And the fun continues...

[scherp69]

James that car is sweet!!! I love the color. I'm likely going to be painting mine red and was wondering that color that is.

[minendrews68]

James that car is sweet!!! I love the color. I'm likely going to be painting mine red and was wondering that color that is.

Is it RED? or is it ORANGE? Or is it RED ORANGE? I agree, it is a good looking color. I've already been trying to get the color from him.
Carl

[David Pozzi]

Here's a video of Carl and James on the track at Streets Of Willow. Notice Steve Rupp taking photos at the fence while the high winds try and blow him over!

[James OLC]

James,
There's more speed in the car than that!
I was taking it easy in several places, especially in braking at the top of the hill. Couldn't find 3rd gear more than half the time so I always slowed early. It seemed like I never got more than 1 lap per session that was clear, I was always catching up to someone.

Yeah, I thought that the braking zone at the end of the dogleg was one of the most deceptive points on the track - especially when one of the slower cars was there. The closure rate was pretty eye opening and I think (I know) that I tended to brake way too soon and way to gradually there.

[James OLC]

The color is a custom mix that was loosely based on the Ring Brother Copperback Mustang. That code was M8013U which is a Diamont/BASF color off their colorwheel. Add some red, play around a little, and you'll get close.

[Mr.VENGEANCE]

love the photos!

[James OLC]

Well it’s been a while since I updated this post on our spring odyssey so I thought I would do a quick update before I head down to Salinas for another weekend of development, tuning, track time and (hopefully) fun.

As most everybody knows in mid-May we ran the Nevada Open Road Challenge. The infamous Steven Rupp was navigator for our 90 mile blast down Nevada Highway 318 while Dave and Mary Pozzi kept us on the straight and narrow for the weekend – providing invaluable tuning, guidance and moral support.



We completed in the optima batteries Half Mile and High Noon Shootouts for fun and on Sunday we finished 4th in our class – 0.37 seconds off of our target time – not bad for a couple of rookies… I won’t repost everything about the event, but do want to say thank you once more to optima Batteries for sponsoring us in the event and to David and Mary for their help – we couldn’t have done it without them. If you’re interested the complete story of our weekend is here… 2009 Nevada Open Road Challenge - it's official - After Race Report

[James OLC]

After the Silver State Classic event our next stop was the Goodguys Rod & Custom event in Pleasanton, CA. This was going to be our first autocross since adding the rear sway bar, increasing the spring rate on all four corners and tweaking the brake bias so we were cautiously optimistic that we were heading in the right direction.



When the dust cleared on Sunday we (both the car and the driver) were both showing improvement – running a low 37 second lap which put us less than a second behind Mary’s winning time in her ’73. We also identified a couple of more places where we can get more out of the car… we’re still pushing in the corners and will increase the rear bar rate to get the car to (hopefully) respond a bit better. We’ve also got too much front brake which is in turn putting too much weight on the front and making the push worse… we’re going to swap master cylinders to try go increase the rear bias. It’s also time to do something about the tuning in the car… Painless has helped us out with a closed loop tune for the MEFI4B and we need to get the idle sorted out before we all lose our minds… it’s been nearly a year… it’s time.

We have also (we think) made some headway with our other ECU related issues and will put our theory to the test next week. If we’re right we should make some power and might have solved our engine cutout problem – we’ll see in a few days.

Next weekend were heading for the American Autocross Series event in Marina, California. David and I will be putting the car through its paces on an autocross course that should give us some running room and really let us see how close we are getting on our setup.

[78 Type-LT]

That is sexy..

[Damn True]

David and James,

Trying to wrap my head around the suspension adjustments made this weekend.

If I understand correctly, the last and most impactful adjustment was to raise the rear roll center. Am I correct in assuming that by doing so, you reduce the length of the "arm" imparting roll into the chassis and thus decrease the roll input or does this increase the "roll rate"?

Is this preferable to increasing spring rate or compression damping as a means of maintaining compliance?

Under what circumstances would you want more spring or more damping in the rear?

[Damn True]

David & James ^^^



BTW David....I heard what you are working on there in your weird science lab. Sounds like something I'd like to see.

When you get a second though, could you post some photos of the rear bar installed on James' car so I can print for reference?

