Welcome to the first official deep-dive tech post on the new blog! In the related video above, we go through what it takes to install a 1998 to 2001 Acura Integra pinion into a 1996 to 2000 Honda Civic EK. This swap is the cheapest, easiest way to get a “Quick Ratio” in what is one of the most-cumbersome-to-handle generations of Honda Civic.
In this article we will be going more in depth on this upgrade in addition to covering some of the basics about steering ratios as well as other related topics.
Throughout the video we went from A to Z on the installation of the “new” Integra pinion into my 97 Civic Coupe. This upgrade reduces the effective steering ratio which also reduces the lock-to-lock; AKA: How many rotations it takes to turn the wheel full left to right. The benefits of this can be huge, especially when racing your car on track or doing Autocross.
Civics of this generation (EJ, EK, EM1, 96-01) have the worst steering ratio of any Honda developed in the 90s. This is pretty unfortunate considering how popular this particular generation of Civics are for tuning and racing. There are a few different options out there for improving the steering ratio, from upgraded quick ratio racks from Quaife to cut-and-weld steering quickener boxes.
A steering quickener, such as this one from Howe Racing, multiples the inputs from the steering wheel to the steering rack.
The option provided in the video was discovered, or at least shared widely, by a user of the now-ancient Honda-Tech forums, sil80drifter. As of this article, their thread was created 14 years ago in 2008. The thread covered in detail how the pinion gear from a 94-01 Integra could be swapped into the 96-00 Civic to reduce the steering ratio for much less than the other available options.
Using the pinion from the Integra in the Civic reduces the steering ratio from 17.7:1 to 16.1:1 and the lock-to-lock from 3.6 turns to about 3.1. Compared to the other options, this is the most affordable and the parts can be obtained from your local junk yard or even online. The main benefit is that you can do this without removing the steering rack entirely from the vehicle; It can be done in your garage at home and you won’t even need an alignment after!
This sums up the video, but there’s more benefits and details that you may be interested in that I didn’t include in the video due to length.
I’m sure you know what a steering ratio is if you’re reading this, but for those that may not, let’s break it down.
A vehicle’s steering ratio is the calculation of how many rotations the wheel makes divided by how much the wheel angle changes, both measured in degrees. Mathematically, that would look like this:
x = Steering Wheel Rotation (degrees) y = Wheel Angle (degrees) z = Ratio x ÷ y = z
When calculated this way, z is expressed at z:1, with 1 representing 1 degree of turning angle. For example, 17.7:1 means 17.7 degrees of steering wheel rotation equals 1 degree of wheel turning angle. This is the ratio for a 96-00 Civic with power steering and we can reverse-engineer this ratio to find out how much the wheel angle changes with one full wheel rotation (360 degrees) using some more math:
x = Steering Wheel Rotation (degrees) y = Wheel Angle (degrees) z = Ratio x ÷ z = y Or 360 ÷ 17.7 = 20.34 (rounded up)
So, for every full steering wheel rotation in a Civic, the wheels turn 20.34 degrees! If we do the math on the Integra ratio of 16.1:1, the result is 22.36 degrees for every rotation of the wheel. It doesn’t seem like much, but it’s actually a decent difference.
A quick note here is that steering ratio is not determined by the rack and pinion alone. Things such as knuckle steering arm length and other suspension geometry aids in the final ratio. To add, variable ratio steering racks do exist which make things a lot more tricky to calculate.
Caster doesn’t change the ratio, but does cause asymmetric steering angle from side to side. The inside tire will have more angle than the outside, how much is dependent on suspension geometry and your alignment.
As described above, lock-to-lock (LTL) is the term used to measure the amount of rotations the wheel makes going from full-right to full-left. Contrary to what it may seem, this number is actually irrelevant in determining how “fast” your steering ratio is.
Lock-to-lock is determined by the total amount of travel your steering rack has available. As you would imagine, the steering rack can only move so far in either direction due to mechanical constraints (rack length, wheel clearances, etc) determined and set from the factory.
The final element in the LTL is, you guessed it, the steering ratio! A higher (slower) ratio will result in more turns LTL while a lower (faster) ratio results in less turns.
With some more math, we can actually find out how many degrees of angle the wheels move from one side to the other when going lock-to-lock. To do that, you must know the wheel angle from the last calculation from the Civic that we did above, coupled with the Civic’s LTL.
y = Total Steering Angle (degrees) z = Wheel Angle (degrees) x × z = y Or 3.6 × 20.34 = 73.22
This means there is 73.22 degrees of total wheel steering angle from one side to the other, i.e. left-to-right, when the wheel is rotated fully 3.6 times from lock-to-lock. This number is actually pretty useful for comparing vehicle turning radiuses since a higher degree of turning angle results in a tighter radius!
