The Technical Questions Thread

[LeonOfTheDead]

Just as a reference, lwb designs were prefered (before of the new 2009 rules) in F1 during last seasons, as opposed to swb designs, requiring circuits like Monaco to see a solid dominance of swb cars.

[RacingManiac]

In Solo II I believe you actually have min wheelbase rule. And it is the same for Formula SAE. Though FSAE do operate in a much narrow confine of automotive design.

Other considerations for a modern competition car is the size of your aero platform, as much of the rules are based on the plane area with relation to the wheelbase and overhang, as such you might drive your design decision based on aero....

[RacingManiac]

Originally Posted by LeonOfTheDead

Just as a reference, lwb designs were prefered (before of the new 2009 rules) in F1 during last seasons, as opposed to swb designs, requiring circuits like Monaco to see a solid dominance of swb cars.

This year is kinda of an anomoly in that the disproportional gain in front grip drives the need for the increase front weight bias and that shortening the wheelbase was use as a fix to increase the front bias. Again though, illustrates the need to design the car for the tire....

Brings back to the FSAE design, in that most FSAE tires is probably a lot less load sensitive than a full-size car(one just need to see how many car may share the same performance level at wildly varying weight on the same tire), and so a compact dimension for the gain of being more nimble on the autoX course is favored above other consideration.

[Alastor]

Originally Posted by culver

The short wheel base car does require less steering input but you have to balance that against the poorer weight transfer characteristics. Ultimately under most conditions the improvement in weight transfer offered by the longer wheelbase and track win out. This is why you see rules often limit maximum wheelbase and track.

Interesting.

[LeonOfTheDead]

just a quick doubt:
how is it called a rim of this kind? In english of course.
You know the one completely filled, reminiscent of classics and usually adopted in classic-ish new cars like the concepts from Bugatti, the Lancia Thesis and so on, as opposed to multi spokes rims.



thanks.

[Bob]

Originally Posted by LeonOfTheDead

just a quick doubt:
how is it called a rim of this kind? In english of course.
You know the one completely filled, reminiscent of classics and usually adopted in classic-ish new cars like the concepts from Bugatti, the Lancia Thesis and so on, as opposed to multi spokes rims.

As far as I'm aware there is no distinction between these and other wheels. I do try to stay away from calling them "rims" because that really refers only to the outer part (rim) of the wheel and not the spokes or center. Also the term "rims" has ricer/tuner connotations, like "YO check deez new RIMZ yo!"

Back to your original question, the only distinction I know of is that multi-spoke wheels are usually lighter metals and thus called alloys, while cheap steel wheels with hubcaps are just called... steel wheels.

Then there are true classic wheels like wire wheels and knock-offs, but I don't think you're talking about them.

[Bob]

Originally Posted by RacingManiac

This year is kinda of an anomoly in that the disproportional gain in front grip drives the need for the increase front weight bias and that shortening the wheelbase was use as a fix to increase the front bias. Again though, illustrates the need to design the car for the tire....

Brings back to the FSAE design, in that most FSAE tires is probably a lot less load sensitive than a full-size car(one just need to see how many car may share the same performance level at wildly varying weight on the same tire), and so a compact dimension for the gain of being more nimble on the autoX course is favored above other consideration.

Or if you're a member of Penn State Racing, you bring a 289 lb car to competition and blow everybody's minds

Our problem was that having only a 72lb load on each tire, no matter how hard we would drive we couldn't get temperatures much higher than ambient

[LeonOfTheDead]

Originally Posted by Bob

As far as I'm aware there is no distinction between these and other wheels. I do try to stay away from calling them "rims" because that really refers only to the outer part (rim) of the wheel and not the spokes or center. Also the term "rims" has ricer/tuner connotations, like "YO check deez new RIMZ yo!"

Back to your original question, the only distinction I know of is that multi-spoke wheels are usually lighter metals and thus called alloys, while cheap steel wheels with hubcaps are just called... steel wheels.

Then there are true classic wheels like wire wheels and knock-offs, but I don't think you're talking about them.

