|
|
-
 Originally Posted by Egoracing
In reference to going stiffer on the LR, Remember if you are transfering 600 lbs from right to left during cornering and you have a 200 lb spring the chassis is going to raise 3 inches just from weight transfer. If you are running a 150 lb spring the chassis is going to raise 4 inches from transfer. This added lift will also increase the centerline of the chassis which will increase leverage on the suspension AND cause more weight to transfer.
If you want to transfer more to the RF go to a softer spring which will allow the chassis to compress it more which will also allow the LR to extend some more. Just dont go so soft that it bottome out.
This is why so many late models are running a stacked LR, it allows them to get into the 100-150 lb LR spring, couple that to the 250-375 RF and they are going into and thru the corner on the RF while in the gas more.
This is making sense to me... I'm gonna give it a try. My problem has been the same as the OP. No heat in RF. I watch the video and all the other cars are doing like you said, riding on the RF like the late models. My car lays over on the RR and the minute I hit a bump or the cushion with the RR it shoves the nose. I softened the RF and stiffened the RR and left the LR alone and cranked more preload into it. I'll see how it works Friday.
-
You're shoving the nose because :
1.too much load on RF(increased dynamic wedge)
2.too much LR spring(increased dynamic wedge)
3.wrong shock package.
To copy attitude of lm's you need:
1.RF-high rebound
2,Lr-high compression
3RR-med. rebound
-
Thats what I have for a shock package now.
-
What brand of tire and compound?
-
-
I believe that is a very hard tire.To get a hard tire up to working temp, it has to have weight put on it.
I would mount a 10-20lb piece of lead right behind upper RF shock.I would also move dynamic roll center to right with longer ball joints starting with upper first.
One of the "mysteries" of reading dirt tires is deciding whether it needs more or less weight put on it.
No doubt, tire prep would help if its "legal" at your track. Diagonal grooves and sipes would help also.
Last edited by drtrkr244; 05-16-2012 at 08:29 PM.
-
Yeah we can sipe and grind, but no grooving. I have the longer Ball joints in. I put a softer spring in the RF and changed the ride heights around a little. I'll see how it works friday.
-
Originally Posted by dirttrackrocker
This is making sense to me... I'm gonna give it a try. My problem has been the same as the OP. No heat in RF. I watch the video and all the other cars are doing like you said, riding on the RF like the late models. My car lays over on the RR and the minute I hit a bump or the cushion with the RR it shoves the nose. I softened the RF and stiffened the RR and left the LR alone and cranked more preload into it. I'll see how it works Friday.
A softer right front spring will not put more heat in it , when you hit a bump or the cushion hit the gas if not the front will come around on you. A softer right front will make the front bite more with the left front, so the car will have more bite in the front and not the rear, making it not so tight ( push ).
What are your tire pressures?? What is your shock compression on right front and rebound on left rear ? Compression on left front and rebound ? Pull the rr back at little to free it up .
Last edited by Dirtrunner35; 05-17-2012 at 08:13 AM.
-
The whole front end just seemed like it had no grip. Shocks are 2-7 RF 6-3 LF 4-4 RR Traction shock on LR
-
Is this a spring behind car? Does the front have less grip because the rear has more ?????? Meaning to tight of a car ?? A push or tight car is because the rear has more bite then the front.
-
It appears the car has too much drive.His springs versus what GRT recommends points to being too tight.
I would change springs to what GRT says and/or reduce rear to 55%.
If the RF was still alot cooler than RR(10 plus degrees), put a piece ol lead on RF bar and soften RF spring.
-
Sorry about the confusion... My car isn't a GRT. Sorry if I hijacked the original posters thread. Just a similar problem...
-
Friday night my RF tire had no heat at all on a slick track. Entry was ok and a little loose off.
-
Were the other cars driving off from you? Sometimes its not possible to get good drive off, if the track is super slick.
Sometimes, you have to treat the gas pedal like it was an egg.
If thats not the case, drop RTT bar, increase 5th coil spring, raise LTT, or lower LBB bar.
-
Originally Posted by Dirtrunner35
A softer right front spring will not put more heat in it , when you hit a bump or the cushion hit the gas if not the front will come around on you. A softer right front will make the front bite more with the left front, so the car will have more bite in the front and not the rear, making it not so tight ( push ).
What are your tire pressures?? What is your shock compression on right front and rebound on left rear ? Compression on left front and rebound ? Pull the rr back at little to free it up .
If the existing RF spring is not allowing weight to transfer to the RF a softer spring that will allow weight to transfer will increase the load and get the tire working which will increase the temp of the tire.
-
Originally Posted by Egoracing
If the existing RF spring is not allowing weight to transfer to the RF a softer spring that will allow weight to transfer will increase the load and get the tire working which will increase the temp of the tire.
EGO, check out grt's "Tuning car with springs" under Set-up Help.
I'm from "Show-me-state", so I put a car on scales and changed springs, using a ratchet strap to get car to dynamic ride height. You will be amazed at what you find out.
-
EGO. I wouldn't think a 600 lb spring is to much, he could add more compression to the RF shock and build more heat, but since his car is tight I would think it would be worse if he did that.
My example
Take 4 springs the same height with different lbs , put them on the scales and put a board on all of them. Put 100 lb of weight in the center of the board and see what scale shows the most weight.
I still say your car is too tight IMHO. Fix what the car is doing and worry about the temps later.
Tight/ loose syndrome, after the first turn being tight, he starts to drive different and car gets worse, IMHO.
A tight car is too much traction in the rear compared to the front.
A loose car is too much traction in the front compared to the rear.
Let us know if you race this weekend how it goes. 
Last edited by Dirtrunner35; 05-23-2012 at 09:49 PM.
-
putting weight on a spring on the scale OR strapping the car up with rachet straps will not tell you what is happening during cornering with weight transfer. If a car has a throttle push because the RF is not working when you get the RF working you may actually loose the push.
http://www.integrashocksandsprings.c...ckTuningGd.pdf
TO MAKE CAR STEER MORE
POSITIVE ON CORNER ENTRY
AND THROTTLE
• Soften right front spring
-
Weight transfer is just like changing your cars left and rear percentages.
The only way to change it is by moving lead or components.
Softening Rf spring only cures tight entry while on throttle, ie. decreasing wedge.
Are we to assume you think Joe Garrison doesn't know what hes talking about in his setup info?
-
A stiffer RF spring will loosen the front and make the push worse , now if the car was loose I would agree and say put a stiffer spring in the RF.
More weight transfer from left to right in either end of a car will loosen that end. I would get a 13 inch Lr spring or lower the cross even more.
What ever changes he does I hope it's better this weekend.
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
-
Forum Rules
All times are GMT -5. The time now is 03:58 PM.
|
|
Senior Member
Reply With Quote
Bookmarks