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Modified set up

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Modified set up

I watched NASCAR once | Posts: 2 | Joined: 09/08
Posted: 09/23/08
03:13 PM

Anyone out there that has run a modified (78 chev camero fron clip)on asphalt have a good idea on front moment centers. We have not had time to mesure the front for moment center, but I have to belive there is only a few ways to go with upper control arm angles with the stock clip. We have heard "shoot for 18-21 degrees on the RF and 10-12 degrees on the RF". We have heard this will get you in the ball park, but no mention on rear track bar settings. Anyone go through mesuring and entered it into a program to verify the "ball park"? Thank you.
13/4" front sway bar
LF spring-650
RF spring-700
No set back
3 link rear
RH mount J-bar short-11 3/4" LH 13" RH mount
10" slicks  

clemenskid21 clemenskid21
I watched NASCAR once | Posts: 3 | Joined: 01/09
Posted: 01/28/09
08:56 AM

I do not have a camaro clip on the modifieds i have built, but the moment center location should be similar as they are similar style cars. From what I have found the moment center location should be about 3" to the right of centerline, and 2.5" - 3" high. Now the moment center placement will vary depending on the track banking and such. Usually 18 degrees upper a arm angle at the RF and 14 Degrees at LF will get you ball park, but to be accurate you should probably purchase a RC calculating software. performance trends offers a nice one for under $100.

Remember that almost everything in the front end will affect moment center. Your camber, a arm length, anti-dive, stagger, ride height,spindle height so be sure that when you do check it that all of this is set first! Also, a big priority for setting moment center is to keep its movement minimal. I have captured mine to within 5 inches of movement under dive and roll

Hope this helps!

Also here is a basic setup on a modified for 1/2 Mile 15 Degree banking
53% wedge
58% left
51% Rear

1" stagger in front and 2 1/2" - 3" in rear with spool

LF 500 5   Shock   RF 550   6/3 Shock
LR 175 4/6 Shock   RR 150   5   Shock

7/8" Sway bar...which I only run neutral.

I also usually run 2" split uphill towards RR in Panhard bar (hooked to chassis on right) 12" high on left, and 14" high on right

This setup has been proven on four different clipped cars, that have won over 40 features and two championships in the last 4 years. I also don't change setup much from track to track. Have raced it on a 1/4 mile all the way up to 3/4 mile with minimal changes. Has been competetive everywhere.

Not sure if you will see this post because I am about 4 months behind previous post, but Hope this helps anyone else in search of info  

CtTech CtTech
I watched NASCAR once | Posts: 23 | Joined: 11/07
Posted: 02/23/09
08:14 AM

I sure hope he reads that Clemenskid21, because it is very good information. I think it's very good of you to share such valuable information with other racers. Too often teams will "protect" this kind of information.

Many modified teams have been experimenting with moving the MC more to the left to just left of centerline. What really determines the balance of the car is the analysis of the left side tire temperatures. If the LF tire is cooler than the LR tire by more than 5 degrees, then the car is not balanced. Adjust the panhard bar height and/or the RR spring rate to increase the LF tire temp. Raise the panhard bar and increase the RR spring rate to bring more temperature to the LF tire.

Be sure to make cross weight adjustments as you make those changes in order to maintain the handling balance.  

clemenskid21 clemenskid21
I watched NASCAR once | Posts: 3 | Joined: 01/09
Posted: 02/23/09
09:42 AM

I know I have had a hard time coming up with this information because of other racers unwillingness to share it. It has taken me a lot of time and money to get to where it was. I hope by sharing this information I can save other racers the valuable time and money. From my experience most modified teams are one or two person operations, which means time and money is at a premium. I feel that if I share this info, it will make the competition better, and in the long run make me step up my game.

Also, I guess I should have stated in my previous post that my Static MC starts at 2.5" to the left and under dive and roll the Dynamic MC ends at about 2.5" to the right. I have experienced a bit with the MC over the past few years, and this works the best for where I race regularly. Either way, I think the most important aspect was getting it under control and being able to adjust accordingly.

Thanks for the post, and I hope others will contribute as well.  

I watched NASCAR once | Posts: 2 | Joined: 09/08
Posted: 02/23/09
09:22 PM

Wow, thank you very much for that detailed of information! I did give up on a answer and found this post on the internet! We are indeed a small family team, with limited resources and this will help tremendosly.
We have been discussing some set up software but every penny this year is really streched, this will defenitly help get us to the track for some test and tune. I race in a club located in Western Washington, called the Vintage Modified Racing Association. We all share whatever we can with each other, so I will share all this information with any of the guy's I race with. I owe them anyways,they have been racing since before I was born and have shared almost everything they know to help us get going.
A couple of questions if I may? How heavy was the car you set up? We where thinking of going heavier on the springs this year, we are switching from a 302 to a 351 due to budget (we had the parts for the 351). And we will be nose heavy, probobly 52% with a left side at 55.5%. Any input? Thank you again for your original post, and all the additional comments. I do appreciate what you have done.  

clemenskid21 clemenskid21
I watched NASCAR once | Posts: 3 | Joined: 01/09
Posted: 02/23/09
09:35 PM

The cars I have built/raced typically weigh about 2550 race ready with the driver (imca type modifieds). I missed the part of not having any setback in your first post. I also used this same set-up with 56% leftside to race FASCAR, and was not noticeably affected. I think maybe some stiffer front springs would help if the motor has no set back, but shocks may have to be stifffened too. Some other things you might want to give us info on is the crank height, overall weight engine offset if any etc. the more info you give us the more we might be able to help. I also noticed that you mentioned a short J bar. From my experiences I prefer a much longer panhard bar, they are less reactive. Also, if you have to add lead, get as much of it as low and center as possible and if possible balance the front to rear weight percentage a little more. Increasing the rear weight should help rear bite.

Good Luck,

racer94 racer94
I watched NASCAR once | Posts: 1 | Joined: 02/09
Posted: 02/24/09
02:42 PM

Hi there im also on the same modified race team and the more infosuch as crankshaft you needed is 13 in.,centered in the clip with about a 10 in.chassis offset to the left total vehicle wieght is about 3100 lbs. with driver and added wieght to get a 50-50 wieght ratio.I have also noticed that the car does'nt seem to want handle good with a ride height lower than 4 in. on the left side.any other help or suggestions will be lots of help                                                                                                                Thanks                                                       Mark