Tuesday, December 29, 2015

POWAA Build Part III - POWAA Garage X RZCrew Garage

Words & Snaps by Ben

We've been hard at work, as you would have read in the Part I and Part II of this high compression NA build for my Toyota Vios' 1NZ-FE. But the work wasn't over yet. 

Luckily, with JC from the RZ Crew providing the build with affordable original parts, but also helping me with the engineering needed to turn this engine into a monster, things went smooth and we were getting nearer to putting the car on the rollers.

The next steps of the build were to install the new engine head, optimise the intake and exhaust, bring some improvements on the drive train and tune the powerplant.

First things first, we finally received the head from machining...

And it was a thing of beauty! Here's a close up of the intake:

And the exhaust.

We also added seat radius machining, which is the equivalent of a 3-angle valve job, for Toyotas.

Thanks to JC's and the machining shop's engineering, the air flow in the head was optimised, as shown by the flow testing's very satisfying results:  

Compared to the original head, the intake airflow increased by 14% while the exhaust increased by 26%. 

A quick live compression check showed a healthy 12:1 on all four cylinders. Nice, but with the setup we were putting together, we knew we could push it a tad further, so we gave the head another round of skimming, to reach a static compression of 13.4:1. With this, the cams would free out their full power.

While the head was open, we took the opportunity to work on a detail that will prove worthy at a later stage of the build: customise the exhaust cam gear to allow us to adjust it.

This process involved drilling holes in the original cam gear...

And machining a custom adapter plate that we would be able to rotate to adjust the cam angle.

And here is the final result, with graduation marks allowing us to adjust the exhaust cam gear at +/- 5 degrees.

With the custom exhaust cam gear in place, JC was able to calculate the valve-to-vale clearances to maximise the tune. 

The unknown element in the calculus was the max degree of the VVTi, which opens, on paper, at a max of 40 degrees. Not knowing the exact angle of opening, we had to keep a conservative adjustment on the exhaust cam.

With the improved airflow in and out of the engine head, it was then time to up the game of the intake and exhaust to match the flow and free the horses.

Sadly, we were still doing the clearance calculations for the Individual Throttle Bodies, so we had to come up with an alternative intake to run on while the ITBs were being worked on.

We calculated that to match the intake air flow, we needed a bigger throttle body. Much bigger. We were going to upgrade the factory 54mm TB to a 70mm. The catch was, Toyota does not do such a big TB.

The solution came in the form of a 70mm Skunk2 TB for Honda.

The next step was to match it to the metal air intake, so we chopped it up...

No hard feelings here, it looked better with a beefy 70mm pipe anyways.

And here's the result: a proper, high flow air intake!

Exhaust-wise, the modification rules in Singapore do not allow us to change much, so I prepared a second exhaust line for the track, while I will run a factory line for my daily commuting, at the expense of a bunch of horses.

For the racing line, the RZ Crew helped me source for a custom, high flow 4-2-1 header made specifically to match the compressions and air flow of the engine.

Since I will only be using this header for track, I honestly have half a mind to hook it up on the wall when it's not in use, but I fear my significant other might have something to say about it... Sadly.

With a whole bunch of horses building up in the engine, my next concern was to make sure the drive train would handle the uprated stress, so I opted for an Excedy 3-puck clutch, and a Cusco 1.5 way LSD for good measure.

With the engine head, intake, exhaust and drivetrain installed, it was time to put the car on the bench and see some results.

To ensure the engine would run trouble free, we filled up the engine and gearbox with Motul's 300V and Motul Gear FF-LSD Type 2. (I kept the Motul Inugel aside for later, as the aluminium radiator I ordered was taking its own sweet time in assembly).

The E-Manage Blue my car was running on at the time surely wasn't going to be able to handle the new requirements, so we upgraded the engine management to Greddy's top of the line E-Manage Ultimate.

It was then time to hit the rollers!

We ran a few progressive pulls, and the results started to show...

The first pull showed a measly 123bhp and 146BNm of torque, but the tuning guru at Torque Racing was just getting started...

And here's the final run, hear her roar!

At the end of the day, we hit a satisfying 149hp@7,400rpm and 166.7Nm@4,300rpm of torque at the crank (131.3hp & 146.5Nm at the wheels)!

That was 35.3 horses and 10.7Nm of torque more than before (and 1,200rpm more too!)  - Refer to the blue (torque) and red (hp) lines for the high compression setup, and the green (torque) and orange (hp) for the stock tune. 

The dyno used was the same for the stock and the high compression setups, which allowed us to have a valid comparison.

More than just the power numbers, the fat, flat torque available right up the bat made it perfect for tracking, allowing me to pick up at any gear. This was also pretty enjoyable on my daily commute!

The story did not end there though, and next up were the ITBs, read all about it in the final part of this exciting built!


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