JBH

At 25 F, my car would not start. It would catch briefly then die. It did this until the battery ran down. I borrowed a battery and then it wouldn't even catch. We tried choking it, ether, etc. I pulled the plugs to find a lot of carbon. I changed the plugs and it started, albeit reluctantly. By now it was 42 F. I have tried Al's procedure, but it makes no difference. Temperature makes a big difference - it has to be fuel vapor pressure - indicating my startup map is too lean.

There was a discussion on seat belts a few weeks back in a "Musings" thread in the General Sevens section that discussed many of the safety issues and mounting locations for five and six-point harnesses. I recommend reading the Schroth document (http://www.schrothracing.com/docs/Competition_Instructions.pdf) to get a sense of the issues. It is pretty comprehensive and should give you all you need to know to make a decision and locate the proper mounting points. A few things to remember: - your mounting locations must be able to withstand the forces of a crash without failure or substantial deformation - in a crash, all belts stretch so you want the shortest distance between the mounting point and your body - as someone pointed out above, belts are intended to be in contact with the structural parts of your body: your hips and shoulders. - combining the three concepts above, in a crash you want your body and belts to remain in a fixed relationship to one another. A six point harness is the way to go. A seven pt. may be even better.

Yellow (sorry, I don't know your name) I assume you have a Caterham - How are you getting 10" wide tires to fit under the front wings? I am now running 185/60-13 Hoosier R6 radials in front and 225/50-13 in the rear. The aspect ratio is less than ideal, but the setup works very well on the track (13" radial race tires are really hard to find). The car is very balanced and predictable. The front tires barely fit and I had to bend back the wing supports a little bit to keep them from rubbing. Jeff

If you believe Caterham USA, the specs for my Zetec engine are: Displacement: 1988cc # of Cylinders: 4 in-line Bore: 84.80mm Stroke: 88.00mm Compression ratio: 10.5:1 Valves: 16 Camshaft: DOHC, performance billet camshafts Ignition: Fully PC Programmable Direct Fire Firing Order: 1-3-4-2 Fuel: Premium Unleaded 92 Octane Fuel System: Throttle Body Fuel Injection Maximum RPM: 7,500rpm Maximum power: 202bhp @ 6,800rpm Maximum torque: 165lbs/ft @ 5,000rpm

If you are thinking track events, Lime Rock is cutting their track days in half as they transition to a motorsport club. That means very few available days and those that are will likely go to clubs that have run there regularly. Watkins Glen is an awesome track in a very beautiful part of NY State. I would drive from NC for that event. Let your SE Regional Coordinator know I am available and willing to help with the May event at VIR.

One more Porsche advantage to add: safety. Your chances of surviving a crash is probably 10- 20 times greater in the Porsche compared to a Seven or kitcar. I am certain this will be disputed by others, but statistics say a motorcyclist is 35 times more likely to die in a vehicular crash. Given the Seven or kitcar has marginally better protection, chances for survival may be better.

Porsches are great cars - why wouldn't you want one? If you can get it at a decent price, drive it, enjoy it and then sell it in a year or two. P-cars hold their value well after they go through that first phase of depreciation, so it could be a fun way to try out the car at a pretty reasonable cost. I have driven n/a and turbos on the track for almost 15 years. They are a different, but very rewarding driving experience that will expand your skills and experience level. In the hands of a good driver, they are exceptionally fast. There is a large support base for these cars - clubs, forums, aftermarket suppliers, etc. There is no other marque that even comes close to what is available to Porsche owners. Obviously, I say go for it. Here's mine - a very trick 964 Turbo in Coral Red http://www.usa7s.com/aspnetforum/upload/1350388672_Turbo Reduced.JPG

I watched a segment on TV recently that documented the recent record set by two guys driving coast to coast. There was very a clear display of them doing 170mph, the use of high power binoculars to look for police and an admission by the driver that he drove that fast. When asked about the speed differential with other vehicles, he rationalized by saying he radioed trucks ahead that he was coming and asked them to pull over (I don't know what he thought about the passenger cars whose drivers are probably too busy talking on their cell phones to use their mirrors). Anyway - I am not sure you can use video to incriminate someone without proving both the time and the location it was shot.

Before going too far and spending too much money, I recommend talking to someone that is a tuning specialist. I know Geoffrey Ring at Racetek Engineering in New York. He is a Motec Dealer, but familiar with many ECU systems and quite capable of tuning a Caterham. He also teaches at EFI University which trains both amateurs and professionals in theory, equipment and tuning. Give him a call to see if he knows someone in your area. If he doesn't, it might still be cost effective to pay for his travel and time. Rather than spending days on a dyno when only hours are required may in the end save you money. Just an idea.

