Roads Less Taken

[Straight8]

Hello all! I've been pondering (it's early days yet) various out of the ordinary solutions for an F1000, in particular a F/R layout. Granting that this alone flies in the face of 40 years of convention, I've at least established elsewhere on the forum that the rules don't prohibit such a design. That leaves me with the choice of conversion or full-design and build. Regarding conversions, I've narrowed it to three types, more or less going from least to most radical:

- A Clubman, such as a Mallock U2 or similar; proven chassis, proven aero, so this basically focuses on adapting an appropriate engine. Of my engine choice, more later.

- An INEX/600 Racing Thunder Roadster or Legends car. Granting they are heavy in stock form, these already use motorcycle engines (sealed Yamaha FJ units I believe), so it's engine swap plus adapting an appropriate aero kit.

- A USAC National Midget or one its derivatives (a Focus or Kenyon midget) or a Three Quarter Midget, the last of which, if memory serves, uses the Suzuki GSX 750 engine and all of which are the right weight in their stock form and should be right on target once modified as well.

For the engine, I'm thinking either V-Twin (Harley Sportster 883 or similar: if the rules and budget permitted, I'd just source a full-race spec Harley XR750...) or VFour (Honda VFR if I can lay my hands on one).

Thoughts on these ideas are greatly welcomed. Of course, "it can't be done" this way. Which of course is why I'm thinking along these lines!

Rudy Pyatt,
a/k/a Straight8

[RussMcB]

Rudy, I like your spirit.

Two quick comments:

1) If you want to be competitive in the corners your car will need to be low and wide like current formula cars. On the long straights you'll need a narrow body for less drag and to get clean air to the rear wing. The chassis choices you mentioned might not offer those characteristics.

2) I'm not sure if a V-twin engine is allowed. I seem to remember someone else considering a non-Japanese inline 4 cyl and they got responses that it would not be within the rules. If you haven't already, print off the rules and get familiar with them.

<wetblanketmode> I can't imagine your plan being successful, but I understand your desire to do something different. The end result should be fun to drive and unique, but may have low resale value. </wetblanketmode>

[Straight8]

Rudy, I like your spirit.

Two quick comments:

1) If you want to be competitive in the corners your car will need to be low and wide like current formula cars. On the long straights you'll need a narrow body for less drag and to get clean air to the rear wing. The chassis choices you mentioned might not offer those characteristics.

2) I'm not sure if a V-twin engine is allowed. I seem to remember someone else considering a non-Japanese inline 4 cyl and they got responses that it would not be within the rules. If you haven't already, print off the rules and get familiar with them.

<wetblanketmode> I can't imagine your plan being successful, but I understand your desire to do something different. The end result should be fun to drive and unique, but may have low resale value. </wetblanketmode>

Thanks Russ!

I did check the rules on this and posted a question in the Rules part of the forum to boot. From what I know so far, a V-twin would be compliant. On its face, the rule states "motorcycle-based four stroke up to 1000cc". Actually, that's broader than I was thinking, because it doesn't limit you to "production" in the AMA/FIM (currently produced) sense of the term.

Whether this engine would be a competitive proposition is another matter. The rules mandate stock internals and compression, but leave you free on injection/carbuertion, exahaust and cooling. You do have to run the stock ECU (irrelevant on a carb'd engine). But if basic breathing tricks (ported and polished heads,bigger valves) are permitted within these constraints, then there's no problem.

Chassis-wise, I'll try to post some pics of the conversion sources I'm considering. For now, if you Google or Wiki "Mallock U2" "Clubman racing" you should get some idea of that one; ditto "Thunder Roadster," or else you can find the 600Racing site. From what I understand, the Mallock's performance approaches that of an F3 car, but in any event at least falls between that and a good FF.

As for midgets, I know that they can top out between 140 and 150 mph. How they'd do on a road course remains to be seen. I don't know that its been tried since Roger Ward's effort at the innaugural USGP. And he did prove the worth of the concept by his famous win at Lime Rock Park. By the way: what kind of terminal speeds are we talking with F1000?

