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Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 3:05 pm
by BrazilianZ28Camaro
Old as Dirt wrote:
BrazilianZ28Camaro wrote: my car pull the wheels off the ground, runs a couple feet then the wheel touch the ground, then they lift again...then they come back to ground....seems like the weight transfer is too fast and the IC is a bit high.

Probably I'll work on these settings next race and see what happens....what you think , sounds like a good move?

Thanks for reply!
Take a friend with you and do some more video.. pay close attention to the "Rear" tires and see if they are "bouncing" at the hit.. and slipping a little before biting again.. like he talks about.. stiffen the rear shocks until they settle down.. then see if you can adjust the fronts to provide the transfer without the bounce..

If the front end travel is allowed to come up really fast, the negative result is what happens when you run out of suspension travel. If you do not run out of suspension travel gently, you will unload the rear of the car because you just jerked the tires off of the ground resulting in a shockwave down the chassis unloading the tires."


you'll figure it out.. been doing a great job so far.. have fun!

On the video I linked here, at 4:06 you can see exactly what is happening. At launch, the rear tires bite , the front start to lift, the rear end start to rise and the front suspension too.

Car do wheelie, rear is high, but soon the front tires bounce on and off the ground. Looks like the front is rising too fast and unloading the rear, but aparently, the rear tires are still planted.

The caltrac bars are set on the lower holes front and back...I'm considering set the bar at the upper hole in the axle side to lower the I.C. to try to soften the hit a little.

What you think?

I'll try to have a friend filming on 60 FPS the car launch next time.

Thank you very much for the help and good words! =D>

Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 3:16 pm
by BrazilianZ28Camaro
jim_ss409 wrote:Way to go!
The engine sounds great! =D>

Thank you again Jim, my ears still hurt a little since last sunday :lol:

Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 3:34 pm
by BrazilianZ28Camaro
F-BIRD'88 wrote:This car is the BOSS.

Looks like Grumpy Jenkins classic 70 pro stock drag pics.
=D> =D> :notworthy: :notworthy:
Thaks alot F-Bird!

You know, my initial dream about my car style was to make it like a 70 S/S Jenkins car clone...but to build it decently, I should have the correct engine parts, like the T-ram and carbs, instruments ,seats,etc,,,wich were hard to find....so I went to the next style I love, the Pro-Street wich is very hard to see overhere.In fact my car is the first one to follow this school in my State.

Funny you mentioned Jenkins... he and Dick Harrel are my greatest inspirations regarding personnal behavior, dedication and techinical knowledge. I just LOVE the S/S cars soooo much , so just being compared to look like one of my Idols is a big honor.The day I own five percent of their knowledge I'll be a realized person. :)

I own my car since 2001 and worked a lot on it, to make it a street strip car like I always dreamed about. I didn't saved any effort to make things right, even if I had to do things twice. I feel like I'm blessed because this is the very first engine I built of this power level, and the car responded soo well ,so soon.

Thanks again for the good words. Hope I can improve my times. I'll keep you friends updated :D

Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 6:11 pm
by Old as Dirt
Before filming.. paint a vertical stripe on the sidewall.. will help to see if it is slipping a little as the front bounces.. and a 1" wide stripe around the outside diameter of the slick to see if it rolling under.. you may also want to match mark the rim to the tire so you can tell if the tire is slipping on the rim.. should prove interesting..

Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 6:17 pm
by BrazilianZ28Camaro
Old as Dirt wrote:Before filming.. paint a vertical stripe on the sidewall.. will help to see if it is slipping a little as the front bounces.. and a 1" wide stripe around the outside diameter of the slick to see if it rolling under.. you may also want to match mark the rim to the tire so you can tell if the tire is slipping on the rim.. should prove interesting..

Yeah,, I intended to do that,, but was in a hurry the saturday before the race and forgot the chalk at home! #-o

At the launch I'm footbraking the car to 2000 rpm ....I'm just wondering what a good ol transbreak would do to the sixty foot 8)

Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 8:14 pm
by F-BIRD'88
You can "Film" the tire/chassis launch reaction using your smart phone or a digital camera with video function.

You can then process the vid using the VLC computer video software and can extract frame by frame stills
and really see whats happening to the car/tires/suspension as you launch.

VLC player is a free download for your computer and for your smartphone.
Google it.

Re: Camaro is back to the action....finally!

Posted: Sat Oct 31, 2015 8:33 pm
by BrazilianZ28Camaro
F-BIRD'88 wrote:You can "Film" the tire/chassis launch reaction using your smart phone or a digital camera with video function.

You can then process the vid using the VLC computer video software and can extract frame by frame stills
and really see whats happening to the car/tires/suspension as you launch.