My Caterham wheel is a Racetech 260mm with a quick release hub - it has Caterham inscribed in the body. I just bought this Momo wheel for and will use the same hub and release on the Racetech wheel. You can find steering wheels from authorized dealers on eBay or internet for less than Pegasus I bought the flat bottom to give me more room for my knees. http://imagehost.vendio.com/bin/imageserver.x/00000000/crowderscustomizing/.mids/MOMO_Mod_12.jpg

If you are fairly certain you will be trailering the 7 and not much else, I would go with the recommendations above. If you think there might be larger cars in your future or if you are concerned about resale of the trailer, check out Trailex. They are all aluminum, excellent construction and sell used for close to new price. They are a favorite among the Ferrari and Porsche people. That should also be your clue that that the price is not cheap. My trailer is 20' (not Trailex) and it is spacious enough I can carry nitrogen tank, chairs, tools, extra wheels and tires, fuel etc. Personally, I would not go smaller than 16' BTW: enclosed is the only way to go. At a minimum, I prefer to be able to sit in the trailer when the weather goes bad. http://www.trailex.com/buycat.cfm?cat_id=93

I was watching that hood through the entire video. You can see it moving up and down as you pick up speed. Did you notice it during the race or does it always do that?

I think most people know what I am talking about, but unless they have experience with Caterhams, and the tire options they are just guessing - this includes the experts. The reason I run staggered width is because my car's weight distribution (with me in driver seat) is 642 lbs in front and 745 lbs in the rear. It is not a huge difference, but enough to warrant the use of wider tires in the rear. So the question is, what is the right ratio of widths front/rear - that's what I am trying to figure out. I know the CR500s work really well, so in the new tires I order, I want to keep that ratio constant. It may work, it may not. But by trying, I'll get some important information that can guide my next tire selection. I know it's trial and error, but sometimes that's the only way to learn. If the car pushes excessively, I'll go to smaller tires in the rear. You are correct about tire temperatures and pressures. I tried different pressure combinations front and rear on the ACB0s. After talking to Sasco about the Avons, they agree I was right in the ballpark for tire pressures (hot). I ordered the Hoosier 185/60 and 225/50 so I will post results after I run them a bit.

Nice car - glad to see it on the track. What kind and size tires were you running? What engine do you have. I am going to try to get down to Roebling one of these days. If you ever come up to VIR, give me a shout. FYI: Many Porsche Clubs would not allow you to run with your current roll bar - your helmet is clearly above it. If you are serious about track, I strongly recommend changing to a taller roll bar - it's for your safety.

5 speed gearbox on the soundtrack. No paddles, just fast feet. Sounds like a 12 cylinder Ferrari to me.

This is my rationale - I am not sure if it is right and that's where I need some help. The 175/55 and 205/55 CR500s that were on the car had a section width of 6.9" and 8.1" respectively. Thats a contact area ratio, front/rear, of 0.85. Using Hoosier's section width data for the 185/60 and 225/50 tires, the ratio of contact area should be 0.83. If that is correct, I am adding slightly more grip in the rear. So yes, going into the turn the car will push a little more. However, it has been my experience that I can break the rear end loose coming out of a turn if I apply full throttle, so by adding more grip in the rear, hopefully I can be more aggressive in exiting. Turn exits are where I tend to to catch and pass most cars. More grip in the rear also tends to favor trailbraking - something I like to do often (sometimes not by choice) I do not think this tire combination would work at all for Autocross applications If I am missing something, let me know.

My intended usage is fast track day. Most people like the ACB10s, but you are right, the camber should be close to zero. This requires changing the Dedion ears in the rear (not a big deal) and resetting the front. I ordered the ears, a new set of wheels and I got a good deal on a set of ACB10s so next year I'll try that set up. But while the car is set for radials, it seems a good time to try that set up. Here's what I am thinking...I'll go with the Hoosier 185/60 and 225/50 front and rear. They should offer a fair amount of contact area - more than the CR500s while keeping the ratio of contact patch front/rear close to the CR500s. I sort of understand the comment about too much tire - I assume you mean that in lightweight cars, it is easier to get heat into a small area. I am not sure I agree. Friction creates heat and as long as the weight over the contact area is uniform, the tire should heat up just fine. One just has to drive the car a bit harder

