4 link adjustment on drag radial

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soslojoe1970
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Re: 4 link adjustment on drag radial

#16 Post by soslojoe1970 » Fri Apr 10, 2009 1:39 pm

I bracket race the the car all the time and with the 31-10.5 slick the car 60foots a 1.33. I tried last weekend to run the radial and it didn't work.

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Dave Morgan
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Re: 4 link adjustment on drag radial

#17 Post by Dave Morgan » Sat Apr 11, 2009 3:21 pm

Soslo,
You're getting a lot of great advice. You already know you shortened the IC, but listen to the advice about more rear weight and using the shocks. The tire psi recommendation also sounds good to me. By the way, what brand of shocks do you have (I hope they are not Aldan Eagles.)
Dave
Author of "Doorslammers: The Chassisbook"
Drag Racing Chassis Seminars and Videos

soslojoe1970
Posts: 67
Joined: Wed Apr 08, 2009 5:43 am

Re: 4 link adjustment on drag radial

#18 Post by soslojoe1970 » Sun Apr 12, 2009 12:55 pm

There koni double adjustable rear shocks. I also just bought your book and will be doing some reading this week. Im getting ready to go out and do some wrenching. Any suggestions on an IC?

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Dave Morgan
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Re: 4 link adjustment on drag radial

#19 Post by Dave Morgan » Sun Apr 12, 2009 9:56 pm

Soslo,
For IC length, refer to the chart on page 132. If your car is properly sprung, you'll find those values to be a little aggressive so add four inches to every dimension.
Dave
Author of "Doorslammers: The Chassisbook"
Drag Racing Chassis Seminars and Videos

soslojoe1970
Posts: 67
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Re: 4 link adjustment on drag radial

#20 Post by soslojoe1970 » Mon Apr 13, 2009 5:34 am

I glanced at that when I got the book on friday. I didn't think my car fell into that chart. 3000 lbs car and runs 8.90's on motor in 1/4mile?

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Dave Morgan
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Re: 4 link adjustment on drag radial

#21 Post by Dave Morgan » Mon Apr 13, 2009 8:09 am

Sorry about that, heavy cars were'nt running that fast when I wrote the book!
I would aim for an IC about 46 inches long. Just remember to listen to what your rear shocks tell you (pages 92-93).
Dave
Author of "Doorslammers: The Chassisbook"
Drag Racing Chassis Seminars and Videos

soslojoe1970
Posts: 67
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Re: 4 link adjustment on drag radial

#22 Post by soslojoe1970 » Mon Apr 13, 2009 2:11 pm

Thats about where it is now........ 46 and about 8" high. I have always had the shocks set pretty loose (old street racer).

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Dave Morgan
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Re: 4 link adjustment on drag radial

#23 Post by Dave Morgan » Mon Apr 13, 2009 2:19 pm

What happens when you stiffen the rear shocks?
Dave
Author of "Doorslammers: The Chassisbook"
Drag Racing Chassis Seminars and Videos

soslojoe1970
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Re: 4 link adjustment on drag radial

#24 Post by soslojoe1970 » Mon Apr 13, 2009 3:51 pm

I turned the bottom setting from 0 to 3 clicks which stiffened the rear shocks and car still didn't move.

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Dave Morgan
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Re: 4 link adjustment on drag radial

#25 Post by Dave Morgan » Mon Apr 13, 2009 9:19 pm

The top setting is the one that will tell you what your IC wants. Try stiffening that, then work with the lower adjustment, starting at 0.
Dave
Author of "Doorslammers: The Chassisbook"
Drag Racing Chassis Seminars and Videos

soslojoe1970
Posts: 67
Joined: Wed Apr 08, 2009 5:43 am

Re: 4 link adjustment on drag radial

#26 Post by soslojoe1970 » Wed Apr 15, 2009 12:03 pm

Hey Mr. Morgan was was reading a little more of your book last night. I woundering if there is an english version, It seems I have one written in a foreign language.

soslojoe1970
Posts: 67
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Re: 4 link adjustment on drag radial

#27 Post by soslojoe1970 » Sat Apr 18, 2009 6:12 am

I wanted to thank you guys for your input. Working much better now.... 1.28 60 foot time on the radial on motor. Better 60 foot time then I had on the slicks. But I still have some fine tuning to do. I always chauk the outside edge of the rear tires to see how its hitting the track and helping me adjust the tire pressures. The car doesn't leave every time consistantly. The passenger outside edge of the tire isn't scubing the tread all the way to the edge of the tire like the drivers side is. I also noticed after the pass the passenger tire pressure is lower the the drivers side. So I imagine when it is lauching its lifting the passenger tire up and not planting like it should. So shock adjusting.... pre load .... sping????? Please now need some fine tuning advise?

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Re: 4 link adjustment on drag radial

#28 Post by want-a-be » Sat Apr 18, 2009 12:39 pm

soslojoe1970 wrote: I also just bought your book and will be doing some reading this week.
I bought Daves book the first year it was out. That thing has been read by a lot of my friends. I read it cover to cover the weekend I got it. That next week I went to a friend of mine, Mike Sullivan, and we went over a ton of questions that book created for me. Mike taught me a lot about tuning race cars. Reading Daves book did a good job of teaching me some things to look for. Mike taught me how to use the information and what to be looking for at the track. I'll probably pick up a newer edition to see how different the old and new books are some day.

soslojoe,...good to hear you got your chassis lined out.

Don

soslojoe1970
Posts: 67
Joined: Wed Apr 08, 2009 5:43 am

Re: 4 link adjustment on drag radial

#29 Post by soslojoe1970 » Sat Apr 18, 2009 2:38 pm

Any idea on next set-up change? Im running out of test and tune time. First points race coming up.

want-a-be
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Re: 4 link adjustment on drag radial

#30 Post by want-a-be » Sat Apr 18, 2009 4:21 pm

soslojoe1970 wrote:Any idea on next set-up change? Im running out of test and tune time. First points race coming up.
What engine are you running? What and where are the HP and torque numbers? What stall converter are you using? Who made it? What launch RPM are you using, ( the low side chip in the 2 step ). Gear ratio? Tranny type? Front and rear spring rates? % of weight on the rear tires? How long a shock do you have on the front, and the rear? when the car is just sitting there, how much shaft are you seeing out of the shocks? Both front and rear. How low is the car? What kind of timing are you running? Is the distributor locked out or do you still have mech/vac advance in it?

Since you got the drag radials working better, does the front end come up? If so how far out does it carry the tires? Does it still run the 8.90s with the new tires?


This ought to get us started. :scratch:

Don

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