rudypoochris

Thanks for all the replies! I get it now about the single vs. twin piston calculations. Also that sounds great as far as pedal travel and feel BlueOval. I can't wait to actually test this all out. I shall look at Mike's setup.

I think the main issue with running Wilwoods in front and 240sx/280zx in rear is that even with out any resistance in the rear line the most braking force you can get is something like 10% compared to the front. So 90-10 bias. That doesn't sound like enough at all. I know everywhere I read they advise NOT to put the proportioning valve on the front line... is this out of safety if the valve locks up? It seems that in a case of 90-10 distribution, limiting the front would help alot. BlueOval, glad you could comment. Is the pedal hard or soft? Do you find yourself running out of pedal travel? Lastly, are you using a 15/16" single master setup? Thanks!

Thanks for the insight. I will go ahead and try this MC out. If it doesnt work out well then I shall step up the size. I like a hard pedal personally.

Thats a bummer about your Explorer. Were you running OE pads? Was the car well bled? Is the peddal spongy when static? I drive a 1992 and it has quite a hard pedal. I have never experienced fade personally. The most I have ever done is 3 sequential stops from 70-75mph at I would say 90-95% of threshold (I went over a bit on the first stop and from then on it was like I could feel right when it was about to go over again, if that makes sense). I found the modulation to be surprisingly good. The pedal would start to run out of travel a bit towards the end, but never required a re-pump. I stopped since I felt it was pointless abuse. I was actually deliberately trying to get it to fade. That being said 92 and 98 are different... ABS and rear disc on the 98... Back on topic... I have heard that drilled rotors are crack prone. Is that in ALL cases, or is that only in cases where drilling was done on normal rotors. Furthermore, does slotting actually give an appreciable amount of increased braking performance, does it wear pads out, and lastly if it does give better performance why are the most common Wilwood race rotors typically blanks? Lastly, J-hooks? Thanks guys, I am learning!

Ya. I worried that much too. I guess I will have to look once the rear end is put back together.

Thanks! That looks almost exactly how I want to do it. Although I can't seem to figure out how that caliper mounts or functions in the lower picture.

Yep yep. I noticed that too. I would really appreciate if you typed whatever findings or thought you have into my other thread linked above. I think alot of people probably wonder these same things.

In all honesty I could not tell you. I can refer you to the earlier page in this thread where I have pictures of clearances using a mock up wheel and some basic dimensions. The backspacing for these wheels is 4.5" so measure using that distance from the hub. Here is the link to the earlier mention of sizing with pictures: http://forums.hybridz.org/showthread.php?t=123576&page=3 Read post #60 -------------------------------------------- For the rest of you. I have been in contact with Rota. They have reopened the factory (was closed for holidays). The -19 vs +19 offset issue has been ironed out and they have let me know that "it will be ready soon". They also will be sending me a sample (I did not request it but am willing to see it naturally) before the -13 are presented as an option, but I have been assured that they are indeed an option. Hopefully the language barrier has made it clear enough that the -13 setup will be on a 9" width wheel, not the 9.5" wheel the -19 setup uses. Other than that I have no concerns. Everything seems to be going well. I shall be ontop of it.

^ Thanks. I have 1.75" 4 pistons in front and 4 piston 1.38" rear. I have a proportioning valve as well. I was wondering exactly what you stated, which is why I created a thread two weeks ago. No one replied though. http://forums.hybridz.org/showthread.php?t=128619 Calculated my range of distribution to be from: 83.9%F and 16.1%R and 62.5%F and 37.5%R I think that is most likely an acceptable range, but I digress. ---- Any chance at a link to those axle mounted parking brake setups? I would like to stay away from hydraulic as the main issue was that these systems are not designed to hold line pressure for extended periods of time. People wishing to do this could use the Wilwood calipers and a line lock.

Calculated load on 15 degree incline, 2640lb car, 3.54 gears, 26" OD tire, and 3" brake disk radius: (1200kg*9.81m/s^2)*sin(15) = 3046.8 N of force trying to move the car. 3046.8N*(1/3m) = 1015.6 Nm -> 749.0 ftlbs at axle. 749.0ftlbs*(1/3.54) = 211.6 ftlbs at flange. 211.6ftlbs*(12in/3in) = 846.3 lbs loading the caliper. At 25 degrees (not shown) = 1381.9 lbs loading the caliper. Calculated load on a bicycle using 1 brake disc at 4" radius to stop at .5g, 29" OD tire, 100kg total: (100kg*.5g*9.81m/s^2) = 490.5N of force at tire. 490.5N*(14.5in/39in per meter) = 182.4 Nm -> 134.5 ftlbs at axle. 134.5ftlbs*(12in/4in) = 403.5 lbs loading the caliper. Did I do these calculations correctly? If so it might be wise to use two bicycle calipers per car or source a stronger caliper. I think the real limitation will be the bolt diameter to attach the calipers to the differential. Does a bicycle brake at more than .5g?

Let us know how it looks in there. Has yours been rebuilt before (to you knowledge)?

Well I live 15 miles from San Francisco, but i don't park there. I am drawing up a basic design in CAD. It looks like it will require welding though or be prohibitively exxpensive to machine, from the current design idea anyway. I will do some equations to find the load at 15 degress and say 25 degrees.

I am interested too. Did they actually rebuild it or buy a rebuild from Kragen? Did you have any reaction disk related issues with the rebuild?

