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Mods and upgrades explained - Very Long!!

335K views 422 replies 178 participants last post by  Mpowered1 
#1 ·
Hey

A lot of people on the fest ask what mods are best for their bimmer so i thought i would list the most popular ones and describe why they are good for your bimmer. Will put them in order you should do them too.

These include engine performance mods as well as stability etc

This is just my view but will try to be as accurate as possible. Am sure MANY of you will disagree with some of the things that i say, but that is the beauty of a forum. These are compiled from my experiences as a racing driver, test driver as well as an avid Bimmerfest member

1 - Decent petrol
People often go and spend HUGE amounts of money on enhancements or their cars and then use rubbish fuel. E36's are fitted with 'knock sensors' which will advance and retard your timing to sure different octane fuels. The higher the octane of the fuel, the higher the flash point. You want to make sure that the fuel is being ignited in the cylinder at the right time and not any where else. I recommendV-Power 98 RON or at least the highest octane car fuel you can find in your area (US octane ratings work a little different. Not only will you get more power and a more drivable car, but your engine will be cleaner and you also get better MPG.​

2 - Good Spark Plugs
Ok, so you have you good petrol being sprayed into your cylinders, now you need to make sure there is a good spark. The OEM plugs are great but improvements can be made for a small cost.​
The best plugs out there are NGK IRIDIUM IX plugs. They are brilliant and the affects can be felt right away. The car is smother through the rev-range and pulls better at low revs. They are cheap too and should only set you back around 35GBP ($70).​
DONT go for Platinums as they are very problematic and can cause some very strange engine issues. Iridium has a massive melting point and so the electrode gap stays the same no matter how hot or how hard you push your car​

3 - Decent Tyres
So often people spend loads of money on upgrades and then put crap tyres on their cars. Remember, your tyres are the only things connecting your car and power to the road and so decent tyres are an absolute must! Tyres are very personal and need to suit your driving style. I always run Pirelli P6000's on my cars as they are perfect for normal driving as well as when i push it. If you want them to last a long time but dont need massive amounts of grip then a hard compound like Bridgestone. If you want lots of grip but dont mind replacing them often then a soft compound like Yokohama is the way to go. There are of course tonnes of others out there!!​

4 - CAI (Cold Air Intake)
The most common upgrade for the E36 (and most cars for that matter) is a CAI. A CAI allows cooler, denser air into your engine. Dense air contains more oxygen and the more oxygen you have, the better the bang in your engine leading to more power. The stock airbox on a bimmer is very restrictive and so does not let in the maximum amount of air into your intake. A CAI is a cone filter (such as K&N) with a metal heatshield that replaces the plastic air-box. The heatshield creates a cold pocket of air around the filter that blocks a lot of the heat of the engine. The result is a more powerful (up to 10BHP) and smother engine that also sounds amazing. A good CAI will cost around 150 GBP ($300) but you could get the cone filter without the heatshield for 60GBP ($120) and will still see big gains due to the increased air flow. I recommend K&N​

5 - Brakes
Ok, so you have more power by adding the bits above, now you need to stop the flipping thing. An E36 weighs around 1.5 tonnes and so you need some decent brakes to stop it. The OEM brakes are ok but if you need to stop from a high speed in a hurry then you are going to get 'brake fade'. Brake fade is the sporn of all evil and occurs when your brakes get hot. The pedal goes hard and your braking efficiency is massively reduced. You need to install cross drilled discs (rotors) to dissipate the heat caused by the friction as well as some uprated pads. I recommend EBC Green stuffs pads for normal to spirited driving or EBC Red stuffs ceramic pads if you like to really push it or do track days. The increased braking is amazing and brake fade is almost completely eliminated. To get rid of it, you will need to install braided hoses. When your brakes get VERY hot, your brake fluid boils and the standard pipes expand losing efficiency. The uprated discs (rotors) should also stop 'warping' which can be VERY nasty​

6 - ECU re-map/chip upgrade
All cars that roll off the production line have to conform to emissions and country laws. They are also made to allow for the worst fuel, the worst drivers, bad servicing and bad weather conditions. Although the ECU is adaptive and so will advance/retard the ignition timing as described above, there is still plenty of power locked away behind your ECU maps. An ECU remap done via your OBC port or a physical replacement of your chip modifies the map to the most efficient possible. This give you lots more power throughout the rev-band and increased MPG as the engine is working at it's best. NEVER EVER EVER add cheap devices that claim to trick the ECU into thinking the air is colder. These are a con, plain and simple. Always go for a well known, reputable companies product. Your ECU is your car's brain and you should never short change it. You would not go to back alley doctor for brain surgery and the same goes for your bimmer. Price is anywhere from 100-300GBP ($200-$600)​

7 - Performance exhaust
After fitting the CAI, you will have increased airflow into your engine and it needs to get out. OEM exhausts are restrictive like the intake and so a decent cat-back exhaust will give you more power gains and a lovely sound too. There are many many brilliant companies out there that supply excellent systems for the E36 depending on what you want, what sound you like and how much you want to spend. Prices are anywhere from 100-500GBP ($200-$1000)​

8 - Strut Brace
Strut braces stiffen up the geometry of the front and rear suspension giving you a more positive turn in. Prices are around 50-150GBP ($100-$300)​

9 - Underdrive pulleys
Underdrive pulleys are smaller and lighter than the OEM ones and reduce the parasitic drag caused by running your alternator. Gains of around 6BHP can be seen with no ill affects to your electrical system. Prices are around 100GBP ($200)​

10 - Uprated Engine Bushes
Engine bushes hold your engine in place and the OEM ones can cause the engine to move under hard acceleration/braking and spirited cornering. This increases momentum and can destabilise the car. These stiffen up the engine and stop it moving around so much​

There are of course many more out there (including suspension upgrades) but these are the most common and the ones i have the most experience with.

Hope it helps

Pirate (Pete)
 
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#421 ·
NGK Iridium Plugs

I found the NGK Iridium IX plugs but apparently it is not compatible with a 92 325i? Is there a huge difference between the stock Bosch plugs? I see them on sale online for like under $50 but I don't want to wast the money..

Thank you for the great write up, I'm new here just picked up my first bimmer
 
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