slngsht Posted November 11, 2006 Posted November 11, 2006 Since the real differentiation between a 'Seven' and a 'Regular' car is the power-to-weight ratio, wouldn't it make sense to have a weight classification, and then subcategories based on engine displacement? Secondary to this discussion, but... For autocross purposes, the real difference between a 'Seven' and a 'Regular' car is not power-to-weight. It's really weight and size. A typical 150 hp Seven has pretty much the same power/weight ratio as a 400 hp C5 Z06. Z06 has really no chance against a Seven in an autocross. Watching Sevens go straight through offset gates is frustrating when in a regular car you have to tap the brakes and flick the wheel from side to side to clear the same cones.
manik Posted November 11, 2006 Posted November 11, 2006 http://www.motorsportsne.com/ has a list of classes by power to weight ratio. Very nice, thanks for that. Remind me not to bring a Ford Fiesta or Aspire to any event... Now with a 250HP engine and an 1,100 lb curb weight, one could do a lot worse. (0.227 ?) tm
sb427f-car Posted November 13, 2006 Posted November 13, 2006 I'll add one more thought then I'll go back to lurk mode. This years SCCA National was an anomoly, I think that's how you spell it, in that it was the first time we've all run on that asphalt surface. We, the SPRINTO team, made a good guess by thinking there wouldn't be as much grip as there was on the old concrete surface we've run on for the last few years. We correctly guessed extra weight would probably help our tires get up to temperature faster. The 350 pounds the car was over minimum in D Mod trim made a big difference in grip. The front and rear spoilers were BIG psycological advantage. If you can't out run them, distract them. Back to lurk mode. Del Long HAHA, that's old school right there (unless you're not admitting to everything). But I take it Smokey Yunick was a childhood hero?
Locostdude Posted November 13, 2006 Posted November 13, 2006 HAHA, that's old school right there (unless you're not admitting to everything). But I take it Smokey Yunick was a childhood hero? http://www.usa7s.com/aspnetforum/images/emoticons/cheers2.gif Who, me? Del Long http://www.usa7s.com/aspnetforum/images/emoticons/coolgleamA.gif
whittlebeast Posted November 19, 2006 Posted November 19, 2006 I would realy like to see D and E split by D-Mod is street capable homebuilts including all "stock 7s" and all the others. The class could have commerically available DOT 200 tires and 5" ground clearance from the front tire CL to rear tire CL. 50-50 weight dist with driver or less rear. Bring all of the Cobras and "Cobra Clones" Leave E-Mod for the slamed hombuilts running the existing rules on any tire and lets go race. In America, a "wing" is a device that produces downforce by providing a longer airflow path under the device as compared to the air going over the device. A splitter or air dam will not work at our speeds, a wing does work. We would have to deal with tunnels in this new devision of classes. Windshields ar not worth defining and regulating in D-Mod/Street class. It's all about CG height and CoF. All of us can make "enough" HP. Lastly, I know of no car that is 25 years old technology in all of autocross that is still competive without serious mods. AW
slngsht Posted November 19, 2006 Posted November 19, 2006 and 5" ground clearance from the front tire CL to rear tire CL. AW By the time my oil pan is 5" off the ground, my seven will look like an offroad vehicle http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif
Grintch Posted November 20, 2006 Posted November 20, 2006 For autocross purposes, the real difference between a 'Seven' and a 'Regular' car is not power-to-weight. It's really weight and size. A typical 150 hp Seven has pretty much the same power/weight ratio as a 400 hp C5 Z06. Z06 has really no chance against a Seven in an autocross. Watching Sevens go straight through offset gates is frustrating when in a regular car you have to tap the brakes and flick the wheel from side to side to clear the same cones. As Del posted in the DMOD forum, a typical 7 is comparable to most small cars (the Miata was Del basis of comparison) in width and wheelbase. We have less front and rear overhang, so our overall length is shorter but that is the only size advantage. It is not at all uncommon for a well driven Super Stock Z06 to beat a 7 in an autocross. Look at the Solo Nationals results. Bruce F.
