Flexicoker

Hey! I have driven on their dyno! Lowest hp car to ever turn the roller at LG, haha.

That is glorious!!!!!! What process are you using to create the model? I would love to do some CFD on that if you're going to be distributing the model (and when I have time)

Thats not saying it won't work, its just saying that several people don't think it will work. It will only be proven to work or not work when somebody builds and tests one. I think it will work, maybe just a little, maybe alot. But as long as the increase in rear downforce is balanced with an increase if front downforce I don't think it can hurt. Also, riveting through carbon fiber is not a good idea, CF doesn't handle point loads well... you want as much surface area as possible, ie. epoxy

I can get you a picture from my book on Friday if you'd like... it has a diagram of the V and the _

It makes perfect sense that they should line right up, thats what I did when I put mine togethor the first time, but the second time I consulted my '73 FSM and it said the slot should be to the right of the V. ...weird

If I remember correctly (it was only 3 days ago) the little line is supposed to be to the right side of the V, ie. the leftmost end of the line lines up with the right most side of the V.

I'm not saying what you did was worthless... Force = mass * acceleration. You have less mass, the same force, therefore you will accelerate faster. If you put your car on an INERTIA dyno before and after lightened pistons you'd see a hp gain, same as you would if you put on lighter wheels, a lighter driveshaft, etc. However if you put it on a water brake dyno and held it at a constant RPM you would NOT see a difference. Do you see the difference? The relationship between the crank and rods is one of energy transfer. When the piston is slowing down, you are transferring its energy to the crank, when the piston is speeding up you are transferring some of the cranks energy to the piston. If you had a friction-less piston/rod/crank in a perfect vacuum it would spin forever, as energy would be constantly transferred between them. You could have a 100lb piston and it would still spin forever, provided there was no friction. Now, to accelerate this perfect system (increase RPM) it would take energy, and the heavier your piston the more energy it would take.

I looked through your math and didn't see any errors. But I know that lightened internals don't gain you any hp. Then I showed it to my roomate, and he pointed out that you didn't analyze the entire system. His theory (which I agree with) is that as the piston is reaching TDC its being decelerated, and if you draw a free body diagram you'll see that the force thats pulling down on the piston is also pulling up on the crankshaft... in the same direction its already going... accelerating it. Then right after TDC the crank is transferring its enery to the piston, accelerating it, and decelerating the crank. The entire process repeats at BDC. So by lightening pistons/crank/flywheel your gains will be marginal at best, and solely due to less friction. HOWEVER, you have less mass you have to accelerate, so you will see an increase in the vehicles acceleration or on an inertia dyno. On a water brake dyno you will not see any gain other than those due to less friction.

The ultimate turbo Harley http://www.danddexhaust.com/boarzilla.htm I think they're making around 325 hp. On Methanol. Supposedly they have to tie it tight onto the dyno with the rear tire flat, and the rim touching the roller, then air up the tire. Otherwise it just spins. We help them with fuel tuning, and they help us with mufflers and exhaust parts.

Those look really really good. Are you running them with stock struts? What sort of clearance do you have between the strut and between the fender?

I have no idea how much interference is required when pressing in a valve seat, but for that to happen it seems to me like it was a machining error rather than a defective valve seat, ie. too little interference.

I might not be seeing it right... but this scares the ♥♥♥♥ out of me: Are those ALUMINUM rod-ends? In hardcore bending?

Haha, Rube Goldberg contraption... I was going to call it a clusterf***. Same thing Thanks guys, thats the info I needed.

I've got a somewhat functioning dealer add-on AC compressor in my '73, it makes grinding noises and weighs about 40 metric ass tons. Will the later compressors fit my L24 if I have the bracket they mount with? ie. does my block have the threaded holes that the later bracket requires? Where do they mount? My current one mounts above the alternator. Thanks, Eric

Sweet, thats what I wanted to hear. I'm probably going to plug it and run a vented gas cap... Or just run it up and back down. High five!

