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Known E34 Upgrades and Common E34 Myths

199K views 176 replies 47 participants last post by  1trishanne 
#1 · (Edited)
I will start with Upgrades in this first installment, and then move on to Common myths (i.e. off the shelf engine additives) as my contribution in a series that BMW_LVR, robertobaggio20, and myself will be writing for general knowledge and reference.
There are many upgrades used on E34s that are BMW OEM from other models such as the M3. But others are completely mythical.

ENGINE
We'll start with the 540i AFM (Air Flow Meter) upgrade: MYTH! Many E30 owners like to put in the "24V upgrade" which would be M50 or S50 motors because they came stock with M20s (12V motors). It was conjured up in this realm of 24V engine swaps that a 540i AFM would allow for more air flow, equating to more power, because they bolt up to the M50 intakes and are from a bigger engine, 4.4L. It is thought that the AFM would tell the engine to take in more air, as if it were for a V8. This is false. The AFM doesn't tell the ECU how much air to take (1st off it cant do that) but rather it tells the ECU how much is being taken in by the engine. It's simply telling the ECU "Hey man, the engine is taking in this much air, please compensate with fuel." A receding cylinder can take in a certain amount of air through an open valve, and can only be adjusting by leaving the valves open further and/or longer (cams) or forced induction. A K&N air filter will allow for more air in your engine, this is a recommended upgrade by yours truly. I love mine and it is easily serviced, and lasts forever. Putting a 540 AFM on a 525 has the same effect as 540 wheels on a 525, confirmed by sources at Turner Motorsports.

Next up, Headers! M50 engines come with cast iron manifolds, where S50 or S52 engines come with tubular steel manifolds. Some generalized differences are design and material. Starting with material, cast iron, is bulky, heavy, and rough (inside and out), and steel is lighter and smoother, and easily formed so as to make an efficient shape. Design differs from manifold to header as well. Manifolds are like a dumping ground that the exhaust port spills into that is then poured through a single exit. Headers are a separate exhaust path for each cylinder exhaust port and are then eased into each other for a much better flow and less back-pressure, which equates to more power. Because M50 and S50/52 share the same block and configuration, these bolt right up. When installing your new headers, be sure to replace gaskets, because there will be more airflow and old gaskets will only get worse and they're ~$25 (c'mon). The S50 headers bolt right up without any modification. S52 headers, require some light modification. Because the S52 headers are from OBDII vehicles, they have secondary vacuum lines at the manifold side, and O2 ports close to the cat-side flange. The O2 holes are easily plugged with M18 oil drain plugs from a 1985 Land Cruiser, found at any hardware store. The vacuum lines may have a plate welded over them, or with an OEM Plates that bolts over it.

On to the Cams! As most of you know, I've been working on this project, locating and acquiring parts and ordering pieces. I'm well versed in this topic with an abundant amount or research and knowledge. There are many how-to's on installing them on many different forums, don't be intimidated. S50 and S52 cams will be the ones to find. They offer virtually identical power gains, confirmed by, again, sources at Turner Motorsports. They offer more duration and lift than stock which equates to more power. Cam specs can be read, simply put by their duration and lift. The lobes of the camshafts are what determine these specs and are what cause the differences between each other. The DURATION of the cam tells us how long a valve is open for. Having a valve open longer equates to more air flow meaning more power. On on the exhaust side, it means it can relieve more pressure and rid your cylinder of exhaust gasses more efficiently. The LIFT of the cam lobe tells how far a valve can open. this is the same principle of how long it is open. The further it opens, the more air, the more power; the same is true for the exhaust side. The more duration and lift a cam has, it is said to be more aggressive or "hotter". They are difficult to come by however. S52s are easier to find but they require the cam trays to match as well because of their square core design. They bolt up to the stock VANOS unit and sprockets. They are seating in the stock bearing caps. One thing to keep in mind though is that non-VANOS cams can only be used in non-VANOS cars, single VANOS cams is only VANOS car, and dual VANOS cam in only dual VANOS cars.
Things like valve cover gasket and VANOS bits should be replaced, but that will be discussed by BMW_LVR.

Ram Air Intake is the most efficient and easy to produce modification on your car. This, however, is not for everybody. If you remove the backing of the driver side headlights, you will find that the air box intake hole lines up rather nicely to the high beam light. You can go to Home Depot, Loews or any other large hardware store to pick up a couple that will fit from the high beam hole to the intake box. Removing the High beam and, at speeds, you will have air, directly and unobstructedly forced directly through the filter. This will allow for a greater amount of airflow into your engine rather than around the high beam bulb. Some drawbacks to this though, many people don't like the lopsided look of having only one high beam, or they don't like a hole in the middle of their grille, or they are worried about debris and water getting in. The former two are your own prerogative but the latter can be addressed. Putting some sort of fine filter over the end of the tube by the light's empty space will keep out large debris (rocks, sticks, stones, branches, boulders, trees, low-flying birds, small children) from your air box. The filter will be able to block out the water effectively, save for a torrential downpour. People have used women's stocking cut and fitted over the end of this tube as a filter, as a point of reference.

