Why the BSD saves our Motors
 

So what is the theory of why our BS is causing our car to sneeze rods? And at what whp should it be deleted?

If there is a relevant thread, please link. I didn't have much luck using the search feature.

search for BSD works... You have to read the threads... not just the titles.
http://www.mazdaspeedforums.org/foru...earchid=530886

tizi went 8 months with 347whp, reworked stock turbo and meth. he did the bsd, and blew 2 days later. just fyi....

Thank you, now everyone can stop thinking the BSD saves motors.

...which suggests the issue was there before the BSD was done, and it was probably too late for the engine regardless of what he did. Doing the BSD won't save your engine magically if its about to pop. Nor will doing the BSD properly cause your engine to pop.

If you don't want to do it, then don't. No one will care. The BS is a useless piece of metal either way though, and you get more oil for your engine when you take it out. That's why it's worth it to me. Not because it will make my engine bullet proof and let me increase the rev limiter to over 9000.

I was thinking of doing this, spoke to a friend just a few days ago about it bc I just wasn't sure, never done that before never had too,and he stated a good point, by the deleting the BS your throwing your crank of balance, not 100% sure but he made sense and pushed me away from doing it.

No you're not. The crank shaft is not balanced with the BS on it. If it were, and you took off a 15lb weight, at 6000RPM you'd have so much unbalanced force in your engine bay your engine would leave. How people can spout such blatantly incorrect "information" is beyond me (and I'm not blaming you here, but your friend, and many people like him). We literally just had the same discussion on 6club, so this isn't an isolated case of misinformation on the topic either.

No... unfortunately, the SINGLE scenario does not suggest anything at all. It is what it is. Until someone can prove that the BSD does anything to save a motor, it's all a guess.

If it helps you (general "you".... not just YOU, Ed ;) ) sleep better at night and that's your reason to do the BSD, then go for it.

I'm sick of hearing BSD this, meth that.... nobody outside of Mazda knows or has released that information.

All I was saying was the way randy posted that made it seem like he wanted to infer that BSD supporters claimed doing the BSD at any time in the engine's lifetime would revert it back to 100% health and ability to run 25psi boost. I doubt that was the case, but that's what I was refuting.

fwiw... i have no opinion on the matter. im anxious to pick darrell coxs brain on the matter soon.

i simply stated the info on toms motor to add to the "opinions" out there. ive done it and will continue to do it. i dont think it is any worse or better than alot of things out there. worse case its probably at least does no harm.

+1, that's my thinking too.

It'll be cool to see what DC thinks.

The theory of the BS assembly causing motors to pop is bullshit, UNLESS of course someone can prove that is is starving the rod bearings of oil.

I also think it's waaaaaaaaaaaaaaaay too soon to start singing, "Ding dong, the witch is dead!" considering there are very, very few people out there running the BSD mod on this car. I'm willing to bet the number is under 50 people. Certainly not the kind of number I'd bet the life of my motor on.

According to a poll on this forum, less than 30 respondents said they had done the BSD (out of 100 votes). Chances are those are a good number of those that have done it, and that 50-60 people total is probably not *that* far off.

can someone name ONE disadvantage of doing the BSD?

advantages:
more oil
cooler oil
17lbs lighter
faster revs
more HP

vibes.

If that's a disadvantage, don't bother modding your car beyond an intake, testpipe, and non performance mods. The more power you have, the harder you need to bolt it down with stiffer mounts etc. The BSD adds so little vibes it doesn't even matter at that point. If you have no plans on modding your car further, I'd keep the BS in and your warranty in tact so that if your motor pops you can roll the dice with mazda.

yes please let us know what DC says....about the ballance shaft....and about why they may be popping in general

Tizi blew? Damn! More info please.

The BS does not add wear to the engine. The theory was that it locks up. Now you can throw that out the window in this case.

Do they remove the balance shafts on any other big power 4 cylinder engines? (with the exception of boxer engines since they don't have 'em)

I mean, the SRT-4 guys pull 'em off right? Do the Evo guys pull 'em off? Do the 944 turbo guys pull 'em off? Seems to me like its not a cure all or an explanation for why we're blowing... but it certainly can't hurt.

And for $20, I'll do the damn thing.

You also have to consider that our engines original design didn't include a balance shaft assembly, it is something Ford added to the Duratec which in turn was developed to the MZR iirc.

