The M3 was not designed for forced induction. Neither were the high-revving, high-compression, VTEC- Honda motors.
However, there are numerous after-market S/C kits for these cars. (and I've owned them). If you keep the boost reasonable (<6lbs), manage the fuel, timing and intake temperatures - then it works.
__________________
06M5 Silver
The Following User Says Thank You to carlsturm For This Useful Post:
Dave, I'd like to see your calculations indicating 700 h.p. with 6.0 psi.
In addition to the math, please include the following:
1.) How are you going to beef up the engine internals, block & head alloys, hollow camshafts, pistons, rods, crankshaft, main bearing caps, pulleys, belts, radiator and other misc parts? Have you found suppliers with these aftermarket parts in stock or will you have them custom manufactured? Approximate cost?
2.) Same question about beefing up the clutch assembly and rear differential? Same question about suppliers with these aftermarket parts in stock or will you have them custom manufactured? Approximate cost?
There is one supplier currently on the board hawking a "competition" clutch, no clutch assembly. They're offering either a 90 or 120 day warranty.
3.) How will you modify the ion analysis system to guarantee it will function properly with a more highly pressurized charge? Or will you just wing it and cross your toes?
4.) What type of cooling systems are you going to use, to cool the intake charge and the blower's heat generation?
5.) Do you have a unencrypted copy of BMW's Operating System, to integrate with the blower and possibly MeOH injection systems?
6.) Have you calculated the the blower's parasitic power drain at high rpm? Is the 700 h.p. you calculated gross or net of the ~100-200 h.p. lost when the S85 revs up into it's power band?
According to Jaguar, their supercharged engine consumes 100 h.p. at max rpm, which is lower than the S85's.
As I asked M V10, if you think you're calculations are accurate and you have all the necessary parts, bolt on their supercharger and please provide quarterly reports. Maybe local drag strip time slips? The board could start a 2nd pool, betting on how long your engine or power train will last.... Poof
Wow.
Ok, general guideline is max power = [(14.7 + boost)/14.7] * base hp. This rule of thumb has provided a pretty good estimate based on the s/c'd cars on the e39 side of the fence. Of course other factors, including headers, tune, throttle bodies, head mods, cooling, etc add additional variables to the estimate.
1 & 2) Remember, I'm not talking about beefing up anything at these lower boost levels. And I'm not doing anything with the tranny... I was looking only at the engine strength. Any major upgrade to the S85's power (turbo or s/c) will face the same questions on the drive train.
3) I have no information on the ion analysis system, but basic anti-knock systems work just fine on supercharged S62s. I would be surprised if the ion analysis system is not similarly robust to some added pressurization (again - same question pertains to a turbo set up).
4) As for cooling - that is for the tuner to work out. Personally, I would prefer an air-water inter (after) cooler. They are wonderfully efficient, as I've seen in my own set up (which includes two IAT sensors for monitoring efficiency and status). Dinan has clearly shown air-air works just fine for lower boost applications. It will be interesting to see how ESS approaches this. For such a low projected cost, it sounds like they will be examining a non-intercooled set up like their e39 set up.
5) MeOH injection is EZ to integrate. The pump is simply activated by boost.
6) The Jaguar uses a Roots-type blower. These blowers are in general less efficient across the rpm band than centrifugal blowers. For Jag (heavy sedan with desire for low end power/torque), roots is a good fit. For the high-winding S85, a centrifugal s/c is a good fit. No boost and free wheeling at lower rpm (minimal power requirement), and exponential boost at higher rpm. Don't look for gobs of torque until you've got the rpms up... similar to the general characteristics of the S85 currently, so you guys should be used to it!
Don't look for gobs of torque until you've got the rpms up... similar to the general characteristics of the S85 currently, so you guys should be used to it!
Dave
That right there will be a turn off for everyone! Including myself
I wouldn't do it because of my own reliability concerns. I see on
the ESS site they do supply a supplementary warranty for an
additional charge (3-4k) but it's only valid for the term of the
original factory warranty. Those of use going out of warranty
soon are forced to fend for ourselves.
I'm not willing to test the limitations of the S85 outside of
any type of warranty. And that goes for any product that could
put extra strain on the +20k engine. That's not to say that things
won't hold up but from my standpoint the reward is not worth the risk.
