4 Link System - Step by Step

[Mike Peters]

Guys,

Here is the movie of the last race:

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

I'll wait new comments!!

Thamks,

Jeff, what changes did you make to the car for this race and what were your previous ET's and 60' times compared to these?

[Jeff 4100]

Jeff, what changes did you make to the car for this race and what were your previous ET's and 60' times compared to these?

Mike,

This race happened in August!! There we changed the rear axle ratio (3,90 to 4,27) and more weight on the rear.

Until this race, my best 60 ft was 1,969s and the ET was 12,300s!

The other improvements that we talked last week will be tested on this weekend.

Thanks,

[Mike Peters]

Jeff, what changes did you make to the car for this race and what were your previous ET's and 60' times compared to these?

Mike,

This race happened in August!! There we changed the rear axle ratio (3,90 to 4,27) and more weight on the rear.

Until this race, my best 60 ft was 1,969s and the ET was 12,300s!

The other improvements that we talked last week will be tested on this weekend.

Thanks,

Looks like you're headed in the right direction. List the changes to the car you're making for this weekend's race. Are you experiencing tire spin on launch? Did the weight increase over the rear eliminate the tire spin? Were you able to find some of the Hi-Tack and apply it to your tire bead to prevent the slippage on the wheel? Are you able to find some places to remove weight from the car while keeping the weight over the rear tires?

[Jeff 4100]

Looks like you're headed in the right direction.

Owww...It sounds like a sing for me...Thanks!!

List the changes to the car you're making for this weekend's race. Are you experiencing tire spin on launch? Did the weight increase over the rear eliminate the tire spin? Were you able to find some of the Hi-Tack and apply it to your tire bead to prevent the slippage on the wheel? Are you able to find some places to remove weight from the car while keeping the weight over the rear tires?

For this race, our main issue is the gear box!! I had a lot of troubles with it. I think my ET will fall 0,2sec just If I change the gear box...today I'll finish it!!!
Because this, I'll just remove the front sway bar, apply the Hi-Tack (I got one similar!) on the rear tires and, maybe, put softer springs on the rear...
What do you think about the rear springs?? The car's rear don't drop anything down...

About the front weight...I'll remove just for the race on december...

Thanks!

[Mike Peters]

What do you think about the rear springs?? The car's rear don't drop anything down...

According to Dave Morgan, you could plant the tires harder if you used some springs with stored energy in them. In order for springs to have stored energy, they will need to be taller than your current springs and a lighter rate. This type of spring will allow you to maintain your current ride height of the car but, during launch will push the rear of the car up and therefore, with equal and opposite force, push the tires into the track. This could possibly give you more traction.

Let us know how the new modifications work for you this weekend.

[BillyShope]

With regard to "stored energy," see page 32:
http://www.racetec.cc/shope

[Jeff 4100]

I know is when you remove the front sway bar, you're front suspension will move easier and therefore increase the transfer of weight to the rear.

Mike,
The front sway bar is free!!!
Yesterday, I removed some bushings and the front sway bar got too loose!!!

You had to see how my gear box got now!!!!!
I'm so excited to enter on the 11 seconds this weekend!!!
So, the cars are basically ready to fight!!!

Let's goooooooooooo!!!
Thanks,

[Mike Peters]

I thought maybe you could remove the sway bar completely or is that not allowed in the rules? That would be weight removed from the front if possible. If not, you did the next best thing.

[Jeff 4100]

I thought maybe you could remove the sway bar completely or is that not allowed in the rules? That would be weight removed from the front if possible. If not, you did the next best thing.

Yes Mike, I can't remove this bar because the rules...

It would be a good weight to be removed...

[Mike Peters]

Yes Mike, I can't remove this bar because the rules...

It would be a good weight to be removed...

I was assuming you couldn't or you would have removed it. You've certainly got a unique set of rules. What if you were to bend some very lightweight tubing to resemble the front sway bar since it no longer functions? Also, replace the existing brackets that were holding the sway bar bushings with some lightweight versions.

[Jeff 4100]

I was assuming you couldn't or you would have removed it. You've certainly got a unique set of rules. What if you were to bend some very lightweight tubing to resemble the front sway bar since it no longer functions? Also, replace the existing brackets that were holding the sway bar bushings with some lightweight version.

Very good idea Mike!!!
Let's study a form to do it!!!
Thanks!!