I need to replace all the rusted out hardlines that run down the tunnel, since the asbestos cement goop they were incased in holds water real nice. Sooo... This is a '73, and I really don't want to have to weave the vapor recovery line in there since the engine/tranny and everything else are in place. The brake/fuel lines shouldn't be as hard. So for those of you that disconnected it, did you just plug the line at the tank? Did you route a vent tube with a check valve somewhere? Did it stink like gas after you did it? Thanks, Eric

I.... don't know. I don't think that the stub shafts move in enough to fully compress the stack. Our shafts have the CV cup right up against the housing, so they can't pull inside the case more that 0.010-.020" or so. In that case you'd be fine with 6 washers as they won't get squashed flat, and they'd still stay in the retainer. I think.

I think that your spacer setup could maybe work, with )spacer( If the sidegears don't get closer to each other during operation. I don't think they do... but I'm not sure? One other problem I could see is that less washers are going to increase your spring rate, pretty drastically if you're taking out 2/3 of them. So you'd have to account for that when you figure out the length of your spacer. If you you 6 washers instead of 8, they wouldn't be compressed flat. If you had them stacked )()()( would the center 2 washers have enough gap between their bases to engage the retainers? I think thats whats happening in our quaife.

I just took a real quaife apart about an hour ago. It had six belleville washers stacked: )()()( I think it needs that arrangement so that the wide part of the washer is seated against the washer retainer. If it were ()()() then the 'point' of the washer would go through the lip on the retainer. I aligned them with my pinky, then put the retainer on top. Having them covered in gear lube will help keep them in place. I also had it in a vice oriented with the stub shafts running up and down. Then when you put the stub shaft in there should be less than 1/4 or so of the side gear showing above the element gears. If theres more than your washer stack fell over and is stuck inbetween the retainers. I beleive that if the diff were manufactured with a spacer instead of the belleville stack, it would still work as intended IF and only if it were manufactured perfectly and there was no slop at all. So the spring stack is taking up the slop in the middle. It seems to me that the belleville stack and retainers, and the spacer are allowed to 'float' side to side. So that while differentiating the whole center spring assembly and the stub shafts move side to side. This is going to cause more friction against the endbells on one side and less on the other, and this is where the torque biasing comes from. I heard that the ONLY way to change the torque bias ratio is by changing the angle of the helix on the gears. Thats one incomplete theory, my other, more believable theory is that those are black magic helical gears. Soaked in a potion of elfs blood and rosemary while someone chants 'beetlejuice, beetlejuice, beet....'

Honda CBR250... 20,000 rpm. You can't find them in the states.

No, lightening the flywheel, or any rotating component for that matter does not reduce torque. It reduces inertia, which can make it more likely to stall, and make launches a little bit slower. But it will also make you accelerate faster. And thats good.

I should have said 'statically neutral car' like in a skidpad. I also realized that I made an error, you need the wheel rate, not the spring rate for that formula. Which, with struts, is going to be close to the same number. The wheel rate is going to be motion ratio^2 * spring rate.

The relationship you're talking about is called undamped natural frequency. Its defined by: 1/(2pi) * sqrt(k/m) Where: k is your wheel rate in lbs/ft, NOT lbs/in. For a car with struts its going to be very close to the same as your spring rate. Its motion ratio^2 * spring rate. I would probably just use the spring rate if I was doing basic calcs for a Z. You'll just need to multiply by 12 to convert from lbs/in to lbs.ft m is the mass of one corner (note: mass = weight in lbs/32.17, the unit is slugs) Your answer will be in Hertz, and should be between 1 and 3, although thats a very broad range. The higher the number, the stiffer your car. This number is basically the number of times per second at which your car would oscillate if disturbed and there was no damping or friction. Alot of people believe that equal natural frequencies front and rear will create a neutral car... alot of people don't.

That is how carbon fiber parts should look. Awesome.

I was welding on one that I washed with water for about 10 minutes, and then filled with water right up to where I was going to weld, and it still blew up in my face. Not very much fun. Now I will never do anything but purge with argon. Brazing is also going to give you alot better odds for getting a leak-free connection.