this stuff just doesnt work!!
Ok we all hear of the crap that is sold on ebay posing as a "performance chip"
many claim incredible gains of up to 30bhp
ITS ALL CRAP TO TAKE YOUR CASH
FACTS GUYS NO FICTION!!
1. The air and fuel must get into the engine easier/faster/cooler. (EG. an induction kit will place less restriction and keep the air cooler going into the engine)
2. The engine must burn more of the air/fuel when it burns it. (EG. Better spark plugs will burn more of the mixture)
3. The exhaust gasses must leave with less resistance. (EG. a racing manifold will help the exhaust gasses out quickly)
These are the only things that will physically increase BHP.
Anything else that claims to increase BHP is probably rubbish. Here are a few examples...
Mod chips work by 'fooling' the ECU into using more fuel or advancing the ignition. A popular type is placed on the mass airflow sensor on the cars air intake. The Mod chip causes the sensor to tell the ECU it is freezing so the ECU thinks it needs more fuel. Good idea you might think but the problem here is as the sensor is incorrect it means all the other sensors are incorrect too which leads to your cars catalytic convertor failing because too much fuel is being burned. A dodgy cat is an expensive MOT fail. The other type of mod chip fools the ECU into advancing the ignition. Short term this will not do too much damage but over a length of time or if you drive like Colin Macrae it will burn a hole in the centre of each of your cars pistons and render the engine useless. My advice is to avoid fitting these 'chips'. I know they are cheap but they will do your car in big time!
A turbocharger or supercharger works by forcing more air and fuel into your engine. The more mixture in your engine the bigger the bang and the more power there is. Easy! However, scammers have got onto this too. If your car doesn't already have a turbo, you can buy a kit with a turbo, a different exhaust, an intercooler, a reprogrammed ECU and all the stuff to fit it but you will still need to take the engine apart and have a machine shop change the compression ratio.
recently I have noticed people selling fan kits that fit into the air intake and blast air in. Sorry but they don't work! Turbos and superchargers will force mixture in at several BAR of pressure. A fan in a box doesn't have enough puff! Despite their claims, the motor in these units spins no faster than 3000rpm. A turbocharger is roughly the same size but to generate any sort of power increase it has to spin anything up to 10 times that. If the unit is not spinning as fast as the air going in usually goes it will restrict the flow and actually cost you BHP. To put it bluntly, if these worked so well why would people go through all the hassle of developing turbochargers and superchargers when they could just stick an electric motor on?
Go faster exhausts do make your car faster. They make it sound better too. Sports back boxes will make your car sound sporty too but they will not necessarily make it faster. The fact the tailpipe is larger and it lets the gas out easier (that's what makes it louder) might increase the power but the extra big tailpipe its self robs the car of its backpressure that helps suck the new air and fuel into the cylinder which costs power.
They are about £50 each . The valve is placed usually in a breather or vacuum pipe (like the one going to the brake servo). I am not sure how they manage to get the power increases quoted in their adverts because all that is inside them is a bit of gauze and a small one way valve. They do not pump more fuel or cool air in, they do not cause the ignition to burn better and they do not help the exhaust gasses out. Either me, every tuning expert in the world ever, everyone who has studied physics and everyone who has smashed one up is lying or Ecotek are!
Fuel and oil additives.
I am not saying if you use an additive you will not notice a difference because you might. Fuel cleaner additives can clean the fuel system and restore lost performance but they will not add more power than your car originally had. Octane boosters may increase the performance by making the fuel burn better but only if your engine has been set up to run with higher octane fuel. Otherwise nothing wil happen! Friction reducers (usually put into the oil) may decrease the friction inside the engine but only if all the additives already in the oil have broken down. They will only break down if you don't change the oil regularly. My advice is to use good quality oil (Catrol or similar) and change it regularly. This will keep your car running nicely and cost far less in the long run rather than relying on unproven additives.
The basic rule with tuning is (like everything) if it sounds too good to be true it probably is!
Few hardened engine tuners would notice the difference a 5bhp increase would make. Most drivers don't notice anything less than a 10bhp increase. So if your car feels faster because you gave it a bottle of STP or changed the dump valve for one that sounds like a rocket taking off I am afraid its all in your head! In my experience the only way to increase a cars performance is to change one of the 3 points I made to begin with. Sometimes it is cheaper to sell the car you have and just buy the sportier version than make what you have go faster. Sorry but I am afraid its all true!