rv-4mike

R1, I can relate to the time thing. My RV-4 airplane project is in its 12th year. Hope to fly it in the next couple of months.

I chose to go with an Ultralite S2K because I thought it would be more streetable than a BEC. But being a long time sport biker, everytime I see (and especially hear) a BEC I want one. Thats awesome! Cant wait to see a vid of it moving under its own power. Do you have some vital stats? Maybe a website with some pictures of it under construction? How long has it taken you to get to this point? And why the R1 instead of Hayabusa power?

Yeah, it isnt all that cheap in Britain either, although the guys over there on that forum all seem to think its a screaming deal. Cost is what sent me looking at Sevens, which I figure have to be pretty close in performance. Given the choice between a new Caterham or an Atom, I think I'd choose the Atom. Price seems pretty comparable. But compared to the Ultralite I've chosen, the Atom is close to twice the price. I doubt its got twice the performance. Still, I hope to see some real comparison between the two some day just to see how they stack up. In California there are guys registering the Atom via SB100, though that probably isnt totally legit. Other states seem to be a piece of cake, some there is no way.

Just to revisit the 0 - 60 performance thing. Found the following info in a thread on the Atom forum. This data comes from a test done by Car and Driver magazine that is in the March issue. Lap times Z06 2:01.00 Exige S 2:04.30 911 GT3 2:01.50 Atom 1:58.30 Noble M400 2:00.40 Brock Coupe 2:02.70 0-60 Z06 3.6 Exige S 4.1 911 GT3 3.8 Atom 3.0 Noble M400 3.3 Brock Coupe 3.7 0-100 Z06 8.3 Exige S 11.1 911 GT3 8.7 Atom 7.5 Noble M400 7.8 Brock Coupe 8.4 1/4 mile Z06 11.8 @ 122 Exige S 12.8 @ 107 911 GT3 12.0 @ 118 Atom 11.5 @ 117 Noble M400 11.7 @ 120 Brock Coupe 11.9 @ 119 Braking 70-0 FT Z06 153 Exige S 154 911 GT3 145 Atom 148 Noble M400 157 Brock Coupe 153 300-FT Skid Pad Z06 0.99 Exige S 1.00 911 GT3 1.05 Atom 1.08 Noble M400 1.02 Brock Coupe 1.12 Lane Change MPH Z06 66.3 Exige S 75.8 911 GT3 70.9 Atom 70.8 Noble M400 74.4 Brock Coupe 72.4 Atom Noise Level Idle 72db Full throttle 118db 70-mph cruise 103db I havent gotten the magazine so just cut and pasted this from the Atom forum (the poster there does have the mag). The Atom equaled or bettered every car here including the Z06. Shame they didnt include a Seven in the test since I think it comes closest to the Atom conceptually.

Atoms are being street registered. Some states are easy, some difficult. There are several registered in California including Jay Leno's.

Pretty cool! Looking forward to see how the Sevens stack up against an Atom on the track. Only a matter of time. There are several Atoms in the Dallas area and there are a couple of Atom guys up in the Bay area who race occasionally as well. Curious to see how they will compare.

I think most magazines use a data acquisition systems when testing cars, at least the ones I read do. I dont know if the mags I read the Atom articles in do. They also usually correct all performance measures to standard atmospheric conditions so you can compare apples to apples. The data acq. would take away any trickery with staging. 10.85 out of stock Z06? I'd have to see that to believe it!

The 2.7 - 2.8 second times I've read about for the Atoms were from independant testers (magazine articles). A 12" roll isnt exactly 0 - 60 is it? http://www.usa7s.com/aspnetforum/images/emoticons/confused5.gif Never heard of that before.

The Ariel Atoms with 245HP - 300HP Honda and Ecotec engines are 0 - 60 under 3 seconds. The 245HP cars are actually just as quick because the 300s are traction limited. Anybody know of a Seven that runs sub 3 seconds 0 - 60?

Too bad this get together is all the way across the country instead of somewhere centrally located. I'd be tempted to go as an observer if it werent so far away.

Would have been interesting to see how the Seven would have fared if the bike had been leading. What I'd really like to see is a clip like that with a Seven and a Cobra to silence my Cobra loving buddies who scoff at my plans to build an Ultralite. They just cant get past the 4 cylinder engine and all the arguing about power to weight falls on deaf ears.

Andy, I had kinda the same experience while deciding on the Ultralite S2K. Brian Anderson doesnt want to release these details to protect his design. Even after I sent a deposit, the best I have been able to get from him is "the kit includes everything except wheels/tires, paint, and drivetrain". Not really an acceptible answer, but in the end I made a leap of faith on the basis of conversations and email exchanges with other Ultralite owners. While I would be happier with the kind of info that Factory Five provides, I am so fired up about the car I think its worth the gamble. Brian did agree to a refundable deposit. And I do intend on going to Texas to meet with him and answer these questions definitively.

Stan, Thats cool! Small world. I dont fly as much as I should considering what I have invested in flying toys, but dont think I could give any of them up. The 1-26 is definitely the best bang for the buck toy I've ever owned.

