ATI Harmonic Crank Balancer - Want to safely rev your S52 to 8k?

[jvit27]

when the limitations of this balancer have been reached, it then becomes a question of what it takes to move forward beyond that point. that may be the time where it becomes increasingly difficult and unrealistic compared to other options, but until we get there we won't know...

If you are so adamant that this mod is the godsend you think it is, why haven't you done it already?

Fact is the engine cannot flow the amount of air it needs to make power efficiently at those RPM's. You'd need some serious headwork, and at some point past the $10,000 mark you will have a motor that isn't an S54 but pretends to be one for its owner. As it is, these motors are making almost 100hp/liter with all the bolt ons; that's 20% higher than what it was designed to make almost two decades ago while still maintaining good reliability. I'd say it's pretty impressive you can come within ~15hp of a Euro motor (which has alot more going for it) without completely ruining the driveability...

There is no magic - you're expectations are just too high, so please accept that you'll never make S54 power with an S52. Cruising around at 7000rpm all day simply isn't realistic.

[jworms]

If you are so adamant that this mod is the godsend you think it is, why haven't you done it already?

i haven't done it because unfortunately, i have many other things that take priority in my life right now and this isn't one of them. that doesn't mean i won't do this in the future and certainly doesn't mean i won't put the information out there for others to try.

Fact is the engine cannot flow the amount of air it needs to make power efficiently at those RPM's. You'd need some serious headwork, and at some point past the $10,000 mark you will have a motor that isn't an S54 but pretends to be one for its owner. As it is, these motors are making almost 100hp/liter with all the bolt ons; that's 20% higher than what it was designed to make almost two decades ago while still maintaining good reliability. I'd say it's pretty impressive you can come within ~15hp of a Euro motor (which has alot more going for it) without completely ruining the driveability...

the fact is that even if the engine proves to have breathing problems at 7500RPM+, there are many other benefits to revving higher than just power and let's not forget FI applications. it's time to think outside the box.

for the record, i've never seen any factual data to show it won't breathe enough at 7500RPM, though i'd love to see it if you have it.

There is no magic - you're expectations are just too high, so please accept that you'll never make S54 power with an S52. Cruising around at 7000rpm all day simply isn't realistic.

there is no need to make S54 power from an S52. as for a stock S54, the S52 can already do that without revving higher than 7000RPM. i'm not sure why people are stuck on the S54 vs S52 comparison. using that kind of logic stagnates the playing field for all "lesser" engines.

[Mad Dog 20/20]

let's not forget FI applications.

You keep mentioning "FI".
Seriously, what are you talking about?

I already showed earlier in the other thread how there is zero net benefit to revving an SC'ed S52 past 7k (there is actually a significant loss of power under the curve). http://forums.bimmerforums.com/forum...&postcount=110

So lets talk turbo's. Have you seen the power/trq curves of 95% of turbo S52's? The trq begins to fall off by 5k rpm and the power is flat by 6k rpm. http://forums.bimmerforums.com/forum...80&postcount=1

The only FI S52 app that would benefit is the 750whp+ monster turbo set-up that has "weak" (compared to peak) power below 5k rpm. This is a truly miniscule number of cars.

[KnudsonsM3]

there is no need to make S54 power from an S52. as for a stock S54, the S52 can already do that without revving higher than 7000RPM. i'm not sure why people are stuck on the S54 vs S52 comparison. using that kind of logic stagnates the playing field for all "lesser" engines.

Well you made a thread about 8k plus revving in an s52. From reading this thread it seems one will need about 10k plus do do it correctly. So with that cash why not get an s54?

[gk325is]

You keep mentioning "FI".
Seriously, what are you talking about?

I already showed earlier in the other thread how there is zero net benefit to revving an SC'ed S52 past 7k (there is actually a significant loss of power under the curve). http://forums.bimmerforums.com/forum...&postcount=110

So lets talk turbo's. Have you seen the power/trq curves of 95% of turbo S52's? The trq begins to fall off by 5k rpm and the power is flat by 6k rpm. http://forums.bimmerforums.com/forum...80&postcount=1

The only FI S52 app that would benefit is the 750whp+ monster turbo set-up that has "weak" (compared to peak) power below 5k rpm. This is a truly miniscule number of cars.

Really no ones knows until it is tried and proven either way. In theory reving higher and maintaining tq will increase power that is why jworm and I are so interested.

I am really wanting something different then the norm and am willing to spend to get their, if you love the set up you have then love it and let others do as they will. None of us will ever have the fastest car in the world unless you go buy a veryon so i say really performance isn't everything.

