540i vs M5 differences-eng,tran,susp,body?

[Black Beast]

I am new to BMW and have searched but can not find the facts.
What are the differences in engines between the 540 and M5?....ie-intakes,cams,pistons,crank and can any of the M5 parts fit the e39?

What is the difference between rear end gearing in the sport 540ia,540i,and M5?

What about the sport suspention vs. the M5's?

All facts would be great.....Thanks

[///MEric]

Well the engine is completely different higher compersion more rev happy and a little more torque. The hole car is designed to me muchmore sporty.

[e30sd]

http://www.bmwworld.com/engines/s62.htm

[Lscman]

Well the engine is completely different higher compersion more rev happy and a little more torque. The hole car is designed to me muchmore sporty.

Actually, there are far more similarities than differences. It's much like comparing a Ford Mustang GT to a Cobra. Cosmetic differences between M5 and 540i sport involve mostly plastic bolt-on's. The 540i spare tire was replaced with a right side muffler.

Handling is very similar. M5 and 540i sport springs carry the same factory part#'s. M5 has slightly larger swaybars to deal with about 200lb added girth. The interior is tweaked, but M5 is hardly sportier than a 540i with the sport option.

The biggest difference between the two vehicles (by far) is due to:
1) engine displacement, induction and cams and
2) rear differential
3) exhaust configuration aft of cats

As a result, the M5 is 3/4 of a second faster thru the traps. Clutch is the same size and the transmission is the same. The M5 clutch is inadequate. The 540i radiator is weak.

The brakes on the M5 are a little better, but still single piston...many folks wind up replacing the M5 system with aftermarket BBK.

The struts and shocks on both vehicles are made by Boge and basically garbage.

The later 540i cars with staggered wheels have the same front wheel width as a M5, namely 8". The rear 540i wheel is 9" vs 9.5" for M5. Staggered width wheels are not desireable from a handling perspective, so the 8"/9.5" setup is no bonus.

[Black Beast]

LSCman thanks for the info....do you know what rear end gearing in the sport has vs the M5.
Thanks e30sd that link is just what I was looking for....great info.

[mikemaster]

sport 540ia 3.15
sport 540/6 speed 2.82
M5 3.15 LSD

The M5 is the only e39 in the US to get a LSD from the factory.

[bmerluvr]

Doesn't an M5 have a 3.45 LSD?

[e30sd]

LSCman thanks for the info....do you know what rear end gearing in the sport has vs the M5.
Thanks e30sd that link is just what I was looking for....great info.

no prob. i love posting that link everytime, cause the s62 is such a damn sweet engine. imagine that thing with solid lifters...

[Black Beast]

Can the LSD pack be added into the diff.?...is the diff. the same part # as the M5's?

[Lscman]

Diff upgrade is not cheap. A 540i quaiffe posi costs around $3K. An M5 posi upgrade will cost at least a grand more. The M5 upgrade involves new half shafts for 540i, unless you retrofit some oddball 15 year old 7 series bearing to the carrier assy to allow retrofit. Such an upgrade is not done often, so info is sketchy. You gotta really want posi to dump 25% of the car's value into one. Common sense usually prevails. If you want to drag race and impove 60' times, you should look at a Mustang or some machine with a solid rear axle assy. The 540i sport is for handling, not standing starts. Some folks trying to drag race M5 have broken the aluminum rear frame assy. Such duty is abusive in a car with good weight proportion (lot's of weight on the rear wheels). The car has lightweight suspension for good handling & it's an awfully heavy car for clutch-popping starts.

[sirc1228]

Actually, there are far more similarities than differences. It's much like comparing a Ford Mustang GT to a Cobra. Cosmetic differences between M5 and 540i sport involve mostly plastic bolt-on's. The 540i spare tire was replaced with a right side muffler.

Handling is very similar. M5 and 540i sport springs carry the same factory part#'s. M5 has slightly larger swaybars to deal with about 200lb added girth. The interior is tweaked, but M5 is hardly sportier than a 540i with the sport option.

The biggest difference between the two vehicles (by far) is due to:
1) engine displacement, induction and cams and
2) rear differential
3) exhaust configuration aft of cats

As a result, the M5 is 3/4 of a second faster thru the traps. Clutch is the same size and the transmission is the same. The M5 clutch is inadequate. The 540i radiator is weak.

