Pro Turbo 10.5 Class Rules

Pro Turbo

DownloadDOWNLOAD 2015 Rules (PDF)

Ladder Type: Pro
Field Size: Up to 32 qualifying cars
Qualifying: 3 scheduled rounds
Light Type: 0.400 Pro
Staging: Courtesy Staging Encouraged, Deep Staging Allowed
Min. Qualifying Time: 10.99 seconds (11.49s at Bandimere Raceway)

Class Summary

A new class for 2015 established to push the limits of performance on the popular 10.5-inch racing slick or 345mm DOT radial tire. Unibody AWD, back-half RWD and full-tube frame FWD vehicles are all permitted. To encourage participation in the new class, there are no turbo size or vehicle weight limits. V8 engines are restricted to a single power adder, while V6 and 4-cylinder engines may have multiple


All vehicles must have functional taillights and at least one functional headlight (exception is made for a one-piece front end.) Fiberglass, fiber-reinforced plastic (FRP) and carbon- or aramid- (Kevlar®) fiber body panel replacements are allowed. One-piece front ends and polycarbonate windows (i.e. Lexan®) are permitted. Both doors must be functional, with the ability to open the doors from the inside and outside of the vehicle.

Chassis and Suspension

Full tube chassis FWD and 1/2 chassis RWD conversions are permitted. AWD vehicles must remain unibody with all factory shock towers functional in the OEM location. Wheelie bars permitted on FWD and RWD vehicles.


OEM and IDRC approved 4-and 6-cylinder OHC engines are allowed. Two-and three-rotor rotary engines are also allowed. Currently the DART B-series engine is the only approved non-OEM engine. Racers wishing to certify other non-OEM engine platforms must submit a request for approval to the IDRC technical department. Engine “swaps” are allowed, as long as the swap is from the same manufacturing group (i.e. Honda/Acura,Toyota/Scion/Lexus, Nissan/Infiniti, etc.). Billet engine blocks or cylinder heads are not permitted. Cast aftermarket cylinder heads are permitted. Engine location may be setback up to six inches from the original location. Engines may run only distilled water forcoolant. Up to 16 ounces of surface-tension reducer (i.e. Royal Purple Purple Ice additive) per cooling system is permitted. No ethylene glycol or propylene glycol coolants are allowed.

Intercooler Systems

Either an air-to-air or air-to-liquid intercooler system may be used.

Approved Fuels

Pump E85, E98, VP Racing C16, VP Racing Pro Import, VP Racing Q16, VP Racing C85. No propylene oxide or nitromethane is permitted. IDRC will perform random fuel tests and fuel tests upon protest (charges apply).

Transmission and Axles

Open to OEM manual or aftermarket manual or automatic transmission.

Fuel Cells



Any exit location that doesn’t interfere with the staging lights is permitted.

Nitrous Oxide Systems

When used in addition to another power adder (i.e. supercharger or turbocharger), nitrous solenoid must be a cross-flow design (no bottom dump) with a maximum orifice size less than 0.080”. This includes Nitrous Supply #26020 Powerstar, Nitrous Express NX Mainline, NOS #18020 Powershot, ZEX NMU (#82007 or #82008). When used as the only power adder, no restrictions on solenoid size exist.


Slicks limited to 28.5-inch in height and 10.5-inch in width. DOT radials limited to 345mm in section width.


All crewmembers accompanying the vehicle on track (up to three) must be in like uniforms. Uniforms can be as simple as matched t-shirts and jeans. All crewmembers must also sign the additional liability release waiver.


Class payouts will vary based on each event. However, larger fields will receive larger payouts. Fields smaller than eight vehicles will receive a pro-rated payout based on the number of qualified entries. Eight-vehicle fields will only payout winner and runner-up. Fields with 16 and 32 cars will also payout semifinalists.

The IDRC West-Coast Nationals & International Finals (1-day events)

32-car Field 16-car Field 8-car Field
Winner $1,000 $700 $500
Runner Up $300 $200 $200
Semifinalist $150 $100 ------

Up to $7,600 in Payouts per race + Thousands in Contingency Awards!!!