for you all using VR-1, if it is truly a racing oil, it won't have detergent in it,
I bought five quarts of it the other day. It says (on the bottle) "high performance formula for push-rod and flat tappet engines"
On the back of the bottle it says "High zinc/phosphorous for extreme anti-wear protection, including flat-tappet and performance cam applications"
"For use in classic and modern muscle cars, race cars, and high performance passenger cars"
"Friction modifiers help deliver maximum horsepower"
"Enhanced anti-foaming, even under high stress"
"Exceeds API Service SL"
SL is for automobile engines older than 2004.
The Valvoline FAQ says "....include fewer detergents than regular conventional motor oils"https://www.valvoline.com/about-us/faq/racing-oil-faq
And "Valvoline VR1 racing oil is conventional, non-synthetic racing oil."