Why Do Pro Racers Remove Brake Boosters?

[@hpa101]

Building a fast car? Get $400 OFF the VIP package and never pay for another course, EVER: hpcdmy.co/vipy22 Brake System course. Design & optimise your set up. Now 50% OFF. hpcdmy.co/brakes007 TIME STAMPS: 0:00 - Power Vs Stopping Power 0:20 - Factory ABS & Motorsport 0:45 - OEM Vs Motorsport ABS Focus 1:25 - Not All ABS Is Equal 1:50 - Is Motorsport ABS Harder To Use? 2:35 - What Is Different With Aftermarket ABS? 3:13 - 'Ice Mode' 3:38 - What Is Needed For Bosch ABS Fitment? 4:27 - OEM Parts Usage 5:04 - Brake Boosters & Pedal Boxes 6:01 - Why Remove A Brake Booster? 6:45 - Brake Bias Adjustments 7:35 - Crosslinked Brake System 8:02 - Front Rear Split 8:18 - ABS Won't Work Magic 9:00 - Driving Style Vs ABS Setup 9:58 - KEY POINT! 10:36 - Driver Adjustment Options 11:12 - Driver Preference 11:38 - Data Logging & Vehicle Dynamics 12:10 - Thanks 909 Motorsport! 12:25 - BUILD.TUNE.DRIVE

[@25aspooner]

Nice Kit but for a base of $8,000USD it is waaaay over priced. Their other kits are $12-14k. Yea, it is cheaper than a car crash but also, no where near affordable for an entry class racer to install.

[@newagetemplar6100]

Yeah they are on the pricy side , best to drop on a used one from a race team . Thing is though most people including club drivers will constantly spend money on power, drivetrain, suspension upgrades just to go a second or 2 a lap quicker . That’s not cheap either. So do you spend thousands putting extra stress on your car and probably make it more unreliable or buy a decent abs and get the benefit of not bending your pride and joy ???? ABS for me

[@reggienotorious6824]

Look into s2000 abs I’ve seen the system adapted to a lot of cars, it’s kinda like that secret mr2 electric steering pump that’s tunable not super hard to adapt to any system

[@johnvigolo4972]

@@newagetemplar6100 Wholeheartedly couldn’t agree more! Best bang for buck smart investment to make, considering the seconds in lap time improvements one can make, especially in wet conditions & not to mention, the most important, added safety aspect. Most motorsports drivers pour much more money into performance mods for minimal gains & higher maintenance costs, including problems, headaches & unreliability. Furthermore, flat spotting a tyre is quite expensive at well over $700 per tyre. Even more so, when you hit a wall or another car, especially on a wet surface with a non ABS car.

[@roda1999]

Best bang for the bucks is the mk60 from bmw

[@johnvigolo4972]

@@roda1999 It’s certainly cheaper & quite popular choice for most. But, you only get what you pay for at the end & with no guarantee that it will work properly for your specific needs. I have learnt the hard way in life to do things once & properly. Whereas the Motorsport ABS offers optimal tuned system for your track/race car & specific requirements. It’s like comparing apples & oranges.

[@fraserwright9482]

The M70 for the E46 M3 is a standalone and although set up for understeer, compared to the CSL flash. It's predictable and if the car weighs proportionally the same as an M3 it's ok. The icing aspect can be eliminated with a g axis sensor. The Bosch Motorsport ABS is very very expensive and as he pointed out you need to map everything, wet, bias, tight vs long tracks etc. We found you only gain with the M5 abs is if you can test to build and log.

[@zachogdahl210]

The mk60 from the csl or competition package m3s has a reflashable chip, and you can get them re tuned using the motorsports software. I have a mk60 in my e30. They are a very affordable 4 channel abs system. The major downside is no adjustability in the strength.

