We keep loosing forward drive after a few laps on a dry slick track. We have been fighting this all season. So any ideas, thoughts, and or ramblings will be appreciated.
Here is the particulars:
GRT chassis, steel block late model class.
Here is the setup we ran yesterday (15aug15)
Springs... LF: 550#. RF:325#. LR: 225#. RR: 225#.
Percentages: Left: 52.7%. Rear: 54.6%. Cross: 52.5%.
Total scaled weight in the shop: 2463#
Bite: 128#. (Then adjust to add 50# for feature.
Gear: 5:83. Turned 7100 rpm in feature.
Pinion angle: 7°.
Tires: Hoosiers. Compound on rear for feature were LR: 1325. RR: 1300.
Stagger: 3-1/2".
The car is scaled every week and the changes are making it better. But we are missing a key element. The car had its best finish two weeks in a row. 6th. I know there are top fives in this car!
If we can get the car to stick!
Thank you
Wanted: Chassis Whisperer
Started by buckboard, Aug 16 2015 11:05 AM
50 replies to this topic
#2
Posted 16 August 2015 - 11:13 AM
If I had to bet the driver is pushing harder and harder each lap and once you spin the tires your done. And then your trying to catch back up and end up spinning even worse. Why the 1325 on the left and 1300 on the right ? Most track surfaces like one or the other
- ToddW45 likes this
#3
Posted 16 August 2015 - 11:34 AM
Sorry. I miss-typed. 1325 acoss the rear.
#4
Posted 16 August 2015 - 12:54 PM
Put a 250 on the right rear that will help
#5
Posted 16 August 2015 - 01:09 PM
Toolbox, that's the way we had it till a few weeks ago. It's better with the even split. I haven't tried a 200/225 split yet
#6
Posted 16 August 2015 - 01:16 PM
A stiffer right rear sure as he'll isn't going to improve your situation. If anything it will make it worse. When the car rolls right the rods lose thrust angle taking drive away from that tire and favoring the left. Softer on the left rear should help but I would go 175 so there is a significant difference for you to tell if you like it or not .
#8
Posted 16 August 2015 - 02:19 PM
I agree with a softer lr spring but the rr 250 does work
#9
Posted 16 August 2015 - 02:22 PM
Yes
#10
Posted 16 August 2015 - 02:49 PM
Thanks legend, toolbox, and duece. Ur input is appreciated and respected.
#11
Posted 16 August 2015 - 03:12 PM
Contact Bob Close at http://www.closeracingsupply.com/ and talk to him. He's been running and selling GRT's for many years.
#12
Posted 16 August 2015 - 04:41 PM
We run 200 lr 225 rr
#13
Posted 16 August 2015 - 05:22 PM
The last thing you want to do is get advice on a forum board,just keep working with the guy you have been and he will get you there, i have already seen improvement, just be patient, getting advice from multiple people will only have you chasing around in circles.
- Paul55 likes this
#14
Posted 16 August 2015 - 06:37 PM
Buy an Aluminum engine!
#16
Posted 17 August 2015 - 08:45 AM
200 lr 250 rr more rear % will help. And how about tires? How many runs on them?
Matt D
#17
Posted 17 August 2015 - 09:10 AM
Tires were brand new that night. The feature was their first race.
#18
Posted 17 August 2015 - 10:07 AM
I would try changing the springs and if you have any weight on your neutral bar take it off and bolt it on the left rear. That will get your rear % up and you may have free it up a littleTires were brand new that night. The feature was their first race.
Matt D
#19
Posted 17 August 2015 - 11:07 AM
Lol ok
#20
Posted 17 August 2015 - 11:31 AM
When a car typically isn't even on the rr spring anymore coming off the corner how is a stiffer rr going to produce more drive ??
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