tube80z

There's already been a lot of discussion on this but I thought I'd chime in with my take. For hillclimb how fast you can get the tire up to operating temp is critical to help minimize run time. Generally you'd want the smaller wheel for less rotating mass, which helps both acceleration and braking. But many times the larger tires may be better developed by a manufacturer and that trumps the lighter weight. You also really want a plan in place so you don't end up buying things more than once, which has a tendency to get really expensive. For both autox and hillclimb you don't need huge brakes so you can run smaller wheels. But that limits your tire choice and many of the better tires that heat up quickly are in larger wheel sizes. JohnC mentioned the advantage of AWD for hillclimbs. What I've found is that it's better at launch and then only if you have traction limited areas on the course. 2WD is often faster if the launch can be close because you have less weight running up the hill. In the PNW our hills are often very steep with sharp corners and you'd think AWD would be king but there are many fast record holding cars that are only 2WD. George Bowland came out a few years ago and decimated the records at most of the hills with his snowmobile powered AM car. But those records are getting close to being taken down buy a 2WD Locost running LS power. For what it's worth my Z (Braaps old car) is setup to run 13 inch diameter wheels and 10.5 inch brakes. I prefer less rotating mass and the smaller mass of the tires help them to heat up faster. Good luck and be safe. Hillclimbs are some of the most fun you can have but they have a high level of risk you need to manage. Hope this helps, Cary

The other idea that might be useful would be to hang another muffler to the side between the bumper brackets. A 90 into this muffler would help if you ever run into severe restrictions like 90 dB. I've seen this done on a couple of 911s that were rather loud. Cary

You've already got a lot of good advice. The one thing that would help a lot is if you can find some pictures of the car loaded up in a corner. These can tell you a lot. Is the car rolling too much, how is the camber, how does the front look compared to the rear. One reason you're getting advice to add a lot of camber is two fold. Not only do the tires need it to get the maximum rubber on the ground but with the soft spring rates you're running the car will roll a lot. Typically it does this by compressing the outside spring a little and lifting up on the inside spring a lot. And on a strut car you lose camber at almost the same rate as roll. One thing that's been done on a few chump cars that might be worth trying is to limit some of your droop. This will make the car work like you have stiffer springs and could be something you put on at the track. I would try it first at a lower speed event like an autox before you jump into the deep end on a track at a HPDE. I'd probably try running around 1 to 1.25 inches of front droop and 1.75 to 2 inches in the rear. You can try less and see if that helps. The car will probably change direction a lot quicker that you're used to, which is why I'd try the autox first. This trick will help to limit the amount of roll the car sees by stopping inside lift and making the car push the outside down for any more roll. It might make a good compromise if you want to keep the car softer for the street and not reun higher rate springs. Hope this helps, Cary

If you look at how much room you have between the seats and measure a transaxle you'll probably find they won't fit.

Here's a document from Performance Friction with a lot of good information, http://www.starmazda.com/competitors/2009/resource-cd/PFC%20Brake%20handbook.pdf. One thing we found on the EP car (which is underbraked) is cryo treating the rotors will make them last longer. Before this we sometimes had to change discs every day. Because of class rules the discs are small and you have all kinds of issues you shouldn't have to deal with. As Mike said lots of air will help and Jon's idea of a fluid recirculator would help alot. The EP car has modified backing plates for air into the rotors and a custom scoop to force air into the calipers around the pads.

