I see here that there is a lot of healthy interest in a couple of things :
a) Downgrading engine to a lower capacity to take advantage of lower road tax.
b) Upgrading performance to negate the loss of power that comes from taking action a) above.
c) Improving the vehicle's general handling and nimbleness in traffic.
d) Doing all-of-the-above without needing to send our kids to the local sweatshop to make ends meet...
I've finally worked out the 'modification pathway" of my vehicle. My objective is to create a vehicle that maintains the dignity of a Cefiro (manic career executives like myself need to hide our wilder sides from concerned employers and customers alike), creates a slightly more sporty profile, with power under the hood (more than a 3l stock...and we are not talking forced induction here), but is virtually unrecognizable as a modified vehicle from the outside...even with the bonnet open..with the exception of the cold air intake. And I think I can do it to benefit us all.
Stage 1
Change engine to a 2.5l. Here I intend to purchase only the long block i.e. an "engine kosong". I would re-use my 3l manifolds, throttle body, MAF, fuel rail and injectors (have to determine if the injectors are the same, but here, someone is sending me a Nissan electronic parts catalogue), starter, gearbox, etc.
This change will lose me approx. 25 bhp in power, and a bit of torque as the final drive ratios of the 3l gearbox is slightly different from the 2.5l. Not sure if the manifolds will make enough difference, as I will only be able to measure them when the engine is out.
Stage 2
Install a cold air intake with an air charger. This will gain me about 10 - 15 bhp negating the effects of the engine change almost completely.
Those who do not intend to turbo their vehicles may also invest in a Y-pipe. I haven't looked under our cars carefully, but there may be 2 pre-cats in the exhaust that, by now, would function as mere restrictions to air flow. This will gain another approximately 20 bhp. A Y-pipe may be fabricated quite easily.
Stage 3
Install a piggy-back ECU of some kind. Those not intending to turbo may use a simple SAFC whilst those who have some form of forced induction in mind may invest in an e-manage. Properly tuning the vehicle's AF ratio at different rpm's will gain us quite a bit of torque as the VQ tends to run quite rich at certain points of the power band. The power gain here would depend on how the car was tuned i.e. how the power curve was tweaked.
Stage 4 (Optional)
Forced induction. Either a turbo or a supercharger. This will require a completely different project paper.
Now, how is this going to benefit us? The key words here are "group purchase". I've done some research into costs and here is what I have calculated that it will cost me doing it alone.
a) Engine long block RM 2,400
b) Odds and ends parts/oil etc RM 500
c) Workmanship RM 800
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Total
RM 3,700
The motor I found was built in 2003...has spent 6 months at the scrapyard, so probably has only been on the road for about 2 years. The parts requirements assumes that you have sourced a good engine with minimal repair requirements eg. you do not have to change the water pump. Here, we could probably negotiate on the cost of motor and the workmanship.
Stage 2 will probably cost about RM 1k, but the advantage is that it is not mandatory to the engine change so we can spread out the expense. Also, a group purchase will probably save us a lot, with regards to the Y-pipe since the material cost is marginal, and most of the cost is workmanship.
Stage 3 can vary with regards to costs. A second hand SAFC could run from RM 400 - RM 1,000 though I would never pay anything more than RM 600 for a used SAFC.
A used e-manage would be around RM 1k+. A new e-manage Ultimate would cost RM 2,800. So, there are many options for many levels of affordability.
Stage 4 is a separate project and will require a separate budget. Probably have to save for 6 - 12 months to get it done.
There are also many other power boosting options that can be looked into.
i) Adjustable fuel pressure regulator. Costs about RM 350 and properly tuned can add power and responsiveness by increasing the degree of atomization of fuel i.e. a more homogenous air-fuel mix resulting in more efficient ignition.
ii) An uprated fuel pump to ensure that all injectors are adequately supplied with fuel and to maintain fuel pressure and flow. I've heard that a Volvo turbo fuel pump does wonders for our cars and fits into our stock positions. I'm researching this and finding out if I can get a few out of the local scrap yards.
iii) Ignition stabilizers. I have a reasonably cheap, Malaysian designed ignition stabilizer in my car, and it improved responsiveness of the motor significantly. Even surprised me, and I'm an electronics man.
These are some of the things you can do to your motor. Even if you do not intend to change your motor, stages b), c) and d) can still apply along with the other options.
Next...suspension mods...