When it comes to a K-swapping a legacy chassis (ie. golden era Honda’s: 88-00 civic/90-01 integra), there are many axle companies on the market with tons of axle stage choices (DSS, Hasport, ProFab, etc). It can get quite convoluted and frustrating. For those looking for an ‘OEM axle’ setup you’re in luck! I personally went the OEM axle route a years ago (2009 or so) after researching on K20A.org along with help from Brian Karwan (Karcepts.com). Some quick back story… When I dropped in my EP3 K20A-R engine (summer ’04), I used a set of axles from a company by the name of ‘Pro Fab’. I don’t think they exist anymore but their axles held up just fine for the period of time I used them. Except they had one seriously annoying flaw. Upon acceleration, in the lower sub 4000rpm range, they would shudder (ie. shake/wobble sensation during acceleration) from 1000rpm to about 4000rpm. That shuddering drove me f**king insane over time. Made my car feel like an EF w/B16 swap from the early days. As it turns out, these ProFab axles didn’t have a dynamic damper on either axle unlike factory Honda axles (the black donut on the center of the axle shaft – this helps eat up or dampen vibrations). So, I looked for alternatives which brought me to the OEM axle setup. Once I switched to OEM axles, car life was renewed – no more shuddering on acceleration and my civic felt normal.
Note: All axle measurements were taken when ‘fully compressed’. (photo soon)
- EP3/Civic Si:
Driver: 24″ / Passenger: currently unavailable / 25.3mm thick shaft
- 06-11 Civic Si:
Driver: currently unavailable / Passenger: currently unavailable / 26.3mm thick shaft (assumed)
- RSX Base model:
Driver: 24-1/8″ / Passenger: 22-5/8″ / 25.3mm thick shaft
- RSX Base model (w/swapped inner joints):
Driver: 24″ / Passenger: 22-3/4″ / 25.3mm thick shaft
- RSX Type-S:
Driver: 23-5/8″ / Passenger: 22-5/8″ / 26.3mm thick shaft
- RSX Type-R:
Driver: 25-1/4″ / Passenger: 23-3/8″ / 26.3mm thick shaft
Driver: 23-7/8″ / Passenger: 23-1/8″
- Hasport (EGKAX):
Driver: 24-1/4 / Passenger: 23-1/2″
The ‘OEM’ axle setup consists of the following ingredients:
- Using a pair of factory Acura RSX axles (Base,Type-S, or JDM Type-R model).
Depending if your vehicle was originally 4-lug or 5-lug converted will help dictate which RSX model you need to use. Note: there are 32mm 5 lug & 36mm 5 lug conversions!
- Swapping the inner joints are key!
Doing this forces the use of the whole driver side axle onto the passenger side of the vehicle & the passenger side axle onto the driver side of the vehicle. The point of this is to gain maximum axle length on the passenger side of the vehicle – getting it as closer to 23″ inch length as possible. The RSX passenger side axle, specifically Base model, in its unmodified stock form, is a bit too short for a K-series swap into 88-00 civic / 90-01 integra chassis’s. Once the inner joints are swapped the driver side axle becomes the passenger side axle and is at its closest to 23″ total length.
Though some have said they’ve used RSX Base axles with unswapped inners and say they haven’t ran into any issues.
- 4×100 with 32mm axles
If your vehicle is 4-lug like most civic/integra’s are (excl. Type-R), you will want to use a pair of factory RSX Base model axles. Base model axles, by default, have the the 32mm splined outer joints. Base axles will plug n’ play into any legacy chassis with 4-lug front wheel hubs. Simply swap the inner joints, install axles, and you’re done. EP3 axles can be used but with caution, see below in the Alternative axle section.
Note: I’ve found that swapping inner joints is not even really necessary for Base axle use. It’s more of a peace of mind thing. I’ll leave the joint swapping choice up to you.
- 5 Lug 32mm axles
If you have converted to US Integra Type-R or JDM CTR EK9 5 lug (aka 32mm 5 lug) on your legacy chassis, RSX Base model axles are usable as well. The US Type-R 5-lug front wheel hubs cater to the outer axle spline joints that utilize a 32mm axle nut-outboard joint. Simply swap the inner axle joints, install axles, and you’re done.
