BACK TO BASICS TUNING

Induction kits/air filters

Standard air filters fitted to most cars are there to serve a purpose, designed cheaply to filter air best as possable but in doing so cause a few problems. Firstly standard paper filters are restrictive meaning your engine has to work to pull air in, put simply it robs your engine of hp.
Secondly standard air filter boxes have a habbit of being in the right place to soak up heat which makes the air less dense so there is less oxygen in it, less oxygen = less power.

Here are a few facts to bear in mind when buying filters-

1.Most aftermarket air filters claim to give increased bhp but most of them dont, they may flow more freely but the gains are over come by the huge increase in charge temps due to silly positioning under the bonnet.

2.Air boxes situated near the front of the car (away form the engine) usually have a 100% cool air feed so a simple pannel filter will do alot more for your bhp than simply removing the airbox and shoving a cone filter on the end! e.g-sierra coswrth touring cars used standard air boxes with pannel fiters for the best results.

3.Cone filters allow you to hear the induction roar created by all engines unlike pannel filters.

4.Foam filters out perform all other filter types in nearly every way.

5.K and N filters are actually one of the worst aftermarket filters due to the fact that the material used gets blocked very quickly and can restict the air flow over foam,mesh etc.

And finally the best aftermarket filter kits are sealed airbox type filters that take a 100% cold air intake from the front of the car (lower down the better) such as BMC airfilters and CDA, with the added bonus of having carbon fibre which reflects heat!
Its also proven that long lenght smaller diameter piping from the throttle body to the air filter its self will improve air stability and fast flow giving better torque through the mid range and lower down.

hope this helps, jason

please dont reply to these posts as they are for reading only thankyou

EXHAUST SYSTEMS

The story with exhaust systems is much the same as above, a standard exhaust has two jobs,,,,,take the gasses to the rear of the car where there is less chance of gasses entering the car and to keep the sound levels down.
They tend to be small in diameter, very restictive and rob the engine of torque.

when choosing an exhaust for a car it helps first to understand a few things about what will help the most to gain more torque and bhp - (n/a only)

1. When it comes to N/A engine without a turbo bigger is NOT better, if you think otherwise take your car to a rolling road and try your 3" pipe and compare it too a 2" pipe, the torque will be massivly altered and so will your view on the matter.

2. The best way to increase torque is to have medium sized pipeing (for a 2.0l 16v engine around 2") this will ensure there is no restriction but more importantly than that (the bit people dont no) is that the smaller pipe will flow the gasses much faster meaning a vacume will be caused by the momentum of the fast flow of gasses at the next cylinder about to release exhaust gasses and this will cause whats called a scavange effect on that cylinder meaning it will help pull out old inurt gasses and pull more fresh charge in while the valves or on overlap,,,meaning loads of extra torque!

3. Smooth bends (mandral are best) will keep gasses flowing fast and smooth so it doesnt restrict the engine.

4.Modern quality back boxes have a straight through design which causes hardly any resistance and use a wool like material to absorb the sound on the way through, if you come across a box that doesnt have this design dont buy it! it will hold you engine back.

5. In an ideal world wrapping your entire exhaust system with heat lagging will give gains in bhp!! why??,,,,,beacause by doing so the gasses in side do not loose energy to heat escaping through the metal and allowing the gasses to slow down, inturn the gasses will travel through the exhaust faster.

6.Removing the cat from your exhaust will more than likley improve the bhp because the cat tends to be the most restrictive part of an exhaust.

Manafactures spend alot of time developing an exhaust system for your car to give the best gains in both torque and bhp, dont think you can do better unless your on a budget

jason

please dont reply to this post as it for reading only thankyou

EXHAUST MANIFOLDS

The most important part of your exhaust when it comes to fine tuning your torque curves!

Manifolds are massivly miss understood, fitting just any you find isnt always a good idea, what manifold you choose widley depends on your current engine spec, fitting the wrong manilfold to the wrong engine can have negative effects (ryan (c2vts) can vouch for this) here is why,

Firstly there are two types of manifold, 4-2-1 and 4-1 branch types for 4 cylinder engines. As a rule fitting a 4-2-1 is the most sensable for road use because they are designed to increase torque low down and in the mid range!
the reason why is because on a 4 cylinder engine the first and last cylinder are connected (untampered with by 2 and 4) and this means as the gasses are exspelled down the first header it will pass number 4 cylinder making a big vacume in that header, then when number 4 releases its gasses the gasses will be pulled out causing the scavenge effect again which will give a huge torque increase (gasses dont have to be traveling fast down the header to cause this effect due to there being only 1 other header to cause the effect on). Hence why they give good low-end torque.
The length of each header effects the timing and the strenght of the scavenge affect which inturn effects where in the rev range this effect will be at its best!