VLC player is a free download for your computer and for your smartphone.
Google it.

Will do!

Great tip F-bird! =D>

Re: Camaro is back to the action....finally!

Posted: Mon Nov 02, 2015 2:16 pm
by BrazilianZ28Camaro
wyrmrider wrote:any chance of a wheele and you should have already tied your chassis together or a cage hate it when they bend in the middle or even start showing wrinkles on the quarter panels

Talking about tie it together,, this topic might be a cool reading to you friends:

viewtopic.php?f=11&t=44747

Thanks again.

Re: Camaro is back to the action....finally!

Posted: Mon Nov 02, 2015 6:22 pm
by Old as Dirt
Diego, have you tried launching the car at a lower rpm? Maybe loading the suspension with a tight converter is taking away some front end travel.. and with the throttle pressed to get 2000rpm footbrake, maybe you only have half the "Shooter" volume left in the carbs accelerator pumps.. might be worth trying to hit the converter harder with less rpm off the line..

Re: Camaro is back to the action....finally!

Posted: Mon Nov 02, 2015 6:43 pm
by BrazilianZ28Camaro
Old as Dirt wrote:Diego, have you tried launching the car at a lower rpm? Maybe loading the suspension with a tight converter is taking away some front end travel.. and with the throttle pressed to get 2000rpm footbrake, maybe you only have half the "Shooter" volume left in the carbs accelerator pumps.. might be worth trying to hit the converter harder with less rpm off the line..
Yes, I tried to launch at lower rpm , but the engine stumbled. I still have some accelerator pump tune to do, so I can try to launch the car better.

There was little time between rounds, so my time to tune was limited.

Thanks for asking!

Re: Camaro is back to the action....finally!

Posted: Tue Nov 03, 2015 9:45 pm
by rfoll
By now you know what I was talking about when I said the torque will make you silly. I'm glad to see all of your hard work pay off. Your dedication to the sport puts most of us to shame.

Re: Camaro is back to the action....finally!

Posted: Wed Nov 04, 2015 1:52 pm
by BrazilianZ28Camaro
rfoll wrote:By now you know what I was talking about when I said the torque will make you silly. I'm glad to see all of your hard work pay off. Your dedication to the sport puts most of us to shame.
:lol: :lol: :lol: :lol:

Torque...you have to feel it to understand it :) ...yes, it did me smile ear to ear....for a few days.

First time at the strip I felt the slicks biting and the revs eating the gears I was really impressed and had no time left to fear the acceleration :lol: ...I never raced a car that quick before.

You know, when you born with high octane gasoline in your the veins,,you're always working on cars. They say when You work with total dedication on the things you love to do, the success is unavoidable.

Thank you very much for the nice words,, as I said before, all the friends that helped me here own a part of these results I'm having now. =D>

Let's see If I can inprove them. 5th, December is the next race.

Re: Camaro is back to the action....finally!

Posted: Mon Nov 09, 2015 6:02 pm
by BrazilianZ28Camaro
Old as Dirt wrote:
The rear of the car with this added weight transferred from the rising front will lift very little but it should not go down (squat).
An inch or two is normal and can be best seen by looking at the relationship between the top of the slicks and the rear fender lip.

"
Looking at some pictures of my car launching I'm wondering if the excessive rear end lift may do any harm to the ET or the leaf springs.

As I see its not common to see the leaf spring arched that much.

What do you frieds think? Any tip? Maybe adjustable rear shocks or a different Caltrack bar setting/preload ?

Image

Thanks again for the help!

Re: Camaro is back to the action....finally!

Posted: Tue Nov 10, 2015 8:58 am
by enigma57
Diego, there are many forces at work when you launch that hard. I do not have the answer regarding Cal-Trac setting, but have broken a main leaf once. Whatever you do, get your car on a lift and make a close inspection of all your rear suspension components, welds, etc. before you go out onto the track. You don't want to have this happen......

https://www.youtube.com/watch?v=V2tk8X8tZok

Best regards,

Harry

Re: Camaro is back to the action....finally!

Posted: Tue Nov 10, 2015 10:48 am
by Old as Dirt
Yes Diego, adjustable rear shocks with an increase in rebound stiffness.. will slow down the lift(separation)in the rear.. if that doesn't do the trick on the stiffest setting, you may have to go with a bit stiffer spring and a softer shock setting....

When you get in the ballpark with rear spring/shock combo's.. then work on the front..

You could also increase the rebound setting on the fronts to slow the front end rise before the suspension tops out(runs out of travel and jerks the tires off the ground vs. coming to the end of travel softly)

There is also a huge thread on Yellow Bullet that has some good info on CalTrac settings..
http://www.yellowbullet.com/forum/showt ... p?t=288916