Performance Software can be used to improve the hand you're dealt. The software is a small chip that clips into your ecu. It is a very simple DIY, especially with these instructions. The chip is like a small floppy disc that the ECU looks to to find answers to situations. The chip contains an increased rev limiter, usually ~500 revs higher, and removes the top speed governor. In addition to these perks, it holds air fuel mappings, so as to get the most power from your engine given the stock setup. It will add more fuel to better compensate for air flow at certain revs, equating to up to 10-15 horsepower/torques gained.

SUSPENSION
Lowering Springs
Lowering springs are a nice upgrade both for visual and functional applications. They work by compressing at different rates than stock springs, or by having fewer coils in the same height spring. They will lower your car anywhere from $300. Springs should be complimented by shocks and struts to improve upon spring functions, and strut mount longevity.

Sport Shocks and Struts
Sport shocks and struts are good compliments for lowering or sport springs. The springs will be holding the same weight lower with less room for wheel travel, creating a stiffer ride. the Sport shocks and struts will compensate for the limited wheel travel by having shorter damping rates and rebound rates. Damping is how fast the shock cylinder will compress into the absorber, this differs between shocks due to the pressure inside. The more pressure inside the shock, the less damping it will have, and create a firm ride because of less wheel travel. Low damping rates also lead to high rebound, which is how fast the the shock will expand, pushing the tire to the road. Lower pressure shocks will have a softer rider, because they compress faster and deeper, but are slower to release and expand. The sportier the ride, the less damping and more rebound you'd want. Bilsteins seem to be the most common for our precious chariots. When installing springs and struts/shocks, it is highly recommended to change the mounts also. Meyle HD mounts are popular but even an OEM would do just fine.

Sway Bars
As far as OEM sway bars go, they do their job of keeping a comfortable daily-driven ride, just fine. An upgrade that would be on the affordable end, Would be OEM E34 M5 sway bars. they are the thickest made from factory. A thicker sway bar, makes for less torsion in the bar, which equates to a stiffer chassis, a better handling car, and helps to reduce understeer, by holding the car straight through a corner. On the aftermarket end, adjustable sway bars, like Racing Dynamic bars, are relatively expensive, but they are even thicker than M5 OEM bars. the offer three different holes on the end for the bottom of the end-link to bolt into. Each hole on the sway bar will adjust how much or how little the chassis is stiffened. These are a must for an weekend racer.

BRAKES
E34 540i/E32 740i/L
For all of you non-540 owners, you'll like this. You can upgrade to 540 brakes!! The brakes have the same diameter, but are thicker. They allow for faster stopping power, and fit onto your OEM MacPherson assembly, and fit inside your wheels. They bolt on exactly like when you do a regular brake job. You can find these off of parts cars, or junk yards, all you need are the calipers and the brake carriers. You can take the rotors and pads if they are in good shape but that's a last resort. Try to get replacement rotors and pads, obviously for the 540i. Aftermarket rotors and pads for performance may also be bought, make sure they fit your calipers and hubs though, they are also up to you for research.

Steel Braided Brake Lines
Steel braided brake lines were not offered OEM so you wont find them in any junk yard or parts car. they replace your brake lines by the calipers. There are no disadvantages to to these lines, only gains to be had. Our luxo-liners come with rubber lines, which, over time, can become worn from use. Every single time you hit the brakes, pressure builds up in the lines and causes them to weaken ever so slightly. They will eventually bulge which, in the long-run, decreases brake performance. This weakening in the rubber, also helps to contribute to brake-fade, which is an Achilles heel to all racers. Steel braided lines do not deal with this flexing, weakening, or bulging. They remain constant and can hold much more pressure than stock lines can. they are unaffected by heat, and will give you constant and linear performance. They are about $120 for the whole set (reliable sets have been found on ebay for as low as $60). They are an excellent upgrade for any one of us, racer or daily-driver.

Stil Adding Daily!!!
 
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#175 ·
I will start with Upgrades in this first installment, and then move on to Common myths (i.e. off the shelf engine additives) as my contribution in a series that BMW_LVR, robertobaggio20, and myself will be writing for general knowledge and reference.
There are many upgrades used on E34s that are BMW OEM from other models such as the M3. But others are completely mythical.

