>>> 1.)Can I run an ITR legal Mazda RX8 in STL at 3000lbs?

No. ITR-spec cars are not compliant to the STCS.

>>> 2.)Can I run a renesis engine in an ITS,A,B,or C car at 3000lbs no matter what kind of car it is?

Yes, as long as it's a Mazda, with RWD adder as appropriate, and as long as it's compliant to all other open ST regs (e.g., Renesis in a first-gen RX-7 will require an FIA-spec fuel cell). It is *not* compliant under the ITCS allowance (unless there's an ITA/B/C/S compliant car that uses the Renesis).

>>> 3.)Or can I only run the RX8 as an STL car with all STL requirements like fuel cell, 17" x 7" rims ect...

Yes, at 3000 pounds plus the 2.5% RWD adder. Make sure the stock cams are within class limits.

GA