Looking at the base numbers from the Integra, you would think that it had the superior setup being that it has a tighter ratio and less lock-to-lock. Let’s use the Integra’s LTL and it’s calculated wheel angle from above:
2.98 × 22.36 = 66.63
Now, if you’ve driven an Integra and a Civic of these generations, you already know that the Integra has a pretty poor turning radius. But these numbers don’t lie: the Civic has much more available turning angle, nearly 7 more degrees total side-to-side.
The Integra (left) has a worse turning radius than the Civic (right) even though the chassis are nearly identical in length. This is due to the lesser steering angle, as snipped here directly from manufacturer service manuals.
Thanks for sticking with me through the basics, they’ll be helpful for getting through the rest of the article! Let’s get back to the main topic at hand.
Referencing back to the video recap, there are multiple options available to reduce the steering ratio of the Civic EK. From Quaife rack and pinion kits to multiple options of quickener boxes that can go all the way up to 2:1, effectively doubling the speed of your inputs to the steering rack.
Depending on your technical level, each one of those options have their benefits from an installation standpoint. Quaife rack upgrades offer a “simple” bolt-in solution for a mild improvement over factory at an affordable price tag compared to buying a new quick-ratio rack. Quickeners offer much more aggressive reductions in ratio but require fab work. However, both of these options have their caveats as well.
The general consensus among the community was that Quaife rack parts were overpriced and not of the greatest quality, proving more hassle than they were worth. This viewpoint did vary, however, so don’t take my word for it.
On the other end of the spectrum, steering quickener boxes can be pretty tricky and time consuming to install. Individuals have had to sacrifice steering height adjustment for a fixed steering column, while some have replaced the column entirely. If they aren’t welded properly, they can break or fail, or simply just be off-center resulting in steering feedback that feels like you’re driving a car built in ToonTown.
The Easiest (and Cheapest!) Option
The pinion swap is easily the best option in this regard for those of you who (like me) don’t want to hassle too much with a steering quickener and also want to save a few bucks. After all, we aren’t trying to build a full race car (yet), right?
Because the 96-00 Civic and the 94-01 Integra power steering racks have the same 32 tooth rack gear, you can hot-swap the pinions to either car and they would work. The main difference is the tooth count on the pinion, with the Civic having 8 teeth and the Integra having 9. This is where the benefit is gained as that extra pinion tooth adds another ~2 degrees of turning angle per full steering wheel rotation.
This reduces the Civic’s steering ratio to match the Integra at 16.1:1, improving steering input speed. Steering feedback will be improved and response sharpened, while reducing the need to shuffle hands on the steering wheel through sharper corners on track or during Autocross.
Mind you, it won’t get you anywhere close to, say, a S2000 CR with a ratio of 13.9:1 and a LTL of 2.4 turns. But, with this chassis, any improvement should be welcomed.
The Finer Details
A lot of this is covered in the video, but I wanted to expand a little further for those that wish to tackle this install. When this was originally posted over on Honda-Tech there was a ton of conversation regarding how to do it, what needed to be changed, and what didn’t. When doing this myself, I ran into quite a few obstacles that I had to discover on my own.
Primarily, there wasn’t any information regarding the ability to retain power steering when swapping the pinion. Many individuals who do this opt to de-power their power steering rack, completely circumventing any testing with a powered system. Luckily, the valve bodies are the same between both cars, even though the housings have different port locations externally, so it works just fine.
There also wasn’t much information in terms of the shims that are installed both on the pinion assembly and inside the steering rack body. This is very important as the shims work in tandem with one another to set the depth of the pinion gear in the rack to ensure optimal gear teeth contact and even wear.
For clarity, you’ll want to use your Civic pinion housing and original shims from the Civic pinion with the new Integra pinion. This means disassembling both pinions and reassembling the Integra pinion with the Civic shim. If you don’t swap the shim over, the bearing will not seat properly, the housing may not sit flush, or the rack and pinion will wear prematurely.
As you can imagine, all of those problems can eventually (or immediately) prove catastrophic for the life of your steering rack.
With everything apart, it is a good idea to measure washers, bearings, and depths to make sure that everything matches when swapped over. You want all measurements to match the originals from the Civic or you risk having issues post-assesmbly.
Covering the Bases
There is a select group of people who have swapped the Integra steering rack into their EK. However, this isn’t the best option. It is a ton more work as it also requires swapping over the entire Integra subframe and control arm assembly. Additionally, if you recall earlier in our “math” segment, the Integra has a worse maximum steering angle.
