jt1

If you can find a set of plate engine SB2.2 heads, the ports are a lot smaller than the open track heads and might be about what you want. Custom pistons, custom cam, and Jesel rocker setup all adds up pretty quick. A fellow around here builds a lot of SB2.2/1st gen hybrids for dirt late models. They go out the door at about 900hp, so there's a lot of potential there! jt

I use a Racepak datalogger. My car pulls around 1.35 g on Hoosier 225/50/16 R6's. jt

Pulling a Z on an open trailer, I would guess you would drop 4-5 mpg, but that's just a guess. One consideration is you're not going to be towing a lot, so several trips to the track a year wouldn't be a big expense overall. Be sure to check out if it's got a hitch that's strong enough for your trailer, or if you're going to have to add a hitch. If you can buy something like that reasonably cheap, it's not going to depreciate a lot, so you could buy it, try it, then resale if it doesn't work out. The big vans are very comfortable on a trip. jt

If you're using rubber lines, try switching them. Sometimes the inner liner comes apart and blocks the fluid. If the problem switches sides, you know it's the line. The stainless lines are a nice upgrade. jt

Jon's right about the 6.2 Chevy's. They're weak, the injection pumps are problematic, they need the oil changed every 2500 miles, and noisy as all dickens. I used to have a 89 4 door we used as a crew truck, and they joked if there was a head wind it took them longer to get to the job. If you want a diesel, the Dodge Cummins are hard to beat. jt

One thing I've tried is sticking a big magnet to various parts to see if that changed the frequency. Worked pretty good on sheetmetal, sorta inconclusive on other stuff. Might be worth a try. Does it resonate at the same mph if you use third gear? Have you tried putting the car up on a lift and running it? I spent a lot of time, effort, and money chasing a vibration in a vette I used to own. It can be a frustrating experience. As a side note, do you know of a good source for R200 shims? Last one I worked on I had a heck of a time finding any shims. jt

It looks nice in the pics, but........ It looks even better in person. Very nicely done with a lot of nice details. Notice in the second pic, looking down the side of the car. This thing is gun barrel straight and has a near show quality paint job..... to go with the fire breathing motor and the big stickies. jt

Sounds like you've got the mounts and driveshaft well covered. Jon is correct that changing the backlash from whatever it is from the original wear pattern usually makes a noise worse. However, out of numerous R200's, I've only had one that was noisy enough to be heard in the car. It's unlikely you would get three bad ones in a row. Have you tried changing the rear ride height, to vary the angles of the halfshafts? How are you determining the frequency? jt

I agree with Mongo, it's more likely the diff mounts or driveshaft alignment. What type of diff mounts are you using? The solid aluminum type transmits a huge amount of noise to the car. jt

Just rotate the crank one revolution. Then the marks will be correct. Just joking. It doesn't matter whether the cam dot is at the top or bottom. The line may not be needed, but the nipple on the carb needs to be capped. Track down the line and see what it goes to. Does the keyway in the damper hub line up with the mark on the damper? jt

How are you finding TDC? Are you checking piston position, or going by the marks on the damper? Do you have the damper off now? If so, look and see if the keyway for the crank key lines up with the tdc mark. Are you using a stock timing cover pointer, or aftermarket? How are you checking ignition timing? "eddy" is slang for an edelbrock carb. It has nipples for vac lines to attach to it, usually a large one on the baseplate and a smaller one higher up. All these should be capped at this point. jt

Check the TDC mark on the balancer to make sure it's correct; Check your timing at idle and whenever all the mechanical advance is in; Make sure all the vac nipples on the eddy are capped. I don't think a lack of vac advance is causing your problem, something else isn't right. jt

It looks like the car's getting pretty close, Jared. Any idea on when it will be complete? What are your plans for the car then? And once again, it's gorgeous. John

Valve lash OK? Cam timing OK? Double check intake and exhaust CL on several cylinders, verify overlap and opening and closing points. Piston to valve clearance OK? If the cam got put in wrong you may have tagged the intake valves. jt

General concensus around here is the A6's are a softer compound which heat up quicker than the R6's, have more overall grip, but then fall off quicker than the R6's. On a roughly two minute course, the A's are considered about 1/2 to 1 sec quicker than the R's, and the R's about 1 1/2 to 2 seconds quicker than the RA-1's. Wear and heat cycling are the opposite, so the A's wind up costing a good bit more. No surprise there, huh? Full race slicks are quicker yet, but even more expensive and good for only a few heat cycles. jt

