RSAE 2007 One Lap of America

[AR4me]

Quote:

Originally Posted by Nikoror I think that for a race car the coil-over+torsion bar configuration is very... "inefficient".

[Nikoror]

i mean inefficient in terms of optimum design. not that it's not doing its job right. maybe "not optimal" is a better way to describe it. the problem is too much weight...

[AR4me]

Are you saying a coil-over adds more weight than a 33 mm torsion bar?
Jes

[RSAE]

The Utah afternoon video is now up on page 2.

Does anybody have the weights of the various diameter torsion bars?

-damen

[RSAE]

Day 5: Pueblo Motorsports Park, Pueblo, CO (morning)

The drive from Utah to Pueblo, CO took us along US highway 50 through the rockies up to 12,000 feet at around 3am. It was 26deg F up there with 4 ft of snow along the sides of the freeway. Driving through there the driver was able to bundle everything up except for the feet, and the open hole at the base of the windshield (under the rain tray, leading into the passenger compartment) was blowing 60mph air right on the drivers feet. Without any form of heating or insulation, we had to stop and switch drivers each time the current drivers feet went numb. Also, the Yokohama summer tires were less than ideal for the conditions. It was a miserable transition (even though it was only 600 miles) that put us into our hotel in Pueblo around 6am

Up again at 8am, we arrived at the track to find that it was a much better configuration for the Alfa (although the 2500' front straight was longer than we would have liked) and we were able to place much better: 43/75.

This was the first time I had seen this track, but it was a really fun configuration. I apologize for the camera spazzing, it's something I'll have to look into for next year (especially since we are considering doubling the stiffness of the suspension).
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-damen

[Nikoror]

Quote:

Originally Posted by AR4me Are you saying a coil-over adds more weight than a 33 mm torsion bar? Jes

[AR4me]

Too bad you don't have the opportunity to compare. Anyway, each to his own...
Jes

[Nikoror]

Quote:

Originally Posted by AR4me Too bad you don't have the opportunity to compare. Anyway, each to his own... Jes

[Grant]

Jes,

Have you been able to drive a car with just big T-bars? If so, how was it?

[AR4me]

Not 33 mm, but bigger than stock 3.0 - forgot the actual number. Some time ago, but I don't recall it being like the coil-overs. It was a different car, so many other variables...
Jes

[Nikoror]

i don't get your point. are you saying that torsion bars+coil-overs are better than just coil-overs or better than just torsion bars of the same rate or that going with coil-overs on top of the torsion bars is the best option we are not talking about any specific brands or specs, just setups in general

[AR4me]

You originally said/claimed that bigger torsion bars are a better option than a combination. I was/am simply trying to find out why you think so.

My comment above was in response to Grant's question.

Anyway, this is not going anywhere and lets not ruin this thread.

Jes

[Greg Gordon]

I favor the coil over/Torsion bar combination for the following reasons.

1. Large 33mm torsion bars are a huge pain in the butt to install and or make ride height changes.
2. Large 33mm and even 27mm bars in some cases lead to chassis cracking in post 1985.5 models.
3. I suspect in the case of the RS racing suspension vehicle weight will be lower compared with 33mm torsion bars and bigger rear springs. I don't have data on this but that RS kit is LIGHT.

I favor it over straight coil overs for the following reasons.

1. You have to do a lot of chassis strengthening to convert to pure coil overs. This adds weight. It's also complex, and if done incorrectly can lead to disaster (ie structuaral failures, reduced crash protection etc.)

[Nikoror]

Quote:

Originally Posted by AR4me You originally said/claimed that bigger torsion bars are a better option than a combination. I was/am simply trying to find out why you think so. My comment above was in response to Grant's question. Anyway, this is not going anywhere and lets not ruin this thread. Jes

[RSAE]

Day 5: Pueblo Motorsports Park, Pueblo, CO (afternoon)

Because we ran so well in the morning, we ran much higher in the afternoon. Unfortunately I had a few miscues (i.e. some drifting action around 2:38...) during the afternoon run and didn't improve on my time from the morning. A few other people did, so we placed 46/72.

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-damen