johnc

Quite true.

IMHO, a stiffer chassis allows a higher spring/wheel rate.

Sorry, dumb joke.

I edited the title for ya...

Probably. measure the spring OD/ID and height and compare it with the Ford/GM part.

Suburban Fullerton, CA and the local cops just got two new 1975 Nova police cars with the hot 350 police special option. For a couple weeks we saw them racing around town for no particular reason other then the cops were having fun with their new toys. They pulled over a friend in a Camaro and did a chickens%$t arrest on him (couple crumpled foil balls that they claimed had hash, lab came back and said Ding Dongs, which my friend had explained) and had his car impounded. Me, being the superhero that I thought I was, decided to avenge my friend. For the next week I would stalk the Fullerton PD Novas on my Kawasaki 750 H2 (http://uk.youtube.com/watch?v=gPGhuepihmc). Blowing past their radar traps witht he front wheel off the ground generally got their attention, but that was usually the last time they saw me. A near wreck at the end of the week convinced me to sell the bike and put my superhero cape away. But the damage to their egos had been done as reported to me by my little brother who had a police scanner.

If you were referring to my jacking point suggestion, you can if you want or just stitch weld the longitudinal tube to the rocker panel. Jacking loads are small compared to the accident loads.

For road racing weight reduction is always better, unless rules get in the way. Weight distribution is not as critical was weight reduction. ITRs have a 63F 37R weight distribution and they get around a race track pretty fast.

There isn't any kind of algorithm like, "100 lbs less equals .1 second faster lap" so you're not going to able to quantify things exactly. Race series that use weigh adds (rewards weight) typically do it in 50 lb. increments with the first "reward" being 150 lbs. That's usually enough to move a car back one or two finishing positions.

In the naturally aspirated world "typical" two valve head engines can be build and tuned, with a lot of money, to make 100 to 110hp per liter. "Typical" four valve head engines can be built and tuned, with a lot more oney, to make 120 to 140hp per liter. A L20B making 245hp is beyond what's typical for a top end, high compression (over 12 to 1) build so I would be skeptical until some real, SAE certified numbers are posted.

You might as well connect the two seat tube longitudinally under the rocker panel with another tube. That will give you a center jacking point to lift the whole side of the car up with one jack.

I think you need to go to the various pad manufacturer sites and figure out what's a best compromise pad. The Hawk HPS+ would be a good choice. Also check Carbotech. The Corvette guys love 'em - the AX6 is their autocross compound and the XP8 is their first level racing compound.

I angled the gap towards the intake valve and +/- 30 degrees is fine. Just make sure the gap isn't pointed down onto the piston. The electrode needs to be down.

I guess we're talking about two different things. I was referring to the radiator and you were referring to the ducting. Again, the radiator itself provides little, if any downforce - and it shouldn't if its going to operate efficiently as a heat exchanger. In my thinking, the ducting in front of the radiator should be designed to improve the efficiency of the radiator first, and then secondarily add some aero benefits. The primary aero benefit, IMHO, is to keep airflow through the radiator as limited as possible (per engine cooling requirements) to reduce drag and increase downforce. The ducting behind the radiator, in my thinking, should meet the same requirements as the ducting in front of the radiator, although the downforce benefits are very limited because the radiator reduces air velocity by an order of magnitude. Ducting at the front of the hood as pictured above has an indirect affect on overall vehicle downforce by exhausting high pressure under hood air into the low pressure area at the top of the hood. This reduces overall front lift by some amount.

Do you want to run street pads? Is there a reason you're running different pad materials front and rear? I'm asking because your pad choices are adding some variables to your brake testing/setup. For me its easier to have the same exact pads front and rear to keep pad coefficient and bite out of the balance equation.

What Jon said about my quote above - it was about cooling efficiency. I've actually never heard of anyone using the radiator as a downforce generating device. IMHO it wouldn't be very effective in that role because its supposed to have air lowing through it perpendicular to its orientation. Angling the radiator also requires angling the airflow to give it as straight a shot as possible.

