Nissan Forum banner

Status
Not open for further replies.
1 - 20 of 89 Posts

·
I miss good ol' OT
Joined
·
1,716 Posts
Discussion Starter #1
I dropped this note in another part of the forum, thought it better served here. I'm wanting to take the balance shaft out, anyone have a clue how? I have a UDP on order and I want to remove it then. I think ThaiB mentioned this in a earlier thread. Help!
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
OhTwoAltimaSE said:
I think you need a kit. JWT makes one if I'm not mistaken.
Makes about 6 hp to the wheels just removing the shafts and the JWT unit makes 8-10 as it controls windage around the crank better.

Mike
 

·
I miss good ol' OT
Joined
·
1,716 Posts
Discussion Starter #4
What kind of install/removal is this? Something I need to take a mechanic or can Slurrpie and I tackle this?
 

·
Registered
Joined
·
8 Posts
removal

This mod is not easy, I would suggest doing it buy yourself without a service manual, unless you have torn down the bottom half of engines before. It really is a-lot of work, for so little IMO
 

·
Registered
Joined
·
178 Posts
Altim8GA said:
I dropped this note in another part of the forum, thought it better served here. I'm wanting to take the balance shaft out, anyone have a clue how? I have a UDP on order and I want to remove it then. I think ThaiB mentioned this in a earlier thread. Help!
I remember seeing that thread, but it seemd to me the added vibration was not worth the HP. I could be way off though.
 

·
Yea, I'm a freak..
Joined
·
560 Posts
Re: removal

rlvq35de said:
This mod is not easy, I would suggest doing it buy yourself without a service manual, unless you have torn down the bottom half of engines before. It really is a-lot of work, for so little IMO
you mean you wouldnt suggest it without a service manual.
 
J

·
Guest
Joined
·
0 Posts
I never saw the thread on this subject, but I'd be hesitant to yank the balance shafts out of the QR if your car is a daily driver that you envision yourself driving a few years down the road. Unless your Altima is an all-out drag car, why take the risk of watching your engine vibrate its way out of the bay at 6000 rpm for a few horsepower?

The QR is a big, highly undersquare four cylinder with an 89 mm bore and a 100 mm (!) stroke. Such a design inherently lends itself to wicked second-order vibrations, which is why Nissan decided to equip it with two balance shafts, a first in its U.S. lineup. Removing them initially may not hurt anything other than the fillings in your teeth, but as the miles pile up the added vibration will be tough on journals, bearings and the like. Not good, methinks.
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
Re: Re: Balance Shaft removal

SILENT_RUNNER said:
I remember seeing that thread, but it seemd to me the added vibration was not worth the HP. I could be way off though.
The difference in vibration is very small, so small that a person not super familer with the car won't be able to tell.

Mike
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
JKWright said:
I never saw the thread on this subject, but I'd be hesitant to yank the balance shafts out of the QR if your car is a daily driver that you envision yourself driving a few years down the road. Unless your Altima is an all-out drag car, why take the risk of watching your engine vibrate its way out of the bay at 6000 rpm for a few horsepower?

The QR is a big, highly undersquare four cylinder with an 89 mm bore and a 100 mm (!) stroke. Such a design inherently lends itself to wicked second-order vibrations, which is why Nissan decided to equip it with two balance shafts, a first in its U.S. lineup. Removing them initially may not hurt anything other than the fillings in your teeth, but as the miles pile up the added vibration will be tough on journals, bearings and the like. Not good, methinks.
Balance shafts just cancel the second order natural up and down moment that all I-4 motors exhibit. The vibration that kills the motor is the torsional stuff that twists the crank and stresses the motors internal componets. The QR is an internaly balanced engine and removing the balance shafts does not affect this.

In fact if you have a highly moddifed QR, it is important to remove the balance shafts as seizing the shafts is one of the engines frist failure points. The balance shafts also create a great deal of crank windage and can contribute to oil control problems. Removing the balance shafts improves oil pressure and volume to the bearings as well.

On a QR removing the shafts results in a barily perceptable increse in vibration, the motor is still smoother than a KA24 and nearly as smooth as an SR20. As far as durabilty, Dave Colemans Pro-Rally QR has yet to suffer an engine problem in that punishing abuse of an engine.

The World Challange motor that Sunbelt Racing built has its balance shafts removed. It is common to remove the blance shafts on the Honda H22 and Mitsubishi 4G63 to improve reliablity and oiling on these motors as well.

Mike
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
Re: removal

rlvq35de said:
This mod is not easy, I would suggest doing it buy yourself without a service manual, unless you have torn down the bottom half of engines before. It really is a-lot of work, for so little IMO
To me this is very easy, easier than putting on a header. The gain is also substantial.

Mike
 

·
Registered
Joined
·
81 Posts
Does anyone know about warranty issues?

Is this something you would want your Nissan Dealership doing to avoid voiding warranty...:confused:
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
JBL85 said:
Does anyone know about warranty issues?

Is this something you would want your Nissan Dealership doing to avoid voiding warranty...:confused:
Like any internal engine mod it will void your engine warranty, but not other non-engine related parts.

Mike
 

·
I miss good ol' OT
Joined
·
1,716 Posts
Discussion Starter #14
I'm willing to bet that any problem you had with your transmission or drivetrain would be linked back to taking out the balance shaft. So you could kiss your warranty goodbye in those cases.

I've emailed JWT asking about this kit, as it was not listed on their website. I'll let you guys know what they come back with.
 