I'm glad you added the qualifier 'almost' to your post. I'd be heartbroken if you went over to the dark, er E60 sideWe need more FI E39 M5s not fewer.
Ray
Not a chance... we can get all the power we desire from our little 302 eight banger S62, AND we get to have our cake and eat it too (low end torque PLUS high end power...)
Indeed, the world IS a better place w/ more FI M5's--both e39 and, I'll add, e60...
Guys & ladies, if you want to force feed your engines, go ahead and do so. It’s your car and money. I provided the initial ZR1 and S85 comparison as a courtesy for board members considering the force feeding route. I have no products or services to sell, simply a member like you, trying to provide unbiased information for an informed decision.
IMO force feeding increases an engine’s internal wear, if the internal parts aren’t beefed up, it’s only a matter of time before something breaks. Watching a piston or rod exploding through a hood reminds me of a hand grenade exploding. I value reliability and the cost of a replacement S85 engine. If you like to gamble, roll the dice.
Consider the following:
“Alpina’s partnership with BMW is particularly helpful when tweaking hugely complex 7-series electronics to deal with a supercharger. The current B7 is powered by a 325 h.p. 4.4 liter V-8. To handle the 11.6 psi of intercooled boost provided by the centrifugal supercharger, the engine gets lower compression ratio pistons (9.0:1) as well as a stronger crankshaft and connecting rods.
A centrifugal supercharger doesn’t make big boost at low rpm, the initial power surge appears around 2,500 rpm.
In Europe, Alpina offers a full lineup of modified BMW’s in addition to the B7, including 5 and 6 series cars (B5 & B6) with the B7's powertrain. We think the B5 and B6 could find a following here as they have just as much horsepower as the M5 and M6, a bunch more torque (516 pounds-feet verses 383), an easier to live with automatic, a 30% better fuel economy rating and even more performance. In fact, in a test by the British mag Autocar, a B6 outperformed a M6 to 60 mph, to 100 mph and back.”
– July 2007 C&D
IMO our M5s need more torque, not horsepower. If you’re wanting more power at speeds less than roughly 60 mph, torque is more important than h.p. In U.S. everyday driving, the B7 or B5's 516 ft-lb would make our beasts much more responsive than an equivalent amount of additional h.p.
I recently wrote Mike Miller, BMW CCA Roundel Magazine’s Tech Editor, concerning my M5's long term durability and whether shop manuals or additional technical information will become available after the E60 line ceases production.
Mike replied, “You bought the first year production of an extremely complicated and totally electronic BMW... Your service advisor is correct that the clutch wears out quickly in stop-and-go urban driving... However, the warranty has insulated you from paying for first-year-production teething pains and I'm thinking the car will be pretty well sorted out by the time it falls off warranty. That is not to say, though, that it's going to be an inexpensive ownership experience; no BMW is after the warranty, and that's doubly true for M cars.
I don't expect a publicly-available factory BMW shop manual for any model ever again. We are very lucky if we get a Bentley manual at some point, but I really wouldn't expect one to cover the E60 M5. You can access the factory BMW service manuals for a fee at BMW TIS EPA but BMW has almost zero technical service information that is specific to the M engines or the M drivetrain. There are no diagnostics. Technicians are left to figure M engines out by themselves. Even if there were diagnostics, you wouldn't get anywhere without the BMW diagnostic computer.”
It’s been rumored that only Dinan has decrypted the M5's operating system, with cash and confidentiality agreements being exchanged for passwords. If this is true, all the other U.S. tuners are operating without the type of full knowledge and cooperation Alpina utilized when designing the B7.
To poster Kelster, concerning his question, “But then again how do you explain the success of the E39 M5-S3?” The E39 engine is not the E60 engine. As a graduate engineer, why don’t you create a comparison analysis of the two power plants and perhaps answer your own question?
To poster wilsodh about the supercharged E39 engines, the same response. F.Y.I. The E60 M5's ion analysis system is unique to the S85 and the newer M3. It wasn’t used on the E39.
One thread poster quoted Steve Dinan as saying (the new V8) is “exactly the same motor with two cylinders missing. He said the programming and codes are identical. This is why it took them less than 12 months to develop the M3 stroker, instead of over 2 years for the M5 stroker. Everything just transfered over except for a new crank.”ESS supercharger E60 M5
This information is incorrect. Among the differences between the new V8 and V10 are:
1.) Developed especially for the new eight-cylinder, the M double-VANOS now featured on the new engine requires no more than normal engine oil pressure in order to operate at maximum speed. The S85 uses a high pressure system.