[@forbiddenera]

​@@zachogdahl210ya I've totally read stuff like this.. getting close with jy or cheap parts compared to like 10k is decent option

[@ClaytonYatescarenthusiast]

C7z, I've looked into bosch abs but without vehicle specific kit its overwhelming. Ice mode is a real deal but adding coilovers and insuring perfect rebound and compression settings can reduce dynamically

[@josephbargo5024]

I’m sure there are plenty of M5 units on c7zs out there. Someone like GSpeed would be able to help

[@racingdatasystems3708]

Ice Mode is driver induced.. every time.. The ABS unit is not "on" until after it sees the brake light switch *and pressure. If it sees pressure before the brake light trigger? Ice Mode. I can train every driver out of it and have for many years. Drivers who have won championships in multiple pro series. *Some of it is often triggered because of air gap to brake light sensor or sensor is out of adjustment. Porsche released a shield several years ago for the factory race cars to keep the drivers from kicking the light switch when doing driver changes.

[@suprakillavr4]

@@racingdatasystems3708 I disagree. I can hit it almost at will on certain courses by hitting the brakes when I still have one of the rear tires in the air. It also will not reset until I get off the brakes and then back on. It will sit there and pulse while slowly slowing down in a straight line on the center of the track. I'm sure it's system dependent, but hit it with sumitomo ABS, Bosch mk60, and ATE ABS. There's something in the programming of all those systems to where if one wheel stops faster than it expects is possible, it will dump pressure to all wheels until you release the brakes all the way.

[@fraserwright9482]

If you have wheel height sensors and pitch/g sensor plugged in you can shield it. Yes it will occur with the older system as a default. But with these it provides the ability to trail brake as it won't go to ice mode as it knows you are unweighted.

[@neion5044]

it’s not that difficult to figure it out

[@3800S1]

I remember driving my friend's VR which was among the first Australian built cars to have ABS as a standard option on some models and boy was it scary and a huge step backwards compared to my VP which didn't have ABS. Sure, no wheel lock but also as mentioned in the video it had bad pedal lockout and no amount of pedal effort would overcome the lack of stopping power. 100km to 0 took some approx 70m or so! As for the booster removal. That is an interesting point and it gives a more consistent and fast pedal response at the cost of braking effort. An interesting thing is my car, still a VP has the old single stage booster, so the effort isn't great but it has nice long pedal travel and very easy and fast pedal response compared to modern cars which have great booster effort but firm and short pedal travel but most importantly have an extremely slow pedal response speed. So, although modern cars stop way better, I find them hard to drive as the pedal takes forever to press down so I try to compensate by pushing harder in the lack of anything happening, then the brakes suddenly slam on hard. Very frustrating! Lightly but briefly tapping the brakes does not work at all in modern cars I found. Very similar feel to DBW, brief tap = nothing happened. I can totally see why race cars have their boosters removed, a modern booster is very inappropriate in a consistency and speed sensitive environment that is motorsport.

[@hpa101]

ABS has come a long way thankfully!

[@forbiddenera]

​@@hpa101yeah once I hit ABS for the first time in my 93 db2 gsr (one of the first hondas with abs, also first vtec besides nsx in na) especially on ra1s and almost rear-ended someone i deleted it the next day. One day maybe ill do the Bosch system or see if I can hack the production version from a jy to motorsport firmware

[@LongWeiner-x9y]

Keep the throttle on some during braking....it will kill some of the booster

[@theodorgiosan2570]

I've always driven cars with no ABS. My current car (79 Subaru ) could come with or without a brake booster. As it stands, the brake booster does almost nothing because of the vacuum at idle being too low (big cam). Swapping to one with no booster just involves removing the booster and bolting a master cylinder for the non boosted cars to the firewall with the correct pushrod. The holes are already there and the pedal has a higher hole for a higher ratio from the factory.

[@jackweta]

Great episode. My Honda EP3 ABS has worked well, the brake booster is hard to articulate well, since adding braided brake hoses that has improved. Nankang AR1 tyres.

[@forbiddenera]

The braided hoses didn't help. It was your flushing when installing that did. They still look nice and are more durable but yeah it's been reasonably debunked that brided lines do anything compared to rubber, they're just rubber under the braid anyway.

[@Wszyc]

about that brake booster discusion I went with 4d68t alternator for 4g63 that alternator got vacum pump on the rear, it removes prpblem of non consistent vacum for the booster. 4d68t dont have throotle body thats why it got the vacum pump

[@newagetemplar6100]

Forgot about some alternator’s having a vac pump , don’t need to do it personally but good info 👍

[@CJ5EVOLUTION]

Which Cars come with that 4d68t alternator?