Save your negative comments for if we fail or until you can prove us wrong.

I think we just need to all meet up and hunt down some jerks in intergras and take out our anger on them.

[Mad Dog 20/20]

Save your negative comments for if we fail or until you can prove us wrong.

They are not negative comments.

They are facts.

If you are serioous about this endeavor, you should want the facts, not pie in the sky "rah-rah" talk devoid of any factual predicate.

[Kenshiro]

8K is pie in the sky.

Alpina did, however, make an S52 variant with 3.4L and 305hp with a 7200rpm redline that you can, in fact, cruise around at all day - full BMW warranty and everything.

It's not that higher revs are impossible, it's just that the returns on investment are vanishingly small.

[jworms]

You keep mentioning "FI".
Seriously, what are you talking about?

I already showed earlier in the other thread how there is zero net benefit to revving an SC'ed S52 past 7k (there is actually a significant loss of power under the curve). http://forums.bimmerforums.com/forum...&postcount=110

so, just so we're on the same page...according to that dyno, you're saying there are benefits to revving higher with an s/c kit?

let me lay some groundwork out so i can better understand this. i'm no expert, so this may not be right. feel free to correct me where needed:

assuming the efficiency of two blowers are the same and one has the ability to rev to 7k RPM while the other can rev to 8k RPM with the same boost (12psi) which is the max amount of boost allowed for this hypothetical engine.
12psi at 7k rpm is defined as a certain amount of torque produced.
12psi on that same setup at 8k rpm is defined as the same amount of torque produced...but at 8k RPM.

torque is not defined by RPM. horsepower is, so...an example:
let's assume this 12psi generates 300rwtq
300rwtq at 7000RPM = 400rwhp
300rwtq at 8000RPM = 456rwhp

So lets talk turbo's. Have you seen the power/trq curves of 95% of turbo S52's? The trq begins to fall off by 5k rpm and the power is flat by 6k rpm. http://forums.bimmerforums.com/forum...80&postcount=1

The only FI S52 app that would benefit is the 750whp+ monster turbo set-up that has "weak" (compared to peak) power below 5k rpm. This is a truly miniscule number of cars.

looking at that dyno, it looks like power is still building all the way to 6700RPM or so. i can only guess, but i would think that if there was an extra 500RPM for that car to use, the car would be faster as each shift would drop it into the meat of the powerband more than shifting at 7k would.

we can play the dyno chart game all day. look through this thread ( http://forums.bimmerforums.com/forum...d.php?t=271293 ) and see how many could benefit from an extra 500+RPM. there are quite a few just on the first page.

let's also consider the tuning that goes into these setups. they are meant to work within the current RPM restrictions for the S52. i'd be willing to bet that there's a bit of wiggle room to make more power in higher RPMs with just tuning adjustments.

Well you made a thread about 8k plus revving in an s52. From reading this thread it seems one will need about 10k plus do do it correctly. So with that cash why not get an s54?

on the contrary. this thread shows that it might only require around $500 to rev to 7500+RPM. the thread is about how the ATI harmonic balancer has been shown to alleviate some of the block limitations notoriously associated with revving these engines higher.

[gk325is]

They are not negative comments.

They are facts.

If you are serioous about this endeavor, you should want the facts, not pie in the sky "rah-rah" talk devoid of any factual predicate.

Well my attempt at peace was rejected.

[GotBHP?]

Really no ones knows until it is tried and proven either way. In theory reving higher and maintaining tq will increase power that is why jworm and I are so interested.

Save your negative comments for if we fail or until you can prove us wrong.

I think we just need to all meet up and hunt down some jerks in intergras and take out our anger on them.

No, it is up to *you* to prove everyone else wrong, and that the numerous failed attempts over the past 15 years were just anomalies. Don't be one of the people that starts these threads in an attempt to feel like he is different, or just to thrive off of the me-against-the-world B.S.

Go BUY this damper, go BUILD your engine. Until then, stop telling people they are wrong when clearly all information suggests otherwise. Best case scenario: you have a high revving S5X. It might make 75-100 less whp than an S54 with bolt-ons, but hey you can come back and shove it in everyone's face. Worst case scenario: You spend a lot of money, and end up with a big and heavy paper weight. At least you stimulated the economy in the process, and I would commend you for that.

[jworms]

No, it is up to *you* to prove everyone else wrong, and that the numerous failed attempts over the past 15 years were just anomalies. Don't be one of the people that starts these threads in an attempt to feel like he is different, or just to thrive off of the me-against-the-world B.S.