2.) Upgraded MSS60 engine control unit for optimum coordination of all engine functions with the various control systems in the car. Taking more than 50 input signals...
3.) Brake Energy Regeneration with intelligent alternator control.
4.) The power curves are different, with about 85% of the engine's maximum torque available throughout the engine speed range of 6,500 rpm, with 340 Newton-metres or 251 lb-ft available from just 2,000 rpm.
5.) The new engine uses a wet sump lubrication. The entire system features two oil sumps - a small one in front of the front axle subframe and a larger sump further back. A separate reflow pump, in turn, extracts oil from the front oil sump and pumps it to the sump at the rear. The S85 uses a more complex dry/wet system.
As BMW leaves a black hole of information on it’s Motorsport cars, most tuners are guessing and using trial and error in producing aftermarket parts. Before leaving your beast and a pile of cash with a tuner, consider the following comments from those in the business:
“There are so many products out there that seem to be just too good to be true and there are too many people out there that are more than willing to take advantage of another’s lack of knowledge. There are also so many out there that are willing to play on peoples emotions, you know, the whole you can have amazing results for practically nothing, and for only minutes a day at no cost to you. We’ve all heard it before.... You might ask yourself, can adding something that small to my vehicle produce as great results as so many people tell me they do? Or will these items really pay for themselves in the form of added fuel economy, and reduced wear and tear on my vehicle? It is these questions about these products that I am going to address, and at the same time educate, because knowledge is power my friends.
If you were to modify a gas engine for performance, you would be required to install a different camshaft, bore out the cylinders to increase displacement, install high compression pistons and heads, increase fuel intake capability by installing a larger carburetor or injection system, adding a turbo charger or supercharger, adding a chip, and enlarging the exhaust system.
If you were to make those changes to a gas engine you would truly have a ground pounding beast, but would lose every day drive ability.”
"But, just because you can buy a Turbo or Supercharger does not mean you should, because most engines require a lot of prep work before being able to utilize any power added. A Turbo or Supercharger adds a lot of strain to an engine, so replacing internal parts of an engine is highly recommended to support the large increase and boost of horsepower. Furthermore, even after a turbo or SC is installed it's important to make sure your car is properly tuned before going WOT(wide open throttle). If you don't take the proper steps, installing a power adder may just blow your OEM engine apart."
"You mention to anyone that you work on superchargers and instantly their first question is; Can I supercharge my car?
Here is the deal. Adding a supercharger to a car without one runs about 3-5K. Yes, $3,000 - $5,000. You are not plugging in something, you have to modify the whole engine.
I get that most people do not understand what a supercharger really is, but at least know that a supercharger engine is completely different than one without it."
Both the current engines are designed to produce horsepower at high RPM, using light weight parts, materials and manufacturing techniques. A 12.0:1 compression ratio is very high for street pump gas. Without the complex electronics, probably would self destruct over time (bent valves, etc.)
All the factory force induction models I’ve posted have been extensively modified for the additional stress.
If you just have to try forced induction, I’d suggest using a 335i-type staggered sized turbocharged system instead of a supercharger. The smaller turbo will provide more torque at low rpm, with the larger unit providing as much additional h.p. as desired.
Either way, IMHO I think you’ll be creating a grenade engine, with unknown durability and life span. If you’re a gambler, roll the dice and keep the board informed.
I've got nothing more to add to this discussion. Good luck.
__________________
When someone with experience proposes a deal to someone with money, too often the fellow with the money ends up with the experience and the fellow with experience ends up with the money.-- Warren Buffett
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The Following 2 Users Say Thank You to Dylan Thomas For This Useful Post:
Guys & ladies, if you want to force feed your engines, go ahead and do so. It’s your car and money. I provided the initial ZR1 and S85 comparison as a courtesy for board members considering the force feeding route. I have no products or services to sell, simply a member like you, trying to provide unbiased information for an informed decision.
IMO force feeding increases an engine’s internal wear, if the internal parts aren’t beefed up, it’s only a matter of time before something breaks. Watching a piston or rod exploding through a hood reminds me of a hand grenade exploding. I value reliability and the cost of a replacement S85 engine. If you like to gamble, roll the dice.
