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Chassis Heeltoe Explains

About Chassis Braces

Chassis bracing may be the most under-rated and misunderstood modifications available to a vehicle. If the chassis accounts for the frame, steering, and suspension pick-up points; then this assembly must be as rigid as practical to perform at its best. Some compliance in the chassis helps dampen noise, vibration, and harshness (NVH), and it is not possible to completely eliminate flex. However, using strategic pick-up points, aftermarket chassis braces can be very effective at enhancing the feel of steering and suspension systems, greatly improving driver confidence and, as a byproduct, speed.

Strength

Bracing works by resisting the forces of compression and tension. Keeping two points at a fixed distance apart is the goal. With a rigid mounting between them, two points cannot bend toward each other. Judging a brace by its assembly* or how heavy it is may not be giving credit to the actual function of the part.

Materials

Braces are most commonly made out of steel or aluminum. These materials are inexpensive and strong. Aluminum has a lower weight, but fabricating it to be effective does carry a higher cost than a steel part. The most intricate parts of braces are the mounting points. Some manufacturers will, therefore, use steel for the mounting points and aluminum for the joining bar stock, and attach them with bolts. Carbon fiber and titanium are other materials chosen for their lightweight and strength, in the face of their expense.

Construction

Braces made out of one piece, or being a welded-up assembly, are assumed to be stronger than those made of multiple pieces. This statement is a risky one because it is taking design and quality out of the picture. A well-designed brace made with quality materials that bolts together would be preferable to a cheap, flexible brace made to be one-piece. It is generally true that brace which is installed as one piece would be more rigid, but unless the brace is then welded to the chassis itself, this point is largely irrelevant if the brace made is of high quality.

Placement

In general, bars mounted laterally (side-to-side) are effective at reducing twist in the chassis. Twisting movements cause the center points of the frame to move closer together. By fixing these points, the twist is resisted. Also, subframes and uni-bodies are made to accommodate the installation and mounting of other vehicle systems (exhausts, suspension parts, and drivetrain assembly) and closing these open areas “boxes” them in making the entire chassis stronger in that area. Lateral bracing will be felt more in turns where there is a high load.

Longitudinal braces help resist bending in the chassis as the front and rear traverse bumps in the road. The front and rear work together more than most would assume. By simply going over a bump, the chassis will bend, and in these bending moments, there is a numbness that reduces confidence. It’s not as apparent at road-speeds, but at highway or HPDE speeds, confidence is very important. Also, keeping the chassis flat reduces unwanted changes in wheelbase that can make the vehicle hard to set in turns after high-braking zones.

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Chassis You Can Do It! DIYs

Ultra Racing Chassis Braces For Acura TSX & TL

Heeltoe has been offering the Ultra Racing braces for a while, and due to the comprehensive suite of braces available for the 1g TSX/CL9 chassis we had a customer that took the plunge and bought them all. This article outlines impressions and installation for 04-08 Acura TSX models, however, bracing for other Honda/Acura models have similar fitments and benefits.

Driving Impressions Before Install

I drove the car before and after install. The suspension was Tein FLEX (which rode remarkably well as a matter of fact…this kit is NOT hands-off for street performance drivers!). The car handled reasonably well before, but the owner was complaining the car was too soft, and I felt what he was talking about. The FLEX is firm yet is tuned well for the street. For some performance drivers stating they really want a firm ride, I’d say they are not going to be firm enough.

For lack of a better suspension option to firm things up, we recommended bracing out the car. It just so happened the Ultra Racing bars we ordered just before this meeting had come in, so we did a test fitting. The hope was that we would keep the suspension more rigid and add a significant amount of feel to the car. We hoped the chassis would tighten up and allow the suspension to do it’s job better. We wanted to eliminate the springing effect the weak chassis was injecting into the car’s ride and handling.

First Impressions of the Product

First off, the staff at Ultra Racing are nice and attentive to our requests. We look hard for such qualities in our vendors because being able to communicate well with them directly impacts the service we can give to our customers! The first major reason to pursue sales with them is their great initial service.

Now, THE BARS.

The bars offered by Ultra Racing fit well and work great. We give the product a high ranking on these points.