If you don't mind, I'll post something to you on the side to explain my F/R fixation. I've actually got an article prepared for Racecar Engineering on the subject (it's excerpted from a book I'm trying to write; maybe I'll submit it to SAE instead) and I'd like your feedback.

Thanks again for listening,
Rudy Pyatt, a/k/a "Straight 8"

P.S.: Your Green Machine looks wonderful! Let The Good Times Roll indeed! Now, if Kawasaki sees this and gives you a leftover 990cc MotoGP engine (insert evil laughter here...)

[carnut169]

I too like your spirit but think that you might be dissapointed in the end. Perhaps as a 1550cc Busa powered FS machine...

Formula cars perform better then anything else available- low center of gravity, low weight, great aero and balance that the mid-engine format provides. I'd stick with those key ingredients.

[Dave Gomberg]

Thanks Russ!
... But if basic breathing tricks (ported and polished heads,bigger valves) are permitted within these constraints, then there's no problem.

Sorry, but none of that flies.

D.2 Engine internals and compression ratio must remain stock.

There are exceptions made for the clutch and oiling (dry sump and/or pans), but you certainly don't think that valves are external to the engine. Likewise, porting and polishing are not allowed.

Dave

[Straight8]

Sorry, but none of that flies.

D.2 Engine internals and compression ratio must remain stock.

There are exceptions made for the clutch and oiling (dry sump and/or pans), but you certainly don't think that valves are external to the engine. Likewise, porting and polishing are not allowed.

Dave

Sorry if this prints twice. Something glitched.

Thanks Dave. This still doesn't rule out twins. Or triples. So Ducati, Triumph, Harley, Yamaha and (of course) Honda are still on.

As to "internals": I AM a lawyer after all Rule D.2 CAN be read as NOT dealing with the cylinder head, but crank, rods and pistons. Even without the classic port and polish hot rodding tricks, the rules at least appear to permit blueprinting the engine; together with the exhaust mods permitted that should be enough.

I do agree with the restrictions though: the Suzuki and Harley aftermarkets, alone, are so vast that an arms race would be inevitable -- with all the costs that go with that.

BTW: I see you're down home. I grew up in Maryland.

Rudy

[Lee Stohr]

Although I like different thinking, there may be some flaws in your plan. First, Mallock gave up on the front engines and started building rear (mid) engine sports racers in 1995 or so.
The Thunder roadster has been raced in SCCA and was something like 25seconds a lap slow.
Full out Midgets are very fast, but they have very expensive engines, I think the Focus series was set up to cut costs with stock engines. Midgets are lighter than we are allowed. They also have totally inadequate brakes for road racing, totally inadequate cooling systems for gasoline engines (they run alcohol), no transmissions, no starters and no ground effects.

Now regarding the rules, if you are new to SCCA you will discover that the rule book is pretty much incomprehensible to anyone but those who wrote it. Unfortunately neither engineers or lawyers are involved in the process. You need to figure out the intent of the rules, who is enforcing them, how they will be enforced (or not), and how they can be changed. Sometimes that's easier than you might think.

Having said all that, a bike engine weighs less than the driver, so unlike car engine formula cars, the weight distribution would not necessarily be bad with a front engine F1000.

If you are going to build something, start with a clean sheet of paper.

[JackPim]

I also like your spirit but I must say i think the front engine design would better fit as a DSR. I have actually thought of the idea, although I still lean toward a GT car for myself. The Panoz was very succesful as a front engine protype.

http://www.mulsannescorner.com/panozlmp1.html

With a DSR you could get a very low rear deck height and have lots of room for very large tunnls. Rules very similar to F1000 upto 1005cc 4cyl motorcycle (plus other options) any and all engine mods allowed. Turn the engine sideways and run a drive shaft setup like the Legends car, it would be a neat setup.

[martyb]

In addition to our Stohr FB, we are running a car that is very loosely based on a Baby Grand, which uses a shaft drive turboed stroker Hayabusa, Atlantic tires, a midget quickchange, etc. It runs in SF region Super Production. When it is really running right (which hasn't happened often), it runs about the same lap times as a decent DSR. An earlier version of the car ran normally aspirated Hayabusa's and was a lot slower. I can only guess how much slower it would be if it had our GSXR in it instead of the Hayabusa's.

