AE86 with S13 front crossmember for SR/KA swap and AE86 LCA

donkayroo
Posts: 8
Joined: Thu Jan 10, 2013 10:36 pm
Location: San Diego

AE86 with S13 front crossmember for SR/KA swap and AE86 LCA

Postby donkayroo » Sat Dec 13, 2014 1:36 am

Hey peeps, just posting a few comparison pics between the AE86 front crossmember and S13 front crossmember for those interested in doing a KA24DE or SR20DET swap into their hachi without having to spend hundreds on swap mounts or fabricating your own mounts.

For reference, I also took pics of what a manual SR5 steering rack looks like when placed in-line with the S13 crossmember steering rack mounting points on the S13 front crossmember. The AE86 manual rack will not fit onto an S13 crossmember without making custom mounts. I'm just mentioning it so it's officially documented online.

I also have pics of what the AE86 LCA/spindles look like when mounted onto the S13 crossmember utilizing the AE86 LCA mounting bolts. The width of the AE86 inner bushing is approximately 4.5mm narrower than an S13 LCA so a 4.5mm spacer/stacked washers are required to close the gap. See pics below. The S13 crossmember pushes the AE86 LCAs outward which extend track width approx. 12mm or more on each side. I haven't taken actual measurements yet. Using the S13 LCA/spindles with the S13 crossmember increases the track width even further out. Using S14 LCAs push track width wider than the S13 LCAs.

I just began the swap and already have the S13 crossmember mounted. Using an S13 front crossmember is by far the cheapest solution to a SR/KA swap while upgrading the front suspension to have increased track dimensions, enhanced suspension travel and a wider array of less expensive front coilover selection.

Previous threads mentioned how they oblonged the holes or enlarged the holes of the S13/S14 crossmember but none mention specific dimensions. I will…I simply increased the S13 crossmember chassis mounting bolt holes using a harbor freight step-drill-bit and plowed down to the maximum 3/4'' size. It's the perfect diameter which keeps the AE86 crossmember mounting bolts nice and snug on the S13 crossmember and keeps the crossmember perfectly aligned/squared on the AE86 chassis. As mentioned by previous guys who have done the swap, you have to slightly hammer out the pinch on the AE86 frame rails just enough so the S13 crossmember sits flush on the frame rail. A 3lb sledge works perfectly.

I paid $40 for the S13 crossmember, $30 for the S13 steering rack, $40 for the S13 LCA/spindles/4-lug hubs/rotors/S13 stock brake calipers w/lines. Keep in mind that the stock S13/S14 OEM front brakes are a lot beefier than the AE86 stock brakes.

You can use the AE86 LCAs with the S13 crossmember as a temporary setup until you upgrade to the s-chassis suspension components but as previously mentioned, you'll need to add a spacer/washers between the front (radiator side) of the AE86 LCA to eliminate the gap. You also need to drill the sway bar mount hole and tension rod holes on the AE86 LCA 10-12mm inwards so those components can be lined up properly. If you're going to do track events, I would not advise using this rigged setup unless you have a proper spacer/bushing made.

The reason I'm posting these pics is because after extensive searching, I have never seen images of an S13 front crossmember mounted to a hachi with the AE86 LCA and AE86 spindles. There are tons of pics with the S13 front crossmember with S13 LCA and S13 spindles.

Please don't comment on this thread saying "why don't you just throw in a 4AGE, 20V, 3SGTE, they're more reliable blah blah blah…" I have had all those motors in the past and they all require extensive work to get decent power/torque. Of course they're great motors but I can care less about revs. I'm actually not a fan of high revving car motors with narrow power bands to begin with. Just more wear and tear and I'm sick of dealing with retarded timing belts. The most lame engineering technology ever…a rubber belt in an engine that has to be replaced every how many miles. If I want to get my rev fix, I just hop on my 2011 ZX6, twist and in the blink of an eye I'll be at 15k rpms.

I had a kouki S14 that was KA-T (ran the hell out of it) and from my extensive experience with the KA24DE/DET, it has been 10x more reliable than any of the Toyota motors I've had. Sure I blew a ring land when I accidentally overboosted a couple times but that was me thrashing the motor with stock internals pushing to see how much abuse a boosted KA could take. It can take a massive beating. The guys with KA horror stories…they're the ones who check their oil once every 3 months expecting the levels to be full cause they ain't showing visible signs of leaking and change their oil whenever they can afford oil. Anyone who pushes any motor to the limit regularly, well, they know it's mandatory to constantly check oil levels 1-2 times every few days even if you're not leaking oil. Peace of mind and preventative practice.

Anywho, I still have a storage full of KA's that I collected over the years and because I miss the low end grunt of the KA, I wanted to throw one into a lightweight hachi. Please don't comment saying…"you're gonna destroy the handling characteristics…" For those guys who love to rant about that, I'll tell you a little secret…a talented driver has the ability to adapt to any car they drive and possesses the skills to accurately apply the necessary inputs to get the car to hit the optimal line on the track. And if they can't, they know how to either communicate their handling needs to their tech or know how to tweak the suspension settings themselves and come closer to obtaining the handling characteristics that suite their driving style. That's the fun of "tuning". It's all about testing, tweaking, testing, tweaking. But hey, I'm not an actual pro so why should I even talk? Wow, went off on a major tangent.

On with the pics. The very last image shows the S13 crossmember mounted with the AE86 LCA/spindle installed.


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S13 crossmember on top, the AE86 crossmember on the bottom.

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TMA-1
Posts: 9
Joined: Sun Jan 04, 2015 3:04 pm
Location: ATL

Re: AE86 with S13 front crossmember for SR/KA swap and AE86

Postby TMA-1 » Sun Jan 18, 2015 6:22 pm

Any progress on this? Thinking of picking up a friends s13 crossmember, rack, and front suspension so I can go SR down the road

donkayroo
Posts: 8
Joined: Thu Jan 10, 2013 10:36 pm
Location: San Diego

Re: AE86 with S13 front crossmember for SR/KA swap and AE86

Postby donkayroo » Mon Jan 26, 2015 4:10 am

TMA-1 wrote:Any progress on this? Thinking of picking up a friends s13 crossmember, rack, and front suspension so I can go SR down the road


Haven't had a chance to get a lot done due to work and the holidays. The goal is to finish dropping the motor/tranny in by the first week of February. I'm still debating on tubbing the fender wells and shaving the engine bay.

I'll update as soon as I get some work in.