Creating a "package" is the best way of releasing your car's potential. Tuning car's is expensive....unfortunately, but there are ways around the huge named compaines with their 200% mark up.
I'm not here to say everything expensive is crap but once you understand the basics and a little more about how/why/where performance is gained then you can get why £multi-million car tuning compaines are so profitable.
Air Filters : - The most common 1st product of any young wannabe racer's tuning list (mine too). Induction kit/cold air intake are gerat buzz words which makes you buy the product yet manufacturers claim 10, 20bhp ?!?!? Sound too easy for your £50-£150? Well it is, these high flow air filters are great for added noise (noise makes you go faster?..), but high up the rev range, they can cause your Air/Fuel ratio (AFR) to lean out, which causes detonation (really dangerous in a turbo-charged car). An air filter as part of a package yes....by itself....NO
So, where next...
Exhaust : - The next one the list. Exhausts do one thing, channel the unwanted gas made from fuel/air out of the engine and vent into the atmosphere. This next statement is mainly targetted towards the women reading this :BIGGER ISN'T BETTER heehee. A huge exhaust >2.25" will be useless. Air flow will slow down and less exhaust gas will be expelled, than a smaller unit which forces gas out as it has no where else to go. If your car is post 1992 then use a decat (a catalyitc converter is a performance hunter's nightmare). The exhaust needs to be a straight as possible and with the fewer bends the better. Lightweight also, as weight saving is free performance. A specially built, manderel bent cat back will make some nice sounds and you will be on your way to the next upgrade.
Exhaust MANIFOLD : - Unbelievably over-looked part of the engine bay. The manifold design can bring "just an exhaust gas channeller" to a BHP chaser's dream. There is a little bit of maths involved with manifold design as it depends on cam lift/duration, how much air the cylinder head can flow, which I won't bore(pun intended) you with as its far easier to get someone to build one. I recommend getting a full exhaust and manifold built by an engineer type, who knows his stuff. These guys are usually found on industrial estates, and do work for rally/racing cars but don't scream and shout about it. A "normal" garage with a monkey that you used to go to school with who can get ya a tenner off, might not have the same quality...
Porting :- While you're getting your exhaust manifold built, take a look at the ports, sometimes matching the ports with your new manifold helps.....however, on Honda's specifically the mk2 CRX this is not the case, a step down is far better and more gains will be seen. This is due to the scavenging effect, which sucks exhaust gas out as well as being pushed/forced out. This has a kind of cumulative effect for example, the higher the revs the faster the exhaust gas is being pushed/sucked out, hence the hunger to reach peak torque. Most cars are different, but if your ports are rough and alot smaller than the manifold then a dremmel with a carbide tip can be used to tidy them up. I'm not even going to give polishing its own paragraph as it is maxpower hype and sounds good, as I have just said, if the ports are rough then tidy them up.
Head - Skimming : - Upping the compression will see gains, a light head skim will buy you some bhp for around £30. Although, the cam timing may need adjustment, in which case some vernier pulleys will help even more to dial in the cams (getting to them) perfectly. As the valves are now closer to the top of the piston the same amount of air/fuel going in, but less space, hence more pressure and higher compression from the explosion of the fuel. Easiest way to think of it, fireworks night, small firework = oooohhh, small firework in a scaffolding pole/milk bottle = oooOOOOOHHHHH aaaAAAAARRGGHHH. More spectacular.......Don't try that please, its just for reference :-)
Mid break Summary :
Rightyho where are we upto? Head Skim £30, Verniers £80ish, Manifold and exhaust £800, Airfilter £50, Porting = free or £30 for a dremmel. Safest way to do this is to get a spare cylinder head, get it skimmed and have a go at porting. When you're ready to fit it, get a new headgasket and give the car a service. New power may find weaknesses in old consumable parts. So for just over £1000 (inc service - THAT YOU DO YOURSELF, don't pay someone to unscrew and re-fit parts. You can change a lightbulb can't you.....oil, oil filter, spark plugs, HT leads, distributor cap = lightbulb easy ;-), you will gain around 20bhp but have the basis of an engine capable of more.
And remember weight-saving is key. If you can, dump interior/silly sound systems (you're new exhaust will suffice), lighter wheels -http://www.dm-racing.com/department/rays_volks_wheels/ like some here will lower the unsprung weight and make your car turn in faster and accelerate a little quicker (any BMX'ers will remember carrying a mate on the back stunt pegs, usually the porky one who couldn't be bothered to walk)
Next edition coming soon, cams, headwork, valves, ECU's.
