Project Cappuccino: Modern Tires, Ancient Car

Cappuccino Rear Tire Rub
While we spent a lot of time checking the front-end clearance, we foolishly assumed there would be no clearance issues in the rear. This was incorrect. The inside of the tire rubs on the strut. This was mostly solved by adding a ¼” spacer on the hub (the tire will still rub at full droop, but at ride height, there is plenty of clearance). However, the spacer causes the outside edge of the tire to contact the fender lip under compression. This could be remedied by rolling the fender lip to remove the sharp inner seam. Here you can see the extent of the rubbing. It’s very minor but could cut down the tire over time. So we decided to roll the rear fenders just to be safe
Cappuccino Fender Rolling
We ended up buying a basic fender rolling tool and installed it onto the rear hubs. Due to the small size of the Cappuccino, it was actually quite difficult to roll the fenders. The small height of the wheel well prevented us from getting the right angle on the roller to really press the fender lip properly. With some patience, we were able to get the fender lips rolled enough to clear the new tires. Careful use of a heat gun kept the paint intact as we worked. Normally we would show you the before and after of the lip, but this was my first time rolling fenders and like most first times the end result was a lumpy, awkward mess with lots of apologizing afterward. At least there won’t be any more chafing.
Used Cusco Strut Brace
To top off our handling mods, we picked up a used Cusco front strut brace from eBay. Our Cappuccino is already equipped with a rear tower brace, so a front brace was in order to balance things out. The Cusco brace is the adjustable type and came disassembled. This is a steel brace that will provide more strength over aluminum. For an old, super flexible chassis like the EA-11R, a strut tower brace should really help the front end feel.
Cusco Strut Brace Installed
The Cusco brace was a perfect fit and once again has just enough aging to look like it was always with the car. We put a bit of anti-seize on the threads of the turnbuckle to keep them from rusting together. The brace drops in easily and clears the valve cover and turbo plumbing perfectly. Just like the wheels, the patina on the brace makes it look like it’s been with the car since the 90s, keeping with the JDM survivor theme we’re trying to build this car around. I’ll be honest, it’s really hard to determine the effect of the Cusco brace. It seems like the front has a bit more feel to it, but it would require some back-to-back testing to really confirm that.
Cappuccino Autocrossing
The Bridgestones have made a huge difference in our autocross times, but they have highlighted the weak point of our suspension: lowering springs are crap! The RS*R springs our Cappuccino sits on are way too soft for real performance driving. The body roll is so severe we’re starting to lift the inside rear tire. When we hit the brakes, the dive throws all the weight on the nose and causes the fronts to lock. This creates some really odd handling where the car understeers badly under braking and turn in, then wants to snap oversteer on-throttle (this is caused by the short wheelbase and the Quaife type LSD being unable to deal with the swings in available traction). Not good!

The good news is we now know exactly where to focus our attention on Project Cappuccino to unlock some more performance.  We’ve made our part choices and once are gathering up what we need to further refine and improve our awesome little Kei roadster.  Stay tuned!

Sources

Racing Service Watanabe

Bridgestone Tires

Cusco Racing Equipment

7 comments

  1. When you installed the Strut Brace did you do it with the suspension unloaded by jacking up the front? It helps to do that and then adjust the turnbuckle.

    I have usually been able to feel the. difference with all my braces.

    1. I set the tension with wheels on the ground. I also live in a salt state and I installed the brace in the fall. Snow season started early and I didn’t really get a chance to drive it before and after. The Cappuccino runs terribly in the cold and it has zero rust protection so once the weather gets cold it gets locked up in the garage until the salt gets rained away.

    1. Two reasons: first the lowering springs on the car are way soft. The fronts aren’t even 100 lbs/inch. It would help, but not all that much. Second, the shocks are pretty worn and need replacing, so it would be even more underdamped than it already is. Third, removing the rear shocks requires knocking off the lower control arm. Not something I want to do more than once if I can avoid it you know?

  2. Whereabouts are you again? WI somewhere? Not too far from my home town. Just passed through recently unless WI is dead wrong in which case nevermind.

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