Consider the following:
“Alpina’s partnership with BMW is particularly helpful when tweaking hugely complex 7-series electronics to deal with a supercharger. The current B7 is powered by a 325 h.p. 4.4 liter V-8. To handle the 11.6 psi of intercooled boost provided by the centrifugal supercharger, the engine gets lower compression ratio pistons (9.0:1) as well as a stronger crankshaft and connecting rods.
A centrifugal supercharger doesn’t make big boost at low rpm, the initial power surge appears around 2,500 rpm.
In Europe, Alpina offers a full lineup of modified BMW’s in addition to the B7, including 5 and 6 series cars (B5 & B6) with the B7's powertrain. We think the B5 and B6 could find a following here as they have just as much horsepower as the M5 and M6, a bunch more torque (516 pounds-feet verses 383), an easier to live with automatic, a 30% better fuel economy rating and even more performance. In fact, in a test by the British mag Autocar, a B6 outperformed a M6 to 60 mph, to 100 mph and back.”
– July 2007 C&D
IMO our M5s need more torque, not horsepower. If you’re wanting more power at speeds less than roughly 60 mph, torque is more important than h.p. In U.S. everyday driving, the B7 or B5's 516 ft-lb would make our beasts much more responsive than an equivalent amount of additional h.p.
I recently wrote Mike Miller, BMW CCA Roundel Magazine’s Tech Editor, concerning my M5's long term durability and whether shop manuals or additional technical information will become available after the E60 line ceases production.
Mike replied, “You bought the first year production of an extremely complicated and totally electronic BMW... Your service advisor is correct that the clutch wears out quickly in stop-and-go urban driving... However, the warranty has insulated you from paying for first-year-production teething pains and I'm thinking the car will be pretty well sorted out by the time it falls off warranty. That is not to say, though, that it's going to be an inexpensive ownership experience; no BMW is after the warranty, and that's doubly true for M cars.
I don't expect a publicly-available factory BMW shop manual for any model ever again. We are very lucky if we get a Bentley manual at some point, but I really wouldn't expect one to cover the E60 M5. You can access the factory BMW service manuals for a fee at BMW TIS EPA but BMW has almost zero technical service information that is specific to the M engines or the M drivetrain. There are no diagnostics. Technicians are left to figure M engines out by themselves. Even if there were diagnostics, you wouldn't get anywhere without the BMW diagnostic computer.”
It’s been rumored that only Dinan has decrypted the M5's operating system, with cash and confidentiality agreements being exchanged for passwords. If this is true, all the other U.S. tuners are operating without the type of full knowledge and cooperation Alpina utilized when designing the B7.
To poster Kelster, concerning his question, “But then again how do you explain the success of the E39 M5-S3?” The E39 engine is not the E60 engine. As a graduate engineer, why don’t you create a comparison analysis of the two power plants and perhaps answer your own question?
To poster wilsodh about the supercharged E39 engines, the same response. F.Y.I. The E60 M5's ion analysis system is unique to the S85 and the newer M3. It wasn’t used on the E39.
One thread poster quoted Steve Dinan as saying (the new V8) is “exactly the same motor with two cylinders missing. He said the programming and codes are identical. This is why it took them less than 12 months to develop the M3 stroker, instead of over 2 years for the M5 stroker. Everything just transfered over except for a new crank.”ESS supercharger E60 M5
This information is incorrect. Among the differences between the new V8 and V10 are:
1.) Developed especially for the new eight-cylinder, the M double-VANOS now featured on the new engine requires no more than normal engine oil pressure in order to operate at maximum speed. The S85 uses a high pressure system.
2.) Upgraded MSS60 engine control unit for optimum coordination of all engine functions with the various control systems in the car. Taking more than 50 input signals...
3.) Brake Energy Regeneration with intelligent alternator control.
4.) The power curves are different, with about 85% of the engine's maximum torque available throughout the engine speed range of 6,500 rpm, with 340 Newton-metres or 251 lb-ft available from just 2,000 rpm.
5.) The new engine uses a wet sump lubrication. The entire system features two oil sumps - a small one in front of the front axle subframe and a larger sump further back. A separate reflow pump, in turn, extracts oil from the front oil sump and pumps it to the sump at the rear. The S85 uses a more complex dry/wet system.