[@taznz1]

Late 90s early 2000s Mitsubishi galant, Google "gallant alternator vaccum pump" and you get plenty of results.

[@Wszyc]

@@CJ5EVOLUTION all cars with 2.0 turbodiesels 4d68t: galant e57d, space runners from the same year like galant, lancers and colts from early 90s, mitsubishi forklifts

[@forbiddenera]

Oo that's interesting for packaging, I run an electric pump off a BMW or something but might consider this option if I can fab up a mount without much fuss

[@bobroberts2371]

Time 958 to 1004 " the abs can't generate pressure and can only take it away ." That would be true with a basic system like a basic rear wheel only " Block and Bleed " system found on 2000 ish pickups but a 3 or 4 channel system ( Block , bleed , build pressure ) has a pump motor to build pressure.

[@fraserwright9482]

Yes I would disagree with his view of abs being 1990's era or the worst examples of ABS, like the Mitsi cross path so everyone should go to the M5 Motorsport. The main challenge is it's a standalone ECU it's a professional tool. So you see Porsche Cup cars running the road car ABS ECU as it has a broader base tune, so you don't need to change the map for each circuit or have the driver tweak it manually.

[@Iseenoobpeoples]

I'm about to remove the brake booster and ABS from my 86, the system doesn't understand that big sticky tires are installed, it drops the pressure way too much for way too long, some crazy malfunctions too, like all of the pressure going to one tire. Bosch ABS looks incredible.

[@forbiddenera]

Yeah stock abs and sticky rubber don't mix

[@sigmaprojects]

Would be amazing if a company could provide a method to reprogram OEM systems. I've currently disabled my ABS since with my setup under braking I can have a wheel lift and when it does the ABS would cut all my brakes instead of just the individual wheel, it so jarring and felt incredibly dangerous.

[@fraserwright9482]

Fit wheel height sensors, steering angle and a yaw sensor. This is what most modern abs systems have as they are evolutions of this old problem in 90's era ABS units. There may even be an OEM version in a later car as this information fixes the issue of icing when you get air

[@sigmaprojects]

@@fraserwright9482oh for sure. My ABS system is from 2000, so it's kind of basic and honestly feels dangerous with my stiffer suspension. It made sense on factory suspension and tires, because from the factory it had relatively soft suspension and skinny eco tires, so i get why the ABS would be aggressive. With my setup, oh man too many situations that scared me to the point where I decided to pull the ABS fuse to see how everything would be and since then I never looked back. Even when I got cut off on the freeway, tires locked up slightly, but was easy to control even though I was completely caught off guard. The car weighs ~820kg/~1800lbs, it doesn't take much to get it to slow down.

[@forbiddenera]

6:25 i use a vacuum pump in my car to provide vac for the booster, more consistent, never run out of vac and can 2foot brake in boost without issue. Good cheap solution but obviously a pedal box would be way better

[@hpa101]

Pedal boxes are awesome, BUT, like just about anything they are not free and the most important thing is to have something to use in the first place knowing there will always be areas for improvement. Cheers for sharing and hope you are enjoying your seat time! - Taz.

[@CamaroThings]

It is crazy because I remember downshifting without rev matching into a corner and ABS, Stability Control kicked on and funny enough it was on the extreme side of it because the car SWORE I was about to fly off the road because it is an OE setup. Basically if the car is driven normal the OE setup right now is at it's upper limit and the moment I drive hard it goes bonkers which adds one more thing to mod on the car 😂

[@averyalexander2303]

It seems to me that using some type of vacuum regulator to maintain a consistent vacuum in the brake booster at something always achievable like perhaps 10-15 inches depending on the setup would be a better solution than removing the booster entirely. That way the driver would still get good assistance, but still a very consistent and predictable feel. As someone who has driven cars without the brake booster active just as a daily driver in normal traffic, I can't even imagine how tired my leg would get from repeatedly slamming the brakes on a race track!