The brakes on the M5 are a little better, but still single piston...many folks wind up replacing the M5 system with aftermarket BBK.

The struts and shocks on both vehicles are made by Boge and basically garbage.

The later 540i cars with staggered wheels have the same front wheel width as a M5, namely 8". The rear 540i wheel is 9" vs 9.5" for M5. Staggered width wheels are not desireable from a handling perspective, so the 8"/9.5" setup is no bonus.

Is it really a proven fact that M5 and 540i suspensions are the same? I'm just asking because I would like to change my 540i suspension to M5. Can you make it more specific?

[Lscman]

1) The factory swaybars differ. M5 has 27mm/16.5mm while the 540i sport uses 25mm/15mm. Many M5 owners are switching to ACS or the sister Eibach swaybars...the same 28mm/18mm kit that fits 540i. Aside from paint color they are the same. ACS costs $800 and Eibach costs $400. There's an older swaybar design by Dinan that's an adjustable 17mm rear bar for about $200. It's kinda nice for dialing out understeer, if you have the factory front swaybar. The front swaybar is a very difficult swap requiring you to drop the front frame assembly.

2) The factory shocks and struts differ slightly, if you compare 540i sport or 6spd to M5. Factory BMW-Boge struts and shocks aren't that great. They quickly deteriorate on both cars. Damping rates drop and they begin leaking...usually around 50K. The difference in damping rate between the two cars is very small, due to 200 avg weight differential and 2mm more swaybar. Koni struts and shocks are a good upgrade for both the M5 and 540i & they cost about $700 for a set. A nice improvement can be made by dialing in some negative camber with K-MAC upper strut mounts.

3) Spring rates are IDENTICAL between a loaded 540i Sport II and a modestly-equipped M5. The M5 springs are NOT stiffer or higher performance. The weight of the car will define which spring part# gets installed in it. For example, a loaded 2001 540i and M5 with few options will be shipped with identical springs. Earlier 540i cars are sport I pkg and their rear springs are about 5-10% softer rate to work better with non-stagger wheels. If you're using staggered wheels, the sports II springs are better. If non-stagger, go with sports I or sports II. The sports II will simply reduce understeer a bit. The spring tables are in BMW ETK software. Tell me what year and options & I can recommend springs. There are about 8 different springs sold for M5 and 540i sport, based upon chassis weight. About 6 of them apply to both vehicles. As you can imagine, the heaviest M5's and lighest 540i cars carry their own part#'s, since chassis weights will not overlap between these cars.

4) If you get some take-off M5 suspension parts and put them on an earlier year 540i ('97-'98), it'll likely sit too high. These years of 540i cars were the lightest ones sold (no vanos, fewer airbags etc). The weight differential between the typical loaded M5 and early, base 540i sport approaches 325 lbs. Even later year 540i cars are lighter than "most" M5's. Folks that try this parts swap are usually dissappointed.

5) Aside from swaybars, there's no significant upgrades on the M5 suspension, compared to a 540i sport. The only difference is free spring length, which affects ride height due to chassis weight differences.

In conclusion, if you have the sport option on your 540i, you're best option is to install bigger swaybars and Koni shocks. For optimal handling, you might be better off with factory 540i sport springs. The only decent aftermarket street springs for handling are Eibach's. They lower the car about 1/2" but they are still linear spring rate for predictable handling. Their rate is close to stock sport. All other aftermarket springs are for slamming...they are highly progressive and handle poorly, compared to stock sport. Too many folks take blown out Boges off their car with 70K miles and replace them with fresh Konis and progressive H&R's. They feel a remarkable improvement in handling and attribute it to the springs. Hey...it's the shocks....believe me.

[sl0moti0n]

wow, this thread is great! I just bid on some m5 suspesion parts (shocks/springs) on ebay. It says they have 7k miles on them. Based on the info here it would be a mistake to do this swap even if it only costs $200.00. Would you agree lscman?

[bmerluvr]

I have Koni's, an upgraded rear sway and lowering springs, all Dinan. The car does handle much better, but with a stiffer ride. The understeer I had before is pretty much gone now. However, since I can never leave well enough alone, do you guys think it would be worth the huge labor charge to install a larger front sway? Labor is what kills you with the front. I've heard most people stop with the rear and don't worry about the front, because of minimal gains in handling. The Dinan front sway is 27mm compared to the stock 25mm.