Thanks, never heard of the "ricer" connotation, good to know it.
I'm referring to the style of the wheel where there aren't spokes or wires, just a plain filled wheel.
I was wondering if they have a specific name, or even just a good way to define them.
This wheel is still an alloy, which just looks like a hubcap if you like, being completely flat as if it was covering something else.
Another example:
File:Lancia Thesis 1.jpg - Wikimedia Commons

[culver]

Leon,

This is only a guess on my part but I suspect that style of wheel originated with the turbine style racing wheels that came out in the late 70s. Weight wise the current multi-spoke type of wheel seems to be the in thing. However, when race designers started really looking at aerodynamics they noted that a flat dish wheel had lower drag. The also noticed that you could use the wheel as a sort of pump to draw air over the brake discs. Out of that we got the turbine style wheels.
I'm not having much luck finding good pictures but here are a few.
http://ll.speedhunters.com/u/f/eagam...ns_jb_0015.jpg

Here is a modern interpretation of the same idea:
ApexSpeed

The early versions were typically a part added on to the existing wheel. I think these wheels largely disappeared because they were considered unsafe if the turbine or flat face separated from the main wheel. However, I'm sure if that ever really happened or if that was just people afraid of change etc. It's also possible they simply didn't work that well. However, I've noticed that F1 is now running flat faces inside of their wheels though I think theirs are fixed rather than attached to the wheel.

[LeonOfTheDead]

Originally Posted by culver

Leon,

This is only a guess on my part but I suspect that style of wheel originated with the turbine style racing wheels that came out in the late 70s. Weight wise the current multi-spoke type of wheel seems to be the in thing. However, when race designers started really looking at aerodynamics they noted that a flat dish wheel had lower drag. The also noticed that you could use the wheel as a sort of pump to draw air over the brake discs. Out of that we got the turbine style wheels.
I'm not having much luck finding good pictures but here are a few.
http://ll.speedhunters.com/u/f/eagam...ns_jb_0015.jpg

Here is a modern interpretation of the same idea:
ApexSpeed

The early versions were typically a part added on to the existing wheel. I think these wheels largely disappeared because they were considered unsafe if the turbine or flat face separated from the main wheel. However, I'm sure if that ever really happened or if that was just people afraid of change etc. It's also possible they simply didn't work that well. However, I've noticed that F1 is now running flat faces inside of their wheels though I think theirs are fixed rather than attached to the wheel.

Thanks Culver, this isn't what I was looking for (I was about more classics' wheels), but nonetheless interesting.
Fairings adopted in F1 cars are of two kinds, rotating (at the back) and static (at the front), and made for the purposes you explained.
they are quite popular even if it seems they could be banned next year

[2ndclasscitizen]

Originally Posted by Bob

Or if you're a member of Penn State Racing, you bring a 289 lb car to competition and blow everybody's minds

Our problem was that having only a 72lb load on each tire, no matter how hard we would drive we couldn't get temperatures much higher than ambient

Are you not allowed to use warmers in FSAE?

Also, burnouts.

[NSXType-R]

Just a quick question, was there ever a reason why Ferrari stopped using flat boxer engines and went to V engines instead?

Was the Testarossa the last flat engined car?

Thanks.

[pimento]

From what I know the Testarossa engines were more 180 degree V12s than boxers.. I read somewhere that there's a difference. I think the flat ones were also basically the same engine as the V12s.. just ironed a bit. I think it's because they went from mid engined back to front engined, so they didn't have to try and fit a gearbox beneath it.

[NSXType-R]

Originally Posted by pimento

From what I know the Testarossa engines were more 180 degree V12s than boxers.. I read somewhere that there's a difference. I think the flat ones were also basically the same engine as the V12s.. just ironed a bit. I think it's because they went from mid engined back to front engined, so they didn't have to try and fit a gearbox beneath it.

Oh yeah, that's right, they call them 180 degree V engines, not boxer engines. I fail to see the difference as well.

Then that's just laziness on Ferrari's part.

[pimento]

Originally Posted by somewhere.. about the 365BB

The word Boxer refers to its horizontally opposed 12 cylinders engine. In fact, it was not a real boxer engine. Each crankpin was shared with 2 adjacent pistons, so it was actually a 180° V12 ! this design allowed it to share pistons and con-rods with Daytona. It also explained why the engine displaced the same capacity as Daytona's V12.

Automotive engineers prefer boxer engines because of their low center of gravity. Unfortunately, to package the big 12-cylinder boxer into the middle engine compartment, Ferrari decided to put it above the gearbox to save space. As a result, it actually had higher center of gravity than conventional V12 engines. No wonder it was never competed successfully in motor racing. Ferrari's contemporary F1 car 312T also employed flat-12 engine, but it had the gearbox mounted behind the engine.

There you go.. it's all about the crankpins.