Fab9 Brake Booster Delete/Manual Brakes
#1
Fab9 Brake Booster Delete/Manual Brakes
Does anyone else have this kit? I'm running into some trouble getting everything installed. The kit doesn't come with a clevis to attach the master cylinder push rod to the pedal, and I can't re-use the OE clevis because the push rod in the Wilwood MC is smaller diameter (OE looks like it's M8 and Wilwood looks like M6, I can measure later). Should I just pinch the factory clevis between two nuts on the MC shaft (sounds sketchy and like bad pedal feel), or do I need to find a new clevis? I've tried reaching Fab 9, but I haven't gotten any response for a couple weeks now.
This is being done in parallel to a TSE 11.75" BBK and m-tuned rears. Reasoning for booster delete is weight reduction and consistent braking because my ITB setup doesn't pull a ton of vacuum.
This is being done in parallel to a TSE 11.75" BBK and m-tuned rears. Reasoning for booster delete is weight reduction and consistent braking because my ITB setup doesn't pull a ton of vacuum.
#3
This isn't supposed to be a bash on them, they don't say it's plug and play, but it does say "Kit includes your new Master, Mounting Plate, Hardware and the fittings required...[ ]...You'll simply need to pick up some 3/16" brake line". I will say that I'm having an extremely hard time getting any response from the vendor though.
#4
I have no experience with the Fab9 kit but I removed the booster and installed dual masters a while back.
If you are moving to manual brakes and driving on the street you really need to move the pivot of the pedal to increase the pedal ratio from 4 to around 5.5. Without changing the pivot you'll require a very large pedal force for effective braking.
If you are moving to manual brakes and driving on the street you really need to move the pivot of the pedal to increase the pedal ratio from 4 to around 5.5. Without changing the pivot you'll require a very large pedal force for effective braking.
#5
Thanks for the input. The one time I did get Fab 9 on the phone they suggested a second hole 15mm up from the center of the factory hole. I'm not quite sure what ratio that would put me at. That was before I learned that the clevis doesn't fit...
Is the braking force reasonable for a street car at 5.5? I do street it a bit on weekends/canyon runs.
Is the braking force reasonable for a street car at 5.5? I do street it a bit on weekends/canyon runs.
#6
15mm sounds about right. You should really shorten the top pivot rather than move the clevis point up though. You don't wont the masters being driven from too larger angle. 15mm would have to be close to the limit for the masters.
I'm currently running the stock 4:1 ratio but its a track car with good brakes plus I don't mind the heavy pedal. Next time the dash is out I'll change the pedal pivot to up the ratio a bit.
I'm currently running the stock 4:1 ratio but its a track car with good brakes plus I don't mind the heavy pedal. Next time the dash is out I'll change the pedal pivot to up the ratio a bit.
#7
We got rid of the booster a while back also and just got a smaller master cylinder without changing pedal ratio. First we had a 3/4" master and it worked OK but the pedal pressure needed while towing the tire trailer was too much for me. It was fine for driving in anger. Switched to an 11/16" master and was happy with the result. Have't looked back since.
#8
I do have manual brakes, but I went with the chasebays delete kit. Came with all the parts, and the braking feel is awesome! I did not adjust the pivot point. My car is both street and track driven. I have the FM BBK and don't mind the heavier pedal at all on the street.
Fab9 has a horrible customer service reputation. They don't really offer any support, and when you call about issues they find a way to get you off the phone and then don't answer or respond to emails again. Hopefully this company won't be around much longer, but if Begi is still around with all the issues they have, I bet Fab9 will be around for a while. They won't get my business again!
Fab9 has a horrible customer service reputation. They don't really offer any support, and when you call about issues they find a way to get you off the phone and then don't answer or respond to emails again. Hopefully this company won't be around much longer, but if Begi is still around with all the issues they have, I bet Fab9 will be around for a while. They won't get my business again!
#9
Wow that kit is WAY nicer. I'd never heard of Chase Bays... I was going to say that the 7/8 Master in the Fab 9 kit is worrying, but Chase Bays is using the same size, so I'll give it a shot. I found the clevis it looks like they're using in their kit on McMaster Carr. Thanks for the input.
In case someone else needs it, I think the part number for the SAE zinc plated clevis is 1583K13. The pin is 98340A130, but that's for a pack of 25. I'm going to try and hit Ace hardware and see if they have something locally first.
I don't get why the kit doesn't just come with one. It costs basically nothing to include. Can't say I'll be ordering from Fab 9 again.
