ShialaBEEF
Member
Hi all. Long time listener first time caller 
I have 2 JR drivers in JR1 and JR3 doing quite well on Saturday nights. We work with a reputable engine builder whom I asked this question of but didn’t get a straight answer and I’m wanting to get some thoughts on the THEORY.
The situation: I understand restrictor plates may not be modified according to the AKRA & NKA rulebook. I also understand the associated carb. rules. The orifice in the ARC restrictor plates are offset to the top left of the intake. I do not have access to a flow bench or any way to measure CFM through the carb, plate, and intake.
The question(s): What is the effect on flow with the orifice offset and not in the center of the plate?
Does the offset orifice in the ARC plates further disrupt flow by design?
Does anyone provide a reasonable service for flowing carbs and plates to obtain max flow without challenging the tech man?
Please correct me if I’m wrong - I ran restricted Briggs flatheads as a kid - but I believe the orifice in the old gold plates for the Briggs were in the center of the plate and center of the intake. I’ve been taking the approach of purchasing multiple plates, measuring them with a precision micrometer and using the plate with the largest opening. Granted it may only be a nominal difference in the order of thousands or ten-thousands. However I still have no idea if this improves or degrades fuel-air mixture flow.
Any knowledge backed by data, advice, referrals or services anyone would be willing to share would be greatly appreciated!
P.S. I’m not interested in any cheats, I’d simply like to better understand the design and concepts. My daughter lost a win after tech last year (unrelated to carb and restrictor plate rules) and that was just devastating. I’m not the type of racer dad to defend my JR drivers’ every move on the track. We are grateful for our competitors that push us to improve, and I’m genuinely happy for all of the kids we compete against when they achieve success.
I have 2 JR drivers in JR1 and JR3 doing quite well on Saturday nights. We work with a reputable engine builder whom I asked this question of but didn’t get a straight answer and I’m wanting to get some thoughts on the THEORY.The situation: I understand restrictor plates may not be modified according to the AKRA & NKA rulebook. I also understand the associated carb. rules. The orifice in the ARC restrictor plates are offset to the top left of the intake. I do not have access to a flow bench or any way to measure CFM through the carb, plate, and intake.
The question(s): What is the effect on flow with the orifice offset and not in the center of the plate?
Does the offset orifice in the ARC plates further disrupt flow by design?
Does anyone provide a reasonable service for flowing carbs and plates to obtain max flow without challenging the tech man?
Please correct me if I’m wrong - I ran restricted Briggs flatheads as a kid - but I believe the orifice in the old gold plates for the Briggs were in the center of the plate and center of the intake. I’ve been taking the approach of purchasing multiple plates, measuring them with a precision micrometer and using the plate with the largest opening. Granted it may only be a nominal difference in the order of thousands or ten-thousands. However I still have no idea if this improves or degrades fuel-air mixture flow.
Any knowledge backed by data, advice, referrals or services anyone would be willing to share would be greatly appreciated!
P.S. I’m not interested in any cheats, I’d simply like to better understand the design and concepts. My daughter lost a win after tech last year (unrelated to carb and restrictor plate rules) and that was just devastating. I’m not the type of racer dad to defend my JR drivers’ every move on the track. We are grateful for our competitors that push us to improve, and I’m genuinely happy for all of the kids we compete against when they achieve success.