[Lscman]

It says they have 7k miles on them.

We've all heard that before....hope you can verify, good luck.

Based on the info here it would be a mistake to do this swap even if it only costs $200.00.

Assuming you have a 540i sport, the purpose of such a swap would be to freshen up a high mile car with low mile parts & to obtain a pair of bigger swaybars that would cost you $190 new, thru Pacific BMW. If your car is a '98 or older, the M5 springs will make it sit a good inch higher than stock. The stock spring rate at the wheel is under 150 lb/in, so a slight decrease in weight will raise the car a lot. It may sit high like a 525i auto & look silly. The labor effort is huge. I would not spend those manhours installing used factory shocks and struts. That's just me.

[Lscman]

I have Koni's, an upgraded rear sway and lowering springs, all Dinan. The car does handle much better, but with a stiffer ride. The understeer I had before is pretty much gone now. However, since I can never leave well enough alone, do you guys think it would be worth the huge labor charge to install a larger front sway? Labor is what kills you with the front. I've heard most people stop with the rear and don't worry about the front, because of minimal gains in handling. The Dinan front sway is 27mm compared to the stock 25mm.

Almost nobody buys the overpriced Dinan front swaybar since the factory 27mm M5 bar costs around $100.

If your car handles neutral now, a 27mm front swaybar will cause your car to understeer (again). If you are using the middle or outer adjustment holes on the rear Dinan bar, you could install a bigger front bar and move to inward holes to maintain balance. I've heard that some racers have found the 25mm front bar offers better balance. The bigger bar overworks the front tires in many cases. I would not assume that a bigger front bar is better. It will surely reduce body roll/lean, but it may not improve lap times or handling. The goal is NOT to make the car flat in corners. Such a goal is only necessary for cars with poor suspension geometry. The BMW sticks nice with a plush, compliant suspension. It isn't a Shelby. .....Just some thoughts.

[bmerluvr]

Almost nobody buys the overpriced Dinan front swaybar since the factory 27mm M5 bar costs around $100.

If your car handles neutral now, a 27mm front swaybar will cause your car to understeer (again). If you are using the middle or outer adjustment holes on the rear Dinan bar, you could install a bigger front bar and move to inward holes to maintain balance. I've heard that some racers have found the 25mm front bar offers better balance. The bigger bar overworks the front tires in many cases. I would not assume that a bigger front bar is better. It will surely reduce body roll/lean, but it may not improve lap times or handling. The goal is NOT to make the car flat in corners. Such a goal is only necessary for cars with poor suspension geometry. The BMW sticks nice with a plush, compliant suspension. It isn't a Shelby. .....Just some thoughts.

Thanks a lot for the info. I was afraid that putting on a bigger front bar would counteract the larger Dinan rear sway and dial in the understeer again. As I said earlier, the car handles great now, so I'm going to leave it as is. The rear sway is set to the middle setting btw.

[DMZ]

Correct me if I am wrong, But didn't the M5 come with some aluminium suspension parts which the 540i didn't have? I just traded in my 540i 6 speed for a M5 and I still can't believe how different the handling is.

1) The factory swaybars differ. M5 has 27mm/16.5mm while the 540i sport uses 25mm/15mm. Many M5 owners are switching to ACS or the sister Eibach swaybars...the same 28mm/18mm kit that fits 540i. Aside from paint color they are the same. ACS costs $800 and Eibach costs $400. There's an older swaybar design by Dinan that's an adjustable 17mm rear bar for about $200. It's kinda nice for dialing out understeer, if you have the factory front swaybar. The front swaybar is a very difficult swap requiring you to drop the front frame assembly.

2) The factory shocks and struts differ slightly, if you compare 540i sport or 6spd to M5. Factory BMW-Boge struts and shocks aren't that great. They quickly deteriorate on both cars. Damping rates drop and they begin leaking...usually around 50K. The difference in damping rate between the two cars is very small, due to 200 avg weight differential and 2mm more swaybar. Koni struts and shocks are a good upgrade for both the M5 and 540i & they cost about $700 for a set. A nice improvement can be made by dialing in some negative camber with K-MAC upper strut mounts.

