beachlander Posted September 1, 2014 Share Posted September 1, 2014 So my KE is pretty much ready to run. For those who dont know, im running a 16v 4age with silvertop ITBs. Seeing as the car is going to be a track car only, i was thinking of getting rid of the booster so i dont have to run a vacuum block and to make more room for a plenum for the ITBs in the future. Having never driven a car without a booster before, what is it like? From the research i have done it seems that just getting rid of the booster and putting in an adaptor plate isn't a good idea, but rather putting on a smaller master cylinder. Is there any truth in this? Or would i be ok in just removing the booster? Quote Link to comment Share on other sites More sharing options...
SOHC Posted September 1, 2014 Share Posted September 1, 2014 I run a HQ Holden master cylinder in my old ford with no booster, its like standing on a brick. You could run a remote booster, I think some late 90s Holden comodors have them? Quote Link to comment Share on other sites More sharing options...
Ogre Posted September 1, 2014 Share Posted September 1, 2014 Never had a booster in my green lancer when i used to track it, was much better than having a booster. harder to lock up, better feel etc. I think for smaller cars its all good. if you have low vacume, big cams etc they dont work right anyway. I think going to a smaller master is the way to go. Have to push the pedal further but its not as hard. Quote Link to comment Share on other sites More sharing options...
beachlander Posted September 1, 2014 Author Share Posted September 1, 2014 Yea well i have quite big cams, ie 316 intake and 306 exh. Tis not a heavy car. Quote Link to comment Share on other sites More sharing options...
Bangbug Posted September 1, 2014 Share Posted September 1, 2014 I've got a 323 mc swapped into something and it feels fine and free'd up a lot of space (for plenum).If you're a clever sod you'll adapt anything, or if you're short of time look up "swappable" ones. Mine is a little deeper but it's the width that was causing drama.Racing is hard work, so the less effort the more blood for your brain to race with. 1 Quote Link to comment Share on other sites More sharing options...
Gomaxgo Posted September 1, 2014 Share Posted September 1, 2014 most people seem to alter the hole in the pedal where the pushrod slots into in relation to the pivot point of the pedal to allow more leverage. that being said ive never been down that path so have zero real life experience Quote Link to comment Share on other sites More sharing options...
Roman Posted September 1, 2014 Share Posted September 1, 2014 So my KE is pretty much ready to run, and I'd like to have it off the road for longer This is basically what I read this thread as Drive with your booster disconnected currently, and that's exactly what it will be like using your current MC without a booster. You'll probably find the pedal is way too hard. The only way to improve this is to change the ratio of fluid pushed by the MC per CM of pedal travel. (Or fit a booster haha) So you could: -fit a smaller MC (But it might reach the floor before you acheive full/desired level of braking) -Change the leverage point where the MC attaches to the pedal (Same problem as above) -Make the pedal travel longer for same amount of MC piston movement (Although you can only increase so much until impractical) Basically it seems like a big kick in the balls for not much gained, and will take some experimenting to find out what works well for you. I'd just leave it as is then go do some hoonage 1 Quote Link to comment Share on other sites More sharing options...
Nominal Posted September 1, 2014 Share Posted September 1, 2014 You might have to do some calcs on the M/C size. Smaller piston there will result in greater braking effort for same pedal push, but you also need to move enough brake fluid to the discs. If you just use the same M/C you may not like the outcome. As noted above, you can tinker with pedal ratio too. I've had good advice from Les Hunter in Chch (even though I wasn't buying anything). Quote Link to comment Share on other sites More sharing options...
mjrstar Posted September 1, 2014 Share Posted September 1, 2014 I think there are a number of budget race KP's running no booster on factory size master, so long as you have a strong left leg I see very little problems with running no booster. (that is unless you have decided to put a massive master cylinder in it). I believe you will have to space the master or gut the internals of the booster othewise the internals of the booster may be working against you. Plus factor in making a longer rod to connect the pedal straight to the master. i run my mini without a booster and added 4 pot front calipers, admittedly it does no take a good deal of pedal effort but has good feel. Quote Link to comment Share on other sites More sharing options...
cletus Posted September 2, 2014 Share Posted September 2, 2014 the hobby car manual has the recommended pedal ratios, which are different for boosted and non boosted pedals, i cant remember off the top of my head what they are, helpful eh. another thing to make sure of, is that the master cyl can be used without a booster. some master cyls have nothing stopping the piston falling out the back, ie no circlip to hold it in Quote Link to comment Share on other sites More sharing options...
Unclejake Posted September 4, 2014 Share Posted September 4, 2014 I ran no booster on my race car for years. It required plenty of pedal effort, but the brakes worked very well, and I think it probably helped in avoiding flatspotted tyres. Getting a suitable pedal ratio is important. Don't mess with M/C sizes unless you also mess with the wheel cylinders/calipers too. Getting a reliable source of vacuum on a small race motor isn't easy. I'd ditch the booster and call the weight saving deliberate 4 Quote Link to comment Share on other sites More sharing options...
Roman Posted September 4, 2014 Share Posted September 4, 2014 UJ I bet you only ditched the booster because it didnt work after you drilled weight reduction holes in it 5 Quote Link to comment Share on other sites More sharing options...
Ned Posted September 4, 2014 Share Posted September 4, 2014 Is there a difference between running no booster, and running a disconnected booster? I didnt have a vacuum on the KP for a bit, so left it disconnected and braking was HARD even with my legs (and those legs carry all of me err-day so they arent weak) Would it be better/nicer/easier by removing the booster? i have no idea how a booster actually works either, so no idea what would happen when you remove it vs just disconnecting the vacuum Quote Link to comment Share on other sites More sharing options...
Rookie Posted September 4, 2014 Share Posted September 4, 2014 The problem you have Ned is that the pedal ratio is set up for having a booster, so when you disconnect it the ratio is all wrong and you have to be a beast. But otherwise no, disconnecting a booster doesn't make pushing the pedal harder. 1 Quote Link to comment Share on other sites More sharing options...
V8Pete Posted September 4, 2014 Share Posted September 4, 2014 Why do I never hear of jokers running vacuum pumps in situations like these? 1 Quote Link to comment Share on other sites More sharing options...
Rookie Posted September 4, 2014 Share Posted September 4, 2014 Because we are all half job Harrys. 3 Quote Link to comment Share on other sites More sharing options...
anglia4 Posted September 4, 2014 Share Posted September 4, 2014 My mustang has a hydrostatic(?) booster I think. I have a feeling it runs off the power steering pump but cannot be quoted! Quote Link to comment Share on other sites More sharing options...
V8Pete Posted September 4, 2014 Share Posted September 4, 2014 Some petrol 306s have a vacuum pump driven off one of the camshafs because of shitty manifold vacuum. And also diesels obviously. I still salts at sunroof 205GTIs having a vacuum accumulator tank for the sunroof seal. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted September 4, 2014 Share Posted September 4, 2014 Why do I never hear of jokers running vacuum pumps in situations like these?I've thought about using diesel alternators for this purpose, but I guess in a track car situation you don't want the parasitic losses of spinning the vac pump if you can avoid it. Although you could hook a valve up so it only vacs under decel and just freespins under power. Or too much like hard work so run unboosted. Quote Link to comment Share on other sites More sharing options...
kpr Posted September 5, 2014 Share Posted September 5, 2014 running vac straight from the end 2 vac ports tee'd together, on silver top throttles, will be enough vac for booster. but if need room; as others say. need to mess with pedal ratio's and master cylinder sizes. then may as well go to a wilwood pedal box or the likes, with balance bar etc to adjust bias. Quote Link to comment Share on other sites More sharing options...
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