Go BUY this damper, go BUILD your engine. Until then, stop telling people they are wrong when clearly all information suggests otherwise. Best case scenario: you have a high revving S5X. It might make 75-100 less whp than an S54 with bolt-ons, but hey you can come back and shove it in everyone's face. Worst case scenario: You spend a lot of money, and end up with a big and heavy paper weight. At least you stimulated the economy in the process, and I would commend you for that.

unless i'm mistaken, there have been ZERO "numerous attempts" to rev higher with an upgraded harmonics balancer and the evidence thus far points to it actually working. if you know about a failed attempt with a setup like this then please share.

[GotBHP?]

unless i'm mistaken, there have been ZERO "numerous attempts" to rev higher with an upgraded harmonics balancer and the evidence thus far points to it actually working. if you know about a failed attempt with a setup like this then please share.

Was referring to the attempts to achieve the holy grail of reliable 8000 rpm S52s, which comes up in a thread about 1-2 times a month. This damper may or may not help. Seeing as how I have seen no proof that ATI did any modeling of the particular crank in question here, not sure how a generic damper is going to do any good.

Put the money up to buy, install (needs some special tool), and test this damper. Otherwise it is just talk...and quite boring and redundant at this point.

[jworms]

Was referring to the attempts to achieve the holy grail of reliable 8000 rpm S52s, which comes up in a thread about 1-2 times a month. This damper may or may not help. Seeing as how I have seen no proof that ATI did any modeling of the particular crank in question here, not sure how a generic damper is going to do any good.

Put the money up to buy, install (needs some special tool), and test this damper. Otherwise it is just talk...and quite boring and redundant at this point.

if you are interested in the process of how the damper was built/architected i highly encourage talking to PEI330CI. i can assure you that the most detailed information was likely used in the production of this damper. unfortunately, a lot of the details on the specs are not available out of courtesy to the people who gathered them -- but they were gathered.

yes, this is just talk. that's how these things start. it's an idea that could be tested if somebody chooses to do so. this thread was partially made to satisfy the constant yearning for people who make similar threads wanting to rev to 8000RPM or whatever RPM higher than 7200RPM. at least with this thread there is a path to take if one chooses to do so.

[Poppa Boner]

You are not going to "SAFELY" rev to anything with JUST a harmonic balancer. FACT.

You need a better understanding of air/fuel ratios, valve-train theory, and a more thorough knowledge of head; ports, compression, valves, retainers, springs, etc...

You just need to take your head off and cam/port/valve work it soz your valves can achieve a higher RPM without floating, and then be able to feed that opened up and reinforced head. (standalone, or piggy). This is truth.

Your posts clearly show that you do not understand that the valves, and Fuel injection are a crucial part of "safely" or "efficiently" making the power above a certain point. This balancer is cool and all, and may make some difference, but you must be clear that there will be TONS of other modifications to "safely" rev to 8K. Head, block, Crank, bearings, Journals, Pistons, Fuel Management, Tuning to be efficient in said RPM band, exhaust, fuel sending.. yadda yadda yadda.

I am not skeptical that this balancer balances, but I am skeptical that a misunderstanding about the mechanics of your engine will eventually render it usless with this kind of thinking and persistence.

[jworms]

You are not going to "SAFELY" rev to anything with JUST a harmonic balancer. FACT.

You need a better understanding of air/fuel ratios, valve-train theory, and a more thorough knowledge of head; ports, compression, valves, retainers, springs, etc...

You just need to take your head off and cam/port/valve work it soz your valves can achieve a higher RPM without floating, and then be able to feed that opened up and reinforced head. (standalone, or piggy). This is truth.

Your posts clearly show that you do not understand that the valves, and Fuel injection are a crucial part of "safely" or "efficiently" making the power above a certain point. This balancer is cool and all, and may make some difference, but you must be clear that there will be TONS of other modifications to "safely" rev to 8K. Head, block, Crank, bearings, Journals, Pistons, Fuel Management, Tuning to be efficient in said RPM band, exhaust, fuel sending.. yadda yadda yadda.

I am not skeptical that this balancer balances, but I am skeptical that a misunderstanding about the mechanics of your engine will eventually render it usless with this kind of thinking and persistence.

that's been discussed in this thread. at first 7500RPM would probably be the goal. anything higher than that would definitely require valve springs at the minimum as suggested by many sources. an 8000RPM build might require a bit of money, but a 7500RPM build might not with this damper. again, the damper is just one part of this and is only there to satisfy a condition that was previously a show stopper.

keep in mind, many have revved (and continued to rev) to 7400RPM with the sunbelt kit with good results except for the block sometimes shaking itself apart due to harmonics.