A 4-1 manifold however works differently, the scavenge effect is still there but it is massivley reduced in the lower rev range because-
say number 4 has released its gasses down the header and into the collecter where all 4 branches meet, there will still be a vacume caused but it will be split between 3 branches instead of one which means the gasses in number 4 header would have to travel alot lot faster to take effect, this will only ocour in the higher rev range giving increased bhp at high revs.
some race cars etc will use this manifold beacuse of this.

another fact is that the manifold branches should be the same size and shape as the exhaust port they are mated too other wise unwanted turbulance and speed changes will be caused, all aiding the loss of power and torque!

jason

please dont reply to these posts as they for reading only thankyou

SUPERCHIPS FOR PETROL INJECTION ENGINES

All efi engines have an ecu, chippable ecu,s are fitted with a simple chip which has a 3d map in side, the ecu gathers information from all the engine sensors and using this information it looks at the 3d map to find a point on the map telling it how much fuel to put in and how much advance or retard to give.
A standard map is programed to give a smooth economical reliable engine, and also to work well in a very wide mannor of temprature ranges across the world, inturn it robs an average petrol engine of 10% of its power.

When you fit an aftermarket chip to a n/a petrol engine the major thing that is altered from the standard map is the ignition timming by advancing it, in fact most chips alter only this!

Advanced ignition timming improves the engine bhp and torque by making the most of the rapidly exspanding gasses inside the cylinder when the engine has fired. When the piston is moving towards the top of the stroke with a fresh charge of air and fuel, it will be ignited before the piston gets to the top, this is because gasses take time to exspand and by the time the pistons is just creeping past top dead centre the fresh charge will have started acting on the piston crown pushing it down, if the mixture is ignited too early then the charge will act on the piston while it is still on its way up,,,,,to forces acting on each,,,,,something has to give, and thats normaly the piston crown! this is called detanation (not to be confused with pre-ignition!)

However as the engine gets faster the amount of timming advance is increased to the point where the spark plug may be firing when the piston is only half way up the cylinder at high revs, as a rule more advance is more power until BANG too much! time for a new engine.

You may wonder if more advance is more power then why didnt the manafacturer just do that in the first place!!??
Well like i mensioned earlyer cars have to work at -35 and 100 degrees,and i also mensioned that too much advance will cause dreaded DET, well take your chipped car to death vally and cane it,,,,it wount last long with the chip, this is beacuse the air there is very hot and hot charge temps make fuel more likley to exsplode rather than exspand so where as the advanced igntion works well here over here the limit of max advance is lessend because the hot air would cause detonation at those high lelves of advance.

Chips can also be made to combine with a popular level of tune for example, if stage 1 for your car is an air filter,exhaust and manifold then the chip will be programmed to give just the right increase in fuel and advance to work best with the increase in airflow, go outside of those mods and the fueling will be wrong and you wount be gaining alot.

So chips increase ignition advance to give increases in power and torque and can be matched to an engine spec to give fuel increases and better economy.
A chip is good but the best by far is a remap (custom is best) because the map can be tailored to your engine spec!!

Maps and chips are differnt for turbo cars and diesels!!

jason

please dont reply to these posts as they for reading only thankyou

EXHAUSTS SYSTEMS FOR TURBO CARS

This will be a quick one,,,,a turbo is a big restriction within the exhaust and doesnt need help in anyway getting rid of gasses, for this reason it will work best with as little restiction as possible! such as no exhaust at all,,,but this would cause other problems which i will get too.

Here are some facts to get the most from your turbo exhaust system.

1. Bigish diameter pipes are better,,,they cause less restiction for the turbo to have to fight against.

2. Avoid harsh bends and change in pipe diameters,,,this WILL be causing a loss of power due to flow interuption.

3. Smooth mandral bends help with flow stability.

4. Dont be totaly fooled into putting huge exhaust systems on to an engine that doesnt need it, a turbo does requir some back pressure to keep the turbine oil seal seated or your turbo will leak oil into your exhaust killing your lambda sensor, plus going bigger than nessesary wount increase power,,,just noise, as a rule 2" is good for 200bhp, 2.5/3" upto 300bhp plus and it goes on, fitting a 4" inch pipe to a small engine and turbo is totaly pointless and will simply weight more.

jason

please dont reply to these posts as they are for reading only thankyou

TURBOCHARGING

Right,,,,,im not going to go into great detail in this section because i like to get technical when it comes to turbos so ill save it for another post about turbo technology!!