Matt, We have a simple defroster we install for if there's a chance of a wet race that works very well. It's one inch schedule 40 PVC that was bent to follow the windshield curve and has holes drilled in it to direct the air. One end is capped and in the middle is a tee that goes to a 2.5 inch nascar brake fan. One end fits into a holder and the other is bolted is a single bolt on an adel clamp. Fan mounts to quick release on the passenger seat mount rail and has a weatherpack connector to hook it up. Take less than 5 minutes to put in or remove and keeps the screen clear -- no more squeegee. When it's really wet we go back to a glass windshield and have a single wiper setup that mounts quickly. The defroster is light and works incredibly well and would be a good item to add to the trailer for when you really need it. Cary

Hi Mike, What type of fire system? If you have halon or similar make sure you don't get sprayed directly because even wearing nomex I got a good burn when mine went off in a formula car. It also is very good at displacing oxygen you need to breath. Cary

Most clubs have a test-n-tune event or something similar. If you're doesn't bring it up as an idea as I'm sure you're not the only one who would like the time to work on the car. I've been fortunate to have a club that has a dedicated track and we have a weekend event and Saturday is open practice. It's not uncommon to get 10 to 20 miles of actual autox practice. But if you don't have that option then you need to make the car adjust very quickly and it would help a lot if you can get a co-driver. About the only thing you're going to be able to do is adjust tire pressures, which can help. Other ideas if the class allow would be cockpit adjustable sway bars or have the adjusters somewhere they can be moved quickly if you can't have driver adjustable versions. And on the camber plates if you build a turnbuckle arrangement to move the plate once loosened that might help too. This way you don't have to jack up the car. There's one guy I run with that built strut tops that come off so he can change the springs really quickly. He can do a spring change in about ten minutes per axle. It won't happen in line but it could between sessions if you had a small break. If it were me I'd lobby the club for a test and tune event. Hope this helps, Cary

The one thing that's really important for our cars is to make sure you are either in the car or have driver weight in the car when getting an alignment done at a shop. If this isn't done then you may not be getting the numbers you are asking for. Our cars are very sensitive to roll angle and sitting in the car puts a slight angle on the car that needs to be compensated for. Once you know that info then you could do the alignment without being in the car. Corner weights, ride heights, camber/caster are all in this boat. For camber I bought a fancy digital tool (smart camber) and it can also be used for caster too. Or if I had thought about it I could have used some trig and a carpenters square to get the same info. The latter is very useful at the track when you want to quickly check something. For toe you can build a string system that aligns with the car centerline and it makes things pretty simple. You can also setup a long piece of angle or square steel at hub height and do the same thing. And as Jon mentioned you can use floor tiles, carpet squares and even magazine pages to help level the floor. If you're at a shop or at home doing this it's good to also learn what a flat or a full turn does to the alignment. If you keep good notes you can always make a change this way at the track and not worry so much about all the alignment equipment. But I would recommend checking it later to make sure it was what you wanted. For camber you can use a tape measure with your camber plates to get similar info. For taking tire temps as a one man show there are a couple of options. If you don't have memory tire pyrometer I would recommend a handheld recorder. I quickly get out of the car and start with left front (inside, middle, outer), then left rear (same order), right rear, right front, and then left front again. Then drive the car back to the pits. Once there you can play back the temps and right them down. If you can get a buddy to help or offer to do this for someone else and they help you it works even better but you don't always have that luxury. Why do I do the same tire again? That's to see how they are cooling and figure that into my temps as I came off the track. And from the temps you can get fancy with averages to determine what end is working harder, diagonal, etc. And make adjustments and go faster. Okay, that's a lot to think about. Feel free to ask questions. There's a lot of knowledge on this forum and there may be far better ways to do this than I just offered up. Cary

The one thing to keep in mind besides the weight of the car is the unsprung weight on the corner. If this is the same between the S30 and S13 then the frequency of the suspension should be the same and the damping should work. But the difference between wheels and tires is a lot larger than most people would think and this can throw the frequency and the damping way off. I believe John is referring to the quality of the shocks and the damping curves above rather than the coil springs. You can have a car that's stiff (2.5 to 3 Hz) that is damped in the 65 to 70 percent critical range that doesn't ride too bad. Up that number and the ride is likely to become a lot harsher, which could be bouncy. For a street car where ride is important there are typically setup with what's called flat ride. This takes into account how bumps are encountered and how the car would feel to occupants. Generally this is a setup that has the rear slightly stiffer (higher frequency) than the front. For a race car they are often setup the opposite to help support the chassis and put power down. And these often feel much rougher when riding in them. There are a lot of kits out there that claim they are "valved" for a certain car. I'm sure they were but unless you have a setup really close to the car used for development then you may not get very good results. It really doesn't cost all that much extra to have this done for your car but it does take a lot of work to get all the measurements. You can find more information in the shocks/springs/suspension sticky. Cary

