Pelican Parts Forums - BB2 Track Testing -- a second time out

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BB2 Track Testing -- a second time out

The second testing session at Willow Springs went very well -- with only a few minor glitches.

At the last minute, Dave at TRE Motorsports lined up some other Porsche guys to come and participate. So, in addition to Jack and Tyson driving BB2, we also had Dave (TRE Cup) in his 914-6, Hans Stoehr in his backdated lightweight 911 SC, and a guy named Michael in his stock Carrera. We caravanned to the event, after a 6:15 am breakfast.

What’s more, we got visits at the track from Mike Marshall (MMarsh), Kevin (KevinP73), and Denis Hartigan (Speeder).

So, lots of eyes to see if Tyson and I could improve on the 1:36’s we had run 10 days earlier. We were still on the same street tires, but we’d added a front splitter and rear tail, as well as a new front swaybar from Smart Racing, the Elephant Racing front strut brace (in addition to their monoballs), and the full cage.

The glitches ranged from the small to the large. On the minor side, I was having problems with my Hot Lap timing system, so we only got lap times for the first and last sessions. My video camera was also acting funny, shutting off on all sessions except one, and recording with poor enough quality from the lipstick camera that I suspect I might have put one of the batteries in backwards. Pretty soon, the rest of the interior will go in, and I’ll have the regulated power supplies that HawgRyder built.

On the scarier side, there were two bad incidents during the day. Early on, an Acura lost it in turn 9, and rolled three times. I heard that both the driver and the passenger broke an arm, and that the passenger was knocked unconscious from the impact when the roof collapsed. Another car went off the track with enough force to trigger an airbag, which then obstructed his vision for an instant, and he went into the turn 4 wall.

Also, after running blisteringly fast laps all day, Hans Stoehr overcooked turn 8 and went off the track -- spinning fast enough to throw out his windshield. His car was otherwise undamaged.

But the roll-over was serious enough that organizers decided to put a chicane in turn 8, which is the fastest turn on the track. So our times would not be apples-to-apples, since the chicane made the track slower -- to a degree we could only guess at. The roll-over also made the organizers decide to forbid passengers for the rest of the day, which was bad news for Kevin and Denis, who didn’t get rides they’d been promised.

But the upside was that every adjustment we made helped the car go faster. After running 1:37’s in the morning, without the chicane, Tyson and I both ended up running low 1:34’s by the end of the day -- with the chicane slowing us down. Since we didn’t get times for any of the late morning and afternoon sessions, it’s hard to say what our best times were. I think it’s safe to say that we each probably had at least one 1:33, even with the chicane in place, But we’ll have to wait before we can officially claim a 1:33 on street tires at WSIR

A 1:33 with the G-Forces means we will easily be below 1:30 on r-compound tires. That was the goal for the new car, and we’ve gotten there with only a few wing and swaybar adjustments (and, of course, 12 weeks of very hard work).

Here’s the fuzzy clip (remember, the camera was acting up) of Tyson driving a lap in traffic. You’ll see a 300ZX Turbo and a 350Z both get disposed of in short order. Sorry, Leland, but that 350Z is no 911. ;)

And if you've got a fast connection, here's a clip of both Tyson's traffic lap and also a clean one -- a 1:35.1.

All the clips are in Quicktime format.

For the fast-internet challenged, Tyson's two laps here's a smaller version[/url] of the same double-lap clip.

And here are two pictures from the event, with the huge honkin’ rear tail in place.

http://forums.pelicanparts.com/uploa...sAndJack-T.jpg

http://forums.pelicanparts.com/uploa...TheTrack-T.jpg

Click on any of the thumbnals for a larger version.

It's still not completely finished (unpainted muffler, no deco trim, etc.), but it goes like hell, and you can already get a pretty good idea of what the finished product will look like.

Jack,
That is one tuff car. It looks like it wants to go kick butt. Have you been able to tell what her street manners will be? How does she compare to BB1 for street driving?

So it is faster than BBI, but what is your driving impression? What's different, what do you like / don't like?

Car looks great, Jack. That wing actually looks pretty good in the head-on shots.

Jack, Tyson,

BBII is a super fast car. Congratulations to you both and the rest of Team Marx. ;)

Willow Springs looks as challenging as ever. Is it hard to always nail your braking points on the downhill grades?

Matt Holcomb
MFIWDP
PRVC
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Thanks.

It's different in a lot of little ways, Chuck. The weirdest part is that it's so similar, in terms of steering feel, since the tires are considerably wider. Tyson's front suspension geometry brings the scrub radius so close to zero that you can drive it on winding roads (or the freeway) with one hand.

