LocostUSA.com

I read this thread tonight and found it to be very enlightening. Those who historically have followed this regualarly will see nothing new here (this is from 2005) but those like myself who don't and haven't followed it may learn a thing or two. I consider it a good read.
http://www.sccabb.com/forum_posts.asp?TID=1769

Long read, only partially done. But, in an area (suprisingly) that has no modified cars it should be interesting testing mine. I has of yet to figure out the PAX stuff. I kinda figured the sport would be bigger considering the size of our tracks and proximity to Nashville.

Well, i have to admit I got confused a bit about who wanted what. Essentially the SCCA upped the weight and they (D mod 7's were pissed). Heh, barring my engine, and if they up to the 2.3 like mentioned I may eventually be in D mod too. Though, to me, ballast would more more trips to the Buffet, not adding lead bricks . Would they not be better off just going to some sort of power to weight formula? So anything goes pretty much for each class, just have to meet certain power to weight ratios. Keeping the rules about aero and some other stuff. So you could run what engine you wanted, what car you wanted as long as it fell in certian specs. Also allow BEC's to play.

these are just number out of my head, not specifics

D mod 10 lbs (and up) per 1 hp

E mod 9.99 (and down) per 1 hp

Any fault with this? Ignoring the numbers I stated as I have no idea what good power to weight ratios would be for these two class's.

I like the notion, but how do you know what HP a car is producing? "Yeah, I'm only getting about 48 hp out of this turbo V8...just trying to be true to Chapman's vision and all..."

-dave

Or better yet, how about if I dyno it in Denver and compete in Houston?

Anyway, my used-to-be-legal until they banned bike motors D-Mod Lotus 7 weighs in at 749 lbs and has 115 hp. With driver it weighed 980 lbs and required ballast to make minimum weight.

NASA has a lot of success with dynos in many of their racing series. As I recall, they require each car to be dynoed by a NASA certified dynojet shop prior to each season, a few are randomly selected during the season for re-testing, and anyone can request that one of the race's top finishers be re-tested at the requester's expense. The shops that do NASA testing by me are usually pretty cheap for a NASA test, because they know that the NASA guys know the routine and are not there to tune. I think the shop I have been in near me charges them $30 or $35.

Thats what I was thinking, just a registered dyno. and for big events, with mobile dynos out there, have them available for use and larger regional and national events. Seems like a good idea to me anyway, we get a cheap dyno sheet, the dyno guys get some business and far less worry about weights and other stuff for class's that are supposed to be relatively unlimited. Now, I would say advantage to me in a straight line, but he has an almost 900 lbs advantage in the turns. How well would these two cars compete with one another? Watching the BEC's i have seen on video, I would say that I would lose by a few seconds (if we were close to equal in driving ability) due to the weight difference.

So, his car weighed 980 (with him) with 115 hp at 8.5 lb to 1 hp
Mine (i am guesstimating) 1800 (with me) at 300 hp 6 lb to 1 hp

sorry if this seems discombobulated, was sleepy when posting

Dmod has historically been faster, although this is somewhat course dependent.....

I think it is pretty clear that you can make a 7 heavier and still win in D-mod if you have power and setup, or even ballast up to E-mod weights and compete quite handily....it has been done.

Hmmm my feeling now that the Nationals are back on concrete is that what was seen for the last 3 years is out the window.

I'm currious to see how much grip level there will be at Lincoln next October. I'll be there, but most likelly on a CRX... My buddy Marc should be there on his Locost in D-mod.

I get the feeling that big power will be required, and that means big $$$$... I figure for D-mod you'll most likelly need about 250-300hp... Think 5lbs per HP... The new place will most likelly bring us course that are a lot more open that what was at Heartland Park and the grip should be a lot better. Also the fact that the event will be held earlier, we should see some warmer temperatures, so getting heat in the tire may not be much of an issue anymore.

Cheers,

Fred

Just curious what motor you think with make 300 HP that is autocross useable (Has a wide torque band).

I hear of duratec's making 250 HP without a lot of mods so I don't think it is necessarily super pricey....

I agree that the torque band is the limiting factor... and your right the 250HP Duratec are not so pricey, but the new SBD 304HP is... The K20 from Honda could be interesting also. I've been dicussing this issue with my Solo2 teamate and we both agree that the best way to get the high numbers are going to be the Turbo motors...

The 1.4 multiplier is obsolete... Building a 1.3-1.4 L turbo motor will cost money, but could be the key.

There's tons of other places to build outside the box, or more precisly in a more focused fashion, than just the engine. Current cars have to many gears, no enough ballast to meet minimum weight, and to much rotational masses.

Cheers,

Fred

For a Turbo 1.3, what would you use for a base motor? Only Swift comes to mind. Light. But durability at high boost? Performance/upgrade parts?

I like the Duratec myself - have one in my shed for 7 number 2.

You could try to destroke or otherwise shrink a bigger engine. I'd be interested in figuring out how to make a 1.6L miata engine down to 1.3-1.4L range. Most parts can take boost like a champ stock. I have far too many projects in the wings to figure that out however.

Engines that came to mind were...
Honda D13 for FWD.
For RWD
Ford Cosworth BDH
Suzuki 1.3L
and Toyota 4EFTE

Both the Suzuki and Toyota have aftermaket parts available, I was actually pleasently surprise of what was available for the 4EFTE.

But most likelly the best solution is a destroke a current engine. In either case you would use forged internals so making the step to destroking an engine is not that big. Still lots $$$$$$$$$

But theres still a good debate to have between having the 300HP vs a 250HP car with built to the limit of the rules. There a lot of sprung weight to cut by going to the max of what the rules allow.

Fred

I rember having a wild hair one time and researching a miata 1.6 head on a Feista (or was it a Festiva) 1.3 block. (at Keith T's suggestion) Both are Mazda B series engines. I never found any data that ruled it out as a possiblity.
I dunno, there's a thread around here somewhere. Edit>found it> http://www.locostusa.com/forums/viewtop ... 4f4992fe19