Jump to content

Davemk1

Registered User
  • Posts

    549
  • Joined

Everything posted by Davemk1

  1. On what have been one of the last warm and dry days of the fall I took some time and went for a cruise. I saw this fresh cut field a bit off the road and couldn't resist taking a few photos. One more race this season and then the engine comes out for a bit of work. Enjoy the Fall. Dave http://www.usa7s.com/aspnetforum/upload/54927240_DSC_7148.jpghttp://www.usa7s.com/aspnetforum/upload/751944381_DSC_7158.jpg
  2. Glad to help a bit. You're right those guys with the big wheels are using something. If you have a choice find the lightest tire you can. Not only for the weight but for the flexibility. Most of those tires are meant to carry a car twice the weight of a Seven and can be too stiff in the sidewall. About camber and bias ply tires.........I agree in a big way. I'm running 1/4* camber and it works very well. Dave
  3. If I'm not mistaken we are speaking about two different types of slicks here. DOT slicks (like thee Hoosier A6) and true road racing non-DOT slicks. If you need to drive to the event on the tires you are going to race on there is only one choice from where I stand and that's the Hoosier A6. If you are driving to the event on street tires and the race tires will be put on at the event then Hoosier road race slicks can not be beat. I've used Goodyear, Michelin and Hoosier and the Hoosier are in another class altogether. You can think of it this way........with each bump up in tire you are going to see about 2 seconds of difference on a one minute course. So with high performance street tires you might get a 60 seconds flat. Move to DOT R compounds and you'll be in the 58 second range. Move from there to Non-DOT race tires and you'll be able to get into the 56's. The big difference between an R compound DOT tire and a real race tire is weight and suppleness. A true race tire will weigh much, much less than any DOT tire. They don't have to pass the same (or any) tests to pass the DOT deal so they have a very thin carcass. This makes them light but also allows them to contour to the surface much better resulting in much higher traction. All that BS said................most true road race slicks don't come in a 17" size. Most are in the 13", 15" or 16" sizes only. If this is the case then you are getting road tires. I could be wrong on this. In the end it's much faster on real race tires. They are so good that you need to reset your "what's possible meter". Dave
  4. My Birkin has a heater that might be better referred to as a warmer. It makes warm air but you won't e driving in the cold in a T shirt that's for sure. I use a full top and side curtains in the cold and it works well. It's chilly here in the morning no matter what time of year it is. This morning it was 42* at 7:00 but will be in the low 80's this afternoon. Such it is with such low humidity. I don't end up driving it very often when it's seriously cold but this past weekend I drove it 1 1/2 hours to a race and it was in the low 30's. So I use the full weather gear fairly often when going out early to an autocross. This is what it looks like. This shot is taken on one of my favorite roads right where the road leaves the Bridger mountains and head across the Shields valley toward the Crazy Mountains in the distance. The road goes from very curvy and dead flat and straight.....which is of course the road you see. Dave http://www.usa7s.com/aspnetforum/upload/806709342_DSC_3839.jpg
  5. We have the room for you. The state's population is less than 900,000 in total and the distance form the eastern boarder to the western boarder is the same as from Washington DC to Chicago..............in other words it's huge and empty. If the event was centered in the South West part of the state you could see both Yellowstone and Glacier national parks. Yellowstone is about 1 1/2 hours south from Bozeman and Glacier about 5 hours north. There are wonderful places to stay and lot's a first class driving with the only other thing on the road being cows or elk. I'm an active member of our SCCA club and I'm sure we could arrange for an autocross event to be held during the time of the event. We've got a few national class drivers in the area and the events are fun and fast. If folks would like info on roads or places to stay I'd be more than happy to supply whatever you all want/need. I don't want to be too pushy so if the group is interested let me know and I'll do some leg work and present you all with some info. One closing thought................a group of Sevens going over Beartooth pass early in the AM would be over the top fun. Dave
