without further ado, here is Rev 1.1:
Also note the really nice aluminum plate our fabricator made to overcome the butchered G27 cover
Thanks Francis!The reservoir is actually quite stable like that (I was surprised
) Again the Gain is still the same and I'm only using about 2000 steps of the brake resolution (will use more as I get deeper in).How is it? It is now at a point where I can claim a serious WOW! The feel under heavy breaking is the best I have felt in any sim brake. The ability to modulate is fantastic, and the brake release characteristic is phenomenal. I turned my fastest laps ever, and with a remarkable consistency. There are hardly words to describe how good it felt while driving, I kept saying "wow" for 15 minutes!
This is the short answer to Derek's request. I'll get into a longer description of my findings, with video, over the weekend. And duplicate it over in the Sim Brake Thoughts thread.
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
It's not quite ready for public consumption. The initial design was to test a concept. Now that it "works" it needs refined. I had previously mentioned that there is about $450 worth of raw materials, this has already changed...
Current issues:
- I need a donor set of pedals to do this mod.
- The base plate is NOT solid enough. This was an initial concern and was raised by Mr.Basher at the beginning. It's good enough for testing, but will be a long term problem, plus it is certainly affecting the performance. I will make a baseplate to see how it all goes together, but it would add to the cost...
- There is a LOT of hand work in fitting this together. I could productionize it to an extent but it would still be a manual job.
- The pedals would no longer be console compatible.
- An external controller, in this case a DSD 12-bit controller with amplifier, is required. The DSD Pedal Pal would be a good idea too!
I will have a baseplate to fit within the G27 done next week, and we can look at the whole concept then.
In the mean time, I'll get the video done...
- 1,358
- Redmond, WA
- mrbasherman
This seems to be one of the main headaches with a full set of pedals unfortunately. You can make your clutch and accelerator or you can buy them, either way it starts getting expensive. I have a decent design for these that I will email you on, it's relatively inexpensive yet robust. However, it looks somewhat utilitarian.
Plate *anything* seems to be really expensive these days, at least in sizes that are useful for something like this.
You might look at something a little more modular like 80/20. Not actually using 80/20, but a similar concept. The rigidity would be there and ease of adjustment as well.Thank you very much for doing all this and sharing your progress as well.
Really excellent so far. This is easily fixed and not by plugging Derek's board into something like the SFA1. If you had used a seperate load cell amp and USB controller, the signals going to the controller could be tapped and sent directly to a wheel via the appropriate connector. Care would need to be taken to ensure the voltages were at the appropriate levels though. (T500RS is 3.3v for instance)
See above.
Lastly again. Thank you for sharing all of this with us!
- 227
- Montreal
- SUPERNOVADAVE
- SUPERNOVADAVE
by installing a master with a smaller bore which is a better match to the slave cylinder he used ends up by decreasing the volume of fluid that is displaced from the master to the slave. this in turn will increase the fluid pressure at a given applied pressure at the pedal and the end result will be a bit more pedal travel with better progressivness.
( will make it easier to have a good feel at the pedal ).
Pilmat - i was wondering when you would realise the master bore would have been too big. glad to see you figured it out
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
Pilmat - i was wondering when you would realise the master bore would have been too big. glad to see you figured it out
I tried to use the whole CNC clutch kit, but it will need the 5/8" master cylinder...OK, major setback time...
Polyethylene glycol based fluid and the plastic in the the G27 case DO NOT MIX. A couple of drops of fluid leaked down when doing the initial bleed, these have destroyed the G27 base plate. When I took it off this morning to do a test of the stock G27 pedals (see below), I found a handful of plastic bits
I now HAVE to make a metal base plate!Why did I swap back to the G27 pedals (with GTEye spring)? Because the very nice folks at iRacing changed the tire model in the middle of my testing 👎 I logged in yesterday and was struggling to do a decent lap until I realized that the new update was a major one
So today I wanted to re-baseline my work, only to find I had some ugly looking plastic to contend with too!Back to the development drawing board
- 367
- MobySPD / GTP_MobySPD
OK, major setback time...
Polyethylene glycol based fluid and the plastic in the the G27 case DO NOT MIX. A couple of drops of fluid leaked down when doing the initial bleed, these have destroyed the G27 base plate. When I took it off this morning to do a test of the stock G27 pedals (see below), I found a handful of plastic bits
Why did I swap back to the G27 pedals (with GTEye spring)? Because the very nice folks at iRacing changed the tire model in the middle of my testing 👎 I logged in yesterday and was struggling to do a decent lap until I realized that the new update was a major one
Back to the development drawing board
Naah,
One small step back, one big leap forward in the future for hydraulic brake systems in sim racing. And if it will be affordable on a diy kind a thing my guess it will be even a giant step forward.
Great progress and great project, and to even share all of it. No words... 👍
- 577
- NC
Sadly, normal brake fluids deteriorate many common plastics and of course paint. Besides a metal pedal base, you could try silicone brake fluid. It is very plastics-friendly.
I dislike silicone brake fluid for automotive use, especially for high performance driving. It yields a softer pedal than conventional DOT 3/4/5.1 fluids. Many ABS devices dislike it too. But for Sim use where we deliberately want to add some deflection (hence adding compliant bushings at the slave cylinder) this "give" might be useable to good effect.
I dislike silicone brake fluid for automotive use, especially for high performance driving. It yields a softer pedal than conventional DOT 3/4/5.1 fluids. Many ABS devices dislike it too. But for Sim use where we deliberately want to add some deflection (hence adding compliant bushings at the slave cylinder) this "give" might be useable to good effect.
- 1,086
- St-Hyacinthe, QC
- GTP_pilmat
- pilmat
Thanks 👍 And don't worry, the project is just taking a bit longer now
I'll get into the metal base plate this week! Pilmat, try and reproduce Simworx simple G27 metal pedal box. Its just bent steel sheet with some holes cut out.
Cheers!! Nice lead 👍
Interesting idea 👍
I stuck with what is common and relatively cheap. Seal compatibility with different fluids is an issue I didn't want to get into, but I might have too...
DON'T tell my boss I have other ideas !!! He's not going to be impressed with this one
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