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Discussion Starter #1
Even though we had not driven the '02 Camaro in a year, & made several changes to the car, we decided to head to Baytown ADRL T/S event, because we knew the track would be tight, & with ample safety crews.

The changes to the car include: looser stator for the Coan converter, bigger tires 33.5 x 16.5 x 16 MTs, about 35# out of the car by installing our lighter 16v lithium vs. the heavier Turbo Start battery, & fresh 738.

We really struggled all weekend, but did go a 4.43 & a 4.44 @ 165-166, but with 1.11 & 1.14 60'...usually low 1.0s. The reason for the slower 60' was that the n20 systems would not come on until .50-.65 seconds in to the run, which meant the 2nd system (our smallest 2 systems 32n22f & 34n24f) was not coming on until 1.20 seconds vs. .60 seconds. We decided to change the microswitch, & that fixed the problem, but with no data, we shook hard twice with the n20 coming on at the TB release...once with the smallest 32n & then even with the 34n on first. Our conclusion is that the IC @ 54" is just way too aggressive, & has too much bite...even after we added 10# to the nose, & went up 3/4# on tire pressure. We think the IC needs to be closer to 64". The track was max killer tight...teh "twins" from Brandymere were doing the prep work...badazz dudes.

We also encountered a leaking 6AN n20 line, but were fortunate to borrow one at the track.

Now knowing that the microswitch change was the issue on the n20 activation, on our last run E1 we decided to get after it by turning on the 34n on launch, then the 32n @ .40, & then the 36n @ 1.25. Well when shite goes wrong, it goes way wrong... the car launched like it wanted to run, but @ about .75 the car moved quickly right (from the left lane) to the centerline, & I had to lift. WTF! Going to the back of the car to look around for a cause, I noticed the left wheelie bar laying on the ground, & looked under the car to find the heim joint had been severed. Damn lucky the right side bar did not break, or that I was not in the right lane!

So these are our conclusions;

* We will either change our system of n20 activation from our
current single microswitch to DUAL microswitches, or to a
completely different system near the accelerator pedal;

* Lenghthen the IC to take some bite our of the car;

* Change all wheelie bar heim joints, & keep a spare or two in the
trailer;

* Fix the leaking n20 line, & keep a spare in the trailer;

We are currently using the Dedenbear Command Center to activate the n20 via stop settings. We are considering goint to a simpler delay box for shoe polish racing, & to digisets to activate the n20. Still an open issue.

Thanks to Charlie, Karen, & Robbie for the help this weekend.

Some photos... I will post the GoPro video of the run when the wheelie bar heim broke, if I can get it downloaded...









 

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Sounds good boss. At least you know what it will do now.
 

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Discussion Starter #4
I would say YES. Since we have two cars, I try to replicate what I can, to make tuning & working on them easier. The Dedenbear box was in the '02 when I bought it. We have always used digisets, & this approach has worked for us...have this set-up in the '69 Camaro. Thanks.
 

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At least you learned a lot from the weekend.

If you want less bite to get more wheelspeed, LOWER the air pressure in the slicks, not increase it. Increasing it will increase your bite, so you wanted to take some bite out but you actually added some by increasing your air pressure.

Do yourself a favor and put one of the Omron clutch switches in there for your WOT switch and those switch issues will disappear. After changing out micro-switches 3 times in a season, I caved in and got the Omron switch...that was 4 years ago and never have had a single issue.
 

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Discussion Starter #6
Many thanks, Mike. I agree with you on the air pressure, & that is what Charlie told me too. The Mickey Thompson rep at Baytown for the last NHRA event is the one who told me to raise the air pressure if the tire was on the shaking or close to shaking.

Can you share a link to the microswitch you are talking about, & possilby a photo of the install with bracket, as I remember you posting that in the past on YB. Thanks again.
 

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I think you need more hold downs for your hood!! I don't think its safe only having eleventy billion dzus fasteners, better add more ;-)
Just kidding. Car looks good!
 

