Iniitally the steering was very heavy, which made the car quite difficult to drive.
To reduce the steering effort, we reduced the caster from 4 degrees to 2.5 degrees. This was my idea, based on what I've learned racing karts long ago and confirmed while tinkering with N4 setups. We did this at the track the first time were were at Loudon. As soon as I'd driven the car on the track, I realized that the effort was too high. I could barely turn the wheel hard enough to get through turn 6, which is steeply banked and also at the bottom of a dip, and I also had trouble with the banked turn 2B.
I asked the FFR engineers what the minimum caster we could run, and Jesper said "2.5 degrees". Nate did some calculations to figure out how many turns we needed to take on our custom upper control arm brackets to change the caster from 4 to 2.5 degrees. He was able to make this change at the track, in the morning of the NERC time trial.
We missed a practice session while Nate was working on the car (and I was looking for parts) but it was worth it. This change reduced the steering effort noticeably but it was still too high; we were both exhausted after a couple 20 minute sessions on the track.
Update 2003: see my Power Steering and Front Lower Control Arm mods.
The "stock" FFR setup uses the original Mustang power steering rack, without the power steering pump. This absolutely sucks, giving very high effort apparently due to having to move the pistons back and forth in the rack and also because the gears in the power rack are very small, resulting in high friction when there's no power assist.
We replaced the Mustang with a slightly slower ratio (20:1 vs. 16:1) manual rack made by Flaming River. This made a huge difference in steering effort.
This mod is commonly done by FFR owners, especially those who drive their cars competitively. We knew about this before we built the car. I wanted to do it but Nate was not sure it was worth the cost (about $400) till we tried the Mustang rack ourselves.
It was really worth it.
Even with the caster change, Nate and I were both exhausted after the NERC time trials. The Flaming River rack made a huge difference; the car is now a joy to drive on the street and much easier to drive on the track.
Another very important change we made was to replace the Mustang's rubber mounting bushings with some offset delrin bushings we got from John Lisman (see the Links page). These got rid of the very spongy feel in the steering and also greatly reduced the bump steer, which caused the car's bizarre behavior over bumps and during brake and throttle transitions while cornering.
Note that we had already replaced the Mustang lower shaft (the one with the rubber and cloth "rag joint") with a Borgeson shaft and universal joints. This worked fine, but the lower joint wasn't compatible with the Flaming River rack, so we wound up getting the Flaming River lower shaft as well. (Our Borgeson shaft, which works fine with a Mustang rack, is for sale if you're interested!)
We also used a Borgeson middle shaft, which doesn't make any performance difference but allowed us to skip the step of welding an extension into the Mustang middle shaft.
I would not build another FFR car with the Mustang rack "converted" to manual per FFR instructions. I've driven another FFR Cobra with the Mustang non-powered power rack and it was even worse than ours, due to wider front wheels and possibly also alignment issues. I would consider using the Mustang rack only if I kept the power steering pump so that the Mustang rack is properly boosted as it is in the donor car.
We chose Flaming River's 20:1 rack because our focus is road racing, and we both felt that reduced steering effort was the priority.
For those who are young and strong, and who are focused on autocrossing, Flaming River makes a 16:1 rack. This is the choice of the FFR engineers for their own cars - but they are young and very muscular, and they autocross a lot.
Update 2003: See my Power Steering, Ackermann and Front Lower Control Arm mods.
A large, skinny, slippery wood and aluminum wheel that comes with the kit. This wheel is beautiful and very authentic-looking, but it aggravates the problem of high steering effort because it takes so much effort to grip it tightly.
We put a $3 cloth and rubber steering wheel cover over this wheel. This really helps my hands grip the wheel. This was my idea; I came across this in a VIP auto parts store while hunting for other parts.
I want to get a nice fat-rimmed racing-type wheel but Nate seems unconvinced that this would be worth the money.
Update: Later we bought a fat-rimmed leather-covered wheel from Gary Cheney for significantly less than the cost of a new one. This is a big improvement over the original wheel and feels much nicer than the cheap cloth and rubber steering wheel cover we were using on the original wheel.