Preludes at Thunderhill

When I bought this car I had no plans to modify it, so I certainly didn't plan on racing it and I didn't even know there was a tuner scene out there.  The car is somewhat modified now, and it all stated after driving at Thunderhill that fateful day.

The night after attending the Skip Barber course at Laguna Seca my left leg felt bruised and my arms were very tired. Odd, I thought.  After my first Thunderhill event my arms and legs were sore again, sore enough to bother me for about three days after the event.  By my third time at the track figured out that this was because I was pressing my leg hard against the door to keep me in my seat in the turns and that my arms weren't just steering the car but they were keeping me off the door.  In turn 5a, for example, I could barely stay in my seat even with my leg pressing against the seat as hard as I could.  In one of the sweeping turns I noted the effort I was making with my arms to keep myself in place.  Also, in my last lap of the day at my second track day my brakes started to squeal. They had been fading all day, but now I had worn through the pads.  The very next time out my brand new OEM pads had started to disintegrate due to the heat of all that hard braking.  Obviously I had to start making changes to address these problems, and this has pretty much been my approach to modifying my car. Drive for a while. Identify specific problems or areas for improvement, then take care of it.

Heel-Toe Down-shifting
I really wanted to be able to heel-toe down-shift like I was shown in the Russell Test Drive and Skip Barber courses I took. Consequently, Sparco pedals were my first mod.  These were inexpensive and easy to install, a nice way to start. I needed to be able to get the brake pedal closer to the throttle for heel-toe down-shifting. It did help, but constant practice turned out to be more effective.

Jacked up

Staying in my Seat
Sparco seats and harnesses were my second mod.  No way around it, I had to be able to stay in my seat while driving.  These worked very well, even though the stiffer side bolsters pinched my thighs a bit.  I had to learn to sit differently. But once I had my seats adjusted, I could barely reach the steering wheel, plus I was kicking it with my knee when down-shifting.  I needed to fix this.  I checked around for telescoping steering columns but Honda had never made them for the Prelude.  I looked into aftermarket wheels and while I found some nice (and smaller) Sparco wheels I had a terrible time finding the hardware I'd need to mount it.  I finally found it on a Japanese web site, bought it, and paid more for shipping as for the part itself, and the part was not cheap.  I also got the Sparco horn buttons which I would use for the cruise control buttons.  When I had everything together I still couldn't reach the wheel properly so I added a Sparco extension, and later a second extension. Finally I fit in the car, I could reach everything, and I wasn't sliding around anymore.

Getting Stopped
Brakes About that same time I installed the seats I also installed stainless-steel the brake lines and upgraded to a DOT 4 brake fluid.  I had been told that these brake lines would give me a firmer pedal, but I couldn't tell if there was any improvement. The cheap DOT 4 fluid I started using didn't help much either, so I flushed the system again with a higher quality brand (Motul 600) and upgraded the pads to a street/track pad (Hawk HPS). That worked much better, but brake fade later in the day was still a problem.  Brake rotor warping was also a big problem. Every two events I had to have the rotors turned or replaced. I also started keeping spare rotors around.  Still, as I got faster and more confident in my driving brake fade got bad again and later in the day I was having to push the brake pedal as hard as I could to get stopped.  These problems came up gradually so it was manageable, but I couldn't keep driving like this.  I upgraded the pads to Hawk HP+, figuring they might not work well on the street and I might have to swap them out after each event. It turns out they worked very well for track and street.  Initial bite was more than I was used to so that took some time getting used to, but all is good now. Nevertheless, I still keep extra rotors at the house and I take them with me to two-day events.

Improved Grip and Handling
Now that my main problems had been taken car of it was time to make some performance improvements.  Wheels and tires were naturally the first place to start.  After some research I settled on Goodyear F1 GS-D3 tires and O.Z. Superleggera wheels.  The Goodyears had excellent performance ratings, and the O.Z. wheels had the open spoked look I wanted. Learning to drive again with tires that did not squeal as much was interesting, but this worked out nicely.

Suspension Install

The next performance upgrade was the suspension, and this included new coil-overs (Tien SS) and front and rear sway bars (Neuspeed). It took about a day for me to get these all installed, and when I got in the car I immediately noticed it was lower, and stiffer.  The car barely moved when I sat in it.  I took a short test drive, and I could feel every bump in the road, plus it was noisier. I wondered if I had made a mistake. I took it out on the freeway and loved how solid it felt. The rear end slid a bit on me entering the freeway, telling me I had a different car now and that I had better take some time to learn to drive it. I got used to the harsher ride and now I wouldn't want anything else.

The final upgrade at this point was in the transmission. I got a Quaife limited-slip differential (LSD) installed and headed back to the track.

With these suspension upgrades and the LSD my lap times dropped by 10 seconds. That's a lot!  The car felt much more solid, quicker, and easier to control, and I was getting a lot less tire spin when I got on the throttle after apexes, thanks to the LSD. All in all, a very worthwhile upgrade. True, the ride is a little harsher and on California freeways it can be difficult to do simple things like change the channel on the radio, but that was fine with me.

Revised Safety Mods
Safety Photo In the summer of 2005 I installed a harness bar. This improves the effectiveness of the four-point harnesses, reducing the chance of spinal compression in the event of an accident. It also provided an excellent place to mount a video camera. Of course, now the rear seats were useless, so they came out. I also replaced my Sparco 4-points with Schroth four-points. The Sparcos were not DOT-legal while the Schroths are.

More Power!
I've recently started looking into possibilities of getting more power out of the engine.  I installed a new intake, which was more work than I had expected. I can't be sure if it is doing much for me.  People estimate that it can yield 3 to 5 more horsepower, so I assume that's what I've got now.  Anyway, my wallet dyno says I have more power, and the engine is louder, that is for sure.

Probably a header and exhaust, and later some tuning, and more track days to see how things go.  Maybe Santa will bring me a supercharger.  Or maybe Congress will get me that ear-mark.  Oh yea, and somehow I need to keep it all CARB-legal. 

Or maybe I should just finish the carputer project first.

Here is a quick list of the car's modifications.