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Discussion Starter #8
Mike, I think I found your post on this subject, & the Omron part...thanks!

got ours from Jerry Bickel. Look on his website under Electrical Components/Switches. The Bickel part number is JBRC5509. The switch is made by Omron so you can get it direct from them, through Grainger, as well. It comes pre-wired so you just pick the wires you want to use. Most people mount the switch inside the car so the gas pedal linkage activates it. The actuator arm can be rotated to any position necessary.


__________________
68 Camaro Pro Mod/Pro Street- R-M 846ci -

www.yvonnelucasracing.com
 

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Sorry to hear about the troubles of the weekend.. I just wanted to throw out a couple of my quick thoughts based on where your at...

1. As far as a WOT switch under the gas peddle to me that is a dangerous place. I know many do it and have not had an issue... YET. I have seen several times the linkage break at the carbs and the driver still has foot to the floor waiting for the car to go. At that point is where the carbs usually go BOOM !!!!! When the linkage breaks and the carbs close, YOU WILL HAVE PROBLEMS...

2. That car looks to have a short set of wheelie bars. Short bars are more violent to a high HP car. I myself like a longer set of wheelie bars as they are softer and more forgiving..

3. Tough for anyone to say if the instant center is right or wrong.. The "numbers" mean NOTHING when it comes to instant center in my book. If you have ever looked at an IC plot you will realize you can get the same or very similar numbers with more then one setting. Where the bars are located in reference to the housing and the chassis means a lot more in my book.

4. Not sure if you made any shock adjustments either ?? But the IC and or bar placement can be perfect but if shocks are totally off it won't matter..

5. I'm with the tire reps as well. From the way I have always tuned, if I was wanting wheel speed and wanted to make a change in tire pressure to see more speed I have gotten it from increasing pressure.. The lower you run a tire the more likely they become to cut up under the car and or wad up and shake..

I'm sure this stuff is just like all of this car stuff, everyone will have an opinion of what has worked for them, I just thought I'd share mine too.. LOL Good luck buddy.. SJ
 

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Tire pressure is a double edge sword...........while it does tend to stiffen the sidewall, it also flattens the tire out and puts more rubber on the ground, which a car with a lot of bite rarely needs. Pretty common on cars with moderate power, big tires and lots of bite to have to let the tires down so they "cup" and put less rubber down, plus run the wheelie bars really low, to "prop" the car up on the bars and let it make some wheelspeed.

Have told you before Ronnie......while data is a great thing, somebody watching the car and looking at the tire tracks who knows what they are looking at is pretty important. The tire tracks and how they look will tell you exactly what is going on

Monte
 

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Discussion Starter #11
Big thanks to both Steve & Monte for taking the time to share their knowledge with us. Great info, & lots to consider.

I will try to post a few videos from this weekend, but they are of marginal value, because the car was leaving on Motor for .50 seconds on 1 run, & .65 on the other....and not representative of the power when the n20 comes on at the hit. Our video camera went on the blink for the last run when the n20 DID come on at the release of the TB, so we do not have that data.

Steve, you probably remember that Jon Adams had this car, but with a 638 2 stages (vs. current 5" BS 738). The IC needs to be closer to where Jon had it when we first bought it, & not as aggressive as it is now, i.e. 54". I even added 10# to the nose, & lowered the bars, & it still was too aggressive EVEN ON MOTOR leaving...broke the damn WB heim!
 

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The nitrous guy
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Several things could have broke the heim Ronnie.........One, it just slammed the bars into the ground and broke it, although that generally breaks a top one. Two, tire shake. Maybe just shake in general...........but........if the tire is close to the lower bars, a wadded up tire will actually grab the bar and snap the heim off. Look at the bar and see if you can see where the tire touched it. Happens all the time on Pro-Mod cars, but since they run titanium bars, it usually snaps the bar in two. In your case with moly bars, it breaks the joint

I also agree with Steve, that this car needs longer bars with more flex. Those are super class bars and will be too short and violent for big power

Monte
 

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Discussion Starter #13
OK. Agree. Maybe I can take the Promod "long azz" bars from the '69, & run them on the '02, & put the shorter ones from the '02 on the '69...