Marty

[EACIII]

If you are just looking for a different motor why not try the 984 cc motor out of a XB9S Buell. Right size to start with. Based on a HD but comes with a dry sump system already and fuel injected. Of course it doesn't make the top end HP of the in-line fours. But lots of torque for coming off the corners.

Ed

[Tom Sprecher]

For the engine, I'm thinking either V-Twin (Harley Sportster 883 or similar

I think you'd be very disappointed in the amount of power available in its stock form. The design is more for nostalgic looks than anything else.

How would I know? I have Softail bored out to 1550cc with ported heads, bigger valves, high lift long duration cam, adjustable ignition and headers. I doubt my engine puts out more than 110 HP but it does have about 100# of torque and man you can feel it even on a bike that weighs over 800# including me.

Most of these mods are against the rules and you're starting at one third less displacement.
Just as a guess but I would wager a 1000cc stock Yamakawazuki engine is in the neighborhood of around 140HP.

Stick with the Yamakawazuki.

[formulasuper]

I think you'd be very disappointed in the amount of power available in its stock form. The design is more for nostalgic looks than anything else.

How would I know? I have Softail bored out to 1550cc with ported heads, bigger valves, high lift long duration cam, adjustable ignition and headers. I doubt my engine puts out more than 110 HP but it does have about 100# of torque and man you can feel it even on a bike that weighs over 800# including me.

Most of these mods are against the rules and you're starting at one third the displacement.
Just as a guess but I would wager a 1000cc stock Yamakawazuki engine is in the neighborhood of around 140HP.

Stick with the Yamakawazuki.

According to a mc spec site the new GSXR1000s have 185.1 @ 12k rpm.

[Straight8]

Thanks all for the great feedback.

I should say here that that Panoz LMP 01 is a major inspiration (and some other ingredients, of which more in a moment) and particularly a March 2000 analysis of that car by Peter Wright in Racecar Engineering. Don't know if you all are familiar with it, but, in sum, he points out that there are advantages to front-engined layout, among them aerodynamics -- including more efficient, less drag-inducing ram air to the engine -- and better "mechanical" grip and balance with the tire sizes available under the rules.

Now, all of this should have screamed "sports racer" to me. Here's the kicker: Wright explicitly connected these same issues to F1. Having "a mind that connects things" as a prof of mine once put it, I ran with that and came up with the ultimate heresy: a return to the front-engined single-seater. I actually wrote an article (more like a chapter from an ongoing book project) on it that I'm sending to RE, or maybe to the SAE. Anyway, the thesis is devloped at length there and I can bounce to those of you who are interested...or who've run out of Ambien...

Those "other ingredients" include Roadster Era Indy. Before my time, but I made sure to check out the examples in the Speedway Museum when I went to the USGP that fall and thereafter. MUCH smaller and lower than the "dinosaur" tag had led me to believe, especially the Salih/Epperly laydown that won the race in '57 and '58, but the Watsons also. As low as contemporary formula cars and no wider. So, the thinking goes, what happens if you apply the lessons learned over the last few decades to that layout? Stated differently, how about a modern Watson, Epperly or, for that matter, a modern D50, W125, W196 or 250F?

To my knowledge, only Panoz and Mallock have come close to doing this (and the mid-engine Mallock was effectively a one-off collaboration between Mallock Sports with the other part of that family, RML. They've long since gone back to the F/R layout). I'd like to test my theories on the track and F1000 seems to be a good place to try it. Having said that, there are all the obvious problems of scale (if it works at LeMans, or in OW terms, Indy or Monza, will it work at VIR?) and materials (granting that strength and weight are no problem with composites, this class is classic tubes and welds, so can you make it light enough?). And using an aircooled V-twin (thanks for reminding me that the Buell's already tuned up) maybe does make it an apples and grapes comparison, not even as close as an orange.

So you see why I listed the conversions I did. If I had the cash, expertise and computing power, I'd just take it from my head to the CAD/FEA etc. Since I don't, I'll do it "the other way" and at least plot out a feasible modification.