  6. My Dad sent me this link. I don't know anything else about is but I can tell you it was some barn find deal in Europe. A good number of Lotus in there. Unbelievable. Dave http://WWW.intuh.net/barnfinds/afa70.htm Edit - I just got the below from my Dad in another email that explains it a bit more. Sounds a bit urban legend like but who knows. Cool cars any way you slice it. A man retired. He wanted to use his retirement money wisely, so it would last, and decided to buy a home and a few acres in Portugal. The modest farmhouse had been vacant for 15 year.; the owner and wife both had died, and there were no heirs. The house was sold to pay taxes. There had been several lookers, but the large barn had steel doors, and they had been welded shut. Nobody wanted to go to the extra expense to see what was in the barn, and it wasn't complimentary to the property anyway......so, nobody made an offer on the place. The New York guy bought it at just over half of the property's worth, moved in, and set about to tear in to the barn.......curiosity was killing him. So, he and his wife bought a generator, and a couple of grinders.......and cut thru the welds. What was in the barn...............? Go to; WWW.intuh.net/barnfinds/afa70.htm http://WWW.intuh.net/barnfinds/afa70.htm> and start wishing you had bought the place. When the picture comes up, click next to see all the cool stuff he unknowingly purchased. [And, unfortunately the author of this piece doesn't know American cars at all, nor is he/she interested. One of the most valuable finds is the 1931/2 Chrysler Imperial convertible coupe (a Custom Imperial? - or a LeBaron???).]
  7. Amen to that. The Beartooth highway needs to be seen to be believed. I've been over it a number of times and the beauty is hard to describe. There are some other wonderful driving roads in this area and I feel it would be a wonderful place to hold a get together. I can give details of some of the drives if folks are interested. I'm also very active in our local SCCA club (region 52 which for the third year running is the fastest growing SCCA region in the country BTW) and I'm sure we could arrange it for our club to organize an autocross event for that weekend. Food for thought. Dave Bozeman MT
  8. My car is the fastest car on the planet.....bar none. End of discussion. Dave
  9. A Seven is like porn........I'm not sure I can fully define it but I know it when I see it. The Atom is stunning in it's own way but it's not a Seven. Dave
  10. I agree 100% - the bathroom scales should be more than accurate enough to get reasonable results. It's interesting to me.......in retrospect it seems surprising that my car doesn't have issues with this. It completely makes sense that it would. But, in my car's case, I don't have an issue. It's a curious thing. Dave
  11. Absolutely. It makes sense to me but in practice they lock up at the same time everytime. My records show that the left front is carrying 50lbs more than the right with me in the seat. Only thing I can figure is that there is enough weight transfer to make that 50 pounds a smallish percentage of the overall weight during hard braking. I'll toot my own horn a bit and say that with this set up I just two weeks ago won the Top Gun Meet in Helena MT. The Top Gun event is our state championship and pits the three SCCA regions in MT against each other. Our region (SCCA #52) took the most "first in class wins" and so won the overall trophy for the 3rd year running. Not bad for the smallest (and fastest growing in the country!) SCCA region in the USA. I won my class (DM) and took FTD both days of the event. That was fun. The course on day tow had a 4th gear 85mph slalom. That was the shit. Dave
  12. I'm in the same boat. Stock Birkin with 50% cross weights and both front tires lock at the same time. Stops on a dime. Dave
  13. I'm running a Birkin and I found that having it properly corner weighted really helped in autocross. I can feel it handling more consistently in slaloms.........the right and lefts are the same. For me it was worth the trouble. I made my own corner weight set up with cheap bathroom scales and a lever of sorts. The hard part about using a lever is that the exact placement of the tire on the lever is hard and if it's off it will change the reading a great deal. So I added a pivoting pad on top of the lever. The tire sits on the pad which in turn sits on the lever. This allows for a precise location of the weight on the lever. The underside of the pad has a small inverted "V" on it to allow it to pivot to allow for tire camber. This way a tire with camber won't change the leverage ratio. I used them and they seemed absolutely repeatable even with the cheap scales I used (less than $10 a piece at Target). Months after I did this a good friend bought some Longacre scales and I checked the set up going back and forth between set ups and they were very, very close. I was getting less than a 5 pound variance between the two set ups. The digital Longacre set up was over $1000 and mine target set up was less than $75 all materials included. It's well worth the time and effort and the car will work better at the limit. Davehttp://www.usa7s.com/aspnetforum/upload/556173090_DSC_6960.jpghttp://www.usa7s.com/aspnetforum/upload/1620524268_DSC_6961.jpghttp://www.usa7s.com/aspnetforum/upload/939962813_DSC_6962.jpg
  14. I've been told by folks in the know that my set up should have about 145hp. And if one uses the 15% drivetrain loss correction as recommended by my Dynotech friend (126 x 1.15= 144.9) then my numbers come out just right at 144.9hp. So in my case it all seems to add up. As I recall Dynojet systems correct for altitude as well as temperature. Dave