3) Spring rates are IDENTICAL between a loaded 540i Sport II and a modestly-equipped M5. The M5 springs are NOT stiffer or higher performance. The weight of the car will define which spring part# gets installed in it. For example, a loaded 2001 540i and M5 with few options will be shipped with identical springs. Earlier 540i cars are sport I pkg and their rear springs are about 5-10% softer rate to work better with non-stagger wheels. If you're using staggered wheels, the sports II springs are better. If non-stagger, go with sports I or sports II. The sports II will simply reduce understeer a bit. The spring tables are in BMW ETK software. Tell me what year and options & I can recommend springs. There are about 8 different springs sold for M5 and 540i sport, based upon chassis weight. About 6 of them apply to both vehicles. As you can imagine, the heaviest M5's and lighest 540i cars carry their own part#'s, since chassis weights will not overlap between these cars.

4) If you get some take-off M5 suspension parts and put them on an earlier year 540i ('97-'98), it'll likely sit too high. These years of 540i cars were the lightest ones sold (no vanos, fewer airbags etc). The weight differential between the typical loaded M5 and early, base 540i sport approaches 325 lbs. Even later year 540i cars are lighter than "most" M5's. Folks that try this parts swap are usually dissappointed.

5) Aside from swaybars, there's no significant upgrades on the M5 suspension, compared to a 540i sport. The only difference is free spring length, which affects ride height due to chassis weight differences.

In conclusion, if you have the sport option on your 540i, you're best option is to install bigger swaybars and Koni shocks. For optimal handling, you might be better off with factory 540i sport springs. The only decent aftermarket street springs for handling are Eibach's. They lower the car about 1/2" but they are still linear spring rate for predictable handling. Their rate is close to stock sport. All other aftermarket springs are for slamming...they are highly progressive and handle poorly, compared to stock sport. Too many folks take blown out Boges off their car with 70K miles and replace them with fresh Konis and progressive H&R's. They feel a remarkable improvement in handling and attribute it to the springs. Hey...it's the shocks....believe me.

[sirc1228]

Thanks Lscman!!! That was a good info. I enjoyed reading it! More power to you man!!!

1) The factory swaybars differ. M5 has 27mm/16.5mm while the 540i sport uses 25mm/15mm. Many M5 owners are switching to ACS or the sister Eibach swaybars...the same 28mm/18mm kit that fits 540i. Aside from paint color they are the same. ACS costs $800 and Eibach costs $400. There's an older swaybar design by Dinan that's an adjustable 17mm rear bar for about $200. It's kinda nice for dialing out understeer, if you have the factory front swaybar. The front swaybar is a very difficult swap requiring you to drop the front frame assembly.

2) The factory shocks and struts differ slightly, if you compare 540i sport or 6spd to M5. Factory BMW-Boge struts and shocks aren't that great. They quickly deteriorate on both cars. Damping rates drop and they begin leaking...usually around 50K. The difference in damping rate between the two cars is very small, due to 200 avg weight differential and 2mm more swaybar. Koni struts and shocks are a good upgrade for both the M5 and 540i & they cost about $700 for a set. A nice improvement can be made by dialing in some negative camber with K-MAC upper strut mounts.

3) Spring rates are IDENTICAL between a loaded 540i Sport II and a modestly-equipped M5. The M5 springs are NOT stiffer or higher performance. The weight of the car will define which spring part# gets installed in it. For example, a loaded 2001 540i and M5 with few options will be shipped with identical springs. Earlier 540i cars are sport I pkg and their rear springs are about 5-10% softer rate to work better with non-stagger wheels. If you're using staggered wheels, the sports II springs are better. If non-stagger, go with sports I or sports II. The sports II will simply reduce understeer a bit. The spring tables are in BMW ETK software. Tell me what year and options & I can recommend springs. There are about 8 different springs sold for M5 and 540i sport, based upon chassis weight. About 6 of them apply to both vehicles. As you can imagine, the heaviest M5's and lighest 540i cars carry their own part#'s, since chassis weights will not overlap between these cars.

4) If you get some take-off M5 suspension parts and put them on an earlier year 540i ('97-'98), it'll likely sit too high. These years of 540i cars were the lightest ones sold (no vanos, fewer airbags etc). The weight differential between the typical loaded M5 and early, base 540i sport approaches 325 lbs. Even later year 540i cars are lighter than "most" M5's. Folks that try this parts swap are usually dissappointed.