As BMW leaves a black hole of information on it’s Motorsport cars, most tuners are guessing and using trial and error in producing aftermarket parts. Before leaving your beast and a pile of cash with a tuner, consider the following comments from those in the business:
“There are so many products out there that seem to be just too good to be true and there are too many people out there that are more than willing to take advantage of another’s lack of knowledge. There are also so many out there that are willing to play on peoples emotions, you know, the whole you can have amazing results for practically nothing, and for only minutes a day at no cost to you. We’ve all heard it before.... You might ask yourself, can adding something that small to my vehicle produce as great results as so many people tell me they do? Or will these items really pay for themselves in the form of added fuel economy, and reduced wear and tear on my vehicle? It is these questions about these products that I am going to address, and at the same time educate, because knowledge is power my friends.
If you were to modify a gas engine for performance, you would be required to install a different camshaft, bore out the cylinders to increase displacement, install high compression pistons and heads, increase fuel intake capability by installing a larger carburetor or injection system, adding a turbo charger or supercharger, adding a chip, and enlarging the exhaust system.
If you were to make those changes to a gas engine you would truly have a ground pounding beast, but would lose every day drive ability.”
"But, just because you can buy a Turbo or Supercharger does not mean you should, because most engines require a lot of prep work before being able to utilize any power added. A Turbo or Supercharger adds a lot of strain to an engine, so replacing internal parts of an engine is highly recommended to support the large increase and boost of horsepower. Furthermore, even after a turbo or SC is installed it's important to make sure your car is properly tuned before going WOT(wide open throttle). If you don't take the proper steps, installing a power adder may just blow your OEM engine apart."
"You mention to anyone that you work on superchargers and instantly their first question is; Can I supercharge my car?
Here is the deal. Adding a supercharger to a car without one runs about 3-5K. Yes, $3,000 - $5,000. You are not plugging in something, you have to modify the whole engine.
I get that most people do not understand what a supercharger really is, but at least know that a supercharger engine is completely different than one without it."
Both the current engines are designed to produce horsepower at high RPM, using light weight parts, materials and manufacturing techniques. A 12.0:1 compression ratio is very high for street pump gas. Without the complex electronics, probably would self destruct over time (bent valves, etc.)
All the factory force induction models I’ve posted have been extensively modified for the additional stress.
If you just have to try forced induction, I’d suggest using a 335i-type staggered sized turbocharged system instead of a supercharger. The smaller turbo will provide more torque at low rpm, with the larger unit providing as much additional h.p. as desired.
Either way, IMHO I think you’ll be creating a grenade engine, with unknown durability and life span. If you’re a gambler, roll the dice and keep the board informed.
I've got nothing more to add to this discussion. Good luck.
You've provided a full range of information Dylan, which is nice for general info and reference. I appreciate the time it takes to gather this information, make links, etc. I'm sure it is helpful to a number of board members contemplating the FI option, minimally from the standpoint of giving a conservative position on the subject.
The specific question that I think is on the table is, "Is it viable to moderately pressurize the S85 with stock internals?" And, I think you might also add, "..reliably and without compromise to engine life?"
These were the same questions asked years ago when pioneers like Black M5 were pursuing s/c'g the S62. Many felt the S62 couldn't hold up to the strain. Many felt longevity and reliability would surely be compromised ("The engine was designed for 400 hp, NOT 600+ HP!!!") We now know that a properly set up s/c'd S62 works just fine, lasts a long time, doesn't blow up, and generally provides a high degree of satisfaction to many owners. Even extreme set ups such as the D/A twins (mine having been built by Black M5) have given years of service with no signs of engine degradation, loss of power, or wear down.
We should keep in mind there are two general categories: lower boost and higher boost. The point I attempted to make earlier was that it wouldn't take 11.5 psi to achieve 700 hp in the S85. It would probably only take about half that. That does make a difference in the discussion, as the examples you have cited are higher-boost set ups. I've always maintained that when you start approaching double-digit boost, you should be thinking about strengthening engine internals. We DO have some data points of what happens when you don't. But we also have many many data points on ruggedness and reliability with lower boost set ups and stock engines.
Among the information you've generously provided, I've not seen any specific information that tells me that the S85 can't also be reliably pressurized at lower levels. We can argue that high rpm service will always ultimately result in increased wear and tear... it is the nature of mechanical challenges and limitations of lubricating key engine areas during high rpm operation (eg., rod bearings). In the end, if you constantly pound your engine at high rpm, you can probably expect some compromise in engine life whether or not the engine is pressurized. But the basic mechanicals of rods, bearings, crank, pistons, will be robust enough for moderate boost; they are already designed for high output service. It will be engine speed more so than a moderate increase in cylinder pressure that will produce the greatest strain.