What I've done is get a professional race driver to do my brake testing... I don't feel I'm consistent enough in braking to do this quickly and efficiently. Set the adjustable prop valve in the middle of its adjustment range. The prop valve is the gross adjustment, the balance bar is the fine adjustment. Set the balance bar with a 50% forward bias in the car to keep from spinning and then pick two spots on the track: High speed straight Medium speed straight Run the medium speed stuff first and adjust the balance bar after two braking passes. Run the high speed stuff second and adjust the balance bar after two braking passes. Run both for a couple laps and keep adjusting the balance bar until the fronts lock just before the rears. Hopefully the balance bar is near the middle of its range. If not, adjust the prop valve and try again. If, at any time, you hit the limit of the balance bar or prop valve adjustment, you might be off on your MC sizing. Once things are dialed in you should never have to touch the prop valve and will use the balance bar for all subsequent adjustments. For fine tuning with the balance bar, find four spots on the track Medium speed corner entry - right trail brake Low speed corner entry - right trail brake Medium speed corner entry - left trail brake Low speed corner entry - left trail brake Using the balance bar adjust the brake balance so the car rotates well under trail braking in the above situations. You want more rotation in the low speed corners.

When attaching any safety related component to the unibody you need to spread the load over as large a surface area as possible. Seat mounting is as critical as any mounting in the roll cage so why wouldn't you use the same mounting process that SCCA, NASA and other road race sanctioning bodies specify for cage elements? Your primary protection in a wreck is your seat and your harness. If either fails, you become debris inside the car and now the roll cage is a danger. For my customers I pay as much attention to seat and harness mounting as I do to the roll cage.

I've NGK, Bosch, Champions, and Autolite in various Nissan L6 engines. For a mildly tuned (200hp) L6 running SUs, the Champion projector tip plugs were the best, IMHO. They needed replacement every 10,000 miles, as expected, but they were the most consistent on the dyno. Autolites were a close second. On my 13.6 to 1 CR L6 the NGKs worked the best, but needed replacement every 5 hours, mostly due to lead fouling (I ran 112 octane leaded fuel). The Champions would not lead foul but had problems above 7,000 rpm. What was the most important variable was indexing the plugs. An indexed NGK was better then an indexed Champion and vice-versa. Moroso sells plug indexing washers.

I think you have the Nismo Circle Track/NASCAR lower control arm option. Very rare and very valuable.

Think of a seat mount as another part of the safety/roll cage structure - it should be just as strong. Attachment of the seat mounting should be the same as a roll cage: the mount should be welded to .083" minimum thickness plates no less the 2" on any side. These mounting plates should be completely welded to the unibody, preferably in two planes at the rockers and the center tunnel.

The HTS112 has 6" of shock travel. How much travel do you need? My drag race shock thinking: Front Shocks/Suspension Should be droop limited to balance out front end lift while still keeping the front wheels just touching the ground. Lifting the front wheels completely off the ground is counter productive because you're using energy to continue to lift the front after weight transfer has reached 100%. Having the front wheels just touching the track gives the driver some options if the car gets out of hand and also lets the front suspension control the front coming back down if the driver lifts. Rebound valving should be fast enough to allow the wheels to droop fairly quickly. Compression damping should be firm enough to control the front end as the weight transfers forward. Compression damping should not be too firm because you want the front to drop all the way down by 1/2 track so the car has better aero as the speeds increase. Rear Shocks/Suspension Should be firm enough to keep the the car off the rear bump stops. Bottoming the suspension does bad things from compliance and grip. Uneven bottoming will put the car into the wall or the tree. Compression damping and spring rate are important to control the rear suspension under acceleration. Rebound damping should be firm to keep the car from hopping/popping up if the car breaks traction. It should also be firm enough to control the rear suspension as weight transfers forward. Overall Balance Once past 1/2 track the suspension should be settled enough that the driver has some control and options if the cars squirrelly. At speeds approaching (and past) 100 mph on a narrow track its nice to have some handling capability in the chassis. That's all just my opinion.

They are not a great shock. The are about the same as the stock shocks that came with the car back in 1978 and sound like they will be fine for your car.

Most likely the original owner complained to the dealer about a "vibration" and those plates were the fix.

Having driven trucks for a short time, its always a good thing to move left one lane when approaching a vehicle on the shoulder. You just never know what's going to pop out. I also give truckers room to move left if I'm near them when they approach a vehicle on the shoulder. FYI... here in California, the CHP officers approach a car from the passenger side.