ENGINE
We'll start with the 540i AFM (Air Flow Meter) upgrade: MYTH! Many E30 owners like to put in the "24V upgrade" which would be M50 or S50 motors because they came stock with M20s (12V motors). It was conjured up in this realm of 24V engine swaps that a 540i AFM would allow for more air flow, equating to more power, because they bolt up to the M50 intakes and are from a bigger engine, 4.4L. It is thought that the AFM would tell the engine to take in more air, as if it were for a V8. This is false. The AFM doesn't tell the ECU how much air to take (1st off it cant do that) but rather it tells the ECU how much is being taken in by the engine. It's simply telling the ECU "Hey man, the engine is taking in this much air, please compensate with fuel." A receding cylinder can take in a certain amount of air through an open valve, and can only be adjusting by leaving the valves open further and/or longer (cams) or forced induction. A K&N air filter will allow for more air in your engine, this is a recommended upgrade by yours truly. I love mine and it is easily serviced, and lasts forever. Putting a 540 AFM on a 525 has the same effect as 540 wheels on a 525, confirmed by sources at Turner Motorsports.

Next up, Headers! M50 engines come with cast iron manifolds, where S50 or S52 engines come with tubular steel manifolds. Some generalized differences are design and material. Starting with material, cast iron, is bulky, heavy, and rough (inside and out), and steel is lighter and smoother, and easily formed so as to make an efficient shape. Design differs from manifold to header as well. Manifolds are like a dumping ground that the exhaust port spills into that is then poured through a single exit. Headers are a separate exhaust path for each cylinder exhaust port and are then eased into each other for a much better flow and less back-pressure, which equates to more power. Because M50 and S50/52 share the same block and configuration, these bolt right up. When installing your new headers, be sure to replace gaskets, because there will be more airflow and old gaskets will only get worse and they're ~$25 (c'mon). The S50 headers bolt right up without any modification. S52 headers, require some light modification. Because the S52 headers are from OBDII vehicles, they have secondary vacuum lines at the manifold side, and O2 ports close to the cat-side flange. The O2 holes are easily plugged with M18 oil drain plugs from a 1985 Land Cruiser, found at any hardware store. The vacuum lines may have a plate welded over them, or with an OEM Plates that bolts over it.

On to the Cams! As most of you know, I've been working on this project, locating and acquiring parts and ordering pieces. I'm well versed in this topic with an abundant amount or research and knowledge. There are many how-to's on installing them on many different forums, don't be intimidated. S50 and S52 cams will be the ones to find. They offer virtually identical power gains, confirmed by, again, sources at Turner Motorsports. They offer more duration and lift than stock which equates to more power. Cam specs can be read, simply put by their duration and lift. The lobes of the camshafts are what determine these specs and are what cause the differences between each other. The DURATION of the cam tells us how long a valve is open for. Having a valve open longer equates to more air flow meaning more power. On on the exhaust side, it means it can relieve more pressure and rid your cylinder of exhaust gasses more efficiently. The LIFT of the cam lobe tells how far a valve can open. this is the same principle of how long it is open. The further it opens, the more air, the more power; the same is true for the exhaust side. The more duration and lift a cam has, it is said to be more aggressive or "hotter". They are difficult to come by however. S52s are easier to find but they require the cam trays to match as well because of their square core design. They bolt up to the stock VANOS unit and sprockets. They are seating in the stock bearing caps. One thing to keep in mind though is that non-VANOS cams can only be used in non-VANOS cars, single VANOS cams is only VANOS car, and dual VANOS cam in only dual VANOS cars.
Things like valve cover gasket and VANOS bits should be replaced, but that will be discussed by BMW_LVR.

Ram Air Intake is the most efficient and easy to produce modification on your car. This, however, is not for everybody. If you remove the backing of the driver side headlights, you will find that the air box intake hole lines up rather nicely to the high beam light. You can go to Home Depot, Loews or any other large hardware store to pick up a couple that will fit from the high beam hole to the intake box. Removing the High beam and, at speeds, you will have air, directly and unobstructedly forced directly through the filter. This will allow for a greater amount of airflow into your engine rather than around the high beam bulb. Some drawbacks to this though, many people don't like the lopsided look of having only one high beam, or they don't like a hole in the middle of their grille, or they are worried about debris and water getting in. The former two are your own prerogative but the latter can be addressed. Putting some sort of fine filter over the end of the tube by the light's empty space will keep out large debris (rocks, sticks, stones, branches, boulders, trees, low-flying birds, small children) from your air box. The filter will be able to block out the water effectively, save for a torrential downpour. People have used women's stocking cut and fitted over the end of this tube as a filter, as a point of reference.

Performance Software can be used to improve the hand you're dealt. The software is a small chip that clips into your ecu. It is a very simple DIY, especially with these instructions. The chip is like a small floppy disc that the ECU looks to to find answers to situations. The chip contains an increased rev limiter, usually ~500 revs higher, and removes the top speed governor. In addition to these perks, it holds air fuel mappings, so as to get the most power from your engine given the stock setup. It will add more fuel to better compensate for air flow at certain revs, equating to up to 10-15 horsepower/torques gained.