As I indicated previously, my only misgiving about moderately pressurizing the stock S85 is the already high compression. At a minimum, I'd want a MeOH injection system in place, along with an on-board monitoring LED telling me that the system is working properly. Alcohol/water injection systems are pretty low cost, so I could see this being easily integrated into an ESS s/c set up with an economical price target.
To reiterate, I agree with the concerns you expressed about strengthening the engine... at higher boost levels. This is the territory that Ranger and a few other pioneers will be exploring (ASR 'twins' and the high-boost TT M6 under construction in LA that I know of).
Oh, and to throw out a bunch of information and then say "I'm done with this discussion.." Dude...
As I've already stated, this is an awesome discussion.
Now since myself and M5 Junky are pioneers in the engine build endeavor this subject matter is of much intregue.
I am NOT Abid from ASR nor am I even 0.5% of his knowledge and capability. I have discussed the capability of this project with Abid at length. With a fully built engine as is being done with a 10:1 compression what is to be expected?
I ask, what about the HPF E46 M3 engines? This tuner has been producing turbo charged engines at several levels of power.
This question is not related to the engine durability (which it has shown dependability) but to the tranny (SMG II), drivetrain and axles. These cars are making 600 plus rwhp with stock internals, the older SMG II, and stock diff and axles.
They are running strong and no general issues in breakdown.
The HPF Stage III (or whatever) making 900 plus rwhp E46 M3 still has the SMG II tranny?
The ASR build includes a clutch design to match the power.
Dylan Thomas your posts are extremely informative, valueable and detailed. I read every word and I thank you for your in put.
This further drives me to research my M5's ASR engine project. I will tell you that I have 100% confidence in ASR Engineering to develop this engine build project. There has been extensive fabrication required for this reality. There are some real cool components coming.
It would be good and interesting if you could have a discussion with Abid at ASR (engineer to engineer).
An E60 M5 TT V10 making 750 rwhp comfortably sounds good to me. I would thrilled with such power.
Again ASR is crossing new thresholds here but with a fully built engine I believe ASR will succeed. I have TOTAL confidence in Abid my personal friend who has studied this for a long time and will NOT let me down nor the BMW community.
Gentlemen I hold steadfast to this project with solid confidence.
Some of you may wonder about the time involved but Dinan took over 2 years to develop the stroker engine (a great product). So several months to create what has never been successfully done before is not to bad. Trust me the wait is killing me. I truly miss my M5. I love this car.
During the break in period I will have the body work re-done.
Good things are coming my friends,
Ranger
__________________ 2006 M5 Alpine White/Silverstone Upgrades: Engine: SS headers, Evosport power pulley, ASR ECU remap,
ASR custom air intakes, Dinan throttle bodies, ASR Engineering NOS kit Exhaust: ASR Engineering Gen. II exhaust. Suspension: H & R sport spings,Dinan front/rear CF strut braces. Wheels: HRE P40 w/ 275/30/20 and 305/25/20. Exterior: Vorsteiner CF vented hood, Vorsteiner CF front spoiler,
ACS rear deck lid spoiler, front kidney grill & side gills in CF. Brakes: Brembo GT kit, (F) 6 piston monobloc calipers w/ 16"
rotors & (R) 4 piston monbloc calipers w/ 15" rotors. Interior: ACS titanium CF trim. Dyno results straight motor 460 rwhp, on nitrous 581 rwhp/461 lb/ft rw torque.
ASR TT S85 FULL ENGINE BUILD COMING
2007 GT3RS ORANGE / BLACK 2006 M5 BLACK / BLACK 2010 GT3RS DEPOSIT IN FOR AN ALLOCATION
Dave, like most folks, I work for a living, and with current economic conditions, I’m working long hours and burning the candle at both ends. I see the M5board as a gathering of auto enthusiasts, sharing their passions, knowledge and occasional off-color jokes. Although I enjoy the flow of ideas and info, there are only so many hours in a day and unfortunately work and private life rank above additional detailed posts.