UPDATE: If you find that your passenger side axle does not seem to have enough length or you’re experiencing passenger side axle issues, you should quickly upgrade to an 06-11 Civic Si passenger side axle and swapping your 32mm outboard joint onto the Si axle.
- 5 Lug 36mm axles
If your vehicle has been converted to JDM ITR 5-lug w/36mm splined outboard joint, the RSX Type-S or RSX Type-R axles are the ones for you. 98+ JDM ITR 5-lug front wheel hubs use a larger outer splined joint by default using a 36mm axle nut. RSX Type-S & Type-R axles share the same larger outer spline joint & 36mm nut. So, Type-S/R axles will basically plug ‘n play into these hubs. Swapping of the inner joints is NOT REQUIRED as the axle lengths are perfect for this application (especially with RSX Type-R axles)
UPDATE: I’ve found out (through others and a close friend) that using 36mm RSX-S axles unmodified w/36mm 5 lugged swapped EG/EK/DC2’s doesn’t always work for some. Especially with EK’s using EKK2 Hasport K-swap mount kit and even DC2’s with an EGK1 swap mount kit. This happened with a close friend of mine. The result is the Type-S passenger side axle falls short by an inch or so. The fix for this is switching over to an unmodified 06-11 Civic Si / K20Z3 passenger side axle and retaining the Type-S driver side axle. Turns out the Z3 passenger side axle is the perfect length for 36mm 5-lug users. You don’t want to use a Z3 driver side axle as it is too long and will likely bind. So retain your Type-S driver side axle!
Alternate ‘Hybrid’ and Aftermarket Axle Scenarios:
- Type-S axles w/B-series 32mm outboard joints (4 Lug)
Some are forced into this scenario for lack of parts or finding RSX Base model axles. This setup consist of using Type-S inner joints and axle shafts but using 94-01 Integra or 92-00 Civic SiR (B-series) outer joints in order to get the 32mm axle spline use for vehicles with 4×100 wheel hubs. I’ve tried this scenario before and I found it works perfectly fine for street use (and possibly drag race use) but will fail big time for road racing conditions. Binding occurs within the outer joint creating friction. This friction eventually boils the axle grease and creates air within the axle boot, ballooning the axle boot to the point of almost popping! Now, the axle place that I had put these together for me, might have used 90-93 integra outer joints rather than 94-01 integra outer joints. So, I’m not going to fully throw this axle setup under the bus. So, if you go this route make sure you use 94-01 integra outer axle joints! Otherwise stick with RSX base model axles from the get go.
- EP3 Civic Si Axle Use
The 02-05 EP3 civic Si axles are almost identical to RSX base axles in relation to being “32mm axles”. The length is where the difference is, mainly with the passenger side axle. EP3 passenger side axle is way too short for use on a K-swapped legacy chassis. In fact, I think its the shortest factory K-series axle Honda makes. I know this from personal experience. With an EP3 passenger axle in place on a K-swapped EG, the inner boot is noticeably stretched out and you can see some of the tripod bearings pushing on the inner boot from coming out of the inner cup. Lets just say a spirited pull on a freeway on ramp made a mess under my hood because the axle pulled apart. However, th EP3 driver side axle is perfectly fine to use as-is unswapped. Just stay away from using the passenger side EP3 axle. It’s only usable for its inner and outer joint parts or swapping a RSX base shaft over to it and then disregarding the EP3 shaft. You could possibly re-purpose the EP3 passenger side shaft for driver side use.
- Hasport EGKAX Axles
If you want to go aftermarket axles, these are the ones to get. Brian@Karcepts informed me these are the best aftermarket axles he’s used outside of the OEM axle setup and have held up great for him (he autocrosses btw). Hasport has made these the perfect length as well, so no matter how high or low your car is, the length of these axles will do the job.
- Stage 1234878654785&#^@# Axles
Sorry to disappoint, but I have zero experience with the aftermarket stages 1-5000 axles. OEM axles can handle up to about 350whp which is absolutely fine for me as I’m barely crackalatin’ 228whp vtack to the tire. If I get more information on higher horsepower axle applications I will definitely update this section.