[SUSPENSION] Making the Celica Handle

Project: Making the Celica Handle
Updated January 22, 2002

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March 2, 2000: Upgrading rims and tires.

When I was looking for a set of rims to replace the factory steel wheels, I was going more for looks than performance. The choices for rims at your local Discount Tire or Pep Boys weren't huge. You had to pick what they had on display.

I purchased my rims and tires from Discount Tire. I was thinking about going with some Konig Caffeines when I saw a nice 7-spoke rim lined with rivets on display. I didn't know anything about the rim. All I knew is that it looked pretty. I asked what the name and brand the rim was. They were 16" Enkei RS-Evolutions. I thought long and hard about how they would look. After much debating and photo gawking, I went with the Enkei RS-E's. The tires included were 205/40/16TR Centennial Interceptors.

Little did I know what secrets I would stumble upon. It took me some time to realize a few things. The overall rim and tire diameter was smaller than the factory rim and tire diameter. That meant I had better acceleration but sacrificed top speed. No biggie for me; I hardly go over 100 MPH. One Enkei RS-E weighs 17 lbs. Not bad if you ask me considering I paid $160 for a decently lightweight rim.



Summer 2000: Installing new springs.

If it's one thing I disliked about having stock suspension, it's the body roll. There's just too much of it. Anytime I took a turn it felt like my car was going to tip over. Of course, there's that sensation of being pinned to my door when I'm hanging a right.

A very popular item used to counter body roll is stiff springs. I had 3 choices of springs: Eibach Pro-Kits, Eibach Sportlines, and H&R Sport springs. The Sportlines offered the most aggressive drop. I wasn't too concerned about comfort since I cared more about handling performance over ride comfort.

After installing the Eibach Sportline springs, I immediately felt the car's characteristics change. There was less acceleration squat and brake dive. The car hugged the corners. There was much less body roll than before.



Fall 2000: Installing new front struts.

The whole suspension on the car was blown due to old age. I didn't have much money at the time so I was being very frugal. I only replaced the front two struts with KYB cartridges. KYB's are OE on Celicas so there wasn't much "gain." The rear suspension was left alone despite the fact they were blown.

The first time I raced on the autocross course, I had just rims and tires, springs, and new front struts. For seven events I ran like this. Handling wasn't the worst and it wasn't the best. I knew it could be improved, but on my budget I couldn't afford to improve.

The rear suspension worried me. It was blown from the start. Occasionally, the tail would slip out. It wasn't anything that a bit of steering correction couldn't take care of.



March 24, 2001: Installing new suspension.

It wasn't too long until the front would go out on me again. At this point, I was getting very tired of having suspension woes. I decided to put my foot down: I would buy all new struts all around. KONI's would be used up front while KYB replacements would be used in the rear. Strange as it may seem, I didn't use KONI's in the rear because using KONI's in the rear requires a professional to cut and weld the housing and then seal it again with the replacement KONI inside. It was something I didn't want to do.

Going out and racing with new suspension took a lot to get used to. I had no idea how the car would perform. A few runs on the course showed nothing but understeer. I played with the front suspension settings and the tire pressure to make the handling more neutral. The best I achieved was corner-exit-oversteer.



April 28, 2001: Removing the front sway bar.

I wanted to dial in as much oversteer as possible to counter-act the immense understeer that was plaguing my car. I went to the extreme of removing my front sway bar. Removing the sway bar proved quite well. The car oversteered but only if disturbed properly. Other than that, it would push like any other front-engine, front-wheel drive car. I drove and raced without a front sway bar for the full SCCA season.



July 14, 2001: New tires.

Tires are an important handling aspect. They're the cylindrical black objects that grip the road. Think long and hard about tires. Only four tire patches determine if your car stays on the road or slides into a ditch.

The old tires I was using (Centennial Interceptors) were not satisfying my autocrossing needs. They didn't grip well and they squealed horribly. My next set of tires was Kumho ECSTA 712's, a popular street tire for autocrossers. They're relatively inexpensive for a performance tire. They don't squeal as much as my old set of tires. In fact, I'd have to do something stupid (like take a bad line) or push the car excessively hard to make them squeal.

Some people think that squealing is a bad thing. Yes, excessive squealing is bad. That just means the tires don't grab traction well. It's also a signal telling the driver that he/she is losing traction. The Kumhos do squeal, but that's just a signal telling me, "Hey, you! Lay off the gas!" or "Take a better line next time you take that turn!"

The only bad thing about the Kumhos is the treadwear rating. I do use my tires for daily driving, so it's double-whammy (race wear and street wear). Right now, they've lasted 6-7 months. I'm trying to squeeze the life out of them by rotating them frequently and "flipping" the tires so that camber wears evenly.



December 3, 2001: Why I shouldn't have removed the front sway bar.

I finally figured out the reason to why my struts blew. It took a while but I finally figured the whole thing out. I called Eibach and KONI to discuss my problem. Eibach wasn't the problem and neither was KONI. Both the springs and the struts were in perfect working condition. I had to re-trace my steps and think about what would cause the bumpstops to get demolished so easily. There had to be enough force to smash it to bits. Then, it hit me one evening as I was walking off my university campus. It was my missing front sway bar.

I had to think long about the missing front sway bar since I always thought that it wouldn't matter at all. But it did. The sway bar acts as a link between the left and right struts. When a wheel hits a bump, that side of the suspension compresses, as does the other side (a little bit and not as much). Some of the hit is transferred to the other side. So, it acts like "two" springs and "two" struts on one wheel. Now, with no sway bar, each spring is independent (very independent). When one side hits a bump, that side is taking a full blast of bump. The strut/spring is absorbing the full effect (unlike with a sway bar in, there would a distributed force to the left and right). There is no transferring of force to the other side. Hence, it causes the strut to plow through the bumpstop and destroy the strut.

