Carburetors and Design

[D Collins Jr]

I don't know where you've been looking for motors, but good luck finding an f4i. If you're lucky enough to find one, it's probably broken, or will soon be broken, or has, i don't know, been filled with sand. The RR has packaging and powerband issues, and the f4 w/carbs was discontinued in 2001, I believe. Good luck finding one of those either. Run EFI.

[exFSAE]

F4i's are still really easy to find...

[Biggy72]

Throughout the year I've been picking up f4i parts on ebay. The block we're using I won for $25, I got a spare head for $20, cams for $9.... and if I wanted to get an entire block they're really easy to come by.

If you're concerned about cost learn how to put together a megasquirt unit, if you want it to be more simple get a performance electronics. Either way it's not that complicated and it is way more adjustable than a carb is.

[DPrice]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Not quite the entire back half of that car James. Notice the carbon wheels and brakes Smile We ended up in the design semifinals with the carb too. </div></BLOCKQUOTE>

I like all the parts back there slowly rusting away.



At least that car didn't have wrinkles in it.


-David

[Kyle Roggenkamp]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Superfast Matt McCoy:
I don't remember seeing an abundance of fancy engine electronics, control systems, or turbochargers in design finals. It always comes down to: does it make the car better and can you prove it? I think you would have a really really hard time convincing the design judges that a carburetor is the better option. Maybe it's just me and my belief that carburetors are the fuel systems of Satan. Of the benefits listed above, I would give you Cost, but I absolutely don't think it is worth the trade-off.

Carbs are such old technology. Can you imagine if there was a major racing series that still used carburetors? They might as well just use pushrod engines and a solid rear axle. That would just be loony... </div></BLOCKQUOTE>

Just because it's old technology, doesn't mean it's not worth running. Take the wheel, for example...

[Superfast Matt McCoy]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kyle Roggenkamp:
Just because it's old technology, doesn't mean it's not worth running. Take the wheel, for example... </div></BLOCKQUOTE>

Wow I... I think you completely missed the point.

[fade]

yes the wheel has seen little improvement since its inception.

[Drew Price]

Regardless of re-inventing the wheel:

Yes, Cal Poly made Semi's with the carb setup with that car. It also made something like 18hp on the dyno (David, back me up, I couldn't remember the number exactly, but it was low). I have been told that the fuel injection for that engine, a Yamaha 450 single, was not ready in time for comp, so the carb got thrown back on.

That car also weighed 308 pounds (140 kilos), and took first or second in Auto-X event, and did very well in Accel, because the other systems of the car were particularly well developed, designed, and fabricated.

The car had a carbon front tub with 4130 rear subframe, and 2024-T6 aluminum rear axle, carbon wheels, and carbon-carbon dog drive brakes made from Tilton clutch discs. So yes, it made semi's irregardless that it had a carb, but it was clearly for reasons which we can all agree on. The guys clearly knew their car. That's the takeaway.

Chris, you might not get crucified for running a carb, but you had better do a good job explaining why it's there. Cal Poly did a good job covering up that their EFI was just not ready, and justified it.

Having the intake air having to share the restrictor with the fuel flow volume is a pretty serious issue too, the thing is already restricted, so we have to try to give it as much of a chance as we can.

BTW Cal Poly has been tuning their WR-450 running on EFI for this year. Watch out at West.

Best,
Drew

[Go Hawks]

I'm just gonna clarify some things. We (Cal Poly) didnt do well at all in accel, got about 10th in auto-x but did do well in the skidpad.

[DPrice]

And it was 23 HP, and 319 pounds