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FInding IC on a 4 link #992721 05/15/11 12:22 PM 05/15/11 12:22 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	Well, I got my car up on the rack (level) and took the first set of measurements. With my weight in the car....... Wheel base-- 114" rear axel center height-- 14.5" LH upper bar-- 11 deg down towards the front LF lower bar-- 1.5 deg up towards the front RH upper and lower bars are the same as the LH bars.

Re: FInding IC on a 4 link [Re: WILD BILL] #992722 05/15/11 12:37 PM 05/15/11 12:37 PM
Joined: Jan 2003 Posts: 16,941 NC 440Jim I Live Here
440Jim I Live Here Joined: Jan 2003 Posts: 16,941 NC	I have a MicroSoft Excel file that does 4-link instant center calcs. But the board doesn't allow attaching. Quote: The files you may upload must have the following extension: .gif,.jpg,.txt,.zip,.png,.pdf,.jpeg,.JPG,.GIF If you would like it, email me. Here is a picture of it. You need to put actual hole location measurements into it to match your car. Then you can change holes to see where the IC goes to. Jim 6634218-4-link_example.jpg (182 downloads)

Re: FInding IC on a 4 link [Re: 440Jim] #992723 05/15/11 12:49 PM 05/15/11 12:49 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	Thanks, I'll have to do that when I get home tonight. Here's my bar lenghts LH uppper; 19" (I corrected my mistake ) LH lower; 19 1/2" RH upeer: 19" RH lower; 19 1/2" Gonna take me a little longer to plot out the hole locations Last edited by WILD BILL; 05/15/11 03:23 PM.

Re: FInding IC on a 4 link [Re: WILD BILL] #992724 05/15/11 01:11 PM 05/15/11 01:11 PM
Joined: Jul 2007 Posts: 189 Newark, OH springers340dart member
springers340dart member Joined: Jul 2007 Posts: 189 Newark, OH	i had the same problem you did Bill with the car twisting with wheels in the air. i fixed that by (with the car on the ground) take a bolt of of your top bar on the passenger side. you get in the car and have your dad turn the bar till you can put the bolt back in. that resets your preload and mine left straight and level and didn't have a problem on the top end. this sig pic was before i did it i have one of after. 6634274-scan0001.jpg (214 downloads) Last edited by springers340dart; 05/15/11 01:13 PM.

Re: FInding IC on a 4 link [Re: springers340dart] #992725 05/15/11 01:15 PM 05/15/11 01:15 PM
Joined: Jul 2007 Posts: 189 Newark, OH springers340dart member
springers340dart member Joined: Jul 2007 Posts: 189 Newark, OH	pic 6634283-scan00021.jpg (152 downloads)

Re: FInding IC on a 4 link [Re: 440Jim] #992726 05/15/11 02:30 PM 05/15/11 02:30 PM
Joined: Jan 2003 Posts: 4,821 Moved to N.E. Tennessee GomangoCuda master
GomangoCuda master Joined: Jan 2003 Posts: 4,821 Moved to N.E. Tennessee	Quote: I have a MicroSoft Excel file that does 4-link instant center calcs. But the board doesn't allow attaching. Quote: The files you may upload must have the following extension: .gif,.jpg,.txt, .zip ,.png,.pdf,.jpeg,.JPG,.GIF If you would like it, email me. Here is a picture of it. You need to put actual hole location measurements into it to match your car. Then you can change holes to see where the IC goes to. Jim Jim, can you Zip the Excel file and attach that? In theory, there is no difference between theory and practice. In practice, there is.

Re: FInding IC on a 4 link [Re: springers340dart] #992727 05/15/11 02:31 PM 05/15/11 02:31 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	OK, here's the locations of the bolts (center) of each bar location. They are the same left or right. Upper front; 16" Upper rear; 19 1/2" Lower front; 8 3/4" Lower rear; 8 1/2 " I'll have to try and draw a pic on the computer to show what my hole loactions do as they are curved and not in a straight line. However, the front upper holes are 3/4' on center. The front bottom areand both upper and lower rear hole are 1 " on center. I think my heads gonna explode now

Re: FInding IC on a 4 link [Re: WILD BILL] #992728 05/15/11 02:36 PM 05/15/11 02:36 PM
Joined: Jan 2003 Posts: 4,821 Moved to N.E. Tennessee GomangoCuda master
GomangoCuda master Joined: Jan 2003 Posts: 4,821 Moved to N.E. Tennessee	Just get a piece of chalk and draw it on your garage floor or use thumbtacks and string on your wall. In theory, there is no difference between theory and practice. In practice, there is.