Grintch Posted November 20, 2006 Posted November 20, 2006 To take this discussion further, we need to define a Seven (wish us luck...) 1- Front-mid engined (engine block has to be 100% in front of the windshield mouting point?? 2- Rear drive 3- 2 Seater 4- No rear wing 5- Fenders... Rear: must be substantially round (follow contour of the tire. Front: Must be clamshell style, or cycle fender - again, follow contour of the tire only. 6- No front wing 7- Windshield?? this is an interesting one... there are full, half, or WCM style??? 8- Flat or open bottom between the front and rear centerlines?? any sevens not meet this? 9- Min and Max numbers for track, width, wheelbase, overall length? #5 would outlaw real Lotus 7's, the series 4. Where the rear fenders are not "substantially round". #7 there are a wide variety of windscreens run on even street driven 7s. I would not be in favor of any windscreen or glass requirement (I am am planning to install a small aeroscreen soon). Why are we stuck in DM/EM? We have too much variation in engine types, power, suspension, and wheel and tires sizes to be easily classified in Stock, ST, or SP (plus we don't meet the requirement for a production car). Look at almost any other class where we would seem to have a chance at fitting (SM2, DP, XP), and you find that we would have to add 300-600lbs of ballast to meet the minimum weight requirements. Thus we end up in DM or EM. While we may not be fully prepared for the class, you can be reasonably competitivive in it, have a lot of fun, and not have to do the unthinkable (to the Lotus fan) of adding a ton of weight to our cars. Bruce F. Grintch2006-11-20 12:28:57
slngsht Posted November 20, 2006 Posted November 20, 2006 5- Fenders... Rear: must be substantially round (follow contour of the tire. Front: Must be clamshell style, or cycle fender - again, follow contour of the tire only. #5 would outlaw real Lotus 7's, the series 4. Where the rear fenders are not "substantially round". What is it about #5 that would exclude a Series 4? http://www.usa7s.com/aspnetforum/images/emoticons/confused5.gif EDIT: I see what you mean about the rear. slngsht2006-11-20 12:48:07
MichaelD Posted November 20, 2006 Author Posted November 20, 2006 Bruce, I started this thread trying to see if there was enough interest to warrant a seperate class for "Stock" Sevens and to find out why Caterham Sevens were only allowed in either D or E Mod. I think your post perty much provides the answers. 1. We have too much variation in engine types, power, suspension, and wheel and tires sizes to be easily classified in Stock, ST, or SP. 2. maybe we could enter or apply for (SM2, DP, XP), but who wants to add another 300-600lbs of ballast to meet the minimum weight requirements. 3. There isn't enough interest. Just count the number of names that have commented on this topic from both sites. Thank you all for your comments. I guess I will stay in DM and learn how to drive faster. Like you said it's all about having fun anyway. Michael D. http://www.usa7s.com/aspnetforum/images/emoticons/cheers2.gif
yellowss7 Posted November 21, 2006 Posted November 21, 2006 That's good news Michael, we'll continue our rivalry then. Would have hated to lose you from DMOD just because you have that heavy old Zetec. See you in the Spring. Tom
BrianGT Posted November 23, 2006 Posted November 23, 2006 The 2007 PAX numbers are out: Class 2006 2007 Change DM 0.885 0.889 0.004 EM 0.881 0.879 -0.002 This means that for 2006 on a 60 second run in an Dmod car, a 60.683 sec run in an Emod would be equivalent, as opposed to 2006 where a 60.272 run would be equivalent. Also equivalent to a 66.127 second run in a Mini Cooper S in the stock class on R-compound tires http://www.usa7s.com/aspnetforum/images/emoticons/smile5.gif Full PAX list: http://scca-chicago.com/solo/indexes/rtp2007.html Excel sheet comparing the 2006 vs 2007 numbers: http://scca-milwaukee.org/Solo/2007/RTP06vs07.xls -- BrianBrianGT2006-11-22 20:15:17
slngsht Posted November 23, 2006 Posted November 23, 2006 For autocross purposes, the real difference between a 'Seven' and a 'Regular' car is not power-to-weight. It's really weight and size. A typical 150 hp Seven has pretty much the same power/weight ratio as a 400 hp C5 Z06. Z06 has really no chance against a Seven in an autocross. Watching Sevens go straight through offset gates is frustrating when in a regular car you have to tap the brakes and flick the wheel from side to side to clear the same cones. As Del posted in the DMOD forum, a typical 7 is comparable to most small cars (the Miata was Del basis of comparison) in width and wheelbase. We have less front and rear overhang, so our overall length is shorter but that is the only size advantage. It is not at all uncommon for a well driven Super Stock Z06 to beat a 7 in an autocross. Look at the Solo Nationals results. Bruce F. If I read the link that Brian GT just posted, typically DM cars are faster than SS, even though on any given autox, it is possible for a Z to beat a 7... The time indices I see are 56.24 for DMod vs. 58.96 for SS.
Grintch Posted December 4, 2006 Posted December 4, 2006 If I read the link that Brian GT just posted, typically DM cars are faster than SS, even though on any given autox, it is possible for a Z to beat a 7... The time indices I see are 56.24 for DMod vs. 58.96 for SS. So why bother to drive if the index determines how fast we are? The index got faster for most cars in the new '07 Pax (DM was one of the big movers), does this mean my car is faster now? Looking at the 2005 National Tour & Nationals results (I didn't do detailed tracking for 2006): SS beat DM 3 times, DM beat SS 6 times SS beat EM 6 times, EM beat SS 5 times (DM & EM didn't have competitors for 3 and 1 events respectively) In general Nationals competitors have cars fully prepared to the limits of the rules. However this thread is about "stock 7's", which are not fully prepared. Thus the likelyhood of getting beat by a Stock class Z06 is much higher for a stock 7. Especially when you consider that a 7 is tricker to drive than a Stock class car.
