Spare Engine Rebuild Update: Tomei Poncams

The rebuild is going well and I've sent in my Tomei camshafts + Pulleys and a N1 Water Pump in for the final stage of the project. Looking forward to how the cams perform as not only will they improve response and overall performance but the poncams will also have a positive affect on the R33 GTR's exhaust sound.

And why Tomei? Tomei Poncam camshafts are designed as a "drop in application", so no dialling in required as the nock-pin has been pre-set. The Poncams are also designed to work with the standard valve springs and offer the best drop in performance gain for both street and track use. No machining is required at all.

Tomei manufactures several camshafts for the RB26 engine, the most mild being the Poncams. Designed as an upgrade when compared to stock cams, the Poncams fit all generations of the RB26 engine (R32, R33 and R34), and come in three types, Type A, Type B, and Type R. The differences between the Type A and Type B Poncams are limited, with the Type B version featuring 260° of lift on the exhaust, compared to 252°. This slight increase in duration means more air can enter the cylinders at higher RPM. The downside to additional duration is that low end power is sacrificed, as the turbochargers typically can not move enough air at lower engine speeds. The Type R Poncams were designed by Tomei to cater to those who wish to remain "street legal" by Japanese standards. This means decreased duration for better emissions, as well as compatibility with stock or aftermarket catalytic converters.

Type A camshafts are suitable for engines that will be using stock or larger bolt on turbochargers. Type B camshafts are for engines that will be running N1 turbo chargers or full aftermarket turbo kits. The Type R camshafts should only be used when a car retains the factory catalytic converter, or when you wish to upgrade to an aftermarket catalytic converter.
 
Tomei Pon Camshafts + Pulley Set: Nissan BNR32/BCNR33 RB26DETT Duration IN 260, EX 252, Lift 9.15 (Pon Cam + Cam Pulley IN & EX) 143036 A Type + 153027 Cam Pulley.

Excerpt from nengun.com about the Tomei Poncams:

Tomei presents the popular poncams. Generally, engine tuning is to modify the torque characteristic of engine by changing cam duration timing and height of the cam lift, so as to gaining maximum torque and horse power. However, when tuning the engine strictly, it should be carried out with the idea of securing effective area of the valve not only by duration timing and height of the cam lift, but also by through improvement of its intake efficiency. High valve lift allows huge amount of air to flow in, yet it mechanically damages the system and gains friction loss. Also, wide cam duration will deriver great power at high RPM, but it gives rough engine character at low RPM too. Tomei have worked to get an ideal well-balanced profile of camshaft and succeeded to give it 1.3 to 1.5 times more effective area than regular camshafts.

R33 GTR Upgrade: Kakimoto Racing Full Mega N1

I initially had gone with a HKS Super Drager exhaust setup but found it to be lacking in the sound department. It was installed while I was out of town in December 2010. This entry was actually supposed to be about the HKS system but lets face it, aftermarket exhausts are meant to straddle a fine line between satisfying legal sound decibel standards in countries like Japan, while at same time, meeting car owner expectations. Its a compromise and honestly, nobody likes to compromise unless they really have to.

As for some, exhaust note is a non-issue but for me, its paramount. The R33 GTR is meant to be a fun weekend car. Exhaust note is crucial to the enjoyment of the Skyline as my daily cars are well mannered and refined. So yesterday, I was on a quest to find a suitable replacement to replace the HKS exhaust. 

Which brings us to Mun Lee Autoparts, probably one of the biggest sparepart and halfcut vendor in the Klang Valley area.

 Mun Lee's Puchong warehouse - mind boggling

I actually went to Mun Lee because my personal mechanic said that there was likelihood of finding at least something in that bazaar of automotive parts. And there was. A used Kakimoto Racing Full Mega N1 exhaust set had just arrived from Japan a few days ago via container. It looked in good condition and I purchased it. Why? According to this thread on gtr.co.uk, Kakimoto N1s are known to be louder than other aftermarket exhausts and their website actually rates the N1 at 93db. Nice! Just what I was looking for. With prize in hand (or in boot rather), I made my way to an exhaust shop that I've frequented in the past.

 The N1 being fitted

Upon reaching the Segambut workshop, the car was promptly hoisted up and the exhaust lined up for fitting. I decided to forgo the mid box (no catalytic convertor either) as I wanted a straight flow setup for power. It was my hope too that this arrangement would also generate a rip roaring exhaust note. I hope everyone realises that I was taking a big risk here because I wasn't sure as to whether such a setup would produce a good sound. At the same time, I was concerned that there might be severe in-cabin droning! 

 One weld had to be done to complete the straight flow setup

Once the smell of welded steel had dissipated, came the moment of the truth. The hoist was brought down and the engine started. Couple of revs later and I was a satisfied customer. The exhaust note was deep throated enough to put hair on a full grown man's chest! No droning too! 

First impressions upon sitting inside the car made me reconsider this setup as it sounded a tad bit too loud but after driving it around, I came to realise that I needed to get used to the new sound. The HKS Super Drager was that subdued! Each to his own, as others love the HKS exhaust. Well, I love my Kakimoto Racing Full Mega N1 :). Will post up a video of the exhaust sometime in the near future.