Category: Cars

Loom Fit & Variable Intake Runners

With the wiring (mostly) complete I went ahead and married up the loom to the engine. I am fairly happy with how everything sits. Unfortunately, I lost the factory tie down points for the injector harness due to the adapters I’m using but I can make something work.

I also wired in 2 relays with will act as reversing relays to control the variable intake runners. I toyed with the idea of just locking them in the long position as they can’t be deleted (easily) with this plastic intake manifold – which I’m praying holds up OK to the boost level I’m running. If I go for a bigger turbo down the line I will definitely need to source a ZC31S intake manifold (cast alloy).

The tuner, Rob, thinks that there will be good benefits in having the link control the runners, especially down low. I am once again thanking KAPOW who made a post on the Link forums detailing how to control it. There’s even a great video documenting the logic from Link staff! I have wired it pretty much exactly per the post – it came up pretty well.

Interestingly, the range of motion is very small, like 15-20 degrees.

I ended up re-routing the water line nearest to the dump pipe following advice from other turbo swift owners. Now both the feed and return are on the cold side. I am yet to nail down the feed point but I have some ideas, the tricky part will be avoiding chafing. I also added some heat wrap to the AC lines.

With that, there really isn’t too much more to do other than get the clutch on, bolt the gearbox up and slap the assembly in. I got the flywheel machined last week and fit the concentric slave – all looks good! I will also fit the factory right angle oil filter housing as I realized my current position will make the oil filter very hard to change, I would need to remove the oil cooler lines every time I change the filter…

Wiring Part 2

Finally… The wiring is done!

My crimping skills continued to grow, as did the cramps in my hands.

After all was said and done, I checked each end where I had spliced into the factory wiring with a multimeter. I found two wires, the TPS signal (GRN) and Ignition 3 (BRN) which I had incorrectly tapped in to. This was easily fixed and happened due to there being multiple GRN and BRN coloured wires.

I also left plenty of extra cabling left for the tuner. Where he needs to weld bungs and install sensors – CAN Lambda and Intake Air Temperature (IAT).

I am quite pleased with the results and have begun to tape everything up. You can see in the images below that I have also crimped on the sensor ends, and replaced the Delphi 3-pin connector mentioned in my last post.

I also finally got some 3/4 UNF jam nuts to tighten down my oil filter stud. Local bolt shop even gave them to me free, bless them. Oil filter sandwich plate is now in, with various fittings tightened with a bit of teflon tape.

Wiring Part 1

I finally broke the back on wiring. It took a lot of trial and error with open barrel splices to figure out the right die and pressure for my ratcheting crimper, but I am very happy with the results. Just look at that crimp!

I currently have half the wiring done, with the remainder being all the OEM signal taps:

  • Crank position
  • Cam angle
  • Throttle position
  • Ignition coil(s)
  • Injector(s)

I have left extra loom for the tuner so he can just cut it back and wire in the sensors that require welded bungs – Intake Air Temp (IAT) and a Link CAN Lambda.

I also mounted the Link with the supplied bracket using riv-nuts, pretty happy with how it turned out.

Unfortunately, I wrecked one of the pins on the fuel pressure sensor so I will need to procure another connector just to steal some pins. To my knowledge, it’s a Delphi/GM connector.

Here is an updated wiring table for what is left. “y” indicates done, “R” is for the tuner, blank is another day…

Fuel Pump & Engine Sealed

Good progress recently. I had a bung welded in the sump just above max oil line by one of the guys at work. The fitting was a little worse for wear after welding but I think it should seal fine. I had to shorten my drain line a little, which I may have overcooked it as it was a bit of a pain to tighten but I think it will be fine.

I also installed the Walbro 255 which was a lot more difficult than expected due to the pump being slightly wider and a lot longer than the OEM pump. I made some modifications to the housing and got it to fit but it’s not the prettiest solution. In hindsight I should’ve just bought a Denso equivalent which would’ve dropped straight in with very similar specs to the Walbro.

