LocostUSA.com

This is crap. Mazda rated the engine size on displacement, just like the piston engine guys do. No one says a 2 stroke piston engine has twice the displacement of a 4 stroke because it fires twice as often.

Now as a performance equivalency, 2x made sense in the '70's and '80's. But against modern 4 valve DOHC engines it is too much. Compare horsepower of 1.3L Rx-8 and 2.0L S2000 (238 vs 240, or ~1.5 equivalency) or Formula Altantic / C Sport Racer spec 12A and 1.6L Toyota 4AG engines (both ~250hp, ~1.3 equivalency).

The biggest advantage of the rotary is its small physical size and usually a small weight advantage over the larger 4 cylinder competition. Both are very useful for the Locost 7 application.

I also have a rotary Locost (NA 13B). They ARE hard to quiet & cool. I have a huge 6" dia 31" long muffler, and it is still fairly loud. And cooling is marginal with a similar Griffen radiator. They do make a nice compact package though, especially if you ditch the typically tall & complicated stock intake.

By your name of Rotus and localtion, I am sure you know my old friend Jim Burris. I have not seen him in a long time.

Yes, we are in the same auto club and occasionally autocross against each other. He's a good guy. But he has put his Rotus 7 up for sale. I am not sure what he plans to follow it up with.

He does that with some regularity. Usually with some verbage that he is retiring from this stuff... but it is in his blood, he will quit when he is forced to.

I was a TAC member back in the '92-93 time frame when I was working in the Huntsville area.

I've changed plans a little.
Probably not going to use my Rx-7 as a donor because I can't stand to pull it apart. I have just obtained a 2nd Gen Rx-7 engine-13B, transmission, wiring harness, and a 1st gen rear axle for $100.

So have some questions...

I need my lovely wife to be comfortable when this project is done and we go for a drive. For that to happen I suspect I need to build a plus 4" width because she is going to need about an 18" width to sit comfortably. From the dimensions in The Book a +4" width would get me there.
Is this accurate?

Could someone measure the seat width on there chassis and confirm this?

If the transmission tunnel is built with steel plate (1/8") instead of 1" square tube that would gain me 7/8" in width.
Another option would be to do a +2" width and make it a right hand drive car because it appears the left side seat area is wider.

Of course this is being considered under the assumption I'll still be married when it is completed!


Also I would like to see some pictures of cars that are 4" wider. I'm not sure whether to leave the front at the std width and only widen the rear.

...

A year or two since my last post. At this time I expect to begin building a frame late next year. Since my last post I've purchased a 1990 Rx-7, rebuilt the engine, and this is now my daily driver. Still have the 1982 Rx-7 which is going to be used this winter becasue it has a good set of snow tires and a LSD. So this winter I'll take the '90 Rx7 off the road and do the necessary work on it so it will survive 5+ years of MI winters.
Then in spring I'll sell the '82 Rx7 without all the autocross suspension, LSD, racing carbs etc.
So I'll have available for the Rotus7:
- a streetported S4 13b rotary
- a bridgeported 12A
- an S4 5-speed tranny
- a rear axle out of an 85 RX7 (discs and LSD) from the '82 rx7

I'm not sure if you know it or not, but there was a car called the Rotus long before you put a rotary in a lotus seven frame. You said that your friend is selling his Rotus 7. I'm not clear on whether or not this is an original Rotus, or a lotus seven with a rotary called a rotus also.

I only know about the original Rotus because I met one of the two guys who designed and built it back in the early eighties- John Cummins. He and his wife run a race shop just outside Washington D.C. and he coincidentally races rotary cars. He has been at the head of the pack in championship points many seasons in an RX-3. As far as I recall his rotus didn't have a rotary though.

The story he told me is that they had built the car, and were getting ready to mass produce them when he had a group of Japanese buisenessmen look at the car. The kept saying it looked like a Lotus, but they couldn't pronounce the L, and it sounded like an R. He and his partner thought that was kind of funny, and decided to call it the Rotus.

It's been in the SCCA rules and class structure since it was in production. I'm not sure how many they sold, but it wasn't that many.

I think that that was the first car to corner at a constant over 1g on a skidpad with street tires. It was years ago he was telling me these stories, but I think they could get well over 1 g in one direction. But when they ran in the other direction, the carb bowls would run dry and the car would stall. But it still averaged over 1g.

Just thought you should know. I was also curious if your friends car was a mass produced Rotus, or a rotary powered tribute to the Lotus seven.

_________________
Bill

The more I learn, the more I realize just how much more I need to learn.

I am doing the same as you are - been copying alot. I dont understand how to convert the power rack to non power and how you cut yours down. Could you give me more details? thanks Bill