  15. I could see the heat hurting you a little bit but not nearly that much. I'm lucky to have a good friend who is head engineer at Dynotech here in Montana. Yes the Dynotech dynos are built here. He let me on the dyno for a six pack and it's was interesting. I have a 1997 ZX1 with hydraulic lifters. It's running Webers and headers in my Birkin but it's otherwise stock. I got 126hp @ 5500 rpm and 123 lbs/ft from 3000 - 5400 rpms at the wheels. The air/fuel stays pretty darn flat being between 12.5 - 14:1 all the way. I figured this might give you another data point to help or confuse. Dave
  16. Very interesting. Thanks for sharing. I suppose my Birkin would have more of a rearward bias too with a passenger. My 51-49 is with my skinny butt in the car alone. Dave
  17. As cool as the Atom is (and I do think it's very cool) I just can't se it ever overtaking a Seven in the handling dept. Having more than 60% of the weight on the rear wheels has it's effects any way you look at it. 51% rear - 49% front - Dave
  18. The tire should not be any wider than the wheel. If it is you get the tread rounding out and lots of sidewall flex. It's slower by all accounts. It's tempting to stuff big wide 9" tires on your 7" rims but it will suck. I learned the hard way and the tech guys from Hoosier set me straight and he was dead right. I use 7" tires on 7" rims in front and 8" tires on 8" rims in back. This makes for a very stable sidewall and allows for the use of lower pressures and a bigger footprint without the tire rolling over. Have fun, Dave
  19. I suppose it could be. I think it was sold not last fall but the fall before. Late October maybe. I do think that the guy who got it did so in the last 10 seconds or so. Were you in the bidding? Dave
  20. I've had a few over the past few years. I'm down to a single toy car now with my Birkin. I previously owned and restored this 1966 Lotus Cortina. A wonderful car and a cool slice of history. While owning this I got into autocross and didn't want to risk damaging the Cortina so I bought this 1976 Mazda RX3. It was in a farmers field sunk up to the hubs in the dirt with something wrong with the clutch. It turned out that it was a small spring that holds the clutch fork to the throw out bearing had come unclipped. Stuck it back on and it was good to go. Fully stripped it was pretty darn light and quick. I sold it to a local friend who is still racing it and doing well. Both of these are gone now and I miss them. Dave http://www.usa7s.com/aspnetforum/upload/2028647937__2039.jpghttp://www.usa7s.com/aspnetforum/upload/1696887103_Camera_1962.jpg
  21. I'm not the end all be all of info on this subject but I do have a reasonable amount of experience in autocross. Tire width can be a funny thing. Keeping in mind that the runs are short (about 1 minute in most cases) you'll realize that getting heat into the tires can be a real issue. You are in effect running on cold tires most all of the time. Here in Montana we run plenty of events where the morning temps are in the 50's. I feel tire width choices need to be made considering your temperatures and your horsepower. I'm running a Birkin with about 140hp and 13x7 wheels in front and 13x8 wheels in back. I'm also using Hoosiers (25A compound) in a 7" width in front and a 8" width in the rear. This is a bit narrow compared to national class cars which run 10" in many cases. The narrow tire allows for a much quicker heat build up and in the end better grip than I'd have with a wider tire. If I lived in Texas the choice would be different. So a narrow but warm tire will outgrip and wide cold one every time. I also feel that the choice to run staggered sizes or not depends on your driving style and the cars power and balance. As basic as it sounds, if the car is loose or tail happy then wider rubber in the rear would help..........if it pushes then having the same size all round would benefit. If you have plenty of power then wider rears might make sense. At over 200hp I'd put you in this camp. I drive pretty aggressively and tend to steer a good bit with my right foot and the slightly wider rear tire keeps me from spinning and wiping out cones with the back end of the car. FWIW I've used a few different tire brands over the years and have come to realize why about 90% of the winners at Nationals are all running Hoosier 25A's. They are simply the best for autocross. They stick hard and have a very progressive breakaway which you can use to your advantage. I love them and will never run without them again. So......if I owned your car I'd lean toward running wider rears. I hope that helps and doesn't confuse the matter more. I've attached a photo of my car cornering hard on the Hoosiers. This event was last weekend and I took second fastest time of the day about .3 seconds behind a 125cc shifter cart. Hoosiers rock. Dave http://www.usa7s.com/aspnetforum/upload/161956215_DSC_6475.jpg
  22. Davemk1

    HOT FEET

    I feel a bit like a dummy but here goes - I completely understand the foam around the tunnel deal and that is something I plan to do myself. My question is what does the foam around the radiator do to keep your feet cool? Thanks for sharing your results. Dave
  23. Engineer and first head of the SAE William Stout said (in the 30's as I recall) "Simplicate and add more lightness". He designed a mininvan in the 30's that had suspension geometry that made the vehicle lean toward the inside during corners and demonstrated it's effectiveness by cornering hard with a glass of water on the dash. We was more than a bit ahead of his time. Dave
×
×
  • Create New...