I used the sanding wheel on a dremel to remove a small amount of material evenly from the inside of the housing. Then I cut various tabs and screwed in some stainless screws at the 3 factory tab locations to hold the pump up, allowing for the extra height and giving the filter sock about 3mm of clearance from the bottom. You have to be careful doing this as the pump housing has a cavity around it, you can only drill in to the ‘sleeve’ that has the tabs.

Before re-installing the fuel tank and pump I hot wired it to check it ran fine – which it did. Hopefully I am not missing anything!

I also got the engine all sealed up, pretty much ready to chuck back in once I sort out the wiring (which I am procrastinating a little). I also mounted the fuel rail with my 1000cc injectors. I’ll need to do a quick check once it’s in the car to see if they’re sealing properly. I will be adding a fuel pressure sensor, which I’ve added a tee for.

Here is the wiring table, all I’ve managed to do is some practice crimps using open barrel splices and putting a Deutsch connector on my boost solenoid. I have purchased some fancy wiring, including shielded ground wiring and nice heat shrink. There has been some revisions to my wiring/pin table too which you can see below.

Hot Side Torqued

In my previous post I detailed how I planned to run the turbo lines and work around the oil cooler sandwich plate etc. Well, the parts arrived, and it went mostly as planned.

The exhaust manifold and turbo are now torqued up, good to go.

It took a lot of fiddling to get the oil pressure line to work without contacting either the exhaust manifold or coolant line. I ended up just re-using the HKS kit line with a 90 degree M-F swivel off the top of the turbo. The return line was simpler; however it took me 3 attempts to get the height just right. First it was to low (in the oil), too high (no room to weld), just right (I hope..).

I still need to clean the sump thoroughly for welding and drill the locator hole for the bung. Hopefully, how I have it now is above the oil line as I am finding the stainless braided line a real pain to work with. Even when taping the cut location, it still frays quite badly, making the fit up of the nut very difficult. The plan is to fill the sump with water post cleaning to double check the return is above the maximum oil level but I’m quietly confident.

I’m also hoping the coolant line is OK with the heat sleeve around, everyone seems to think so, but time will tell. Doing a walk around, admiring my work I also noticed the wastegate actuator was sitting on the block. I managed to pry it so there is a circa 2-3mm gap – “clearance is clearance”. The ZC31S block must be slightly different in this location as I can’t imagine HKS had this kit leave the factory colliding with the block.

Before:

After:

This marks the end of the “difficult” mechanical scopes, it’s now time to tackle wiring…

Here are some higher resolution images if how the hot side setup looks:

ECU Wiring

As promised, this post will document ECU wiring. I will be wiring in a Link G4X MonsoonX in a “piggyback” style. Below is a wiring table on what I plan to do.

I have seperated the loom and marked the cam and crank sensor. There will be some figuring out to do on the cam and potentially crank signals as I know they differ from the ZC32S (which Haltech has documentation on).

Unfortunately, there is very little information on aftermarket ECUs in these cars and a lot of people report odd issues with cheaper options like AEM and GReddy E-manage (E-Mangle).

I’ll also need to decide what I do about the variable intake runners either:
a) try to remove it
b) replace with ZC31S intake (may require further head drilling, new intake piping)
c) use the Link to control it (looks doable)

If you made it this far, below are images of the ZC32S ECU wiring for your reference. I found these extremely hard to find, hopefully this helps others. I cross checked a lot of the wire colours and it all aligns, will need to check with a multimeter to be sure.

To view in full resolution, right click and open image in new tab.

Teardown

I had a good day today tearing down everything in order to remove the engine and make way for turbo related parts.

The oil cooler will need to be relocated and the exhaust system up for sale at some point. It’s SuperCircuit headers, RRP mid-pipe and an X-Force catback.

During disassembly I noticed the passenger side gearbox driveshaft seal was weeping a little gearbox oil. As this constituted an order from Suzuki, I also go the opposite side, the OEM oil cooler o-ring, rear main seal and axle nuts.

The engine is now ready to come out, only the mounts remain. Working on the Cube and this car compared to the VR4 really makes you appreciate modern engineering and design for assembly (and disassembly). Both the ZC32S and the Cube allow the engine harness to be disconnected at the ECU, the front bolts off and the drive assembly can simply come out the front – beautiful.