No personal experience, but I have seen a lot of data captured by a Trak-Mate system and it's pretty impressive. I dont know about using something like this for computing HP but its good for performance measurement - especially relative performance. Like before - after a mod to see if you made it better or worse. Also car to car. If you take a look at the Ariel Atom forum archive one of the guys has a thread with a bunch of performance testing in his car and someone elses. Its pretty cool. You can run the two traces simultaneously. Its like watching a race in real time. You can see which car/driver was faster on which part of the track. I think to get truly useful data any system would need both accelerometers and GPS.

Just noticed your from Victorville. I flew the RV up to a fly-in at Apple Valley a year or so ago and there was a Birkin on display there. I actually have a couple of pictures. Was that you?

Sagitta 600, Alula, Rotor, and a pivot wing slope glider of my own design. Also a couple of power planes, and A Calber 30 helicopter and T-Rex electric helicopter. My full scale Schweizer 1-26 sailplane is sitting out in the driveway. Too many toys, not enough time. Need to focus! http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif

Brad, You are welcome anytime. Let me know when is good for you. It is capable of aerobatics. Like the RV-6A the cruise speed should be around 180MPH. Top speed a little over 200. Canopy is plexi, same as all general aviation airplanes in this class. For comparisons sake, empty weight on this airpalne should be between 900 - 1000 pounds where a typical Cessna 172 with the same HP would weigh around 1500 pounds empty. And the Cessna would cruise at about 125MPH. Of course the Cessna has 4 seats (although practically speaking its a 3 seater do to weight and balance issues). The Rv-4 is a little sportier than the -6A. Passenger seating in the back seat is a bit cramped. The -6A on the other hand is considerably more roomy than your 7.

Brad (roll a seven) asked for a little info on my plane in another thread. Feel free to ignore if you arent interested. My avatar is a picture of the RV-6A that I'm currently flying. Two seats side - by - side. 160HP Lycoming engine. Cruises at about 175MPH. Has a non-stop range of about 500 miles and burns a little less than 8 gallons per hour. Works out to about 22MPG. Its a homebuilt, but my partner and I bought it as a completed airplane. When I complete construction of my RV-4 I'll sell out of this airplane to free up the $ to get my 7, a WCM Ultralite. The airplane I'm building is an RV-4. Tailwheel airplane with tandem seating, but otherwise very similar to the RV-6A. My RV-4 is using an engine from an 89 Mazda RX-7, modified for aircraft use. Should produce about 170HP. I've been working on it on and off for about 11 years and hope to have it flying this spring. The RV series of homebuilts have a lot in common with a 7. Small and light with modest power, terrific performance and really nimble handling. The airplane weighs about 1000 pounds empty. They are also the most prolific homebuilt by far with 4000+ flying world wide and probably 3 times that number under construction. They are also a great bang for the buck if you make an effort to keep costs down. I have around $25K invested in the -4, although if you get carried away with power, paint, and avionics its easy to end up with $75K+ invested.http://www.usa7s.com/forum/uploads/20070117_191405_n144mw_24nov200.jpghttp://www.usa7s.com/forum/uploads/20070117_191451_n144mw_24nov200.jpg

Doesnt really fit here so created a new thread.

FYI, the Ultralite seats are Ultrashields. Which are very similar to Kirkeys. I do a little composite fabrication from time to time. Retail on carbon fabric is $50+ per linear yard and there is going to be a lot of fabric in a seat. So you arent going to find any "bargain price" carbon seat shells. Unless you build your own and even then they are going to be pricey.

I should have mentioned, I agree with the suggestion to make sure your profile displays your location. Good idea. I just updated mine.

I guess I'm in the minority here. I just went through this, being a relative newbie, and scored an intro ride from a local Caterham owner this past weekend (thanks Brad!). Will be taking an Ultralite ride on friday, weather permitting. Anyway, its the seperate section that I have an issue with. In my opinion a forum with a bunch of different sections for different types of threads is clunky. Just a real pain for the casual browser looking for info. I havent looked at any of the other forum sections than the general section. My vote? If someone is interested enough in the cars to want a ride, its easy enough to join the forum and post a request in the general section. If it requires some back and forth to coordinate, thats what PMs are for. My $.02 worth.

Nice! Although the engine sounds a little out of place for a 7. http://www.usa7s.com/aspnetforum/images/emoticons/smile5.gif For us newbies, what have you got in there? Hoping to take my first 7 ride tomorrow with Roll A 7 in his Caterham tomorrow morning. Really looking forward to it. Curious as to how it will compare with my friends FFR Cobra.

That DP1 is a cool car, but the BEC is only an interim engine. It will ultimately be V8 powered with a custom engine made from Suzuki Hayabusa parts. 375+ HP! http://www.usa7s.com/aspnetforum/images/emoticons/eek6.gif

Busa, The sound alone on the video clip on Deman's website very nearly sold me on the BEC setup. Love the sequential shifting too. A 7 that sounds like an Indy car as it goes by is pretty appealing. But since my goal is a street driver the lack of low end torque and lack of reverse are ultimately what changed my mind. Not that the S2K is exactly a torque monster.