Ok so im getting started on building a new car for next year I have a 97 miata but want to go F instead of E. Can i just put a 1.6L in the 97 body and be legal?
I say this in the most friendly manner. Please understand the SCCA GCR (General Competition Rules) and the PCS (Production Category Specifications) specifically. The spec line for a 1.6 Miata in F production calls for a 1990 to 1993 year car. The VIN stamped in the front firewall identifies the car. Dumping a 1.8 motor in a 90/93 car would not be following the spec line. Err, the rules.
Also are the miatas competitive in E?
For a person building a race car one should know the current background of which cars are at the pointy end and which cars don't stand a chance in hell of winning. Go to the SCCA site, find the Runoffs event archives and view which cars have won the Runoffs classes the last few years.
Please understand the rules before you spend one dime on your car build. After the fact is way to late. From my observations a typical car that wouldn't stand a chance in hell of winning a national production car race would be the Ford Pinto that is classed in F production.