[Poppa Boner]

that is because it is just revving at that point.
You must look at a dyno chart and see that there
just is NO reason to rev to 8K. In fact, you don't even
need to rev to 7K in an S52 M3. I have a stock intake and
I shift early as opposed to late. Stay in the power. Power falls
off after 6500 ish, so why keep ringing it out? Unnecessary. Redundant.


See at 6K where the HP line tops out, and is just level all the way across 6k-7K, that is still in the throttle BTW.
The natural power curve will NOT benefit from higher revving. You need to completely re-build and tune your engine for your balancer to do anything. Try shifting at 6000 or 6500 and see if your times improve. I bet they will

[jworms]

that is because it is just revving at that point.
You must look at a dyno chart and see that there
just is NO reason to rev to 8K. In fact, you don't even
need to rev to 7K in an S52 M3. I have a stock intake and
I shift early as opposed to late. Stay in the power. Power falls
off after 6500 ish, so why keep ringing it out? Unnecessary. Redundant.

on a relatively stock car with stock intake manifold? sure.
on a car modified to work in that rev range it's a whole different story.
there are reasons why the club racers revved to 7400RPM with sunbelts.

and again, making more power is only part of the reason for wanting the ability to rev higher.

[Poppa Boner]

No.

[jworms]

No.

yes.

using my dyno chart is a poor example. i don't have many high RPM mods (lack of headers, cams, and other intake/exhaust components). in my last reply i only made mention of the stock intake manifold in reference to short shifting with a 7k redline (not optimal with the m50 intake manifold).

here's a fun example:
http://forums.bimmerforums.com/forum...41&postcount=1

you don't think a 7500RPM redline would benefit that car?

figure, on average, each shift will drop around 1000RPM, but to better gauge what RPM you'll be at after a shift, you can use the gearing spreadsheet at diffsonline.com ...which reminds me...you can use more aggressive gearing with a higher redline. that would definitely be beneficial and won't show on a dyno chart. anyway, continuing with this example...

here's a great thread on figuring out the optimal shift point based on torque:
http://www.e90post.com/forums/showthread.php?t=433394

i'm not going to bother calculating it all out again, but if you're interested, feel free to do so and report your findings.


there's also this:

I've run both the schricks and the sunbelts in my IP car and I can state first hand that they do pull right to redline (mine was 7400). My schricks would fall off right after 7k. Thats with my but dyno, also the true judge of performance are laptimes, which also dropped.

source: http://forums.bimmerforums.com/forum...20#post5790220

there are more examples i found, but i'm not going to post them all. the benefits of revving higher are there. the facts are all a search away.

[gk325is]

No, it is up to *you* to prove everyone else wrong, and that the numerous failed attempts over the past 15 years were just anomalies. Don't be one of the people that starts these threads in an attempt to feel like he is different, or just to thrive off of the me-against-the-world B.S.

Go BUY this damper, go BUILD your engine. Until then, stop telling people they are wrong when clearly all information suggests otherwise. Best case scenario: you have a high revving S5X. It might make 75-100 less whp than an S54 with bolt-ons, but hey you can come back and shove it in everyone's face. Worst case scenario: You spend a lot of money, and end up with a big and heavy paper weight. At least you stimulated the economy in the process, and I would commend you for that.

Ok I am. I just purchased a used oem dampener from fleebay and just got off the phone with ATI. I am going to send them the dampener once it arrives. The only measurement they need from me is the diameter of the crank on the s52 to the .xxxx. This might be hard because I don't really want to disassemble my motor haha.

So anyone who would like to help, do you think that one s52 crank will very more then a .xxxx of an inch from another? If not can anyone supply me with these measurements (three different diameter measurements down to the .xxxx mark)?

I will put my money where my mouth is on this one. I will first try just cams and valve springs to go with this and see if the head will flow enough, then go from there.

[GotBHP?]

Ok I am. I just purchased a used oem dampener from fleebay and just got off the phone with ATI. I am going to send them the dampener once it arrives. The only measurement they need from me is the diameter of the crank on the s52 to the .xxxx. This might be hard because I don't really want to disassemble my motor haha.

So anyone who would like to help, do you think that one s52 crank will very more then a .xxxx of an inch from another? If not can anyone supply me with these measurements (three different diameter measurements down to the .xxxx mark)?

I will put my money where my mouth is on this one. I will first try just cams and valve springs to go with this and see if the head will flow enough, then go from there.