I have recently decided to upgrade my rear brakes to the 4 piston Wilwood setups which, as you all know, are not E-brake capable. So I have been thinking, what about adapting a bicycle disk brake, go kart, mini bike, or dirt bike mechanical caliper to mount on the front of the differential to clamp on a metal disk that mounts between the differential and the driveshaft flanges? I have not given thought to clearances yet, and this setup would not be for E-brake sliding. Would this be strong enough to hold a car on a hill though? Any input or ideas are appreciated.

Ordered the rear kit on the 4th of this month. That was our last correspondence.

Arao makes 4 valve heads that use 1 cam, in a V-configuration. http://www.araoengineering.com/LSX.htm

In that case I agree that hp/lb isn't the most useful specification for an engine, but HP/car weight definately is. That is where the high HP of the LS1 would shine, plus the potential to make more power. As I said though, if one is willing to spend, a Buick or an all aluminum Ford 5.0 would be a light high powered route. Wonder if that 326lb is including flywheel and clutch? Most of the LS series actually has a better power to weight ratio then the F20C and F22C, but if you look at it in the car then things become a bit clearer. Say 1900lb Z with out engine, just for fun. With LS1 - 2397lb: 146hp per 1,000lbs With F20C - 2226lb: 108hp per 1,000lbs Okay say the LS1 has a heavier transmission too just for kicks, still isn't going to make the 35% difference back, never mind the torque. Yes 170lb difference is alot, but not when you have an extra 35% useable (not talking about 1500hp vs 2225hp here) more power out of the box, never mind the 400hp, 430hp, 505hp versions. Also if it was an automatic LS1 it would weigh in the 450lb range as well. I could see an argument being made for the I4 if the car was purely for very tight auto crosses though, maybe. Obviously there are pluses and minuses to every engine setup and ultimately people choose to do what they do because they like THAT engine. There isn't anything wrong with any way. Heck, my swap weighs more then the F20C and has less horsepower, but I am content.

Who are you talking to? Quote the text you are refering to maybe?

Well you might want to try and keep an open mind throughout your build or you might end up with a purist's car. Just kidding, but really you might blind yourself to other better possibilities. Its your build though!

Found the source for weights: http://www.sandsmuseum.com/cars/elise/thecar/engine/kingk.html I remembered correct, they state 347.6lbs for the F20C. They claim the Lotus K engine, I believe is 212lbs. I believe the Nissan CA is around 270lbs, the Ford Cologne might be a contender around 305lbs (atleast the earlier ones, not sure about the 4.0L Explorer/Mustang motor), and the Buick/Rover V8 at ~325lbs. All those are lighter then the S2000 motor and the two V motors would move the weight back and down which would most likely be better for handling. Those numbers are from Dave Williams list. Version 00.02.04 http://www.241computers.com/ford/index.php?module=ContentExpress&func=print&ceid=38&mid=30 Not sure on their accuracy but even if they are +/-50lbs it is a nice perspective point.

Imho, if you want to burn money your better off buying an Aluminum block and head Ford 302-331-347. That will weigh in the mid to high 300lb range depending on accesories and such. I *believe* the S2000 engine was something like 347lbs complete sans transmission. If you want to be more frugal maybe concider the buick aluminum block engine, although I must admit I know nothing of the aftermarket and potential. It just seems very strange to spend so much for a savings of 50 or so pounds over much cheaper solutions. As far as an S2000 being quick for the weight, I'm not so sure on that one. If you compare similar power to weight ratio cars, the S2000 is almost always the slower one. I wrote a little hypothesizing as to why that was. I think it is mainly a huge lack of torque on the low end. When comparing a 3000-5000 pull on a stock 5.0L HO to a 5300-8800 pull on an S2000 (this was a simple 1.76x scale up to compare what might be a typical 2nd gear acceleration scenario), the S2k carrys almost 14% less power under the curve. Which in turn would relate to something around 14% less acceleration despite having equal peak power outputs between the two engines. Just something to think about.

I posted to the Brake FAQ and after about a day it still has not shown up. I am starting to think I probably made the post in correctly as it should have been its own thread. Can someone rescue it and make a thread for me as the post was a rather lengthy question about proportioning. Thank you all immenseley!

I have a proportioning valve an piston size selection question. I am using a 15/16" master. The front of the car is 1.75" 4 piston units and the rear has yet to be determined. Originally I was thinking to use the 240sx ear setup, but it is single piston and ~1.125" diameter. The huge disparity in piston area between the front and back makes me think that I would never get the maximum potential out of the rear brakes as I would if I had more piston area in the rear and a proporting valve. So, what is the correct piston size or the rears? I am thinking 1.25" 4 piston units? Is this about right? JSK recommends 1.38" this seems a bit large. Math is below: Piston Area 1.75" (Fronts): 9.62 sqin Piston Area 1.38" (Possible Rear): 5.78 sqin Piston Area 1.25" (Possible Rear): 4.91 sqin 240sx Single Piston: 0.99 sqin The F vs. R percentages are as follows. I think I read somewhere that bias is usually 80% to the front and 20% to the rear as n approximation, this may very well be wrong. 1.75" Front and 1.38" Rear: 62.5%F and 37.5%R 1.75" Front and 1.25" Rear: 66.2%F and 33.8%R 1.75" Front and 240sx Rear: 90.7%F and 9.3%R It is important to remember though that the proportioning valve can only reduce pressure up to 57% maximum. The percentages at maximum pressure reductions become, for any ore maybe the 1.12" Caliper could be used...: 1.38" Rear: 83.9%F and 16.1%R 1.25" Rear: 85.5%F and 14.5%R Thanks for the help guys!

Yes, search.

That 289 was not built off of a 5.0L HO block though, correct? So there is some difference in weight between the newer 302 HO's and that setup? Or am I misguided?