I installed a 22mm MRT front anti-roll bar on Mr. Subie this weekend. Thanks to Chris P. for the use of this bar! The install went fairly well, once I figured out the proper sequence. Just in case you try this, here is the sequence:
-drive the car onto ramps, or use some blocks to allow enough room to crawl under the car
-with the suspension loaded, undo the end link bolts that connect to the anti-roll bar
-remove the center anti-roll bar bushings
-remove the subframe support (4 bolts)
-jack up the car and take the ramps/blocks out from under it
-remove the driver side front wheel
-with some serious fiddling and twisting, the bar can be removed out the side of the car
The most important part about installing the new bar, is to be sure and install the center bushings first! The car has to be loaded on its suspension for the end link bolts to fit too. I pretty much spent more time jacking the car up and down than I did actually working on it.
Overall, I'm very pleased with the install. My initial impressions are that turn-in has been sharpened up considerably. It seems the new bar has taken away some of the "slop" from turning the wheel, having the car lean on its soft springs, then react and turn. Cornering is much flatter. I have not been able to do much in the way of steady-state testing to see how the overall balance has been affected. I'm expecting more understeer but can hopefully compensate with the bigger front tires. My goal is to help tame some of the body motions, and hopefully reduce the camber loss in hard corning. We'll see how things go at Wendover! Pictures of the bar can be seen below:
22mm MRT front anti-roll bar installed.
Another shot of the ront bar installed.
245/45-16 Kumho Victoracer's Fit on the Front!
I wanted to experiment with some 245/45-16 Kumhos on the front of Mr. Subie. I had experienced some problems at the Atwater events with a lack of front end grip. Instead of continuing to take away grip from the rear (lower pressures, lots of toe-out etc.) I wanted to ADD some grip up front.
You have to be careful choosing tires sizes with our 2.5RS, as it is important to maintain a relatively equal tire diameter between axles and corners of the car. The 245/45 and 225/50 tires are only a couple tenths off, but in my application, my nearly fresh 245s and half worn 225s are nearly identical. Here are a few photos to prove they fit:
Plenty of clearance between tire and strut.
I got so excited, I couldn't hold the camera still!
So far, they have not rubbed on the fender liner.
Lots of meat on Mr. Subie!
I've run a few on ramps with soft front strut settings, and have not had any rubbing between the outside edge of the tire and the fender liner. I will be running this setup at the next Oregon Region SCCA event in a couple weeks.
Comparison of Kumho Victoracer V700 and Ecsta V700
I spent an hour this afternoon comparing dimensions and fit of the Kumho V700, in both Ecsta and victoracer designs, 225/50-16 in size.
To start off with, I have been running the Victoracer design for about a year now, and have had some minor rubbing issues in the rear. The tire rubs against the strut body lightly, and against the lower spring perch. It didn't take long before a "bevel" was worn into the tires shoulder. The bevel is about 3/8-inch wide, and once worn to this point, the rubbing has gone away.
Rubbing on strut body and lower spring perch
Rubbing on strut body and lower spring perch
The new Kumho design, the Ecsta V700, features a softer compound, stiffer sidewall spring rate, and a squarer profile. I was worried that the wider profile would cause more rubbing problems. While I have not raced with the new Ecstas on the back, I did take several measurments with them on and off the car.
Measuring across the sidewalls of both tires, the Victoracer design measures 9.050 inches, while the Ecsta measures 1/8-inch narrower, at 8.875 inches. The Ecsta design does in fact use a "flatter" sidewall, that can be seen in the two photos below:
Victorace sidewall shows more rounder shape
Ecsta sidewall shows a flatter shape, and squarer profile
After measuring the differences between the overall widths, I mounted both tires to the rear of Mr. Subie. It was obvious from the start that the new Ecsta would have more clearance between the sidewall and strut body. Using my handy feeler gauges, I measured 0.035-inch between the strut body and sidewall of the Victoracer, and 0.120-inch between the strut body and sidewall of the Ecsta design.
The gap between the lower spring perch and shoulder of the tires was measured next, with the new Ecsta design giving 0.035-inch clearance. The Victoracer measured only 0.012-inch between the shoulder and lower spring perch, and that was with the worn "bevel."
So...what does this all mean? It appears the new Ecsta design will have less rubbing issues in the back of a 2.5RS. It is slightly narrower across the sidewalls, and while the shoulder is squarer, there is more room between the spring perch and the tire.
I'm looking forward to getting two more Ecstas, so I can run them all-around the car.