i've read several posts about BS removal but i want to hear from people with first hand experience. i'm in the process of doing a budget build 2.3L for my track car (mainly use for track but i still drive to and from track). i was set on remove the balance shaft but then i came across the article from Jacks Transmission about the benefit of keeping the BS. so now i can't decide if i want to keep it or not.

http://www.jackstransmissions.com/pa...balance-shafts

i'd like to hear from people who have lots of track mile on their motor without BS. do you experience high rpm clutch drag or bearing failure as mentioned in the article posted above.

my build will consist of basically all Manley stuff. Manley 2.3 crank, rods, pistons, bearings. i don't plan to go crazy with the rev, probably max of 7500 rpm, more likely 7200 rpm.

thanks,

 

I don't have first hand experience but I read that article before as well and it made me think. I still plan on delete the balance shaft for both safety and to free up some hp and drop some weight. I plan on combating the torsional crankshaft forces with a silicone filled fluidampr, this should be able to capture a lot of the torsional harmonics and help with the longevity of the main bearings.

 

The biggest concern I would have with a road race car with balance shafts would be the balance shaft bearings... and a few more moving components that could fail and take out the engine...

 

i replace the BS belts and Timing belts at 15k miles, did over 3 years of track on the car, about 90+ track days. no issues with the BS at all. i don't plan to increase the rev limit with the 2.3L either. i know of two people who have BS belt failure, but it was also around the time that the belts needed to be replaced.

my main concern with the BS is the belt. i could turn up the boost 1 psi to make up the power lost
the small weight saving up front is nice though. i only plan to make between 320-360 whp depending on the class i run in.

 

jacks 100% on if you ask me. I leave them in my personal engines. the fluidampr is a must as well. before I knew better I tried no balance shafts. had the oil filter spin off twice on me. couldnt keep turbo bolts tight either. had to tie wire everything. plus it makes the dash rattle which is extremely annoying.

 

Like we've discussed already, I don't run a balance shaft on my built 2.0L and no issues so far. Only ran 10 track days last season with the new motor though, so we'll see how she holds up this year.

 

What RPM are you guys seeing the increased nvh with the deleted balance shafts? I deleted mine and I don't notice much of a difference either way, not much more vibrations and not much more performance. Honestly if I had to decide to do it again I don't know if it would be worth the time for me other than it being one less belt to fail, one less accessory to have to time.

 

Aaron, what's your rev limit at and do you notice any high rpm clutch drag when you shift. Do you have oem engine mounts or stiff mounts.

My other friend is in the process of building a 2.2 LR for autox and he opt for BS delete since he'll be reving to 9k rpm.

 

Interested in this as well. I decided to eliminate the BS on the current engine I'm building for dedicated track use. I was back and forth for the longest time. Until I had issues with the bearing being jacked up on installation by the machine shop. Made it an easy decision to flip the bearings and ditch the shaft. Unfortunately the motor isn't in the car and so I can't give you any feedback

 

I have personally seen 5 engines vibrate flywheel bolts loose on engines with BS removed

 

I shift at 8200 rpms. The car isn't making increased power on my current turbo/boost levels past 7800 anyway, so I only need the 8200 to avoid shifts through certain corners.

I don't have any clutch drag at all with my Exedy twin-plate clutch. I have OEM engine mounts.

I did have an issue with manifold bolts being loosened however. I have the bolts drilled/wired now.

 

I just had 2.3 built, and deleted balance shafts.
All mounts are Poly, since a while, and the 2.0 was super smooth with balance shafts despite hard mounts.

The 2.3 is premium: Manley-Buschur billet lightweight crank, Carrillo rods, Mahle pistons, all balanced.

I HATE the vibration. Its totally excessive at idle, like NASCAR.
And my turbo does not warrant exceeding stock redline. So no need to rev higher.

I feel that this was big mistake.
I am certain that there is no reason to have scored balance shafts bearings if you use premium oil and change it often, and have no oil starvation.
Similarly, a Kevlar belt will not break if changed every 25K-30K miles.

I am pretty determined to put the balance shaft assembly back.

NOTE: I noticed that some have mentioned that the vibration is so exaggerated when using stock mounts.
But the engine and its bolts/oil filter will still experience this excessive vibration- that is Ok on full-race-car which has only one purpose- but not acceptable for a car that is amateur race or Dual Purpose street/track car.

I wish I knew. Now its 6hrs of hard labor or more.

All the best in your decision

 

^ thanks for that feedback from first hand experience. i have pretty much made the decision to keep the BS. i don't plan to rev the engine over 7200 rpm, maybe 7500 at most if i don't want to shift at certain turns. i used Gates kevlar belts on the the stock motor for over 3 years of track with no issues. my one friend is current building a motor for autox and he's looking to rev to 9k, so he decided to delete the BS since there's higher risk of BS bearing failure at high rpm.

i agree that stock engine mounts could reduce the in-cabin vibration but the engine and drive train will still see the vibration.

 

What did you use to delete them? Stub shaft or AMS/GSC kit? Do you have a Fluidamper?

 

i have a brand new GSC delete kit if anyone wants to buy