The street tires are different. On the track, they make a lot of noise, and grip well -- they're 255's and 315's, so they'd better -- but it's different than track tires. Hard to describe.

The new brakes (power assist, and a 23mm MC) are great. They reveal the lack of track tires more than the curves do. When the track is rough, the stiff suspension makes it hard for the street rubber to grab. Matt noticed that this makes for two tricky braking zones at Willow Springs.

The coils are technically much stiffer than the torsion bars they replaced, but the ride quality isn't significantly worse. Oddly (and by my unscientific experience of it), there seemed to be more noticeable impact from minor road irregularities with the torsion bars, but a stiffer spring response over larger bumps with the springs. You could feel the surface of the road more with the t-bars. You get air over mismatched bridges and straightaways with the springs.

Getting around the cage is a pain in the butt. The removeable steering wheel helps with that.

With monoballs front and rear, the car is louder overall than it used to be. Carpeting the rear half has helped a lot, but it's loud, compared to BB1.

The chassis feels lighter and stiffer -- I guess because it is. The handling, now that we've got it dialed in, is much less anxiety provoking at speed than the old car. I think moving the engine forward helps a lot with that. Now that we've balanced the swaybars, it goes through Willow's big sweepers without much of anything in the way of twitchiness.

The good: The old car handled well. This one handles better. It's a lot faster without being a lot scarier.

The trade-off: It's louder inside the car. And I'm a little poorer than I used to be. ;)

The only difficult braking point on the track is the entrance to turn 3. (Well, the entrance to turn 5 can get pretty messy too!) The pavement there is very wavy, causing the tires to leave the pavement for brief moments under full braking. If you overcook it even a little, it's very easy to lock up a wheel and push very wide.
You can hear the right front tire breaking traction in the video in turn 3.

Also note: My lines in the video are different than the lines I normally take. During that session, the oversteer hadn't been totally dialed out yet, so my corner entrances were changed to keep it smoothed out. Swaybar adjustment and wing angle were changed, and the car responded very well to these. The car became an absolute joy to drive. The front suspension geometry changes worked out even better than I'd expected.

Jack and I are both very happy with the car. An interesting note. Street tires are more forgiving than R-compound tires on the track. That is until you reach a certain level. On a car like Jack's which is able to really overwork street tires, it becomes just the opposite. The street tires have a sweet spot. They are greasy at first and take longer to warm up, then they are great. But after some really hot laps, they just go away on you. In that regard, R compound tires are more forgiving at this level.

And I thought BBII couldn't look any better. Thumbs up to the humongous wing! And...does that still say "2.4" on the grille?:cool:

Good recap Jack.

I bet your glad to be able to hang your hat on some faster lap times after all that hard work. I know I'm chomping at the bit to find out if my winters motor work has any positive impact on lap times.

Sounds like you guys did a good job setting up suspension, further adjustments should be easier with the new equipment.

Bravo! I'm jealous... I can't seem to kep mine running for more than 1 hour per week, I wrongly assumed the motor would be the hard part of the rebuild. :)

The Phoenix has risen from the ashes

http://www.pelicanparts.com/support/smileys/clap.gif

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Awesome vehicle. Long distance appreciation of all the work and minute detail that went into building this car.
Can't imagine, how incredible it must feel on the track.
You are seriously addicted. Others can only dream of such.....

Great film. A pity that the picture is of poor quality.

I love the pictures - you car looks so good, Jack! That is one mean mo********er 911! Good that everything turned out so well.

Jack the car looks awesome. Nice driving Tyson.

Chris, there is a Gingerman test and tune on April 5 and 6 if you're interested.

Jeff,

I'm trying like the dickens to get the car sorted out for that session. Do you have any real info on it? Esther called them like 3 times to get the information and they never called back.

Cost, reg's, groups, etc..

If I can get the ignition and carbs sorted, I'll be there...

Quote:

Originally posted by Mikkel
I love the pictures - you car looks so good, Jack! That is one mean mo********er 911! Good that everything turned out so well. [/B]

YOU TOOK THE WORDS RIGHT OUT OF MY MOUTH MIKKEL! HAAHA

ERICSmileWavy SmileWavy

damn sweet car, great skills at the wheel...thanks!

Simply Awesome! I can't get enough of BB2. She is unique!

Darn Jack....I started reading about the electrical problems...and figured I had screwed up somehow.
Then read on further and found you had not installed the boxes yet....whew....
The rest of it looks great.....keep the pedal down.
Bob

One box is installed, but I didn't have time to solder the line that runs to it, so I went to the battery bag, and I think got a mix of old and new. With the boxes in place, this kind of annoyance will be a thing of the past.