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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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#39 ·
If you think it's just a semantics issue, then maybe you should rewrite stuff so it makes sense to everyone. When you say stuff like "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." which makes incorrect assertions about things with no correlation, it's misinforming people regardless of what they came here looking for or their skill level. Even if that was correct, it's not even relevant to the non-mechanics you are trying to cater to because it's not like manufacturers give out shock dyno sheets to even empirically compare them. Also should probably say compression damping and rebound damping instead of just damping and rebound.
 
#45 ·
hey guys as iam new to this i dont know were i should be posting my questions.
i have e34 520i and i love her to bits but she just needs a lil more up and go, i dont want to blow heaps of cash as
its ment to be my everydayer while i build my project car but u know how it is. any thoughts on wat could be done for a bit more
oommmpph.
cheers.
 
#48 ·
http://forums.bimmerforums.com/forum/showthread.php?t=1550952

This is a start. I have an M50 car. I have literally never touched a V8 E34 but what I can tell you is this.
As far as internals go, 540i components are already forged and can handle a moderate level of forced induction.
Intake is already free flowing. Don't waste money on aftermarket. Look into drop in filters on the forum, there's plenty of information. Ship me some info and I'll put it into the writeup.
Exhaust does nothing performance wise except for sound.
You could look into chips but I dot think there's many out there. After motor work, a dyno tune or custom tune would be preferable.
If you have a 530i, swap the M60B30 for a M60B40.

I'll pick up research again and try to get you V8 guys (compensators lol) some good stuff.
 
#54 · (Edited)
:thumbup: on this thread! this thread is the reason I join the Forum O N i have a Bimmer.
but just a few ?s i drive an 89 bmw 535i what would be the first step i should take toward tuning my beast . or a short list of mods would help two
First things first. Always remember.

Maintenance before performance. If you can make a maintenance upgrade that's good too.

Can't stress that enough. Easiest and best bang for your buck is a performance chip.
EAT chips or Comforti chips are favored for the m30b35.

Going with a sportier suspension wouldn't hurt either.
Koni adjustable struts and shocks are becoming more favored than the traditional Bilstein upgrade.
For Bilstein's tend to be harsh up front. As well, Konis are cheaper and can be adjusted to suit the drivers ideal ride.

Obviously the ultimate combination of the two are coilovers.
Nex, BC, KIDO, K-Sport, Ground Control, Lowtec, KW, Bilstein, Eibachall make coilovers for the e34 chassis.
The majority of coilover systems will need some type of strut modification to you front strut housings.
Some companies offer this modification service for a fee.
Some don't offer to do the work. Meaning you or a shop will have to perform the modification.

Larger swaybars and upgraded suspension bushings are decent upgrades.
BMW offers upgraded swaybars.
Racing Dynamics makes a set which offers the highest size and balance.
Bushings (spherical, Poly, hybrid) are good maintenance upgrades. Especially on the rear subframe.
Two such bushing manufacturers are Moosehead Engineering (spherical),Powerflex (polyurethane),

Braking is area where the e34 can upgrade without complete aftermarket setups.
The biggest calipers we can use without going aftermarket are e31 850i 4 piston or E24 4 piston front calipers and 540 rear calipers.
The bias matches up well.
It may require a change in your brake booster system but for the most part it is plug and play.

We can also use brembo front calipers from a Porsche 996 non turbo with e36 aftermarket brackets.
However the brackets IIRC will need to be flipped for it to work properly.

From there you can go in any direction. NA or FI

Miller performance cars makes a MAF and chip which will give you modest gains in RWHP, Torque, and help you m30 breath better.
But it will set you back about 700 bucks (depending on desired goal)

You can also go with a standalone system like DTA,AEM, VEMS or Megasquirt.
Most who go this route are looking for Force induction gains or have some type of NA swap.

Engine swaps are not as common for m30 owners as for m20 or m50 owners.
The most common M30 swap is a auto to manual swap.
There are plenty out there to research.

Cams are a good performance upgrade which will give nice gains.
However you'll achieve more dramatic change intergrating a well built turbo system. Word of advise on this.

Stay away from EBAY turbo systems.

The ebay turbochargers themselves usually fail and/or don't meet expectations.
However the intercooler systems, piping,and silicone couplers are ok to utilize.
Just shop carefully.

There are plenty of options out there for Turbo kits.
TCD or TurboCharging Dynamics is the favored.
They offer the best options for turnkey M30 turbo kits.
However if yu can also a setup together from a e23 or e32 745 turbo car.
These aren't the most efficient kits but they work with success.
You can pretty much get everything you need rather cheap and have your car running boost after some small changes.

Lastly, if your looking for hp gains.
Have a goal, do your research, and make a realistic budget for your build.
Most FI setups will set you back at least 2500.
My setup tally is currently at 2134 with a few little things needed to be done.

Good luck
 
#53 ·
Great thread. My m50 NV is under the knife right now getting VAC's stage 1.5 head upgrade/w 6mm valve stem conversion, 268/257 cams, 24lb injectors and a tune from miller's W.A.R chip. I will still be running stock air filter and maf, also running stock exhaust mani for now but will try to swap s50 mani if i come across one. I am new to this forum and will start a build thread or just post some results when everything is complete and running.
 
#56 ·
No they are out there. Most just don't go that route.
For our cars they are considered "Hot"air intakes for they take in more hot air than cold.
The air boxes are proven to be the best suited for the e34.
Only most FI setup see gains from a CAI.
Then again most FI setups have some type of intercooler incorporated inthe intake piping.
If you want better intake air flow go with a drop in K&N filter.
As an option you also can remove your right high beam and your air flow will increase.
 
#65 · (Edited)
If we were talking hondas or even lsx monster swaps I'd agree with your point.