[James OLC]

Well I have been negligent in updating our California adventures since getting back from Marina last week (it sucks when the real world gets in the way) but it was such as blast that I have to take a few minutes to look back on the weekend. It was one of those “working” race weekends that can be both frustrating and rewarding at the same time – fortunately this one ended up being both. With the help of David and Mary we have made great strides in getting the OneLapCamaro closer to being right but going into the weekend we were still fighting an understeer ‘problem’ and were chasing our 60 mph vibration. We also wanted to play with the fuel injection – maybe convert the calibration over to closed loop – and take care of some charging issues that could have been the source of our 149 mph “issue”. We were also trying to play with the brake bias to get a better balance and take some weight off the front end under braking.

Wednesday and most of Thursday was spent switching the rear brake and clutch master cylinders. The clutch was a ¾” bore while the brakes (both front and rear) were 7/8” bore; by switching the two we hoped to get more rear brake bias and maybe help the TOB a bit. After bleeding the brakes and slave we road tested the car on a cruise through Carmel Valley to a local cruise night at the Baja Cantina which is a really cool spot that was really hopping – especially with the GP in town for the weekend. Best part was a nice 80 mile cruise on a beautiful Thursday evening.



Friday was spent trying to isolate some charging issues and some minor rewiring. I tried a couple of different calibrations but couldn’t get the car to idle without hunting in closed loop so we stuck with the original setup – hoping to get some time with a knowledgeable tuner some time in the near future.

Saturday morning it was up bright and early and off to the Marina Airport to run with the American Autocross Series. Mary led the way on a typical overcast morning on the peninsula…



I had known going into the weekend that we were up against some still competition – running in the C Prepared class. As one of only two cars in the class on street tires it was immediately apparent that we were up against some stiff competition. The class was dominated by early Camaros and Mustangs which were built to do not much more than dominate autocrosses. Amongst our competition was TAZ – the awesome ’67 Camaro featured by Steve in Camaro Performers a couple of months ago – who was typical of the cars in the class – 2,100ish lbs, huge fender flares to accommodate 13” slicks front and rear, and a gnarly sounding small block. VERY COOL!

The great thing for us was that our goal was to sort the suspension out first and have fun second. The great thing about the American Autocross Series is that you can get a ton of runs in and can have multiple drivers. On Saturday David and I shared the driving duties – making 5 runs each in the morning and afternoon. At one point we were hot lapping the Camaro so quickly that we weren’t even shutting the car down between runs – one of us would hop out, we would check tire pressure and the other would hop in to get buckled up to make a run.



In the morning, we started with no major changes besides the brakes which proved to be a great improvement. The pedal was still really stiff but we were finally able to get a very good balance between the front and the rear and it really helped to eliminate most of our issues while braking before coming into the corners. The car was still understeering badly with the front tires chattering badly in the sharper turns. At lunch we decided it was time to play with the rear sway bar (which David had modified to be adjustable) and upped the rear rate.

Heading out in the afternoon the difference was immediately evident – a bunch of understeer was gone but now the rear end was ‘a touch on the free side’. With the front end behaving better I eventually got myself into trouble, looping the car in what was looking like a great run (ok – the first couple of turns were going great – but it was there). The back end was just so free that the least amount of throttle would get you really out of shape. Making matters worse, as the day warmed up (and due to the fact that we were keeping the car running almost all the time) the engine temps were rising, hovering around 200 degrees. Not enough to be worried about, but enough to cause some detonation when combined with the ‘high octane’ California premium unleaded. With the GP going on that day, Laguna was not an option for getting some race gas. Fortunately MuscleCarJohn came to the rescue with 5 gallons of 110 octane low lead (thanks again John!) and we were able to blend and solve that problem.

Saturday night was frustrating as we discussed what we needed to do to get the car sorted. I was frustrated at my driving – which I thought was getting better but the spin had killed most of my confidence – and we were all frustrated at the car. We went to bed with no obvious solution.

[James OLC]

Sunday morning was another early start. Just as we were getting ready to hit the road and head to the airport, David suggests changing the mounting point for the Watts Link – raising it up one position. His thought was that the roll center for the first gen was fairly high on the front (seemingly much higher than Mary’s second gen) and that maybe by raising the roll center in the back the car would be better balanced. The change took about 10 minutes and then we were off.

Sunday we were running the course in the opposite direction as we had on Saturday and I was first up. I got down the first stretch of zig zags and came into the first long 180 degree sweeper – our nemesis the day before - and as I accelerated out I think I probably shouted a little Woo Hoo as the car rotated like never before and practically shot out of the turn. There was still a little bit of understeer but nothing like the day before and best of all, the rear end was no longer loose. One bolt – 10 minutes – and it was like being in another car.



