Cheap Power Gains For Efi 5litre Commodore  

Stroke it!

Stage One

The most simplest and easiest way to get your 5.0Ltr running good is a good major service.

A fresh oil change, oil filter, new plugs, leads, and air filter (advisable to replace with a decent filter, like a K&N for example) will go along way to keeping it running well, aswell as keeping the power there. Changing the rotor button and distributor cap will do wonders aswell, as these have a tendency to fail over time. If it is of age, it would be worth while changing the coil pack aswell while your at it. Another good idea with the coil pack is to relocate it to another position (that is not behind the motor), like on the strut tower for example, so it is not so close to the heat, and easier to access in future.

With this basic service and new parts performed, you will definatley notice an improvement in throttle response and bit more power throughout the rev range

Stage Two

Stage 2 is abit more advanced, and unless you ave abit of mechanical know how, is best left to someone who knows what they are doing.


First of all, get the motor breathing better. This can be acheived with a free flowing airbox, and a good CAI (Cold Air Intake). One of the most popular set ups is a 'HSV hi-flow' style airbox lid, and a 'SS Inductions' CAI kit. This will make it abit more responsive, and will really help with future mods.


Next up is a good free flowing exhaust system. This is where it gets tricky, and can sometimes be expensive (depending on what you decide). The standard headers are rather restricting, and are best replaced with a set of aftermarket extractors. A few good brands that swing in to mind are Pacemaker, Genie and De-Fillipo. There are 2 basic designs with headers. Tri-y's (4-into-2-into-1) and 4-into1's. Tri-y's are more suited to low down torque, while 4-into-1's give better top end performance. Next, decide if you want to go for a twin set up, or a single set up. Make sure you think ahead and work put what you want in the long run, before choosing your exhaust, otherwise you will most likely have to do it again. The best advice i can give in regards to choosing what system you want is to have a talk to a few people, and see if you can get a listen to what some different setups sound like.

If you are planning on keeping it relativly stock, with just a few bolt ons, i would suggest a single 2.5" system, or at most, a single 3". For a more wilder motor, obvioulsy a bigger system would be required. Match in a catalytic convertor or 2 (depending on your setup) and you will be right to go.


Next up is diff gears. This is another one that is best left to someone that knows what they are doing. A well matched set of diff gears will liven the car up nicely. But be careful not to go to low in ratio, or you will be revving way to high, and doing premature wear and damage to the motor. For a nice all round ratio, i would recommend 3.45:1 gearing. This will give you a decent increase in pick up, aswell as retain alot of its economy, especially on the highway. If you are not woried about economy, then i would suggest a set of 4.11:1 for a manual, and 3.9:1 for auto. Both of these setups will sit at around 2500rpm at 100km/h. While your at it, get a good LSD fitted aswell (if you dont have one).


A set of roller rockers will also help inprove the way your engine will run. Yella Terra are the most popular, and well designed roller rockers for the Holden V8's. This will help your engine rev more freely, and put less strain on the top end of the motor. Aswell as help you pick up a few more ponies.


Now to give some attention to your gearbox (providing it is an auto).It wont help you pick up any extra power, but it will improve the drive of the car,, make the box last longer, and will make it quicker down the 1/4 mile. The best thing to do to the gearbox is to get a stage 2 shift kit installed. While your at it, throw in a stall convertor (this also depends on future mods to the car as to what size you should go). For a car that is to remain rather stock (any of the above listed mods are fine), i would suggest a 2500-2800rpm stall. (If you are planning to build the motor more down the track, it might be worth leaving the stall until the motor is done aswell).

Keep one thing in mind though when getting the gearbox played with. If the gearbox is in bad condition, it will not last long. And it would be best to get a rebuild, or a new gearbox.


After you have done these mods, you will be better off getting a custom tune done on the car aswell. One of the best (if not the best) programs for the 304ci EFI is Kalmaker software. Although there isnt to many tuners around that use Kalmaker software, it will be worth while looking for someone that does. With all the above bolt ons, and a good custom dyno tune, you should be up around the 150+rwkw mark.

(With the above mods, plus a 71mm throttle body, my old VP SS made 152rwkw)

MANIFOLDS
The standard manifold is a big restriction on the 5.0Ltr. On a standard motor, they are great, but once you start to get to about 250kw (at the motor) they start to run out of breath. This is anothe rexpensive excersice, but will make a big difference in the end result. There are many different kinds out there these days. One of the best known manifolds is the Grp A (VN and VL), but finding one of these will prive hard, and very expensive. A good replacment for the Grp A manifold in the TrickShift twin throttle body design. They are one of the closest you will ge tto the original design, and they look great. There is also the C.O.M.E twin throttle body set up, but these are more suited to forced induction and big HP motors.

Another popular option is a hi-rise manifold and quad throttle body setup. The most common brans are TorquePower and Harrop. These come in a range of options, with dual-plain, single-plain, hi-rise and low-rise, depenidng on your application. Match this with a 1000+cfm quad thrttle body set up and not only will you have a great working setup, you will have a very tuff looking setup.

ploice chip pod fitler ectxratorcs ez is nt it

ploice chip pod fitler ectxratorcs ez is nt it

Pilce chip? Why bother when you can run a HSV program memcal chip + knock sensor for bugger all and make more power than the Police ever had

ploice chip pod fitler ectxratorcs ez is nt it