I spent serious time and effort on these posts, for you to say “Oh, and to throw out a bunch of information and then say "I'm done with this discussion.." Dude...”, well, I expect a more congenial response than that. You’re a smart guy, you (and others) can do your own digging for knowledge, instead of expecting answers delivered on a silver platter.
Nonetheless, in the spirit of comradery, I’d like to respond a few of your questions.
You asked, is it viable to moderately pressurize the S85 with stock internals, without compromising reliability and engine life?
Last year the local performance oriented BMW dealership in my area, offered a reasonably priced chassis dyno day, for all makes and models. The dealership competes in organized racing series, running two cars. During the event I talked with one of their competition car mechanics. I asked him about S85 forced induction and he replied that any increased pressure would shorten engine life and lowering the compression ratio would be all but mandatory. The engine simply isn’t designed for it. He added pistons and the other parts he would advise replacing would all have to be custom made and very expensive. The current Motorsport cars are made in such small numbers, they are considered boutique vehicles and not worth the development cost for most aftermarket part’s manufacturers. A Pagid rep also used the boutique car term and made similar comments at a DE.
You also ask about any specific information that indicates whether the S85 can or can't be reliably pressurized at lower levels, as the S62.
I haven’t found any information about pressurizing the S85. As Mike Miller, Roundel's Tech Editor told me, the E60 M5 is “the first year production of an extremely complicated and totally electronic BMW... BMW has almost zero technical service information that is specific to the M engines or the M drivetrain. There are no diagnostics. Technicians are left to figure M engines out by themselves. Even if there were diagnostics, you wouldn't get anywhere without the BMW diagnostic computer."
When I took my M5 in for the first clutch rebuild, the dealership techs really had no idea of what was causing the problem. No fault codes were stored in the computer and the car initially was fine in test drives. Finally their best tech, a very experienced, Dinan certified mechanic in the true sense of the word, experienced the problem and was stumped. They submitted a PUMA and got nowhere. BMW NA & AG provided no assistance of any kind.
Using back channels, my dealership acquired warranty authorization to pull the transmission and start looking for the problem. The clutch disc and assembly parts were broken and worn out at ~10.5K miles! These assemblies are not monitored by the car’s electronics. I’ve previously gotten 50-80K from clutches, the BMW parts simply were not strong enough for city driving. My S.A. eventually admitted the metal alloys are substandard for the task and to expect more repairs. He was right, a 2nd rebuild ~5K miles later. We learned BMW knew there was a problem, but were not telling their dealerships! No tech bulletins, no nothing.
Lack of information is a major problem when contemplating aftermarket modifications. Unlike earlier models, the E60 M5 is a black hole. I’ve gotten the impression BMW sells the cars as halo vehicles, and expects most to be driven until they break and sent to the crusher. IMO they apparently do not want these cars to remain on the road and become classics like earlier models. If I was contemplating buying a M5 for long term ownership, I’d buy an E39, the last traditionally designed and non-over-computerized model.
While the E39's basic mechanicals, rods, bearings, crank, pistons, will be robust enough for moderate boost, I suspect the E60's are not. The S85 impresses me more like a thoroughbred horse, fast and fragile, durability was not in the breeding program. IMHO the E39 is a better (stronger) built car.
Auto makers are currently selling direct-injection-engines with 12.5:1 compression. A 12.0:1 ratio in a traditional engine is very high. A M5board thread on octane concluded 95 RON Octane rating - Wikipedia, the free encyclopedia is optimum for the S85, which means the engine management system is ******ing the spark or some other type of high tech method to prevent pinging with the usual 93 or 91 available in the U.S.
I have no idea how the ion analysis system would interpret a 6 psi boosted system. It might simply further ****** the spark and power or who knows? You may need to use higher octane gas.
Logically a 6 psi system will tax the engine less than 10+ psi. All you can do is bolt the system on and see what happens.
In the May ‘09 Rondel issue there is an article on an AA supercharged E90 M3, using a pre-production unit from a Nissan 350Z. It has both an air-to-air and oil-circulation system. The software was modified, stock fuel injectors and air box replaced, along with high-flow cats and exhaust. Nothing from the throttle bodies down into the engine was touched, and the system ran at 3-6 bar fuel pressure.
You might contact them for more info. Ask them about warranty coverage too.
We need more FI E39 M5s not fewer.
2006 M5 Alpine White/Silverstone
DEPOSIT IN FOR AN ALLOCATION
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