Yes, about the faster revs. The BS creates a small amount of drag on our engines from the rotating mass, thus increasing load and decreasing turbo lag. Though I doubt many people who've done the BSD might sense the turbo lag.

I'm leaning towards doing the BSD on my MS6. I'm not going to do it on my 944 turbo, it creates lots of vibes due to the fairly large displacement, and a good BSD kit costs $200. It's a complete different system than the MZR engines. There are 2 BSs in the 944 that run on separate timing belt. It only robs about 4-6hp. Running a 944 motor w/o the BSs can lead to more serious problems down the line. That is, unless you are planning on rebuilding it every couple years.

reason #4 on your list is why I did it long ago
with the added benny(be it a small one) of the >1 qt. of addtl. oil

so wouldn't the reverse also be true? If the shaft was balanced without a 15lb weight and then they added one, it would be way off balance at 6000rpms again.

the fact the neither situation seems to be the case it points to it not really mattering weather its on there or not.

I'm with the thinking that the BSD can not and should not hurt an engine in proper running condition. and personally, I could really use the extra oil on the track. and with the AP, I can raise the idling RPM so as to minimize idling vibes from the BSD.

Not doing the BSD shouldn't hurt either...

So the balance shafts on the 944 are on a timing belt and not keyed to the crank? Can you elaborate on why you have to rebuild the engine every few years if you DO delete the balance shaft?

Just grasping at straws here but....

Could the problem be the deflection in the crank girdle that PTP was talking about... and having the BS on there exacerbates an already existing problem? Perhaps its not the balance shaft that CAUSES the problem, but removing it allows the problem to continue without immediate catastrophic consequences? Perhaps the deflection will still be putting extra stress on the rods, but the balance shaft just adds to that stress?

4 cylinder engines are not completely balanced. Which causes some unwanted vibrations. All the BS does is try to cancel those vibrations. It's added for comfort.

In a perfect world, an engine should operate fine with or without the balance shaft as:

An "unbalanced" 4-cyl isn't defective...we're talking about harmonic balance here and unless we're talking about boxer engines, inline-6's or v-12's (I believe all these engines are harmonically balanced by design), most 4 bangers are harmonically unbalanced...having a BS cancels out those harmonic imbalances which creates vibes...your engine should not suffer anything from vibes, so it's for ppl comfort only...the BS isn't "balancing" out the engine to keep it from shaking itself apart.

On the other hand, I don't believe the BS is detrimental if you left it in...I don't think Ford/Mazda would release an engine with a BS that'd degrade the actually engine itself...trust in that 95%+ of automotive engineers actually know what they're doing.

the gears on the balance shaft are cut at an angle. it has to carry some kind of axial load on the crank during accel and decel. something to think about.

there's no proof either way, and I'm doing the BSD for very different reasons. but if I was pushing big HP with big turbo and big boost, then I'd eliminate any possible obstacle, including doing the BSD.

to look at it the other way, is it possible that Mazda installed the balance shaft AND left out installing a meth kit just so that our engines will blow?

That and if these cars are failing because of crank walk (thrust baring), like others have stated in other threads, then the BS might be getting in a bind when the crank tries to walk, perhaps causing the engine to blow sooner than later. Of course this is all speculation right now.

i missed this info. seriously when did this happen?

+1...TiZi's ride is mint. And I've actually wondered what he's been up to lately...that's too bad, as I wouldn't be surprised if he had the fastest MS3 in Canada.

one thing to note..is that 17 lbs is off the front end of the car. One of the areas we really need to lose weight :).

But ya, even if its proven the BSD does help prevent a certain type of engine failure...removing the balance shaft is not going to bulletproof your engine. You're still vulnerable to detonation, lean conditions, overboost, fueling issues, etc etc...

Thanks for the info. I thought it wasn't just speculation that the BS is causing motor failures, and that not a single car with a BSD had popped.

I'll wait to do mine until the verdict is out on how the BS causes engine malfunctions.

The EVOX comes from the factory without the balance shaft assembly IIRC - it's a comfort thing ONLY and, well, the EVOX isn't exactly what I would call a "comfortable" car

It's comfy vs the evo 9! lol.

I think they tend to put Balance shafts on I4s over 2.0L...so that could be another reason the evo's dont have them

The 4B11 doesn't have a balance shaft.

it might be too late by then........

but the 4g63 and 4g94 do. both are belt driven however which might make a diff