There are a few well respected tuners and contibutors to the community if not the e34 model.
Rob Levinson is a respected guy and one of the reasons we have products like DSSR, EVO3, etc.
So to say "This information is really old or "it's all bull**** and neither of the party above did testing"
Is kind of like pissing in the wind.
For these cars are... really old cars. That technology hasn't changed in 17 years. Just been improved for fuel efficency.
UUC designs products for our cars.
I am sure if they felt the need to produce a CAI for our NA cars they would have long ago... But they didn't feel it was necessary.

There are countless threads on various forums on this subject on the internet.
Start this debate over in Bimmerforums and see how far you get before a flame war commence.

There are no real gains using a CAI on a e34 which has not been modified to some extent or isn't utilizing it for FI applications.
That's not heresay. It's proven.

Insult to injury, due to this, there are owners who remove the High beam just to gain more air into the velocity stack on the box get the engine breathing better.
A CAI doesn't have nor act like a velocity stack. It pulls air from multiple sources some cold some hot... mostly hot.

So how can you honestly compare it.
A chamber with a velocity stack which sources air directly from the outside
to a open pipe with a cone filter on it drawing hot, warm and some cold air from inside the engine bay.

Which one do you think will be more beneficial to the engine?

The OEM Box is more than efficient to handle the breathing capability of a NA e34.

Now if you want better flowing. Go with a Maf, chiptuning or standalone ecu like Megaquirt which use a IAT sensor.( allows you to remove the AFM for m30 and M20 cars) ,
DTA, VEMS and such. That the proper way to see the gains you think the a CAI gives you.

The only real gain using a CAI on our cars is in exhaust note and engine bay bling.
 
#66 · (Edited)
I have talked to Rob Levinson and he is a very smart dude but a quote in e-mail does not really mean anything.

The airbox in 540I is velocity stack you are right but if you talk about performance I have gotten better HP (small gain 3-5hp but better) on CAI with block off plate (K&N based).

The only thing that was better about stock unit is it was more consistant while CAI suffered from some heat soak but this was on a 95+ day in NYC.

And like i mentioned before my oil and engine are 100% after running K&N so that claim of 'particles' is just that a claim. Think about it.. those particles stay on the filter 99.99% of the time and when they do fly they are so small that with current oil nothing will ever be damaged.

Also let's not forget that UCC sells aFE brand of intakes (competitor): http://store.uucmotorwerks.com/shar...=765861153&CategoryID=299&Target=products.asp
 
#67 · (Edited)
I have talked to Rob Levinson and he is a very smart dude but a quote in e-mail does not really mean anything.

The airbox in 540I is velocity stack you are right but if you talk about performance I have gotten better HP (small gain 3-5hp but better) on CAI with block off plate (K&N based).

The only thing that was better about stock unit is it was more consistant while CAI suffered from some heat soak but this was on a 95+ day in NYC.

And like i mentioned before my oil and engine are 100% after running K&N so that claim of 'particles' is just that a claim. Think about it.. those particles stay on the filter 99.99% of the time and when they do fly they are so small that with current oil nothing will ever be damaged.
That's the point.
It's about consistant, reliable horsepower.

FI applications use them for they have a intercooler within the intake plumbing to bring the temps down.
If your running it stock with nothing to cool that air mass.
The result can be a drop in HP or something worse over time.

Yes you can make a barrier to help cool the environment in which the CAI pulls air from.
However your still pulling in a heated air mass.
You know this from your statement about heat soak.
All CAIs are prone to heat soak. For they don't pull direct cool air.
They pull in mostly hot air.
Thus coining the name "hot air intake"

The stock box pulls in fresh cooler air through the velocity stack more direct with minimal hot air exposure.
The Cooler mass of air enters the intake manifold + greater charge = more power.
So even academically that doesn't make sense on a NA e34.

Your theory would work but you would have to route the end of the intake to the outside of the car.
The best place would be behind the bumper.
However you'll have another issue.
For your going to pick up all types of crap kicked up from the road.
Something you really don't want.

If you still have the stock box.
Take your car to a dyno. Do one run with the box.
The next with the CAI.
Don't sandbag go all out.
I can bet your gains would be greater with the box.

Lastly you and i don't want to leave the impression that any old CAI will work.
Not everything at pepboys is made for our cars.
To allude to it could cause someone catastrophic failure and a bunch of money.

So to sum this all up.

Unless your e34 is turbo or supercharged.
Running a CAI is not beneficial to gains which can be gotten elsewhere.
As well they can possibly damage your car pulling in heated air for All CAIs are prone to heat soak.
The stock box is more than efficient for reliable and consistant power.
You may not get that cool exhaust note.
But that extra 25-100+ dollars can be used to by that chip you've been wanting.
 
#70 · (Edited)
double post
 
#73 ·
Perhaps you could add here that, due to a recent discussion, it has been proven that engine flushes of all kinds being sold and other bootleg flushes such as diesel, while being harmless to an engine when used as directed, do not, in fact, create much of a benefit to either justify the cost or the added time required to do the flush.

This is because :

1. If you run brand name fully synthetic oil, and
2. Change your oil and filter at the recommended intervals.

...no matter how high the mileage of the engine, it will be mostly free of sludge. What little that is left is is too little to make a difference to either the engine's internals or its performance, when it is removed by a flushing solvent.

Perhaps the only time when it is worthwhile to flush an engine would be at your first service interval after you've bought that car, since you don't want to assume that the po (previous owner) has been changing the oil whenever he should and has been using premium brands such as LiquiMoly and Mobil1. when he held onto the car. Thereafter, there would be no need, assuming of course that you're going to do your part henceforth.



rgds,
Roberto
 
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