[Jeff 4100]

According to Dave Morgan, you could plant the tires harder if you used some springs with stored energy in them. In order for springs to have stored energy, they will need to be taller than your current springs and a lighter rate. This type of spring will allow you to maintain your current ride height of the car but, during launch will push the rear of the car up and therefore, with equal and opposite force, push the tires into the track. This could possibly give you more traction.

Mike my friend,

Look the pictures below!! I changed the rear springs!!
My older springs had 227 lb/ft. And the my newest spring has 172 lb/ft.
Visually I didn't see difference on the rear height...this new springs stayed perfect there!!

And the rear movement got softer than the older springs...
Now, the car is ready to run!!!
My goal for this race will be run 1,7sec on the 60 ft!!!

Let's see this improvements on the practice!!!
Thanks!!!!!!!!!!!!!!

[Mike Peters]

Jeff, sounds like you're doing all the right things and there should be improvements for you this weekend. We'll be anxious to hear what your results are. Remember, sometimes when you change things, the improvements are not immediate and will need some practice to make them work for you. In your case, the things you have changed should be an immediate improvement and gain. I will be surprised if they don't.

[Jeff 4100]

Jeff, sounds like you're doing all the right things and there should be improvements for you this weekend. We'll be anxious to hear what your results are. Remember, sometimes when you change things, the improvements are not immediate and will need some practice to make them work for you. In your case, the things you have changed should be an immediate improvement and gain. I will be surprised if they don't.

Hi Mike!!
Sorry for my delay...I’m in my vacations and I’m traveling a lot.
So, I’ve very good news to share with you again.
That weekend began so difficult for us. Saturday morning we had a problem with the crankshaft gear and we gave up to run in this Day.
We came back to our garage and we disassembly the engine to take the crankshaft out to repair the crankshaft gear area.
We started this repair at Saturday 04:00PM and finished at Sunday 06:30AM!!! After corrected this issue, we came directly to the track!!!
Other issue that we fought was the track conditions. The humity was so high because of the raining during all the week before the race.
Anyone didn’t get launch well!! Only us!!! Kkkkkkkkkkkkk!!!
Now we got the first best 60ft time in our category!!! Fantastic!!!
Almost were running 1,970...2,100sec!!! My car impressed everybody!!! I got a lot of CONGRATULATIONS!!!
Our 60ft time were:
- 1,886s
- 1,912s
- 1,902s
- 1,858s (our best time in our lives!!!)
- 1,899s
Look the pictures below. The second picture shows the tire sidewall on the exact moment on the launch. Guy, the tire is deforming!!!!!!! And the tire sliping happened again!!!The tire pressure was 15lbs...I think I ‘ve a problem with the wheels!!! The third Picture shows the my friend’s car that I made the rear suspension. In this car it didn’t happen!!! I think his wheels has more internal area to contact the tire...I’ll test other wheels...I think!
I’m imagining the time that I’ll gain If this problem doesn’t happen...
This car ran 2,025s in its best launch...there we’ve a problem with the driver. He is new in drag races and He’s adapting with the car!!! But, the car visually shows us a right rear and front suspension movement...let’s wait the driver now...kkkkkk

Beside this, the gear Box issue came back again...I couldn’t shift the 2nd gear...and my best ET was 12,200s and I got the 4th place again!!! For me it was our best race in our lives...because all the difficulties that we had and now the car is so Constant on the launch!!!
I’ll replace the gearbox to the DragRace Festival in December...and now I’m sure that I’ll reach the 1,7sec and the ET near to 11,8s!!!

I don’t know now If I told everything or If I told with all the right descriptions...So, ask me please!!!
I’m waiting more Dragstuff friends in my topic!!!
I’m happy with the car and I think I’m going to the right way...Thank you!!!
You are helping me to make it real!!!
Thanks,

[Mike Peters]

Excellent job Jeff. Congratulations for running the quickest 60" time in the class. It sounds like once you get the rest of your problems fixed, you could be running with the top of the class.

Let's talk about the tires you are required to use. You stated they were Goodyear Excellence tires. Are they radial construction? I'm sure the sidewalls are much stiffer than a drag racing tire so, the low pressure won't work as well in them. My concern is your statement that the sidewall is deforming. This is not good with your street tires because the center of the tread is probably cupping and not applying full traction force to the track. Have you been able to look at your tire pattern left on the track? If the outer edges are darker then you will need more tire pressure. I would suggest the next time you go to the track, you try 20 psi. This might also eliminate the tire slippage problem on the wheel. If 20 psi shows an improvement, don't be afraid to try 25 psi for the next pass.