Setright Posted October 18, 2004 Share Posted October 18, 2004 Ever since I sold my Legacy BC7 and bought an Impreza I have been yearning for the firm brake pedal of the first car. Reading around the internet and talking to a driving-instructor who also drives an Impreza, I discovered that the main culprit is the firewall. It's too thin and flexes in concert with the brake pedal. So, my plans to replace the brake hoses with steel braided items, and maybe replacing the drums in the rear, were ditched. And I made this master cylinder support myself. Inspired by looking into the engine room of my girlfriend's parent's Mercedes. And the darn thing works! Pedal is firm and responsive :-) I would strongly recommend this mod to anyone. Take note that no new holes have been made. I will gladly take a few more photos if someone wants to copy this design. Link to comment Share on other sites More sharing options...
ashton_subaru Posted October 18, 2004 Share Posted October 18, 2004 Will this work on a 2001 Forester? The pedal is very soft and I have tried changing the fluid and bleeding the lines, but no luck , I am hoping it will. Next Question , in anticipation of an affirmative, do you have sketches and/or drawings of the part. Thanks, Bill Link to comment Share on other sites More sharing options...
subeman90 Posted October 18, 2004 Share Posted October 18, 2004 More pics please...... Very interested in the design..... Matt Link to comment Share on other sites More sharing options...
Setright Posted October 19, 2004 Author Share Posted October 19, 2004 Well, in principle this will work on ANY car. I know that the Impreza suspension turrets have extra holes, with threaded nuts already welded on, that facilitated a no-drilling installation. The sun is rising here in Denmark and I need to get to work, but I will take a few more photos and upload them this evening - your afternoon. Glad to hear that people are interested! I posted this on a Danish website and no-one gives a damn? Link to comment Share on other sites More sharing options...
who1981 Posted October 19, 2004 Share Posted October 19, 2004 Glad to hear that people are interested! I posted this on a Danish website and no-one gives a damn? Wow, you identified a problem, and not only thought of a solution but also fabricated, implemented, and tested it!!! And we in America have a long tradition of being fascinated with this (it’s the American dream)…And then stealing the idea, patenting it, and marketing it for profit…In the quest of riches! (also the American dream) Anyway you are on to something...I'll have to try it. Link to comment Share on other sites More sharing options...
subarubrat Posted October 19, 2004 Share Posted October 19, 2004 That part has been available since 2000, I got mine from www.autocaresubaru.com and it does help to some degree. The larger problem is that it is a dualstage (in the Impreza) and going to an older single stage booster makes a world of difference. Link to comment Share on other sites More sharing options...
Legacy777 Posted October 19, 2004 Share Posted October 19, 2004 MRT makes a similar bracket. While it does help, it doesn't solve the problem. Almost all brake boosters today are tandem boosters. (not dual-staged) Due to how they're setup they produce that (dead pedal) feel at the very beginning of the stroke. I recently swapped to the single diaphragm booster and will say that it made a world of difference in the brake pedal feel. Link to comment Share on other sites More sharing options...
Setright Posted October 19, 2004 Author Share Posted October 19, 2004 I having trouble getting my USB port to import the photos I have taken today, will keep trying.. Josh, my BC7 had a very hard pedal. After the initial free-play it was very firm and predictable. Mind you, I am quite sure it had a single stage booster. Link to comment Share on other sites More sharing options...
Legacy777 Posted October 19, 2004 Share Posted October 19, 2004 Hmm....I know the US spec BC's got the tandem booster. Here's pics of the single diaphragm booster I swapped in mine. http://www.surrealmirage.com/subaru/images/swap/10/DCP_3250.JPG there's a few more on this page http://www.surrealmirage.com/subaru/images/swap/10/default.htm forgot I have pics of the tandem booster too http://www.surrealmirage.com/subaru/images/swap/10/DCP_3272.JPG Link to comment Share on other sites More sharing options...
Setright Posted October 19, 2004 Author Share Posted October 19, 2004 Yep, my Legacy had the single stage for sure. Did you buy the MRT bracket in the states? I decided to make my own because I would have had to import it from Australia - and once the Danish custom officers got their hands on it the price would race away! My USB port is denying me access to all the extra photos I took today. (ARGH!) Sorry, but I can't say when I will be able to post some more photos. Even with the tandem booster, my pedal does feel a lot better. Brake response is much more immediate and controlled. Link to comment Share on other sites More sharing options...