For me atleast turbocharging is the ultimate modification to an engine, a turbo in basic terms is an air pump, powered by exhaust gasses it forces compressed air into an engine delivering large amount of oxagen into the cylinders which when combined with more fuel gives massive increases in torque, extra bhp is a bonus!

its the best way to give big power increases without fitting a bigger engine that weights alot, using even low pressure turbos on small engines allows them to perform like much bigger engines etc.

look out for a detailed info pack on turbos to the best of my knowledge soon!!

jason

please dont reply to these posts as they are for reading only thankyou

INTERCOOLERS

All turbocharged cars should have one, low boost turbos can get away with not having one but its ideal to fit one.
when a turbo starts to produce boost above atmospheric pressure it starts to heat up the air, the higher the boost level the more heat is produced, this causes a couple of problems. 1 is that hot air has less oxygen in it so less power is made from it and 2. hot air can cause detanation!
An intercooler cools charge temps down by allowing heat to radiate through the alloy/alluminium core into the fins, cooled by air from the outside, as air flows over the intercooler fast it causes the chill factor which means an intercooler works more efficiently at higher speeds.

One down side to an intercooler is it causes a pressure drop from inlet to outlet due to the air density change going on in between, a well designed intercooler will have very small pressure drop where as a badly designed intercooler will cause big pressure drops, my car is fitted with a standard fiat punto gt turbo intercooler and when i fitted it i noticed a drop of 2psi on the boost gauge! gains are still made due to the fact that there is alot more oxygen in the intercooled air but the boost level has to be incresed to reach the required boost level,,,again giving another power boost.

When it comes to intercoolers bigger really is better, but this means the turbo has to fill it before getting to the engine meaning more lag,,,,,,a small price to pay for tons more power and reliability.

jason

please dont reply to these posts as they are for reading only thankyou

Here are afew tip for those of you tuning your naturally aspirated engines

1. Tuning N/A engines is all about getting the air in and out of the engine best as possible with little flow restrictions and well thought out and designed add ons such as air filter kits, exhaust systems, manifolds and mild head work.

2. N/A engines will work alot more efficiently with a higher compression ratio (C/R), ways to achieve this are simple at first then become very exspensive! but sticking to doing it cheaply you can have the cylinder head face skimmed to its max markers or just before for safty, this will give noticable increases in economy, bhp and above all,,,,torque.

3. Use a good qualitly engine oil!!! very important for performance and engine life, thinner oils give engine more bhp due to having less friction, thicker oils seal combustion chambers better for better compression on old or older designed engines giving improved running and power.

4. Once modifications have been done to your engine get it set up with an adjustable fuel pressure regulator to give the extra fuel required to make more power from the added airflow of filters and exhausts, most ecus will only have minor correction factors to deal with added flow, on some cars just an air filter will upset the standard map due to the added flow, and a map sensor will have no idea you have increased the air flow into the engine so it will keep functioning the same leaving the lambda to see a weak mixture and constanlty running on mixture adaption maps in your ecu,,,,,this isnt an ideal tuned state trust me.

5. get as much cold air into your engine and try to make it so the air isnt heated up much on the way into the engine, this will give great figures,,,,,a test was done on a mondeo st220 v6 with the standard airbx and filter with good cool air supply,,the the result was 226bhp, swapping it for a green cone filter in the same place lost it 4 bhp!!! a simple pannel filter gained 3bhp and a full CDA airbox kit gained 8bhp!

6.DONT just turn your fuel pressure up on an N/A! turning the fuel pressure up on a failry standard engine will kill power, its unknown to most but rich mixtures loose power and weak mixtures gain power (within limits) so dont do it, signs of rich mixtures are black smoke, poor acceleration and bad fuel economy and this will ulitmatly leed your engine to its grave by washing oil of your bores!

7. A quick tip if you fit a fuel pressure pressure reg, find out the cars standard fuel pressure and set it to that!!!, the way a vac pipe equiped pressure reg works is to richen the mixture quicker than a standard item not flood the engine with fuel all the time meesing up all the correction factors!

8. For ultimate power and revs fit lighter internals and high compression pistons, its costly but if your seriuos about n/a then its the way to go!

jason

please dont reply to these posts as they are for reading only thankyou