5) Aside from swaybars, there's no significant upgrades on the M5 suspension, compared to a 540i sport. The only difference is free spring length, which affects ride height due to chassis weight differences.

In conclusion, if you have the sport option on your 540i, you're best option is to install bigger swaybars and Koni shocks. For optimal handling, you might be better off with factory 540i sport springs. The only decent aftermarket street springs for handling are Eibach's. They lower the car about 1/2" but they are still linear spring rate for predictable handling. Their rate is close to stock sport. All other aftermarket springs are for slamming...they are highly progressive and handle poorly, compared to stock sport. Too many folks take blown out Boges off their car with 70K miles and replace them with fresh Konis and progressive H&R's. They feel a remarkable improvement in handling and attribute it to the springs. Hey...it's the shocks....believe me.

[Dan]

now how can you tell the difference between a 540i and a 540i sport? what about sport I and sport II? thanks!

[Lscman]

Non-sport offers softer ride with higher ride height. The non-sport shocks have softer damping. The swaybars are smaller than sport. The non-sport is a luxo cruiser setup and not for handling.

As mentioned above, the sport I and sport II front spring rates are similar. The sport II rear spring rate is stiffened slightly to maintain better balance with wider rear rims and tires (stagger). The Sport II cars will understeer less with staggered wheels. Sport I and II have same swaybars, struts and shocks.

If you buy a non-sport car, it's not the end of the world. A set of $400 Eibach swaybars and an $850 set of Koni's and Eibach Pro springs will give you handling better than an M5 or 540i sport. Sport II springs can be substituted for more streetable ride height, if you want to spend a little more cash. The handling will be equivalent.

[The Fifth Element]

So my '97 sport packaged 540i 6speed doesn't have a 3.15 rear?

[Lscman]

I doubt it.

[sirc1228]

Ok, I decided to go for Koni shocks and Eibach springs. Where can I find a really good deal of both. Please advise!!!

Non-sport offers softer ride with higher ride height. The non-sport shocks have softer damping. The swaybars are smaller than sport. The non-sport is a luxo cruiser setup and not for handling.

As mentioned above, the sport I and sport II front spring rates are similar. The sport II rear spring rate is stiffened slightly to maintain better balance with wider rear rims and tires (stagger). The Sport II cars will understeer less with staggered wheels. Sport I and II have same swaybars, struts and shocks.

If you buy a non-sport car, it's not the end of the world. A set of $400 Eibach swaybars and an $850 set of Koni's and Eibach Pro springs will give you handling better than an M5 or 540i sport. Sport II springs can be substituted for more streetable ride height, if you want to spend a little more cash. The handling will be equivalent.

[sde39]

Ok mr smartypants... (Jk i am glad to have someone here who knows there sh*t)

I have a 97 non sport 2.8 with the Eibach sways and Koni adjustable and the Ground Control coilovers. The tires are Falken Azenis ST-115 http://www.falkentire.com/tires/st115_infopg.htm 245/35/19 front 275/30/19 rear. Rims are Breyton Vison 19x9 f 19x10 r.

I went to Buttonwilow Raceway last week with some interesting results. I know these are rain suited tires but i was desperate to race something! Also i didnt have time to buy a race only set.

Anyway there were many nice cars there such as and m5, m3 smg, 350z, g35, 2 nsx's, and other lowly 4 bangers... All stock except one NSX.

To the point, i was comepletly dominating everycar there except the 1 nsx. On rain tires, and limited racing knowledge, and a 200hp 6!

My question after all this babaling is on the hard turns it would push (understeer) pretty bad unless i finagled the gas to bring out the tail.

I know having a staggered setup creates more understeer but your comment on having a thicker front sway bar that would make it push, was interesting.

I plan on getting the ssr competition 18x9 with a undecided 265/35/18 all around. What tire would you reccommend for the avid autocrosser that i would like to become? Also what offset would be best on those rims?

What tire pressure would help to?

Also is setting the dampening rate on the front konis going to help this problem?

So since i have made no sense of this ill just go now... :

btw i have some in-car videos if anyone wants to host them?