That will surely work but it's a little overkill. I drilled a hole in the front of the strut tower for the top of my limiter mount. This is the one you really want to make easily adjustable of you intend to try and tune with them. On the rear just keeping light tension on the spring will be good enough. On the front you can try some compression but I would recommend not trying zero droop. The car will instantly turn but is very bouncy. Perhaps if you had a huge splitter making downforce it might work. Keep up the good work. Cary

I just notices these. Very nice and thanks for posting. The bar from the passenger corner to the middle of the front cross bar is very effective at increasing the torsional strength of the car. I have a few grape models I made I need to post showing some of these small changes and the difference they made. Also adding the boxes in the front behind the wheel is helpful but I think the tube that Jon adding in his cage going from the bottom of the rocker to the top of the front strut rail is much more effective. Cary

And if you have a cage you can tie the pedal box into the front cross bar. If you do this then you will really notice a difference. It's always good to have someone push really hard on the brakes while you watch the pedal box/masters. Many times you'll be surprised at how much all this moves around. Removing that will help with brake feel. And then you just keep going down the line. best, Cary

It should work fine and I like it. Another option you might consider is to link both sides with cable and use some rollers to allow the cable to move back and forth. What this does is allow you to droop limit when you lift the end up but not constrain roll. And then you can start doing tricky things like keeping the amount of lift limited when you hit the brakes or drop the throttle but still have full travel for roll. If you're playing with underbody aero or a diffuser that might be useful. Or if you hillclimb and deal with a lot of road crown this can help to better put the power down. And you can also use the helper springs. Cool idea though. Cary

The one thing you'll want to add if you haven't already taken it into account is a pinion snubber. The ears will not hold the front of the diff from lifting and will eventually break on a V8 car. Just a piece of square across the top with a basic rubber block should be good enough. Cary

Let the splitter be the skid plate. Put a few tubes to capture the back of the splitter on the crossmember and then use this as the mount. Cary

Nice car, now I need to come up with 5K for that awesome manifold.

Looks really good Jon!

That's awesome Cameron. Harold Knoebel is a multi-time national DMOD champion and you beat a host of other people in really fast cars. From watching the video it looks like a couple of sections are pretty rough. It doesn't look like you're that far from being able to fight for King of the hill. Looks like a great venue and sounds very similar to what we have in the PNW with regards to event atmosphere. Great job! Cary

Having been around that car for a long time I can tell you it had nothing to do with the motor placement. It had a lot of other issues. A local racer put the motor even further back in his 510 (Larry Nelson) and it was one of the best handling 510s I've ever had the pleasure of driving. Put another way, the 510 has heaps more PMOI than most sports racers or formula cars and normal humans don't have issues with those. Claude Rouelle shared a number of stories in his seminars about weight distribution and PMOI. Up until the Pirelli tire era most F1 teams arrived and the track and only changed weight distribution according to him. They had sophisticated simulations to determine all the other parameters before they even showed up. Claude shared one story where moving two 7.5 pound blocks was worth three quarters of a second. You can do some simulation based on either data or by guessing by using the free version of Bosch Lapsim. If you have data you can build your own track and create a model of your car. From there you can play with certain parameters and see what happens to laptime. The free version assumes a perfect driver and doesn't really take suspension into account. From what I recall it's predictions matched what John said, which is what you would expect. So if you want to try and optimize you can have lots of fun with that tool. It was fun to build that 1000 HP Z and see what my 0 to 60 time would be. Cary

