260DET Posted July 5, 2019 Share Posted July 5, 2019 With multiple separate throttle bodies there is no way to use the usual booster setup without a vacuum pump arrangement, as far as I know. Simple question, is there a suitable alternative brake boost system available? Quote Link to comment Share on other sites More sharing options...
caperix Posted July 5, 2019 Share Posted July 5, 2019 Most throttle bodies have some sort of vacuum fitting on them. If you connect them all together you may be able to run a vacuum booster off it that is what many OEM individual throttle body setups use. If you are running hydraulic power steering, a hydoboost setup could be used. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 5, 2019 Share Posted July 5, 2019 If you just delete the booster and go to the appropriately sized (smaller) manual master you should be able to get decent brake feel. If you drove my car and I didn't tell you the brakes were manual I doubt you'd say anything about the pedal feel at all. Quote Link to comment Share on other sites More sharing options...
LooseRocks Posted July 5, 2019 Share Posted July 5, 2019 What do you have in your setup? Brakes & size of MC? Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 5, 2019 Share Posted July 5, 2019 Like John M, I also used a Non-Booster equipped Road Race 240Z back in the Day. You have to eliminate the Booster. Make a Custom length Pushrod. Depending on you Pedal effort, you may want to relocate the Clevis Pin hole in the Brake pedal upwards a bit to change the Pedal ratio. About 0.750" to 1.0" is enough. We used a standard 7/8" Master on our ICSCC D-Prod Z . Worked out very well. Good modulation with proper setup. Quote Link to comment Share on other sites More sharing options...
260DET Posted July 6, 2019 Author Share Posted July 6, 2019 It's for the race 350Z I bought, it has two Tilton MC's and no booster. I've always used a booster because it gives a light sensitive pedal feel which for me avoids brake lock up, anyway It's going to get it's first track test soon so we'll see. Quote Link to comment Share on other sites More sharing options...
Leon Posted July 7, 2019 Share Posted July 7, 2019 The dual-master non-assist setup in my race car has far better feel than any assisted brake setup. A light pedal is harder to modulate, in my experience. Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 7, 2019 Share Posted July 7, 2019 On 7/6/2019 at 3:22 AM, 260DET said: It's for the race 350Z I bought, it has two Tilton MC's and no booster. I've always used a booster because it gives a light sensitive pedal feel which for me avoids brake lock up, anyway It's going to get it's first track test soon so we'll see. I've have good luck using the electric vacuum pump from a diesel VW/Audi - they are readily available on ebay - search "VW electric vacuum pump". Harder to find is an adjustable Hobbs (or similar) normally closed vaccum switch (i.e., opens when vacuum exceeds a reset threshold)... Quote Link to comment Share on other sites More sharing options...
260DET Posted July 12, 2019 Author Share Posted July 12, 2019 Thanks Tim, will check that option out. My past experience. To get good pedal feel when using a vacuum booster it has to be set up right, bit of a black art. Anyway one booster was not set up right, the brakes were light switch on/off but boy did it stop, better than anything before or after. Hence my preference for power brakes, it's just part of getting the car to perform as close to the edge as possible without using driver aids. Quote Link to comment Share on other sites More sharing options...
grannyknot Posted July 12, 2019 Share Posted July 12, 2019 (edited) On 7/5/2019 at 2:51 AM, 260DET said: With multiple separate throttle bodies there is no way to use the usual booster setup without a vacuum pump arrangement, as far as I know. Simple question, is there a suitable alternative brake boost system available? You could also put in a electric vacuum pump, Volvo uses them a lot, used ones are cheap. https://www.ebay.com/itm/01-11-VOLVO-V50-C30-C70-S40-SEDAN-ABS-SERVO-VACUUM-PUMP-BRAKE-BOOSTER-MOTOR-OEM/223224522343?fits=Make%3AVolvo&epid=1711309953&hash=item33f937e667:g:3wUAAOSwKCZb5fuc Edited July 12, 2019 by grannyknot Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 12, 2019 Share Posted July 12, 2019 Still need space for the booster though. I think GM's Hydroboost solution would work, not sure, but I keep coming back to wondering why you don't just tweak the manual brakes? Smaller masters will give a lighter pedal, larger will give a stiffer pedal that needs more pressure. It's not that hard to get it right. Here's a youtube video on replacing a broken Hydroboost setup: Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 13, 2019 Share Posted July 13, 2019 Oh, nevermind. I thought the issue was with the ITBs getting in the way of the booster. Was thinking L6, not V6. My bad. Quote Link to comment Share on other sites More sharing options...
260DET Posted July 19, 2019 Author Share Posted July 19, 2019 LOL, very bad. Track test coming up soon so we'll see. If extra vacuum is required for a power brake setup a vacuum switch controlled electric pump seems to be the best option, if needed a vacuum tank can be added for extra capacity so its not going to be, bugger, this is not working so throw it away and try again. I hate that. Quote Link to comment Share on other sites More sharing options...
tube80z Posted July 19, 2019 Share Posted July 19, 2019 Another option that would most likely be all you need is a vacuum reservoir. I'm sure those are available in Oz as a lot of the cammer V8 engines use them to have power brakes when idling on a low vacuum cam. Quote Link to comment Share on other sites More sharing options...
260DET Posted July 26, 2019 Author Share Posted July 26, 2019 So what's happening is that a Z31 turbo vacuum pump is going to be used although before I found out about that a Hella UP28 pump was ordered, duh. Would not touch the aftermarket ones given the ridiculous prices they want and they are as noisy as hell. Apparently. Just need a switch now to keep the vacuum up and then off when max is reached. Quote Link to comment Share on other sites More sharing options...
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