Once again we were hot lapping the car but this time every run was better and better for everyone. I admit that I looped the car again, this time in the final 180 degree sweeper, but it was my own fault – I had gone through the slalom at nearly 60 mph and had neglected to get the car adequately whoa’d up in the turn and when it got out of shape I tried to power through it and lost the battle.

In the afternoon Mary and I were taking turns in the car and, as before, were getting faster as the day went on. On one of the last runs of the day Mary went around the course, finished what was her best run of the day, and immediately pulled back up to the staring line. She was nodding her head and shaking her fist and when the flag dropped she was off on an even better pass. When she got back she got into the staging lane so we could make our last switch of the day… “I got this thing figured out!” she exclaimed, “there’s a 41 in it – go get it.” Well, I’m obviously no Mary and I didn’t get the 41 but I did get a rewarding 42 and change for my best of the day.



Then the dust settled on Sunday it was a completely different story than the day before. The car was working well and we had learned a ton. We made great improvements and ultimately were mid pack in C Prepared – turning faster times than some of the cars that had seemed so ominous the day before. All told we made 40 passes with the car and opened the hood twice – both time more out of a sense of duty than a real need. Mechanically the car performed flawlessly and the handling and setup was coming our way. There’s more there and we’re already chasing it…



As always, thank you so much to Dave and Mary. Thanks to John for the gas - it was great to meet you and see your garage! True – it was a pleasure to finally meet you, hopefully we can get together again next time I come down.

That’s all for now – the adventure will continue next month (I hope) when the AAS returns to Marina…

[James OLC]

Some YouTube Videos…

Saturday Roof Mount


Saturday SplitterVision


Sunday Mounted on the Side


Sunday SplitterVision

[David Pozzi]

David and James,

Trying to wrap my head around the suspension adjustments made this weekend.

If I understand correctly, the last and most impactful adjustment was to raise the rear roll center. Am I correct in assuming that by doing so, you reduce the length of the "arm" imparting roll into the chassis and thus decrease the roll input or does this increase the "roll rate"?

Is this preferable to increasing spring rate or compression damping as a means of maintaining compliance?

Under what circumstances would you want more spring or more damping in the rear?

True,
Raising the watts pivot increases cornering load transfer from the inside tire to outside tire on the rear, while increasing roll stiffness in the rear. It's pretty much the same as a larger rear bar would do. A side effect is, more "jacking" from cornering loads on that end. It's similar to anti-squat in the front to rear direction on a 3 link, - more anti-squat prevents rear squat on acceleration, - a higher watts pivot creates more jacking effect which makes the rear stiffer when cornering.

So, the higher the watts, the more roll stiffness, more weight transfer inside to outside, more jacking effect.

I like to spring the car for proper amounts of front end rise/dive, and rear rise/squat when on and off the power. Then use sway bars to reduce body roll and get handling balance. The shocks slow down chassis movement, and increase weight transfer as you go stiffer. Too soft, and your chassis flops left right and up down. Too stiff and the chassis skates and skitters around.

[Damn True]

So going with a stiffer spring would achieve largely the same result but at the cost of compliance?

[David Pozzi]

Yes but it would take a lot more spring vs a little more bar. You get a lot more deflection out of a bar, one wheel goes up, the other side goes down, so the bar get's twisted much more than a spring would move. We changed the rear springs on Mary's camaro from 175 to 240, and it made very little change in handling balance, maybe 1 hole on the rear bar difference.

[Damn True]

Is a sway bar linear or progressive?

[David Pozzi]

Linear.

[James OLC]

So we're spending the holidays with David and Mary in sunny California (at this point, if it's not snowing it's close enough to being sunny for me) and trying to have some fun with the OLC while continuing on our development path. Hellwig was kind enough to build us some new sway bars which we have on the car now and on Christmas we started on some more mundane modifications...



...preparing the car of the 2010 One Lap of America (in the long term) and a couple of local autocrossed in the short term.

Saturday we headed out to Marina to run with the Lockheed Sports Car Club in an entertaining but challenging autocross.

The day started out cold with low cload and rain threatening most of the day





and eventually the rains did come


Autocrossing in the rain... I think Mary said it best... I'm glad it's you and not me. Funny thing is though, I think all of our best times came in the rain