Head Drilling

Unfortunately, the ZC32S head doesn’t have all exhaust manifold holes drilled and tapped – unlike the ZC31S. I only heard about this reading the documentation from the shop in NSW (One Stop Mechanical) that originally fit the turbo to the ZC32S I purchased the kit off. I later confirmed this was the case when I removed my extractors from my current setup.

I did my best to mark out holes but wasn’t entirely happy with how I had measured and drilled.

With how tight the holes on the HKS manifold are to the M10 studs, you don’t get much allowance for error. With this in mind, I decided to only tap the 4 extra holes to M8 (instead of M10) to give myself a bit more room to play with. This worked out great.

My only remaining concern is the depth of one of my drillings. It’s 1-2mm deeper than the factory drillings. Looking at the casting, I think we are fine. Famous last words?

Injector Selection

The first part that required proper effort as part of the ZC32S turbo build was injector selection, well more injector fitment. Ideally, I wanted to retain the factory fuel rail and find a “drop in” injector solution.

Using Raceworks injector sizing calculator I found I needed approximately 600cc of injector to meet my power goals. However, after speaking my tuner – Rob from RM Performance & Dyno he advised simply go for 1000 cc’s to give me room for future upgrades and to increase my options when it came to physical dimensions.

So, go for the 1000 cc I did.

First point of call was Bosch 1000cc ‘EV14’ injectors. This was because they come in 3 lengths and have publicly available CAD data and decent technical drawings – awesome.

After looking at injectors online for hours and 3D printing some of the Bosch CAD I decided on using the Raceworks modified Bosch 1000cc to suit the “square” lower seal and 11mm o-ring that Suzuki Swift Sport fuel rail has.

The modified 1000cc injectors fit a treat. The only downside was losing approximately 15mm of extended nozzle like the factory injectors have. Speaking with Rob, this is of no concern due to the spray pattern. Additionally, stalking some of the turbo builds in Japan I can see they also use larger injectors with no extended tip, backing up Rob’s advice.

I migrated the upper rubber “seat” and o-ring (making it 2x 11mm o-rings total in the top groove) from the factory injector and added them to the 1000cc injectors, this made it a snug fit in the stem on the factory fuel rail. I am yet to pressure test it but I the engagement feels identical to the factory one.

Due to the slight difference in height between the 2 options, I needed to make a longer plastic spacer to raise the rail circa 4mm to suit the new injectors. I did 3 prints in 0.5mm height intervals based on my measurements, the shortest (19.3mm total height) being the winner.

I also purchase some of these nifty 1pce “USCAR” to Denso adaptors (again from Raceworks), meaning they’re a proper bolt on affair.

My Suzuki Swift Sport ZC32s

Purchased in late 2020 with 67,000 kms this car was to be my new daily.

I attended a track day at MTA Wodonga (Logic Center) one week after purchase to get an understanding of the car in factory trim. This ZC32S was to build on learnings from our previous two swifts and become a street registered “track” car. You can read about my previous cars here.

In 2025 I picked up a HKS turbo kit suit ZC31S that had previously been fitted to a ZC32S. A large driver for this blog was the documentation of this phase of the build.

Current mod list:

  1. Suzuki Works Kurume 1.1-way LSD
  2. MFactory 4.312 final drive
  3. TEIN coilovers
  4. TM Square pillow ball strut tops
  5. Hardrace roll center adjusters
  6. Cusco rear stabilizer bar
  7. Monster Sport rear toe and camber shims
  8. X-Force catback
  9. SuperCircuit headers
  10. GReddy AirNX intake
  11. Blitz oil cooler
  12. Unknown brand rear strut bar
  13. Suzuki Sport gauge set (ZC31S) in Monster Sport 3 meter pod
  14. Evo 8 MR / Ralliart Colt Recaro Seats on Bride Rails
  15. R’s Racing brake lines
  16. ZONE TT brake pads
  17. GReddy rear wing extension
  18. GReddy front lip (colour matched)

Below images are in chronological order.