Inside the car is illegal in NHRA but legal in NASCAR and SCCA. NASCAR runs the dry sump tank behind the driver's seat but NHRA doesn't allow liquids in the driver compartment. We hung the accusump on the rollcage inside the cabin on Tim's road race Valiant and that was fine with the road race tech guys but NHRA wouldn't allow it.
I will say that you don't want an aluminum tube full of hot oil inside the car on a street car. It is just like having a big heater sitting in the cabin with you. After 30 minutes or so the tank will be 180 degrees and the car will smell like hot oil!
I haven’t looked at an nhra rulebook in a long time on this. It seems that I see a whole bunch of cars with intercooler tanks or n2o bottles on the passenger floor. I don’t remember ever seeing a requirement for isolator lines on oil gauges. (fuel gauges- yes)
The last time I had the car recertification was way back when… maybe 2006 or so. The inspector said he didn’t like it. He also said there wasn’t a rule against it, and suggested I move it.
As for heating being an issue, I never felt anything more than a warm sensation that you would be able to rest your hand on for as long as you wanted after beating up on the car a bunch. It isn’t a flow through system. Unless you have some really screwed up oiling problems, the accumulator doesn’t have a continuous heat source.
I used mine for engine safety on extreme decel with my rear sump pan, so a full oil dump was rarely done. That car had a lot af street miles and never once had any issues with in cabin leaks or temperatures.
The only picture I have just barely shoes the ball valve handle for an idea of its location/ proximity to me.