Enclosed are the videos I promised. Again, this was leaving on Motor for .55 & .65 seconds, then 1st stage 32n24f & then 2nd stage 34n24f @ 1.25 seconds. 3rd stage Punisher 36n28f NOT on at all...4.43 @ 165 & 4.44 @ 166, slowpoke 1.10 & 1.14 60'. Our expectation is for it to run solid 4.20s @ 170 when we can get the 60' right, & bring in the 3rd stage.


1st: 32n 34n @ .55 & 1.25

http://s1132.photobucket.com/user/f...t=3&o=5&_suid=1382380912064024892229943831778

2nd: 32n 34n @ .65 & 1.25

http://s1132.photobucket.com/user/f...4.html?&_suid=1382381603191009518518320882574

3rd: To compensate for the weak wheelspeed, we decided to turn on the 34n first, BUT since we fixed the n20 activation with a new microswitch, the 1st stage came on at the release of the TB (no delay), & the launch was not stable with the car twisting on launch when it it the bars...

http://s1132.photobucket.com/user/f...4.html?&_suid=1382381511740015627675958414855

The '69 Bars...about 92" long.

 

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Discussion Starter #15
VS. '02 Bars...

 

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Discussion Starter #16
Monte, you are forgeting that I am a tightwad...LOL.

Let us stay focused, & first fix the existing bars, & change the IC to take away bite, & get some short time testing in. We can make changes from there. Again, the car PREVIOUSLY left flawlessly with these bars & engine & tranny....on less than tight tight tracks. The only changes we made were larger tires (MT 33.5 x 16.5 x 16 vs. MT 33.5 x 10.5W x 16), & a 500 RPM looser converter stator from Coan. Clearly the bigger tires & looser converter must be contributing to the "bite" on launch. A change in the IC closer to 60-64" from 54" should help. Also, we seldom encounter a track as tight as HRP was this weekend at the ADRL race.

Charlie & I have a plan, so we'll see. There is no one clear path, & that is what makes this sport so challenging, frustrating, rewarding, as the case may be!
 

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Discussion Starter #17
Just to show how shitty this 4.43 @ 165 run was... N20 did not come on until .65, & then when it came on the car jumped on the bars lifting the front end, & apparently I got out of it slightly @ 1.65 seconds & again @ about 2.00 seconds, before resetting the stage 1 & stage 2 activation all over again...not a clean run at all!




And even the other complete run 4.44 @ 166 was about the same...



Gives us reason for optimism!
 

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Discussion Starter #18
We made some changes on the '02 Camaro 4 link from 48" to 56" to take some bite out of the car, so we'll see. We are going to our local track on Sunday to participate in a Top Door Slammer race. The track will be much looser than the ADRL track at Baytown 2 weeks ago, so hopefully we have not taken too much bite out of the suspension.

Here is a photo from the ADRL race taken by a friend of mine, Whiz...

http://juslookn.smugmug.com/Events/...qgDgRd/0/L/Adrl World Finals pt.2-06430-L.jpg

Again, the n20 was not coming on until .50 & .65 seconds, & the 60' was way off, so if we got the n20 activation fixed (new microswitch), & the 4 link adjustment helps, we should see some improved #s. The air will be on KILL, maybe UNDER sea level!

Here is the data logger graph from Baytown again with the n20 NOT coming on until .50- .65...lots of room for improvement, & still went 4.34 @ 165 & 4.44 @ 166...1.10 & 1.14 60' is not the usual 1.0s 60'...

http://i1132.photobucket.com/albums/m567/fofolilsumptin/2002 Camaro/null_zps3155b343.jpg

Will report back...
 

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Discussion Starter #19
Sorry, typo...went 4.43 & 4.44, not 4.34, but it should go 4.30s on two baby stages IF we can get the n20 to come on, & traction is not an issue. We still have the larger 3rd stage 36n26f Steve Johnson Punisher we have NOT turned on yet...
 
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