The swap does away with the entire factory intake system and uses a lightly modified AEM TSX short ram intake. Although you could bolt the K20's intake manifold on the TSX engine, you should also know that the intake manifold from the TSX dyno tests better than the one on the K20. Hondata has done extensive testing, and until you do major modifications like iVTEC advance adjustment, a race header, larger cams and more, the TSX manifold will outperform the one from the Si.
Wrap-UpThis crazy swap might not make sense now, but later down the line when Si owners get hungrier for torque this will be the first stepping stone to endless other hybrid combinations. It's a lot of work because of the number of parts that need to be swapped to fit the Si's unique engine mounts and work with the Hondata K-Pro ECU.
Soon Hondata will have a reflash for the Si, then they'll probably have a fully-programmable ECU like the K-Pro, which will alleviate the need to swap half of the parts that we've changed. But for now, we're all stuck with bolt-ons and we already know from years of dyno testing, the K series really comes alive with more than just bolt-ons and it takes a K-Pro to get that benefit.
If you're not Hasport, then just having a new Si will be cool, but having one that has incredible potential (Hasport is planning on turbocharging theirs to the tune of 550-wheel hp with a sleeved block) makes you nearly untouchable.
Swap Parts List* K24A2 or K24 with any A2 head* K20Z3 oil pan* K20Z3 oil pump and balance shaft assembly clearanced for longer K24 stroke* 2003-2005 Accord 4 cylinder throttle body on TSX intake manifold* 2003-2005 RSX-Type S throttle cable* K20Z3 idler pulley* 7 ribbed, 65.25-in. belt* Modified TSX aftermarket short ram intake tube* K20Z3 factory exhaust or '06 Si header* Pi Xsport digital dash* Hondata K-Pro
Brian and Scott of Hasport started this swap by removing the subframe. Make sure to disconnect the electric power steering.
The rear mount connects to a bracket on the oil pan and the subframe. It's a simple "dog-bone" style mount to limit engine movement and is great for preventing wheel hop on "sport-style" launches. The front and both sides are typical Honda affairs and disconnect easily.
If you're lucky, you have a lift and you just push a button to lift the Si away from the K20Z3 (once the subframe has been removed).
This is the stock Si right-hand mount. It has a built in torque arm or "dog bone" to prevent the main mount, which is filled with hydraulic fluid, from tearing under heavy acceleration.
We opted to use the '06 Si tranny for its limited slip and lower gearing. The stock shifter cables wouldn't work if we hadn't-something we found out after the fact.
It's already gone, but this is where the Honda ECU lived. On the new Si, Honda is mounting the ECU under the hood. This will prove tricky on our swap as the K-Pro is not weatherproof.
Although the stock mounts can be used for the K24 engine swap, the Hasport mount will be necessary for the 550-wheel hp turbo motor that will later find its way into the '06 Si. Notice how it removes the "dog bone" upper joint for even greater movement control.
The left-hand mount holds the transmission and is made of two parts. An aluminum bracket bolts to the transmission with a post that sticks upward, and the actual mount hangs off the frame.
Here is the Hasport left-hand mount and bracket. Quite a bit more substantial than the stock mount.
By Tim Kelly
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