Indycars
Well-Known Member
Now that I have my SS tubing I need to know how long to cut each tube. So I setup the car loaded on the springs with a 5° rake and 5° caster angle. Then I measured the distance, center-to-center to each mounting hole. Now I measure each component and what it added to the length of the radius rod or what will be subtracted from the tubing actual length.
![FP04_RadiuRodCalculations.jpg FP04_RadiuRodCalculations.jpg](https://tbucketeer.com/data/attachments/19/19831-1cf888cdbb74481f70be84aa48d45751.jpg)
![FP04_RadiusRodsCutToLength_03811.jpg FP04_RadiusRodsCutToLength_03811.jpg](https://tbucketeer.com/data/attachments/19/19832-bc04d3d9ec168365d671d003ecaafb68.jpg)
When considering how much to leave on the rod end threads for adjustment I wondered how much it took to change the caster by 3°-4°. So that’s when I decided to measure the change over a significant distance to get an average. Below is what I found.
![FP04_RodEndEffectOnCaster_03809.jpg FP04_RodEndEffectOnCaster_03809.jpg](https://tbucketeer.com/data/attachments/19/19833-6ce12f42cc46dc7dd2674b52b9ad364e.jpg)
![FP04_RodEndEffectOnCaster_03808.jpg FP04_RodEndEffectOnCaster_03808.jpg](https://tbucketeer.com/data/attachments/19/19834-d2a322e6ed60d42bef01d2abc5c6c87a.jpg)
The average change per turn of a single lower rod end was 0.6°. Now this was adjusting just one rod end, so adjusting the radius rod with both RH and LH threads would theoretically change the caster by 1.2° for each full turn of the radius rod.
[(8.7-3.2) / 9)]*2 = 1.2°
![FP04_RodEndEffectOnCasterPerTurn.jpg FP04_RodEndEffectOnCasterPerTurn.jpg](https://tbucketeer.com/data/attachments/19/19830-4489a8d63d10100242b4ec06792b72a7.jpg)
Wixey WR365 Digital Angle Gauge
www.amazon.com/gp/product/B0054RJ7VC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
QA-1 1/2" Rod Ends, LH & RH
https://www.summitracing.com/parts/qa1-xml8
https://www.summitracing.com/parts/qa1-xmr8
.
![FP04_RadiuRodCalculations.jpg FP04_RadiuRodCalculations.jpg](https://tbucketeer.com/data/attachments/19/19831-1cf888cdbb74481f70be84aa48d45751.jpg)
![FP04_RadiusRodsCutToLength_03811.jpg FP04_RadiusRodsCutToLength_03811.jpg](https://tbucketeer.com/data/attachments/19/19832-bc04d3d9ec168365d671d003ecaafb68.jpg)
When considering how much to leave on the rod end threads for adjustment I wondered how much it took to change the caster by 3°-4°. So that’s when I decided to measure the change over a significant distance to get an average. Below is what I found.
![FP04_RodEndEffectOnCaster_03809.jpg FP04_RodEndEffectOnCaster_03809.jpg](https://tbucketeer.com/data/attachments/19/19833-6ce12f42cc46dc7dd2674b52b9ad364e.jpg)
![FP04_RodEndEffectOnCaster_03808.jpg FP04_RodEndEffectOnCaster_03808.jpg](https://tbucketeer.com/data/attachments/19/19834-d2a322e6ed60d42bef01d2abc5c6c87a.jpg)
The average change per turn of a single lower rod end was 0.6°. Now this was adjusting just one rod end, so adjusting the radius rod with both RH and LH threads would theoretically change the caster by 1.2° for each full turn of the radius rod.
[(8.7-3.2) / 9)]*2 = 1.2°
![FP04_RodEndEffectOnCasterPerTurn.jpg FP04_RodEndEffectOnCasterPerTurn.jpg](https://tbucketeer.com/data/attachments/19/19830-4489a8d63d10100242b4ec06792b72a7.jpg)
Wixey WR365 Digital Angle Gauge
www.amazon.com/gp/product/B0054RJ7VC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
QA-1 1/2" Rod Ends, LH & RH
https://www.summitracing.com/parts/qa1-xml8
https://www.summitracing.com/parts/qa1-xmr8
.