A word of advice: it's better to upgrade sway bars than remove them. And if you do want to remove it, do it only for the day of racing and not for the drive home.



December 22, 2001: Installing the front sway bar.

I finally get to install my front sway bar that's been sitting in my garage for over a month. The day before, I went to the muffler shop to have the flex pipe remove so that I could install my sway bar with ease. It was supposed to be a quick slam-bam bolt-on job. I thought wrong.

I had this problem with one of the chassis bolts not wanting to screw into the hole. I thought it was due to a mis-aligned bracket. I took almost an hour before finally fixing the problem. Turns out I had to use a certain bolt for a certain side. How ridiculous. You'd think all threading for a 12mm is universal. Not in my case.

Next, it was time to attach the endlinks to the sway bar. At first, I thought I had to slide the endlink on. Nope. There was resistant. I thought to myself that the holes weren't big enough. I went to look for a file, and when I couldn't find one I went back to figure out what to do. I played with the bar for a while and then decided to twist the endlink through. I worked. That's when I realized it was threaded. After screwing it in as much as I could, I realized that there were only a few threads left for the nut to go on. No matter; I screwed the nut on and torqued it to spec.

Now, the big problem arises. I went under the car to attach the sway bar to the undercarriage. Easier said than done. It came to me that the bushings were too big. The brackets didn't slide onto the bushing; it had to be FORCED! Even when forced on, it wouldn't stay on. Even when forced on and slipping off, there was too much bushing material and it wouldn't allow the bracket to bolt on to the chassis. Needless to say, I screwed up trimming the bushing by cutting too much off. I cut off so much, I need to replace the bushing with another set. But I didn't go back to Whiteline. I just ordered some Energy Suspension bushings.



January 12, 2002: Installing the rear sway bar.

I made some time on the weekend to install my rear sway bar. The manuals implied it would be an easy job: remove brackets, remove endlinks, lower fuel tank, and pull out bar. Simple, right? Yes, simple, but not easy. The hardest part was getting the bar off through the obstacles of fuel lines, suspension arms, and chassis.

As with the front sway bar, the bushings that came with the sway bars didn't fit. I couldn't find any 18mm Energy Suspension bushings from Summit Racing, so I went ahead and trimmed the 18mm bushings I already had. Using an air grinder, I sanded a quarter of an inch off. Not too much; I did want some material between the sway bar and the chassis.

The combination of a front and rear sway bar is awesome. It handles so much better now. The tail doesn't feel soft. The front is very responsive. The car has less body roll during hard cornering.



January 18-19, 2002 : Installing the front KONI struts.

I never thought I would have to install another set of front strut again after installing my first set of KONI's. It took me two afternoons to complete the "re-installation" of my front KONI's. Why? I'm a slow worker. I like to be accurate and precise. I torque everything to spec. I make sure nothing's loose. Plus, I had to bleed the brakes and do the alignment after the struts. Alignment takes a while when all you're using is a piece of string and 13mm and 19mm wrenches.

But finally, my car is complete. Full suspension modifications (well, not full but closer to full than ever). Eibach Sportline springs, KONI Sports in the front, KYB struts in the rear, Whiteline 27mm front and 18mm rear sway bars, and polyurethane sway bar bushings. It sounds pretty ghetto with different struts from front to rear. With the amount of money I've spent on suspension, I should've invested in a set of Tein HA coilover kits. But I don't think their struts are warrantied for life.



January 22, 2002: "The suspension guru?"

It might seem awkward that I would take the time to write about my suspension project. Most people have projects in restoring a car, building or swapping an engine, preparing a race vehicle, or designing a show car. The most common "projects" that takes place in the Celica community are engine build-ups, turbocharging, and engine swaps. Mainly go-fast projects. But me, I spend time writing about springs, dampers, and anti-roll bars. Cams or a turbocharger for me? No, thank you. My engine is working, and that's what matters the most to me.

So why do I spend so much effort on suspension and handling? Perhaps it's because no one else really cares about handling. Sure a person can slap on some lowering springs and some KYB struts and say, "WOW!" But that's not good enough for me. I want a "WOW!"-factor times ten. I want to be able to take turns at full speed. I could have a 200-hp motor instead of all the suspension upgrades I have now. But the last time I checked, 200-hp doesn't make a car turn or handle any better.

Overseas in Japan, Celicas have an SS (Super Strut) package. The Celicas in the U.S. get gypped in handling. It has excessive body roll and a super soft, unresponsive suspension. A USDM Celica would die in the European market. The least I can do for my shoddy USDM Celica is improve its handling characteristics. If I wanted roll, I would've bought a boat.

Am I some sort of self-proclaimed "suspension guru" that knows all there is to know about handling? No. I know a lot, but I don't know all. Handling is a relatively simple concept for any person to pick up. Tuning a car to handle its best is a trial-and-error process. Nobody knows how a car will handle on a certain surface with certain conditions.

"What's the chance that the car will be set up perfectly for the course when you roll up to an event site? Zero."

--Mark Daddio, renowned suspension tuner

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So while everyone else is turning their Celica into a mean street car, a super-fast drag car, or a stunning show car, I'm that guy, somewhere in his corner of the planet, thinking of ways he can take turns faster and go through a slalom like he's going down a straightaway. See you on the other side of the apex!

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Source for this article...
http://projects.henryvo.com/handling.html