Boxologist Posted October 18, 2008 Posted October 18, 2008 i hate to bump old thread w/o good reason, but congrats shoudl be passed along to Del Long and Jeff Cashmore for driving the YC-3 to its national championship this year!
yellowss7 Posted October 19, 2008 Posted October 19, 2008 Having just returned from a great day autoxing, I have a few observations. My seven, on Three year old slicks and 45 degrees temps does not make for an easy run.:ack: A new Z06, has anitlock brakes and 7's don't.:cry: Tires make a huge difference. I now understand that just because they have not hit their wear marks, doesn't mean they haven't reached the end of their life due to heat cycles. I had a co-driver for the AM runs. He Turned the same times in a raceprepared 3 series turbo. He said my tires were crap. No way should he have equaled his own times in the BMW. The 7 is the most fun car to drive period. At the end of every run we were a) out of breath as I think we held our breath for the whole run each time. and b) we were laughing hysterically at the end of each run because it was so much fun. Still can't understand why everyone doesn't drive a 7. Everyone that rides with me gets out saying, " I've got to get me one of these" :yesnod: Tom
Davemk1 Posted October 20, 2008 Posted October 20, 2008 Having just returned from a great day autoxing, I have a few observations. My seven, on Three year old slicks and 45 degrees temps does not make for an easy run.:ack: A new Z06, has anitlock brakes and 7's don't.:cry: Tires make a huge difference. I now understand that just because they have not hit their wear marks, doesn't mean they haven't reached the end of their life due to heat cycles. I had a co-driver for the AM runs. He Turned the same times in a raceprepared 3 series turbo. He said my tires were crap. No way should he have equaled his own times in the BMW. The 7 is the most fun car to drive period. At the end of every run we were a) out of breath as I think we held our breath for the whole run each time. and b) we were laughing hysterically at the end of each run because it was so much fun. Still can't understand why everyone doesn't drive a 7. Everyone that rides with me gets out saying, " I've got to get me one of these" :yesnod: Tom I had my last event of the season yesterday and had a ball. It's rare that we can have an event here in October and despite overnight rain and cold temps (40*) in the morning the sun came out and it was a great day. It warmed to about 60* so there was at least some grip. As for tires....... I've been running Hoosiers for a few years now and they work very well as long as they are reasonable fresh. I buy a new set for each season after struggling through using a set until the rubber is gone. You are right that the amount of rubber left is not an indicator of the status of the tire. Heat cycles and age are the real deal. In fact I find that the newer they are the better they are even if they have lots of runs. Age is the enemy. I'll bet your 3 year old tires make the car a handful. One thing that I've found works well for me is bagging the tires when ever they are not in use. I of course bag them through the winter but I also put them in sealed bags after and event even if they will be used the following weekend. Every time you open the bags you get that new tire smell indicating that they are still gassing out. It's this gassing out and the dying that takes place that kills them over time. My big event of the season is the NORPAC divisionals in late July and I buy a new just before then and then run them for the rest of the season and then the following spring to be replaced again before that event. I't funny how mind blowing it is when you go from the old tires with lots of rubber left to the new ones. It's worth a second or two and each season it surprises me. It's almost ski season here and there's snow in the hills and as much as I love ski season I'll miss the car time. Stay well. Dave
basudec1509 Posted January 12, 2010 Posted January 12, 2010 hello guys ... :leaving: its really nice and informative post.... :bs: i just liked it.... :seeya: thanks for your information guys ........... :auto:
Peahioi Posted September 6, 2010 Posted September 6, 2010 Hi, Just learned of this site and of your posts regarding 7's and SCCA... Judging by the dates of the posts, I'm led to believe that nothing happened. I was a one of the founders of the San Francisco Region Solo ll program in 1973 and have fought many of the "good fight" with National over the years... Some successful, others not so... In point of fact, rules exist which were in response to some of my rule observations and subsequent executions. I'm now running a Caterham Superlight-R in SFR-SCCA class OSP (Open Street Prepared... a regional class). I choose (at the present) not to run E-Mod as I have issues with the rules... I prefer to run D-Mod but am not eligible as my engine is 2287cc... I am looking into options which would equalize my entry into some national class... Again, fight the "Good Fight"... I agree wirh a number of your observations but, not all... I'd like to solicit input to an update to your 2006 posts, if they exist... Any and all input will be greatly appreciated. Cheers, Dave
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now