Surge Tank Mounting Location

[smoltz]

For those that have sure tanks, where are you mounting them? It seems that trunk is popular but latest NASA rules seem to indicate that's not OK, specifically...

A single external (to the fuel tank or fuel cell) container that fuel is stored in, or moves through, (e.g. swirl pots, vent cans, surge tanks, etc.) may be used, and that container shall not have a capacity greater than 1.5 liter (0.4 gallons). The container must be constructed of metal with threaded fittings to stainless steel braided fuel hoses. It must be securely attached to the vehicle and separated from the driver's compartment by a separate bulkhead. Any container over 1.5 liters (0.4 gallons) is considered to be another fuel cell and subject to fuel cell requirements.

I would hate to go through the effort and expense of this to have it fail scrutineering.

[downshiftxlr8]

If trunk mounted , the way I'm reading that, you would have to make a separate firewall to the rear.

[GrandSport]

I have a surge tank in two different FTs.
The "best" option is really dependent on your cage design or lack of. But you need to make a sheetmetal firewall. The issue is that the lines coming out of the OEM tank are RIGHT BEHIND the driver's seat.

You need to see if the lines can be outside of the firewall and in the driver's compartment. If yes, you can mount the surge tank in the trunk and even just build a little box around it in the corner (behind rear wheel well?). If not, you could probably mount it right behind the gas tank cover thing behind the driver seat and then build a box around that whole setup. But it might be easier to just drop a sheet metal wall down from where the hatch is.


We are using it for enduro, and have an aux tank. So we need both enclosed. We put it behind the driver rear tire well and then we made a firewall blocking off the entire trunk area.

[smoltz]

Car only has an autopower half cage now but is getting a full cage but still time to take this into account.

I am thinking of maybe removing evap canister and then putting surge tank there but tbh I've never had it all apart so maybe that's not realistic in terms of the size and location of these things.

I had also been thinking of trying to just move to a fuel cell and copy the GR86 cup car setup but that doesn't appear NASA compliant which is a head scratcher as a "factory built" race car.