[RussMcB]

When I look at the front-on view of a modern formula car, I have a hard time imagining how you could package a front engined car and have it be better, or even as good. It seems to me that the driver's body and rear engine occupy the same area (in terms of frontal area), and they are both as low as you can get them. Plus, there's no extra room needed for transferring the drive from a front mounted engine to the rear driven wheels.

Oh, wait. You didn't say it had to be rear wheel drive, did you? :-).

[Straight8]

When I look at the front-on view of a modern formula car, I have a hard time imagining how you could package a front engined car and have it be better, or even as good. It seems to me that the driver's body and rear engine occupy the same area (in terms of frontal area), and they are both as low as you can get them. Plus, there's no extra room needed for transferring the drive from a front mounted engine to the rear driven wheels.

Oh, wait. You didn't say it had to be rear wheel drive, did you? :-).

Thanks Russ. And yes, fwd did (and does) keep bouncing around in my mind. Harry Miller and Leo Goosen did prove that concept didn't they? With the weight, power and torque involved numbers we're talking here, torque steer and tire wear ought to be within reasonable limits. Come to think of it, Miller and Goosen solved for that one too by using a de Dion and over/under quarter leaf springs. Hmmm...A modern, winged Miller 91 or 122...

Front to rear of course, the offset driveline has always worked to get the driver down low. If the rules prohibit that and require centering up the driver with symetrical bodywork, I'd have to deal with a high position and go with something like a Vanwall/BRM P25/Lotus 16 shape around the cockpit to reduce drage. Crazier still (my first idea when I started sketching): Graft a shortened "slingshot" dragster body and chassis to an aftermarket (tubular and at 13 pounds reasonably light) Mopar "A"-body front suspension K-frame (independent, with longitudinal torsion bars), softtail rear, tba live or independent.

Wow. This begins to sound like a V-twin, New Wave T-bucket

[Lee Stohr]

I was going to mention FWD, but I thought that might be too far out. I guess not !
I know a bit about racing history, fwd Millers and the Christie that inspired them.
Keep thinking outside the box, and get something on the track. I'd like to see it.

[Swift17]

Well .....
If you are committed to run a "V" Twin then get a Ducati 996/999 - Desmo valve train 4 valves per cyl - perfect 90 degrees and rev to about 11,500 in stock "996/999Superbike" trim - With a dry clutch/full floater system & fuel injected the power in amazing -- while it doesn't make the top end HP of the in-line fours, it has way more of torque for coming off the corners. So slim, could give new meaning to "coke bottle" narrow at the rear. Call Craig at 10 Tenths he is just dying to put one in a Stohr !!!

[holmberg]

Check out the DP1 here: http://dpcars.net/dp1/index.htm

The engine's next to the driver, with all-wheel drive. 850 lbs.

The engine's not legal in DSR or CSR, but I'm sure a different engine could be fit.

And he only wants $125,000 for it too!


Greg Holmberg
Zink Z10, San Francisco Region

[Straight8]

Wow, the finished product! Thanks Greg! I read something about this awhile back on TheKneesliders website. Didn't realize it was so far along.

[Rick Kirchner]

I've followed the DP1 for about two years on his website. Sort of an interesting mix of genius and WTFDTCF?

For instance, he penned a rough layout, then the shape, and built a car underneath it - which is real old-school and it amazes me that he came up with such a cool chassis and a lot of interesting details despite the fact that he seems to operate more as an artist than as a systems engineer - but he certainly has a lot of talent as both.

Then there's stuff like bushings instead of rod ends for the inner A-arm pivots. It's either utter genius/out of the box thinking or total stupidity, I can't tell.

He made an incredibly simple steel frame but is going to replace that with a carbon tub.....Then again, that narrow little box probably wasn't real stiff.

But to me the car is just a work of engineering art - without the bodywork. For some reason, the bodywork just seems to be all wrong, from the short overhang with no front splitter to the rear overhang with an incredibly short diffuser. Maybe it works - the CFD plots look interesting but there's no reference pressure......

He visited Stohr's shop and a lot of the parts look Stohr-inspired - maybe Lee has some perspective on his design.

The guy must be just swimming in money or leveraged to the hilt.