[@tomassosaoconnor]

The amount of force you have to make, as well as pedal travel, are determined by the ratio between the pump's surface area and the one of the actuators of the breaking system. So you can put a pump that needs more pedal travel but less force. What I mean is that a car where the servo has been straight up removed will need a tremendous amount of force on the pedal, but for performance applications you usually change the pump

[@averyalexander2303]

@@tomassosaoconnor Makes sense, but then there would still be a trade off in the distance the pedal must be pushed if a smaller bore master cylinder was used, especially since high performance multi piston calipers generally need more fluid than single piston stock calipers. Having dramatically more travel in the brake pedal seems less than ideal for a racing application. To be fair, I've driven cars that came with manual brakes and I've driven cars with disabled power brakes, but I've never driven a race car with a fully custom manual brake setup, so it's entirely possible I'm imagining the feel as being totally different than how it is in reality.

[@theodorgiosan2570]

Not all cars make 10-15 inches of vacuum though. My 79 Subaru with a big cam only makes about 4-5 inches of vacuum at idle. That car could come factory without a booster though. The holes in the firewall are already there and the pedal has a higher hole for the manual setup. The car is so light (1800lbs) that the booster is completely unnecessary. It can lock up all 4 wheels with the booster disconnected with little force on the brake pedal.

[@Takeitlightly6]

Oh i miss being in motorsport wiring alliance group….lots of pros there… Anyway motec is also bosch now which might mean there must be heaps of possibilities.

[@maciek5201]

Has anyone have a TVUB values for 185cc 1.8turbo engine ? I need it but i cant find it on internet and want to change it to stock because previous owner make a little mes on ecu. Thanks for help.

[@PhunkBustA]

pretty sure u can calibrate it after mods with "the right tools"

[@Grimgrak1]

909 motorsport location permanently closed?

[@ricepony33]

Why wouldn’t you want traditional power brakes and Bosch ABS? Seems like it would reduce driver fatigue, be predictable and just have the benefit of racing ABS.

[@dan1906]

Good question, but sort of complicated. 1. In a racing environment there isn't much vacuum available to operate such a system, especially in a boosted application (think long intervals at wide open throttle, and positive pressure generated by turbo...etc.). This makes the assist inconsistent, which they mentioned in the video. 2. It lacks feel. A properly setup, non assisted brake system, isn't particularly hard to press, and it makes consistency easier, especially when rev-matching downshifts. 3. It's simpler. 4. Drivers still brake at threshold manually with the ABS being there for incidental lockup, making a bit firmer pedal preferable. Drivers do not just stand on the brake pedal and let the ABS do all the work, hence the pro driver reference. I hope that helps.

[@JamesBalazs]

Nobody (in their right mind) would argue against the fact that Bosch Motorsport ABS (vastly different from factory Bosch Mk60 for example) is faster round a track with less effort than no ABS or brake booster at all. But those systems are $10,000 minimum and most club racers aren't spending that. You *do* see ABS in more top tier motorsport, eg GT3/GT4 ala British GT and GT World Challenge. But the budgets are 10x-100x higher than anyone watching these videos probably has access to. Even higher level motorsport doesn't have ABS purely due to regulations. F1 might be quicker and more consistent with it, but the people making the rules simply don't want it in their series to make it more about driver skill rather than computer assistance (same as traction control, which is present in GT3/GT4 as well).

[@ricepony33]

Thanks@@dan1906 The lack of vacuum is interesting, with my old supercharged setup I would often lose power brakes at higher elevations after some hard acceleration... needless to say is was very sketchy.

[@taznz1]

Bosch Gen 2 iBooster from Honda Accord or Telsa model 3 solves the lack of vacuum issue.

[@el_kuks]

​@@taznz1 pedal feels exetmely squishy with that electronic brake booster. Also i believe it has lag between pressing pedal and assisting which would cause inconsistent pedal feel with partial braking. Definately not a thing you would want in racing application. Installing vacuum pump and vacuum reciever might be better option. On many 2010+ year cars vacuum pupm is already present on petrol engines

[@Iamwolf134]

Quite intriguing.

[@DENZEN220]

11grand for this kit

[@351kostakis]

Absolutely amazing!!!!

[@stevesloan6775]

Trick product…I loved to of heard the actual price.🤨🇦🇺🤜🏼🤛🏼🍀😑😎

[@rabbitdrink]

so damn expensive imma stick to oem in my street car

[@vteckillerfa5]

Very cool

[@teagreen2220]

The less the electronics, the more I like and enjoy the vehicle.