I am not a safety engineer, so I preface my comments by saying I may not correctly understand the construction of the fuel tank in the Caterham or the dynamics of a rear end collision. But, from my perspective... In the Caterham, the fuel tank is sandwiched between the rear sheet metal and the differential. I am afraid there are not a lot of good options. Those old enough to remember, will recall the horrible videos of the exploding gas tank in the Ford Pinto. This actually pre-dates Chevrolet truck side saddle. Here's the problem: http://www.fordpinto.com/images/kboomdrawing.gif You can see the fuel tank was located between the rear bumper and the rear differential. To quote the article: "...Pinto accident reports revealed conclusively that if a Pinto being followed at over 30 miles per hour was hit by that following vehicle, the rear end of the car would buckle like an accordion, right up to the back seat. The tube leading to the gas-tank cap would be ripped away from the tank itself, and gas would immediately begin sloshing onto the road around the car. The buckled gas tank would be jammed up against the differential housing (the large bulge in the middle of the rear axle), which contains four sharp, protruding bolts likely to gash holes in the tank and spill still more gas." Looking at the placement of the tank in the Caterham, there is little distance between the tank and the differential. Perhaps wedging honeycomb panels between the tank and the differential would help - I'm not sure. I don't see how a fuel bladder in the same location helps much since it will undergo the same deformation and with enough pressure will rupture too. The Side Saddle tanks in the article referenced in bsimon's post correctly points out that the best location is above the differential 8" or so from the rear bumper. Unfortunately, the Caterham has very little distance between the seats and the rear of the car - placing a fuel bladder in the boot right up against the seats would be best - I think this is the way they fit the Caterham race cars Edit: I believe ATL makes a fuel cell for Caterham that is suitable for fuel injected engines. Placed in the boot area, it may not be such a pain to replace the bladder. I have heard of fuel cells filled with non-corrosive wire wool instead of foam.

While researching Mog seats, I came across a thread on the Elise forum that addresses the concern expressed here about mounting sub straps. The Elise has the same issue as the Caterham in that there is nothing but aluminum floorboard if one wants to mount the straps according to manufacturer's recommendations. The solution developed for the Elise looks good so I thought I would post it here. This picture illustrates the point, but if you want all the details, here's a link to the thread:EliseTalk http://www.elisetalk.com/forums/attachment.php?attachmentid=50787&d=1175552566

I want to try radial race tires (DOT) before I start altering the suspension geometry for bias-ply slicks. Here's why: I had the Avon CR500 (175/55-13 and 205/55-13) on the car and they worked really well on road courses. Looking for more traction I found a set of Avon ACB0s (6.0X21-13 and 7.0X2-13) and tried those even though they are bias-ply and my camber was set at 1.2 and 1.7 degrees front & rear respectively. They are horrible - the car slides through turns and I have to be careful with throttle so as to not break the rear end loose. If I look at section widths as a measure of contact area, the CR500s are 7" and 8" front and rear. The ACB0s are 6" and 7.2". It is interesting that both tires are the same width sidewall to sidewall. The ACB0s bulge out a lot more than the CR500s. So the fact that the ACBs have less contact area explains part of the problem. I don't know what impact the camber has - I do know that bias ply slicks should run close to zero so that may be part of the problem too. Ultimately, I may change the DeDion ears and front camber to run bias ply, but I thoght I would give radials a shot. First question: does any one have experience with radial tires for road racing? Second question: I researched three major radial tires suppliers (click on the picture shown below for manuf. data). Does anyone have thoughts on the right tire combinations for a Caterham? I think there is a limit to front tire width before it begins to rub the front wing support rod. http://www.usa7s.com/aspnetforum/upload/1819059296_tire choices.JPG Sorry for the long post - there is a lot to assimilate here.

I would spend some time understanding PA requirements and code - if you drive on the street and you are lacking all the parts of a PA road legal car, the police will stop you, issue you a citation and force you to go to inspection. It's one of those things - sooner or later you have to deal with it. The question you need to answer: of all the things missing, how many of those are required by state law? You might try to find others in your area that have titled a "kitcar" There may be certain exemptions (such as the OBDII port) and tips that can save you time and money.

Brad: Where are you going for the next dyno? The good news is your compression and leakdown tests are solid. Then you have to start going through the list of things that cause HP losses: insufficient fuel delivery, timing, air flow, exhaust flow, etc. What was the A/F ratio after all the tuning. I was thinking about going to Focus-Power to tune my Zetec Supersport (like Al's) because I am quite certain I am not getting a full 170 rwhp. I may just dyno it locally to see where I am at, but I am a little afraid to see the numbers. Why couldn't Tom set the cam timing? What gear was selected to run the dyno?

The problem is finding a secure location to mount the sub. My Caterham has the sub straps mounted just behind the seat because it is the only place with sufficient structural strength. Putting just below the opening in my seat would require welding a horizontal bar spanning the width of the frame. Because of the distance, the bar would have to be fairly thick. The alternative is to go to a Formula harness where the straps feed through D-rings on the lap belts. I am going to contact GT Classics in VA. They run several Caterhams in SCCA events - I am sure they have a solution.

Sorry, that was a little confusing...I was suggesting not using a center mounting point for a five-point and since Kitcat was considering mounting the anti-sub straps back to the sides, I thought it would be just as easy to make it a six-point.

Here's what you can do with a five-point harness with the anti-sub straps mounted at the sides. Pretty much all the benefits of a six-point harness using the five-point cam. http://www.schrothracing.com/ximg/1616/sc_subdualsnap.jpg