RSAE 2007 One Lap of America

[Grant]

It looks like you kept on the throttle during the huge slide, NICE!

Does the car understeer on entry, and oversteer on exit? How does it feel?

Sorry if this has been covered before, but what suspension are you guys running?

[Nikoror]

Quote:

Originally Posted by Grant . Does the car understeer on entry, and oversteer on exit? How does it feel? Sorry if this has been covered before, but what suspension are you guys running?

[RSAE]

The car has a general mild understeer condition until you do something brave/stupid (i.e.- too much throttle on exit, let out the clutch in the middle of the turn, braking while turning, etc.) at which point it can get into some violent oversteer. I was very happy with how the car was balanced. The .918 on the skidpad confirms that we weren't too far in either direction.

To confirm what Nik said about the suspension:
Front: 27 mm torsion bars, Koni yellows, Performatek 27mm sway bar.
Rear: Springs to match 27mm torsion bars, Koni yellows, Performatek 25.4mm 3-way adjustable sway bar (set to middle for dry, full soft for wet)

Polyurethane everywhere and new ball joints.

Nik is right in that we need to (almost) triple the spring rates and match some shocks to that. It is far too soft for road racing.

damen

[Nikoror]

unfortunately official pictures are copyright protected, but the car has some serious body roll. see the pics from the dry skid pad we need bigger swaybars

[Grant]

Would you guys be using Andy's 33mm torsion bars and matching spring then, or Ron Simons coilovers? Something else?

Maybe some stability could be gained by heel-toeing or rev matching under hard braking? Or is the driver actually doing it, and I'm just not seeing it

Great job though, you guys seem to be doing this very professionally. I wish my school would enter a car into 1 Lap!

[andythefat]

Awesome video...love the soundtrack!....How can i replicate it? Seriously, i have a 3ltr 12valve engine, what modifications would i need to make....(and what can i get away with) on a street car?

[RSAE]

Grant:

1) I imagine that we will try to go with a coilover setup, I doubt that it will be RSR because of the $$ issue. There are many solutions out there for threaded spring bodies on shocks and the massive availability of 2.5" springs is very attractive. I am no longer the financial decision maker so we will see what he comes up with

2) I would absolutely love to heel-toe on the track in this car, but due to our over-boosted brakes and elusive perfect bleed job, under full braking the brake pedal is close to 3" below the throttle and 3-4" to the left. It is something that will be addressed during this next year because you are absolutely right, it would be a tremendous boon for stability and lap times.

andythefat:

You're probably not going to like the answer I have for you, but here are the modifications we have made that contribute to the sound:
1) Strip all the sound deadening from everywhere in the car (this includes dash, carpeting, nasty tar coating, interior door skins, underhood blanket, etc.)
2) Greg Gordon's cold air intake
3) Ansa headers
4) Full custom exhaust (goes from exit of Ansa headers [2.25" each] into a dual-in, dual-out [2.5"] Magnaflow X-pipe muffler, exits muffler each side [2.5"], turns 90 deg (mandrel bent) towards the outside of car (each side), another 90 deg mandrel bend to get parallel with frame, into 18" long glasspack mufflers, then right out the side of the car in front of the rear jack points.) Notice there are no catalytic converters.

I apologize that I don't have an easier answer, but as cool as this sounds on the track, it is not really reasonable for a street car. Thumbs up to Alfa though for making such an awesome sounding engine

-damen

[Nikoror]

Quote:

Originally Posted by Grant Great job though, you guys seem to be doing this very professionally.

[RSAE]

Day 4 (afternoon): Miller Motorsports Park, Tooele, Utah


This was the longest track of the event with a front straight over 3500' long. The cars higher in the run order were seeing 160+mph at the end of this straight. We saw 110. The track description said the faster cars would see cornering speeds in some places over 140mph. We saw 90 (once, and it was a little too exciting, so the next lap it was 85 ). This 4.4 mile configuration was rough, we were simply too underpowered. It was also at this point that the transmission really started going south, you can hear the whine in the video. We ended up 60/76. Ouch. Here's the video for what it's worth

Because this track was so long, the video of the entire session was too long for youtube, so I cut off the end of the last lap. I think you'll get the idea, and I suspect most won't watch that far anyway

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/f87hkEIW3xk"> </param> <embed src="http://www.youtube.com/v/f87hkEIW3xk" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

-damen

[AR4me]

Quote:

Originally Posted by Nikoror about suspension. 33mm torsion bars seem to be the "wiser" choice.

[jontg428]

Where did the new video go? Violation of terms... Damn youtube, they are censoring alfa vids now!

[BRUCE]

"Day 4 (morning): Miller Motorsports Park, Tooele, Utah"
It does not sound "crisp"; sounds like it's pinking.

[AlfaAddict]

Is this the correct link?:

http://www.youtube.com/watch?v=z79ptshMPDk

[RSAE]

That's the east course. The new video is the full course.

Sorry, the video was too long and got rejected by youtube. I am in the process of re-editing and re-submitting it. Should be up tomorrow.

[Nikoror]

Well with Andrew Kress of Performatek as a sponsor the price/performance advantage is overwhelming I think that for a race car the coil-over+torsion bar configuration is very... "inefficient". to go full coil-over the "right" way we need chassis reinforcement+custom lower and upper a-arms=too much time and too much $$$. i see no advantage in having springs on top of the torsion bars rather than bigger torsion bars... as Andrew Kress said: "wheel rate is wheel rate". if you have considerd bigger torsion bars vs. RS coil-overs in case you have to pay the full price for both (also pay for having the shocks revalved to work with the new spring rate of the torsion bars) then it's another story...