Re: FInding IC on a 4 link [Re: WILD BILL] #992729 05/15/11 02:40 PM 05/15/11 02:40 PM
Joined: Oct 2004 Posts: 1,752 detroit area M moderncylinder top fuel
moderncylinder top fuel M Joined: Oct 2004 Posts: 1,752 detroit area	so you are saying that your passenger bar is 1/4" longer than the drivers side? so you have "reverse" preload? to preload the bar you would shorten it on the passenger side as compared to the drivers side in,, and 1/4" would be alot,, maybe thats your problem i wouldnt change the 4 link positions, it looks like the car left ok and the tire looks ok,,, adjust your preload scale the car with you in it ready to race first,, or after you just change the length of the top passenger bar

Re: FInding IC on a 4 link [Re: GomangoCuda] #992730 05/15/11 02:41 PM 05/15/11 02:41 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	Quote: Just get a piece of chalk and draw it on your garage floor or use thumbtacks and string on your wall. I got it all on paper but would need to do it in PAINT or something like that for you guys to be able to see it. My drawing ability is worse than my reaction times

Re: FInding IC on a 4 link [Re: moderncylinder] #992731 05/15/11 02:54 PM 05/15/11 02:54 PM
Joined: Jan 2003 Posts: 4,821 Moved to N.E. Tennessee GomangoCuda master
GomangoCuda master Joined: Jan 2003 Posts: 4,821 Moved to N.E. Tennessee	Quote: so you are saying that your passenger bar is 1/4" longer than the drivers side? so you have "reverse" preload? to preload the bar you would shorten it on the passenger side as compared to the drivers side in,, and 1/4" would be alot,, maybe thats your problem That's assuming that the chassis work is nice and square. I am guessing that is not because if it was perfect you couldn't put that much preload into it without bending something. To set preload I would take the right front upper bolt out and adjust the bar so that the bolt just slides in. Then shorten that rod say three flats to preload the right side a little and try it out. The direction the car goes will tell you whether to go with more or less preload from here. If you have access to scales thats the best way. In theory, there is no difference between theory and practice. In practice, there is.

Re: FInding IC on a 4 link [Re: WILD BILL] #992732 05/15/11 02:59 PM 05/15/11 02:59 PM
Joined: May 2004 Posts: 12,493 Taxes & Virus's R-US, NY Dragula I Live Here
Dragula I Live Here Joined: May 2004 Posts: 12,493 Taxes & Virus's R-US, NY	'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft) https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car) https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car) https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9) '66 Barracuda AWB Stretched nose Blown 440 Car in build stage '71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph https://www.youtube.com/watch?v=Znuo3jMUXTk

Re: FInding IC on a 4 link [Re: Dragula] #992733 05/15/11 03:14 PM 05/15/11 03:14 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	I don't have acsess to scales I'll try the sliding bolt method but my bars don't have any flats so I'll just have to try and eye ball a 1/2 turn.

Re: FInding IC on a 4 link [Re: WILD BILL] #992734 05/15/11 03:22 PM 05/15/11 03:22 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	My mistake. I just went to adjust the bars and remeasured to verify my starting point and I WAS WRONG. BOTH upper bars are 19" long. I'll go back up and edit the above post. Then double check all the rest of my measurements

Re: FInding IC on a 4 link [Re: WILD BILL] #992735 05/15/11 03:35 PM 05/15/11 03:35 PM
Joined: Jan 2003 Posts: 32,394 Q Quicktree I Win
Quicktree I Win Q Joined: Jan 2003 Posts: 32,394	Bill if no one can help you I think Tom RT540 has a plotter he can figure it out. send him a pm. I bet he can help.

Re: FInding IC on a 4 link [Re: GomangoCuda] #992736 05/15/11 03:38 PM 05/15/11 03:38 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL OP Senior Member of the Junior Dragster Club
WILD BILL OP Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	Quote: To set preload I would take the right front upper bolt out and adjust the bar so that the bolt just slides in. Then shorten that rod say three flats to preload the right side a little and try it out. OK, I did that and quit frankly I think it's right back where it was to begin with but at least know we know what the sarting point is. Bout a half turn of preload.

Re: Finding IC on a 4 link [Re: WILD BILL] #992737 05/16/11 11:39 AM 05/16/11 11:39 AM
Joined: Oct 2006 Posts: 149 Cleveland Ohio Discoquik member
Discoquik member Joined: Oct 2006 Posts: 149 Cleveland Ohio	Bill- Dave Roemer has scales, I would ask him if you could bring the car down and scale it with him. He is very good at making a chassis work right the first time out. He is the one that taught me how to set up four links and ladder bars.

Re: FInding IC on a 4 link [Re: WILD BILL] #992738 05/16/11 12:39 PM 05/16/11 12:39 PM
Joined: Jan 2003 Posts: 16,941 NC 440Jim I Live Here
440Jim I Live Here Joined: Jan 2003 Posts: 16,941 NC	Bill, The attached is the result I emailed to you. I tried to input the numbers you posted. I just used 1.00" as a reference point of the rear holes from the axle centerline. Then I calculated the front hole distance using the bar lengths and front hole heights you posted. It looks about right, as the calculated bar angles are pretty close to what you measured. Jim 6635922-4-link_WildBill.jpg (176 downloads)

Re: FInding IC on a 4 link [Re: 440Jim] #992739 05/16/11 07:09 PM 05/16/11 07:09 PM
Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio VernMotor master
VernMotor master Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio	Well that will make his head spin !

Re: FInding IC on a 4 link [Re: VernMotor] #992740 05/16/11 08:16 PM 05/16/11 08:16 PM
Joined: Dec 2005 Posts: 872 NJ SSDAcuda super stock
SSDAcuda super stock Joined: Dec 2005 Posts: 872 NJ	http://www.racetec.cc/shope/tim.12.htm SS/DA 1924

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