Setright Posted October 19, 2004 Author Share Posted October 19, 2004 In essence: A 3mm thick steel plate, bent to fit around the suspension turret. Drilled four holes to match the two that hold the fuel filter, and the two at the back that were not occupied. A 30 by 30 mm square pipe welded on just where the plate bends, so that it reaches out in front of the MC. The pipe is supported by an extra triangle of 3mm plate, mounted only on the top, there is no room below. A hole drilled through the pipe allows a bolt to go through, there is a lockning nut hidden inside the pipe. This setup allows a little "pre-tension" to take up the slack in the system. Link to comment Share on other sites More sharing options...
subeman90 Posted October 19, 2004 Share Posted October 19, 2004 What is the difference of the dual vs. the single.....I looked at the pics and I am totally lost. What does my Imp. have? Matt Link to comment Share on other sites More sharing options...
RallyKeith Posted October 19, 2004 Share Posted October 19, 2004 That part has been available since 2000, I got mine from www.autocaresubaru.com and it does help to some degree. The larger problem is that it is a dualstage (in the Impreza) and going to an older single stage booster makes a world of difference. Yeah, honestly, we race our 96 Impreza and don't have a problem with it. If I was going to do it I'd make my own. Spending $70 on something that can be lived without would be a waste to me. Good job on taking the initiative to do it yourself! Keith Link to comment Share on other sites More sharing options...
Legacy777 Posted October 19, 2004 Share Posted October 19, 2004 Yep, my Legacy had the single stage for sure. Did you buy the MRT bracket in the states? I decided to make my own because I would have had to import it from Australia - and once the Danish custom officers got their hands on it the price would race away! My USB port is denying me access to all the extra photos I took today. (ARGH!) Sorry, but I can't say when I will be able to post some more photos. Even with the tandem booster, my pedal does feel a lot better. Brake response is much more immediate and controlled. yeah I bought it in the states. I don't remember what exactly the cost is. It wasn't too much. Link to comment Share on other sites More sharing options...
Legacy777 Posted October 19, 2004 Share Posted October 19, 2004 What is the difference of the dual vs. the single.....I looked at the pics and I am totally lost. What does my Imp. have? Matt I guess let's start with what a booster does, provide brake assist via engine vacuum and a diaphragm. The larger the diaphragm, the more brake assist you will get. What the tandem booster does is provide double the amount of brake assist in a much smaller package (diameter). I believe the issue most people have with the tandem booster and the "dead" area is with how it works, and let's vacuum into both chambers. I don't think it does this evenly, or there is some slack or something in how it works that gives you that blah feeling. I got a spare tandem booster, and plan on cutting it open to see exactly how it works, and if the system is truly a tandem only system, or if it's more like a 1st and 2nd stage/level of brake assist. Link to comment Share on other sites More sharing options...
cookie Posted October 19, 2004 Share Posted October 19, 2004 as a racing trick to get better pedal. I think it was on old Porsches that had the pedal and cylinder mounted low and folks would make a little brace out of pipe with a bolt and nut welded for adjustment. Any way you reduce mounting flex will help a bit. Link to comment Share on other sites More sharing options...
Setright Posted October 20, 2004 Author Share Posted October 20, 2004 Okay, this morning my IBM and Motorola decided to be friends again, and the photos are here. To all those who are dissing this mod, quit wasting your time here and provide something positive in another thread please :-) I hope these cast enough light on the matter. "Pipetilt" is included to demonstrate that the square pipe is rotated slightly to make the bolt hit the MC at 90 degrees. (blue line indicates angle) The measurements on the cardboard templates are mm, and not 100% accurate. Expect to do some customising... The only thing I needed external help with was the welding, mainly because I don't have the equipment! I painted the bracket in two layers of primer and four layers of semi-gloss black. Hopefully, that will stop it rusting and ruining looks. Link to comment Share on other sites More sharing options...
subeman90 Posted October 20, 2004 Share Posted October 20, 2004 Once again let me say.... I love it! You did some very creative and good work in my opinion.... thanks for the pics too! The metal you used for the mount plate... shouldn't that be a little thicker or is it ok the way it is? Great job. Matt Link to comment Share on other sites More sharing options...
Setright Posted October 20, 2004 Author Share Posted October 20, 2004 Thanks! 3mm is plenty! 2mm would do the job, but I like to increase the margins. The pipe itself has 2mm walls, but there are two in each direction :-) 3mm is also nearing the limit of what can be bent accurately, without a machine. Link to comment Share on other sites More sharing options...
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