We found overall finish quality to be certainly acceptable but hampered by lack of detail refinement and unconvincing durability on the painted finish. However, product labeling was quite good and clear. There is a definite pride in the branding. It could just be that since these bars are made in Malaysia they could benefit from higher-end manufacturing practices. That being said, we were more than happy and confident to install the bars to see how they’d work, and were not deterred or depressed at all by the finished-product observations.

Should you benefit from these parts, we’d encourage you not to be either. These observations were made only in comparison with arguably overpriced masterpieces from Japan. For parts that will essentially get destroyed under the car, we felt better installing these than Carbing museum pieces.

Before we get to the pics:

* We did not get a chance to install the fender braces¬†because of a lack of time. Unlike the J’s braces, these will require removal of the fenders to install properly. We did line them up and they will fit. We also like the welded-up construction versus the J’s braces. We anticipate these braces to offer more in the way of rigidity, especially when considering torsional forces that could act on this area of the car.

* For some reason I forgot to take some pictures of the Front Lower Arm Brace installed. This is a 2-point brace, fitting in the same location as the Cusco Type-1 brace. It appeared to us that this brace offered good exhaust clearance

* There are two small bars¬†(Front Outer Frame Braces) that come in a pair that don’t fit in conjunction with the Side Lower Floor Bars. We certainly expected to see the greatest improvement in the Floor Bars so we installed these instead of the Outer Frame Braces.

* Ground Clearance¬†LOOKS to be severely hampered however the effect is not nearly as bad as you’d think. The side braces don’t hang any lower than the exhaust does, and the rear brace spans between the rear wheels. Speed bumps are not a problem, generally speaking. But cars lowered more than 2″ will have some contact with the ground from time to time. We do want to note that the customer we tested these bars with told us he had a very gnarly driveway entrance that we did scrape on and thus needed to raise his car. We did see evidence of grounding out. The concern was that as quick as these bars went on they’d need to come off because of ground clearance issues. —- The customer did have some rubbing on the ground but it was not that much and they are keeping the bars on. The reason the rubbing is not bad is simple: These bars keep the car straight and rigid over bumps and dips. The chassis flexes enough to bow the car when large bumps are encountered. These braces prevent the bowing and actually helps the suspension work the car over the bumps better! So while these bars do hang lower than the car, we’d encourage people to try them out ¬†anyway.

Front Lower Frame Brace
Side Lower Floor Braces installed. Driver’s side, front to back
Side Lower Floor Braces installed. Driver’s side, front to back.
Side Lower Floor Braces installed. Driver’s side, back to front. You can see the Front Lower Frame and Front Lower Arm Braces there. The Arm Brace is the one sitting closer to the cat.
Side Lower Floor Braces installed. Driver’s side, back to front. Altered Angle
This is the area where the rear of the Side Lower Frame Brace is installed.
Pull back the plastic and there is another hole revealed. The supplied bracket installs this way.
Rear Lower Arm Brace installed. This is a 4-point brace. See all the other bars? It’s looking like an Indiana Jones Stunt Vehicle now.
Rear Lower Arm Brace installed. Detail shot.
Rear Lower Arm Brace installed. Detail shot again.
A look at ground clearance from the side, frame level.
A look at ground clearance from the side, below ground level.
A look at ground clearance from the rear, frame level.
A look at ground clearance from the front passenger side, slightly above ground level.

Driving Impressions After

After installing the bars and pulling out the driveway, we could feel a difference right away. You can actually feel the suspension articulating over dips and bumps at slow speeds. The steering felt a little lighter and more responsive. I’d speculate that the steering felt lighter because the power rack was able to move the tie-rods better without power being lost in chassis deflection. It makes me want to revise the steering rack mounts better actually!

Once we pulled out onto the street you could certainly feel the car was more rigid. It reminded me of my M3. We took a couple turns at a reasonable pace and I can say without a doubt the car was more confident feeling and certainly more capable. People with less experience tuning have a hard time grasping the benefits of bracing because it seems so obscure. Bracing adds a certain je ne sais quoi to the driving experience that just makes it more fun! A major reason why European cars drive so much better than Japanese ones is that they come from the factory like this!

Combine bracing, mild suspension like the ones we offer on www.heeltoeauto.com, or even the A-spec kit, and a rear sway bar, and you are going to have an FWD street warrior! The braces really show off how good the TSX platform is!