In case someone else needs it, I think the part number for the SAE zinc plated clevis is 1583K13. The pin is 98340A130, but that's for a pack of 25. I'm going to try and hit Ace hardware and see if they have something locally first.
I don't get why the kit doesn't just come with one. It costs basically nothing to include. Can't say I'll be ordering from Fab 9 again.
#10
I have no experience with the Fab9 kit but I removed the booster and installed dual masters a while back.
If you are moving to manual brakes and driving on the street you really need to move the pivot of the pedal to increase the pedal ratio from 4 to around 5.5. Without changing the pivot you'll require a very large pedal force for effective braking.
If you are moving to manual brakes and driving on the street you really need to move the pivot of the pedal to increase the pedal ratio from 4 to around 5.5. Without changing the pivot you'll require a very large pedal force for effective braking.
#15
My opinion, for a street car you have some advantages. You never have to replace the booster even though I understand it is a very reliable part. On turbo cars, you will get the master cylinder a few inches further away from the turbo or exhaust. And as mentioned the vacuum thing also applies to turbo engines though not as much a problem if the system is working perfectly and you are really just street driving. And you have better brake modulation which is great when you don't have ABS.
On a race car weight reduction is only 5 pounds but it is somewhat high and on the heavy corner. I don't know where chase bays gets the 20 pound weight reduction number. I think brake feel is not debatable, it's better with manual. One thing I found with the booster is that when you lock up it is difficult or impossible to get off the brakes enough so you can free the locked wheel and still be stopping. This is much easier with manual brakes because of the modulation. So I would say another advantage is less square tires for racing use.
On a race car weight reduction is only 5 pounds but it is somewhat high and on the heavy corner. I don't know where chase bays gets the 20 pound weight reduction number. I think brake feel is not debatable, it's better with manual. One thing I found with the booster is that when you lock up it is difficult or impossible to get off the brakes enough so you can free the locked wheel and still be stopping. This is much easier with manual brakes because of the modulation. So I would say another advantage is less square tires for racing use.
#16
Well, it took a bit but here's the update. The McMaster clevis part # I listed works perfectly. I had to order a couple of brake line tees and fittings in addition to the kit. I didn't know that AN fittings used a 37° instead of 45°, so I needed an extra tee, but even if I had an AN flare tool, the kit did not have enough fittings. It's a bit of a spaghetti mess right now, but it works.
Brakes are noticeably heavier, but the feel is good and smooth braking during heel-toe is easier.
I'm happy with the change over all, but I would seriously recommend piecing together a kit yourself or getting the Chase Bays kit.
Here's the messy lines setup. The uncapped one is the booster vacuum hard line that I removed shortly after.
Brakes are noticeably heavier, but the feel is good and smooth braking during heel-toe is easier.
I'm happy with the change over all, but I would seriously recommend piecing together a kit yourself or getting the Chase Bays kit.
Here's the messy lines setup. The uncapped one is the booster vacuum hard line that I removed shortly after.
#17
Nice little thing hiding in that page is that mazda, honda, subaru, toyota, nissan, and mitsu, all use the same bolt pattern, which means something like this would work for us. http://www.compbrake.com/product/sub...dual-cylinder/ if only something like that was sold in the usa.
Last edited by Leafy; 02-06-2017 at 10:58 PM.
#18
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Well, it took a bit but here's the update. The McMaster clevis part # I listed works perfectly. I had to order a couple of brake line tees and fittings in addition to the kit. I didn't know that AN fittings used a 37° instead of 45°, so I needed an extra tee, but even if I had an AN flare tool, the kit did not have enough fittings. It's a bit of a spaghetti mess right now, but it works.
Brakes are noticeably heavier, but the feel is good and smooth braking during heel-toe is easier.
I'm happy with the change over all, but I would seriously recommend piecing together a kit yourself or getting the Chase Bays kit.
Here's the messy lines setup. The uncapped one is the booster vacuum hard line that I removed shortly after.
Brakes are noticeably heavier, but the feel is good and smooth braking during heel-toe is easier.
I'm happy with the change over all, but I would seriously recommend piecing together a kit yourself or getting the Chase Bays kit.
Here's the messy lines setup. The uncapped one is the booster vacuum hard line that I removed shortly after.
#20
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Join Date: Oct 2006
Location: Las Cruces, NM
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Total Cats: 524
I think that there would be less chance of failure if the lines and prop valve were mounted to reduce vibration damage. His setup looks like it has some weighted parts suspended by the lines.