This is because of the mechanical limitations of the Integra steering rack and associated components. Sure, you’re getting the ratio, but you’re also subjecting yourself to way more work than necessary with the additional cost of a worse turning radius.
For a race car, this isn’t a big deal since they generally aren’t trying to get through tight quarters in parking lots or making U-turns. Reducing the maximum steering angle is actually a common technique in race cars that wish to fit larger wheels and tires on their chassis that interfere with bodywork or touch the frame.
In theory this sounds like a great idea, but the reality is that it is just a Band-Aid to avoid properly modifying the chassis for wheel and tire fitment. In doing this, the vehicle is now more limited in its ability to countersteer if things get a little too wild. If the car goes sideways and you run out of steering angle to compensate, say goodbye to your lap and possibly your entire race. Worse yet: your car.
The only reason this would need to be done is to stay within class rules as some associations inhibit your ability to modify the body or chassis. I can imagine it is probably good for reducing CV joint wear, too.
The Year Doesn’t Matter
There’s a lot of information floating around that certain year Integra’s have different steering ratios, specifically pointing to 2000 and 2001 years and the Type R. Unfortunately, nobody has been able to prove that they do in-fact have different steering components than older years and base models.
|92-95 Civic (Manual)||19.0:1||3.88|
|92-95 Civic (Power)||17.5:1||3.58|
|96-00 Civic (Manual)||20.3:1||4.1|
|96-00 Civic (Power)||17.7:1||3.6|
|94-99 Integra (Power)||16.1:1||2.98|
|00-01 Integra (Power)||15.7:1**||2.98**|
Even referring to the factory supplied Honda Service Manuals (alternate source), each model and year shares the same specifications for steering ratio and LTL. The closest thing we have for a source on a different, tighter ratio for the Integra’s is the old brochures that Honda released during the 2000 and 2001 years.
Just to test for myself, I used a pinon from a 2000 Integra for my swap. The pinion fit together perfectly in my Civic and had the expected 9 tooth count. Others have also completely disassembled Type R, year 2000, and older year racks for comparison and found no differences in the rack and pinion gears.
One could bring up the point that perhaps the differences lie in the knuckle of the different year Integra’s. A longer or shorter steering arm on the knuckle can change your steering ratio, reducing or increasing it respectively. However, no differences have been found in the wild and manufacturer part numbers throughout all years and models are all the same.
Safe to say, grab any year pinion and be on your way.
Manual Racks and EG’s
As we reach the end of this article, I want to shed a final light on manual rack EK Civics and EG Civics. To start, the EK manual rack has the worst steering ratio of any Honda since the 70s. At 20.3:1 and 4.1 turns LTL, you might as well be captain of a sailboat. If you’re running this rack, you will benefit the most from this upgrade but it will also be more work.
Manual vehicles will need a full Civic power rack installed. The pump and hoses aren’t needed unless you want to also add power steering. You can either loop the lines or convert the rack to manual with a rebuild. Installing the Integra pinion is much easier while the rack is out. Additionally, you will need the steering coupler from an Integra or power Civic as the manual is different.
This is what the coupler looks like. The manual one will not work, don’t forget!
92-95 EG Civics are like the EK in that its steering ratio is (slightly less) slow and it has a great turning radius. It also shares some power rack parts with the Integra but in the opposite fashion. The pinion is the same as the Integra’s 9 tooth, but the rack gear is different. There are only 27 teeth instead of 32.
Swapping the Integra steering rack over is easy since it’s a direct bolt-on, but doing so reduces the maximum steering angle with no change to the ratio. This means that the differences in ratio come from the EG steering arm length on the knuckles or elsewhere. It seems the aftermarket options are the way to go.
Out of all the different models throughout the decades, these Golden Era Hondas are still the most popular. Turning them into race cars and competing is still a huge pastime and hobby for many, and even career for some.
The key to building a great car is not just throwing parts at it, but knowing how they work and why they are beneficial. Knowledge can save you time and money while ensuring that you get the right parts the first time.
Simple upgrades such as this pinion upgrade are a prime example. With less than a 100-dollar investment and a little bit of elbow grease, you will have a Civic that is much more fun to drive. This is a no-brainer upgrade for anyone wanting to track their EK.
Special thanks to Omar (96dc2build) for shooting over information, photos, and video about his car to provide me with real world comparisons using his Integra. Additional thanks go to all the old-school warriors of Honda-Tech who discovered this and shared it with the world! Finally, thanks to Michael Flare for also spreading the word of this upgrade and putting together this great video on power to manual rack conversion.