Sorry, I should have called it a hydraulic release bearing. These are stiffer and easier to drive. The engagement point will be something you'll want to work on. The small clutch will bite very quickly so any flex makes this harder to manage. Your definition of free play is correct. You need a specific distance from the bearing to the clutch cover. You also need to have a precise pedal stop so you don't over push the cover. That can also damage them. The crank thrust is the bearing area that takes the pressure when you push down the clutch pedal. If the bearing doesn't have the specific free play and is tight these surfaces can be under pressure most of the time. And over time the bearing wears down and then the machined area on the crank. And then things get expensive. As long as you follow the directions you should be good but make sure the free play is correct and the travel doesn't over extend (pedal stop recommended). Then it's just a matter of getting used to how easy these grab when you let out the pedal. Luckily with the V8 you have extra torque so it won't be as easy to kill the engine. Cary

Sorry I missed this part. For the small clutches you will probably need to remove the arm and go to an annular style bearing. These either replace the end on the transmission where the sleeve for the throwout bearing would normally sit or they can be mounted to the bellhouing. These clutches need a smaller bearing and a precise amount of engagement for release. You also need to be very careful you have the prescribed amount of free play or you can run into crank thrust issues down the road. Take a look at what's offered for the LS engines and the T56 conversion. This will give you an idea of what you need to do for the VK56 and G35 gearbox. Hope this helps, Cary

Hi Dave, A button is what they call a friction surface with no ring gear. You use a the stock flex plate and then sandwich on this friction surface (using normal flywheel length bolts), which is exactly what you're looking to do. Only change is longer bolts will be needed for the crank hub. Take a look part way down the page on this forum to see a CADed up view of how this works http://www.audizine.com/forum/showthread.php/333627-GURU-s-official-LS-B5-Quattro-Swap-for-under-5k/page11 The flex plate is usually about 0.125 and the button is around 0.25 or so. This gets you to the normal flywheel thickness. The cool thing in all this is the buttons are usually around $125 new from the speed shops but even a custom one shouldn't be too bad. For a button all they really need to do is take a standard one and put eh VK56 crank pattern on it. They may even sell blanks that you could do this your self. Or I'm guessing that Taylor would do this for you. On the clutch I'm not sure if you found a good deal on this one and that's driving the purchase. You'd be better off with the newer v-drive style as they run cooler. On a friends Z the older style like this in 5.5 needed a rebuild before the year was out. The newer v-drive (optiumum V) has shown less wear. I only gently nudge in the 7.25 range as they are all over e-bay for around $200-$250 for units in good shape. That's what I did for the LS one I have. BTW, as you probably know there's no loading your car on the trailer without a wing with one of these. Cary

Is there a reason you're not using a button and the VK56 flexplate? OR is it a problem with the G35 6-speed tranny not aligning the starter to the flexplate? I had a custom flywheel built years ago for a 510 conversion. For it I sent them the flex plate from the engine to establash crank pattern and general spacing and then a flywheel that fit the other tranny to get the starter gear spacing correct. So with those two and working back from the block mating face you could come up with your dimensions. You'll need to know if the VK56 is flat on the back or has any offset to figure that in. If this is a track only car the 5.5 will probably be okay but if you autox you may find that you have to service the clutch every year or sooner. A 7.25 has a lot more heat capacity and is going to be a little easier to get started. Just my two cents. I went with the 7.25 on my LS swap. C

I'd check your alignment and make sure you don't have anything that's worn out (tie-rods, inner/outer), worn rack bushings. And obvious things like the wheel is round. If all that checks out then it may be the tire. Over the years I've seen some weird wear patterns on tire from autox. I can only assume caused by what's under the rubber. The new GoodYear production slicks get a wear pattern that looks like massive toe-out. You run them once and then flip to take care of it. So another suggestion would be to check with other Nitto owners to see if they see a similar thing.