Pros and Cons to removing the balance shafts?

[AVC-R]

Ok I have a question and I have researched it but i still wanna hear from the guys that know best, I want to know what the good and the bad is with eliminating the balance shafts in a 4G63 engine. I talked to one of the guys at mitsubishi and he said that he gets eclipse's and talon's in the shop all the time that have had them removed and they run like crap and just beat the crap out of the motor's internals. I have also herd from other people that it's not a problem at all and won't hurt anything but I would like to know if anyone has removed them and had a problem with it or if the guy at mitsubishi is full of crap. sorry so long. any help would be greatly appricated.

 

[Jeremoose]

I purchased the kit to perform the removal already, and have heard mainly good things about it. The main problem I hear about is that the first few times you drive your car you noticed a lot of vibration and such through the steering wheel, but you don't even notice it after you've driven it a few times.

 

[Knockin1g]

Good: Frees up lost engine power and
no more risk of a BS belt breaking and taking out your timing belt with it.

Bad: Alot more vibrations, especially if you have urethane motor mounts. But don't worry, you get used to it.

 

[AVC-R]

but it won't tear the engine up? i guess thats my main concern cause i just crankwalked my 7bolt and i am looking for a 6bolt to swap but i wanna make back the loss in power without spending anymore money then i have too

 

[toecutter]

Pros: Less rotating mass, revs up faster, no worrys of b/s belt breaking

Cons: At stops, more vibrations

 

[nightspeed87]

my friends 91gst fully built up he romoved his balance shafts and the first time the guy who did it messed it up and he had to rebuild his whole engine,and the second time he did it himself with the kit and everything and did it right and he said it doesnt vibrate that much more, but he said he didnt really feel any noticeable power gain either, so it was probably so shy that the power you gain from it isnt worth the money or trouble unless your just trying to message every horsepower from your car and just to not have balance shafts... i was going to take mines off but id rather not go thru the trouble personally, ill just replace my balance shaft belt when due. but it may be a different experience per car.

 

[spoolup]

like everyone has mentioned here: http://www.roadraceengineering.com/eclengine.htm scroll down 1/3 of the page.

 

[talontsi101]

i just built my motor about a year ago I took the time to take out my balance shafts after i had already put the motor in ( ya I'm a dummy) but once i got them out it made for NOTICABLE TORQUE gain and the vibration mmmmnotsomuch

 

[Quasimondo]

Noticeable gain? More of a seat-of-the pants feeling if you ask me. Pulling the balance shafts is less of a performance modification and more of a longevity one since a broken belt or siezed bearing can kill your engine. As far as parasitic losses go, I don't see how two 5 lb. shafts can cause that much rotational drag.

 

[AVC-R]

Ok thanks for the help everyone. I think I am gonna get the kit and go ahead and remove them.

 

[nightspeed87]

yea ive never done it, i considered it changed my mind ill just keep my belts changed on time, my friend didnt notice any difference from removing them at all, he only noticed more vibration, so maybe you gain noticeable vibration hp Nah let me stop, but ey everyone has their own experience i guess it all depends on your car .

 

[Chaddycakes21]

Its definetly more of a "safety" mod then a performance mod. I removed the bs in my car. Didnt notice much, except for quite a bit more vibration.

 

[AWD-Tony]

I know this is old but here's a video I found. No butt dyno either. So yeah, there should be a noticeable power gain.

You must be logged in to view this image or video.

 

[Sniffbooger]

My balance shafts are removed, on my current 6 bolt swap in a 98 GST, and together with the 272 cams its a nasty lug lug lug loping idle at 750rpms, and it seems to vibrate all the way thru redline something terrible, but HEY! who cares, it runs strong and quick ...

 

[pauleyman]

My balance shafts are removed, on my current 6 bolt swap in a 98 GST, and together with the 272 cams its a nasty lug lug lug loping idle at 750rpms, and it seems to vibrate all the way thru redline something terrible, but HEY! who cares, it runs strong and quick ...

What motor mounts do you have?

 

[Sniffbooger]

Ahh, yes, forgot to mention, I have the red Polyurethane motor mounts!!! Its not fun unless it shakes all over!

I also have a lightweight flywheel...my understanding is that the balance shafts, the harmonic balancer, the flywheel and even the motor mounts all have something to do with the vibrations coming from the engine...so, mine is probably the worst case scenario...but I don't mind, its a fun car to drive, and every couple days I get somebody in a Mercedes or some other expensive car pulling up beside me drooling over my car, rolling down the windows, saying its really cool and then I leave them behind in my dust....I especially HATE German trash! ...

 

[talon77]

It might be the lightweight flywheel or something else weird causing your vibrations through redline. I've mostly always ran with BSE and red poly motor mounts and I get the vibrations at idle, but they kind of "disappear" and I don't notice any more vibrations after the car is moving. I've always run Fluidamper though, so not sure if that's been helping me...

 

[AWD-Tony]

The harmonic balancer/balance shaft vibration has been discussed in the past. I just went through that thread and I don’t think HB does anything beside dampen the crankshaft harmonics but I ain’t no rocket scientist . I have a lightweight flywheel as well and I don’t think that caused any increase in vibration. I will post my opinion on you he BSE sometime next week.

I am pleasantly surprised on the hp & tq gain on that stock motor just from BSE

 

[Sniffbooger]

BSE = Balance Shaft ENHANCEMENT?? or? Balance Shaft ENLIGHTENMENT? or? Balance Shaft EXTRACTION??? Sorry...I'm not so good with acronyms....

 

[AWD-Tony]

BSE = Balance Shaft ENHANCMENT?? or? Balance Shaft ENLIGHTENMENT? or? Balance Shaft EXTRACTION???

None of the above
Elimination

 

[ist dwa]

There are no pros to running balance shafts in a 4G63.

 

[jpmxrider489]

I know this is old but here's a video I found. No butt dyno either. So yeah, there should be a noticeable power gain.

Great video to provide some data.

I'll comment my experience. I have driven with and without it. I noticed little vibration change with stocks motor mounts. I then upgraded to urethane mounts and still barley noticed a change. I them upgraded to solid subframe bushings and a harder motor mounts. This combination does add vibration that could be annoying.

In the end, you to ask yourself what are the goals with the car. For me, I didnt want to do the matience involved and made timing the engine easier. It is also one less thing to worry about. Just make sure oil pressures are not to high or low. Since I'm revving to 8500-9k, I dont want that belt on my car at all.

This is all my opinion and thought process.

 

[AWD-Tony]

There are no pros to running balance shafts in a 4G63.

Are you saying it doesn't cause more vibration?

 

[jpmxrider489]

There are no pros to running balance shafts in a 4G63.

There are people above that notice vibration differences. So for people just wanting a stock oem good running car would obviously want to keep them and just keep up with repairs.

 

[jpmxrider489]

You people worried about vibrations?

Some people do care about it. Some people want the car running normally and not have to deal with oiling issues. That is a pro for keeping them.