Mark, that looks nice. What's the advantages of the floating rotor? Eliminating the vibration/rotor shimming/knockback issues? Does it float radially, laterally, or both? They must be made of some really lightweight material. I haven't actually tried them, but I'm pretty sure none of my rotors would float. jt

Looks like a cool project. What's the details on the 289? John

That was me when I was a passenger. Tom seemed to take it very well, although he did cut the chatterbox off. Alan, there wasn't any noise I could associated with the chattering. One other clue is that Tom said it wasn't as bad when I was riding with him. Maybe it's a ballast issue. John

I think there's advantages to left foot braking on a road course. When you enter a corner that doesn't require a downshift, you can start rolling on the brake as soon as you start coming off the throttle. Done correctly, this reduces the transition time, since there's no coast, and it lets you manage the weight shift from the rear to the front much more smoothly. This means you can stay on the gas a little longer, and extend the straight. You never completely let off the gas, just enough to let the car push the engine slightly. Then it's real easy to smoothly pick up the throttle midcorner, no transition again, and start accelerating off. Once you get the line figured out, getting around a corner fast is all about the weight transfer and managing the tires. I've compared datalogger graphs from turns I shift to turns I don't shift, and the no shift turns are definitely smoother. At one track, thru a series of turns, I learned to postpone a downshift thru a faster turn, then shift entering a slower turn, and picked up a coupe of tenths. So it works for me, but I've always tried to be a "smooth" type driver. It might not work for some of the curb hopping, sliding type guys. It puts more heat in the brakes, because you're going faster when you begin to brake. I don't make midcorner corrections with the brake, I prefer to do that with the throttle. It takes a while to learn. When I decided to make the transition, it took about a year before I was completely comfortable and could run the car as hard left footing as I did right footing. You quickly learn that your right foot is a lot more educated than your left, and you now have to manage the transition from left to right on shift and no shift corners. If something goes wrong and you get out of rhythm, it gets ugly quick. Lots of flatspotted tires and numerous offs. I do at least one track day a month, and two several months a year, so it took a good bit of seat time to get to what I considered proficient. Maybe I'm just a slow learner. John

They seem to enjoy a good reputation. The spring diameter won't affect the geometry, but it might mean the spring or retainer will hit the rocker. It probably depends on which retainer you use, it's more likely to hit than the spring itself. John

Best idea I've seen so far. I will monitor this situation closely!!!!!!!!! John

I've ridden in Tom's car, and have felt the "chattering". It's pretty hard to describe, but I'll try to hopefully further the discussion and help him get it fixed. One description is that it's like a 4 wheel drive vehicle when you turn the wheels too sharp and it binds, rocking the whole vehicle. Another might be that of the inside rear wheel going over a series of speed bumps, and none of the other wheels do, but it shakes the entire car. Another might be that the car is rocking on an axis thru the inside front wheel and the outside rear wheel, although most of the movement seems to be in the rear of the car, maybe some going to the outside front. It doesn't do it on entry, but under light throttle midcorner, and heavier throttle off. It 's worse in long sweepers, not as evident in quick, tight corners. When the car chatters, the rear steps out, almost like it's jumping in short steps. The more you're on the gas, the worse it is. Tom's car has plenty of power available, and it can get pretty violent. When you're on the gas harder, the frequency doesn't increase, the amplitude does. We tried a few changes at the track to see what happened. First one was take off the rear sway bar and throw it in the trailer. Tom reported this made no difference he could tell, other than pushing more. Then we went the full range of adjustment on the rear shocks, 1/2 turn at a time, from full stiff to full soft. The chattering wasn't as bad at the soft end, but it was still there. By that time it was getting late and we loaded up, still scratching our heads. John

HB, these aren't pics of the hood latch specifically, but maybe they will show you how it works. In the first one, you can see the L shaped bracket mounted to the firewall, right behind the distributor. For some reason, the top piece and latch are laying on top of the brake booster in this pic. In this one, you can see the top piece bolted to the L bracket, which gives you a place to mount the stock hood latch, and gives the safety latch something to hook on. It works very well, I've never had any problems with it. About the only disadvantage is you have to unbolt it to remove the distributor, the realign it when you replace it. John