At Pettit Racing we continue improving our products in an effort to make them better, faster, and more fun. Our ultimate goal is to offer the smartest, simplest parts with the greatest benefits and we are most gratified when we find ways for parts to accomplish multiple job, ...
For the RX7 FD we have done just that, our AST now incorporates swirl pot action, hence AST-SP, The redesigned part further improves system efficiency by more effectively removing entrained air circulating with the coolant.
A very simple design change, we moved the inlet tube to a position that causes the inflow of coolant to create a swirling action.
The AST_SP also benefits from a billet cap neck and hose nipples, all cnc machined from 6061 T6 aluminum then beautifully tig welded in the USA to the highest standards by some of the best welders on the planet.
Offered in black textured powder coat or mill finish suitable for polishing, both come with a 13lb lever vent safety cap, clamps & fasteners MSRP...$199
The new AST-SP accomplishes two jobs:
Improves System Efficiency Removing entrained air (tiny air bubbles) circulating with the coolant. Improves heat transfer, especially when racing or spirited driving puts demands on the cooling system.
Added Protection Removing air from the system also helps keep oxidation levels down minimizing common contaminants from forming, like rust and corrosion that can compromises cooling system efficiency / integrity.
It works like this: With each heat cycle, coolant is discharged from the air separation tank raising the coolant level in the recovery reservoir, then during the cool down cycle the negative pressure continues to increases until it allows atmospheric pressure acting on coolant in the recovery reservoir to push open the pressure cap recovery valve, thereby refilling the air separation tank. If either cap is opened before the recovery cycle is complete will be necessary to top off the coolant.
Please specify what finish you would like, mill finished will be sent by default.