See this is what bothers me about this product. They are only requiring the crank diameter so that the pulley fits? No CAD model of the crank to use with ANSYS (or similar) to do a harmonics/vibrations study? Sure you can estimate things by the overall length of the crankshaft and how fast you want it to spin, but....

[gk325is]

See this is what bothers me about this product. They are only requiring the crank diameter so that the pulley fits? No CAD model of the crank to use with ANSYS (or similar) to do a harmonics/vibrations study? Sure you can estimate things by the overall length of the crankshaft and how fast you want it to spin, but....

ATI told me that they use a lot of the measurements from the stock unit to get details such as this but really it is all over my head.

[Mad Dog 20/20]

so, just so we're on the same page...according to that dyno, you're saying there are benefits to revving higher with an s/c kit?

No I'm not.
The graph speaks for itself. I have shaded the area in green criss-coss to depict the advantage of a 7k redline. The TINY little spec of blue is the extent of the "advantage" w/ an 8k redline. In the real world, the 8k redline car would get torched by the 7k redline car. Is this the type of "gain" w/ a higher redline that you are looking for and celebrating so wildly?

let me lay some groundwork out so i can better understand this. i'm no expert, so this may not be right. feel free to correct me where needed:

assuming the efficiency of two blowers are the same and one has the ability to rev to 7k RPM while the other can rev to 8k RPM with the same boost (12psi) which is the max amount of boost allowed for this hypothetical engine.
12psi at 7k rpm is defined as a certain amount of torque produced.
12psi on that same setup at 8k rpm is defined as the same amount of torque produced...but at 8k RPM.

torque is not defined by RPM. horsepower is, so...an example:
let's assume this 12psi generates 300rwtq
300rwtq at 7000RPM = 400rwhp
300rwtq at 8000RPM = 456rwhp

No. Unfortuantely, that is not how SC's work. The power curves are always totally linear (assuming things are working optimally) - not exponential.

No, the amount of trq produced at 8k rpm would not be the same as that produced at 7k rpm. SC S52's do not have a 7k rpm trq. peak - trq is falling off past 5.5 k rpm or so and continues to fall all the way to redline. Revving the car further would see a continued drop in trq.

looking at that [turbo] dyno, it looks like power is still building all the way to 6700RPM or so. i can only guess, but i would think that if there was an extra 500RPM for that car to use, the car would be faster as each shift would drop it into the meat of the powerband more than shifting at 7k would.

The power is "building"? The power curve is essentially flat as a board and then drops-off before well before redline. Rev it higher and power and trq. only continue to drop like a rock.

The "meat of the powerband" argument fails as well. Because of the turbo's low trq peak, it would not benefit from shifting at a higher rpm.

we can play the dyno chart game all day. look through this thread ( http://forums.bimmerforums.com/forum...d.php?t=271293 ) and see how many could benefit from an extra 500+RPM. there are quite a few just on the first page.

Please identify/post a turbo dyno where power/trq. are continuing to climb at redline - I don't see any in your link, and have never seen any.

i'd be willing to bet that there's a bit of wiggle room to make more power in higher RPMs with just tuning adjustments.

Why would you bet this? These turbo vehicles are tuned by the best tuners in the industry (NickG, TRM, Conforti, Karl @ AA). Why would they leave power on the table?

What you've posted confirms exactly what I and others have been saying. You are celebrating alleged potential gains that have no basis in fact, whatsoever.

[Kenshiro]

Can we please stop talking about this now? Seriously, we're well past put up or shut up time. The proponents are and positing that such a thing is in the realm of possibility - which maybe it is. Convincing someone who holds an almost religious belief in something that it's impossible is a losing game.

Pro: It's possible
Con: Maybe, but a, b, c, x, y, z evidence speaks against it
Pro: But that doesn't completely preclude it, it's still possible
Con: No, d, e, f, u, v, w evidence also speaks against it
Pro: But even that doesn't completely preclude it, it's still possible

Let the dreamers dream. The whole thing is like the beginnings of FedEx - the founder proposed it in business school and all his professors said overnight shipping was impossible and there was no market for it. Then he put up the money and shut them all up. So maybe this is possible, but until someone's willing to put up the funds for it, it's essentially masturbatory bench racing. But if it makes a couple of people who are unwilling to risk their own funds to think of a high revving S52 with their hands down their pants, do you really want to walk in on that?

[Poppa Boner]

and, regardless how much you paint the picture, Logic, explain it, and reason with the OP, he will still come back with some defense that his quest for an 8K S52 still lives on.

Go for it dewd, please! Stop yappin and pull the pin on your S52 grenade already. Please film your research? THanks.