SUSPENSION
Lowering Springs
Lowering springs are a nice upgrade both for visual and functional applications. They work by compressing at different rates than stock springs, or by having fewer coils in the same height spring. They will lower your car anywhere from $300. Springs should be complimented by shocks and struts to improve upon spring functions, and strut mount longevity.

Sport Shocks and Struts
Sport shocks and struts are good compliments for lowering or sport springs. The springs will be holding the same weight lower with less room for wheel travel, creating a stiffer ride. the Sport shocks and struts will compensate for the limited wheel travel by having shorter damping rates and rebound rates. Damping is how fast the shock cylinder will compress into the absorber, this differs between shocks due to the pressure inside. The more pressure inside the shock, the less damping it will have, and create a firm ride because of less wheel travel. Low damping rates also lead to high rebound, which is how fast the the shock will expand, pushing the tire to the road. Lower pressure shocks will have a softer rider, because they compress faster and deeper, but are slower to release and expand. The sportier the ride, the less damping and more rebound you'd want. Bilsteins seem to be the most common for our precious chariots. When installing springs and struts/shocks, it is highly recommended to change the mounts also. Meyle HD mounts are popular but even an OEM would do just fine.

Sway Bars
As far as OEM sway bars go, they do their job of keeping a comfortable daily-driven ride, just fine. An upgrade that would be on the affordable end, Would be OEM E34 M5 sway bars. they are the thickest made from factory. A thicker sway bar, makes for less torsion in the bar, which equates to a stiffer chassis, a better handling car, and helps to reduce understeer, by holding the car straight through a corner. On the aftermarket end, adjustable sway bars, like Racing Dynamic bars, are relatively expensive, but they are even thicker than M5 OEM bars. the offer three different holes on the end for the bottom of the end-link to bolt into. Each hole on the sway bar will adjust how much or how little the chassis is stiffened. These are a must for an weekend racer.

BRAKES
E34 540i/E32 740i/L
For all of you non-540 owners, you'll like this. You can upgrade to 540 brakes!! The brakes have the same diameter, but are thicker. They allow for faster stopping power, and fit onto your OEM MacPherson assembly, and fit inside your wheels. They bolt on exactly like when you do a regular brake job. You can find these off of parts cars, or junk yards, all you need are the calipers and the brake carriers. You can take the rotors and pads if they are in good shape but that's a last resort. Try to get replacement rotors and pads, obviously for the 540i. Aftermarket rotors and pads for performance may also be bought, make sure they fit your calipers and hubs though, they are also up to you for research.

Steel Braided Brake Lines
Steel braided brake lines were not offered OEM so you wont find them in any junk yard or parts car. they replace your brake lines by the calipers. There are no disadvantages to to these lines, only gains to be had. Our luxo-liners come with rubber lines, which, over time, can become worn from use. Every single time you hit the brakes, pressure builds up in the lines and causes them to weaken ever so slightly. They will eventually bulge which, in the long-run, decreases brake performance. This weakening in the rubber, also helps to contribute to brake-fade, which is an Achilles heel to all racers. Steel braided lines do not deal with this flexing, weakening, or bulging. They remain constant and can hold much more pressure than stock lines can. they are unaffected by heat, and will give you constant and linear performance. They are about $120 for the whole set (reliable sets have been found on ebay for as low as $60). They are an excellent upgrade for any one of us, racer or daily-driver.

Stil Adding Daily!!!
Give me some 520i additions... I have inherited this 3 yrs ago and thought it would be great driving it for at least 5 yrs. Then ULEZ in London happened... I thought I'd recycled my Step-dads Bimmer... he loved his retirement 'gift to himself' having driven trains from Steam to Electric his whole life and been in the Airforce during WW2... he drove to the snooker club and back and left it to my Mum with only 22K on the clock. I took it when she passed away 2017. Now here I am having to pay £12.50 per day to drive her... ouch... I'd like to know if I can do anything to cut the ULEZ issue and keep her... is there anything ??? plllleeeeaaazzze :cry:
 
#176 ·
This is primarily a US based forum and we never got the 520 here, but I would assume if it is the m50b20 everything that applies to the m50b25 525 would apply as well. What’s a ULEZ issue. Is that the have to be classed as ultra low emission to drive with out a surcharge in London thing? Nothing you can do about that, it is what it is, unless you can move elsewhere.
 
#177 ·
Thank you Onizukachan ... It is what it is... and it's really unfair... I can't move so it looks like I'm going to have to sell her... and she is too Sweet... so I'm hoping to find her a good home where she can live in the right way.... Thanks again you've let me know what I needed to hear... Happy New Year to you...
 
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