This page hosted courtesy of Regan Rotary Racing. December 2009.

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How-Tos

Interior modifications

Steering wheel

Suspension

Wheels

Boost switch

Single turbo

Fuel system mods

Weight reduction

 

Interior Modifications

This is not a page showing phat interiors with lots of bling-bling and massively powered audio systems.  Instead, I'm listing some practical upgrades that provide a tasteful approach to driving on track while getting the maximum information and feedback to the driver. I'll break this down into four catregories: comfort, data collection, safety and utility.

1. Comfort

The most essential element related to driver comfort is the seat and the seating position.  This is an often overlooked item that has a major effect on one's performance on the track. Ross Bentley discusses this at length in his Speed Secrets texts. The key to a good seat is obviously something that can only be achieved through trial and error.  This is difficult to do in today's mail/internet purchasing age, but I recommend that one sits in as many seats a possible before making a purchase decision.  The seat should also be one that is approved for racing, should that be your goal.  If this is the case, there are many choices out there, but bear in mind that you will forfeit some useability as racing seat back rests are fixed and seat bottoms are often fixed to immoveable attachments. 

I've tried three seats in the RX-7 and am very happy with the Kirkey aluminum road race seat. This seat is quite affordable and is well made.  Since this is not a composite seat, it needs to be braced and supported to a roll bar/cage.  You do not have to do this with composite seats. More on that in the safety section.

Kirkey Seat

The other advantage realized by the use of the Kirkey seat was that it could be mounted to the stock RX-7 seat rails.  Almost no other aftermarket seats can be used in this manner as they raise the seat too far.  

Stock seat rails on Kirkey seat

The proper seating position is such that the driver's knees should be slightly bent and should be able to reach/depress the throttle, clutch and brake with no effort.  The drivers elbows should be slightly bent as well, even while turning the wheel in both directions. The amount of bend is subjective and is often debated.  I recommend an angle that is comfortable and allows maximum range of movement with good speed. 

2. Data collection

A quick glance at the car's dashboard should be all that is necessary to determine the relative health of your car's systems. 

Some folks, usually Joe wannabe racers, go crazy when it comes to gauges, adding lots of unnecessary clutter and information that no one could possibly decipher at a glance.  For example:

 

You've GOT to be kidding me! 

The driver needs to be able to monitor only the most critical vehicle systems which, generally speaking, relate to the engine.  For a turbocharged car such as the 3rd generation RX-7, this requires a little more information than a normally aspirated car. 

For a track car, the essential gauges are ttachometer, boost, oil pressure, fuel quantity, water temperature, oil pressure, oil temperature and air to fuel ratio. An optional gauge might be an exhaust gas temperature.  The stock car comes with tachometer, water temperature, oil pressure, and fuel quantity. However, the water temperature gauge is quite possibly the worst gauge ever put on a car and must be changed.  That leaves boost, oil temperature, and air-fuel ratio. in a space that is rather confined.  Priority must be given to the most important of these, which is the tachometer, boost, and air-fuel ratio. These priority gauges should be very near the line of sight so the driver's eyes don't have to leave the road very much, or is captured by his/hers peripheral vision.  There are relatively little choices in terms of locations for these gauges. Initially, I placed the water temperature and boost gauges on the driver's A-pillar using a-pillar pods from Autometer (below).  

However, after driving on the track for some time, I noticed an annoying tendency to look toward the left side of the track because of the poor mounting location.  I decided to relocate the boost gauge to the steering column mount and move the water temperature gauge to the top radio DIN panel.  This required relocation of the radio to the bottom DIN, but that was an easy fix and I was okay with the move since water temperature is not a gauge that you always have to monitor (you should only have to glance at this gauge say, on a long straight).   

Other, lower priority gauges can be installed further away, such as the radio/DIN panel.  

3. Safety

seats, belts, roll cage, fire 

4. Utility

steering wheel, seats