·
I miss good ol' OT
Joined
·
1,716 Posts
Discussion Starter #15
morepower2 said:

In fact if you have a highly moddifed QR,



Mike

Can you define highly moddified? Intake, pulley, and headers considered highly modded, or cams,ported, polished more along the lines of what you meant? I guess I'm talking about simple bolt on's (not turbo) equalling slightly modded.
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
Altim8GA said:
Can you define highly moddified? Intake, pulley, and headers considered highly modded, or cams,ported, polished more along the lines of what you meant? I guess I'm talking about simple bolt on's (not turbo) equalling slightly modded.
I guess it means once you start getting insdie of the motor, like cams, plus all of the nomal bolt ons.

Mike
 

·
Registered
Joined
·
20 Posts
JKWright said:
The QR is a big, highly undersquare four cylinder with an 89 mm bore and a 100 mm (!) stroke. Such a design inherently lends itself to wicked second-order vibrations, which is why Nissan decided to equip it with two balance shafts, a first in its U.S. lineup. Removing them initially may not hurt anything other than the fillings in your teeth, but as the miles pile up the added vibration will be tough on journals, bearings and the like. Not good, methinks.
i agree - it can't be good over the long term.
 
J

·
Guest
Joined
·
0 Posts
morepower2 said:
The QR is an internaly balanced engine and removing the balance shafts does not affect this.]
Strictly speaking, all production engines are internally balanced. But that doesn't mean that an inherently raucous design such as a long-stroke inline four can't benefit substantially from balance shafts. That's why Nissan sucked it up and increased the cost and complexity of the QR25 by installing them.

In fact if you have a highly moddifed QR, it is important to remove the balance shafts as seizing the shafts is one of the engines frist failure points.

I don't doubt this, as balance shafts are basically large counterrotating weights. In a track-only or off-road application, removing them wouldn't present a problem at all, as NVH are the last of the bottom rung of considerations in racing applications. But pulling them out of a family sedan that's still under warranty and driven to and from the grocery store twice a week seems overkill to me, particularly if you're talking about a very minor horsepower gain. The trade-off just is not worth it. To warp one of my favorite lines, "My warranty for a pair of balance shafts!"

On a QR removing the shafts results in a barily perceptable increse in vibration, the motor is still smoother than a KA24 and nearly as smooth as an SR20.
Having owned two SR20s and a KA24, even sticking those two engines in the same sentence seems to me a bad idea. ;)

The term "barely perceptible" is of course relative. What's barely perceptible to a gung-ho-nitrous-equipped street rodder is overwhelming to John Four Door. Clearly, if the gain in adding a substantial amount of cost and complexity in the form of balance shafts in the QR25 were as small as you describe, the Nissan beancounters would never have approved their installation. Considering that the company couldn't be persuaded to part with an extra hundred-spot per Altima to upgrade the interior to, say, Malibu level, it makes no sense to assume that the company would drop several hundred on balance shafts that provide only "barely perceptible" decreases in NVH.

My advice: If your Altima or Sentra is a mild daily driver that you plan to keep for a few years and also in fact hope to sell for actual cash monies one day when you're done with it (rather than the alternative of wadding it up and tossing it into the ditch), leave the balance shafts in there.
 

·
Icy Hot Stunta
Joined
·
2,366 Posts
JKWright said:
Strictly speaking, all production engines are internally balanced. But that doesn't mean that an inherently raucous design such as a long-stroke inline four can't benefit substantially from balance shafts. That's why Nissan sucked it up and increased the cost and complexity of the QR25 by installing them.



The term "barely perceptible" is of course relative. What's barely perceptible to a gung-ho-nitrous-equipped street rodder is overwhelming to John Four Door. Clearly, if the gain in adding a substantial amount of cost and complexity in the form of balance shafts in the QR25 were as small as you describe, the Nissan beancounters would never have approved their installation. Considering that the company couldn't be persuaded to part with an extra hundred-spot per Altima to upgrade the interior to, say, Malibu level, it makes no sense to assume that the company would drop several hundred on balance shafts that provide only "barely perceptible" decreases in NVH.

My advice: If your Altima or Sentra is a mild daily driver that you plan to keep for a few years and also in fact hope to sell for actual cash monies one day when you're done with it (rather than the alternative of wadding it up and tossing it into the ditch), leave the balance shafts in there. [/B]

In the first Jarrod, you are wrong, there are many production engines that are externaly balanced, like most domestic engines!

As far as the validity of removing the balance shafts, no its not going to affect the engines durabilty and may even improve it under some conditions. The first few QR25's that were modifed for racing use failed because of extensive damage caused by balance shaft assembly failure. The shafts seize at high rpm, much past 6500 rpm in fact.

The reason for the balance shafts exsistance is not for durabilty but because the NVH target for the QR25 was to meet or exceed the NVH chariteristics of the VQ30DE engine. However I bet that many people wouldnot be able to tell that the balance shafts were removed if they were not promted, thats how subtile the differences are. In fact I had a hard time telling myself!

Plus for most people, finding 8-10 hp in a naturaly asperated engine is quite a large amount, especialy if its free hp without a fuel consumption penalty. This mod is also easily reversable, you can reinstall the balance shafts when you sell the car.

What you are stating as fact is only conjecture on your part and your opinion. You have never done any of these mods nor do you modify any of your cars. I have had these sorts of arguments with you on other forums before. In fact your famous Bosch spark plug argument was proven wrong once more data was avalible but after you dropped off that mailing list.

You are correct in your advice that if you are not a person into modding the car whose primary concern is to have a warranty and a lack of NVH, then don't remove the balance shafts, in fact don't consider any modifcations, keep your car totaly stock.

Here are the facts without any opinion from you or I.

1. Will void engine warranty
2. Will give 6-10 wheel hp depending on how done
3. Will improve durability under racing conditions
4. Will increase NVH by a very small amount.
5. With the JWT kit, is easy to reverse and put back to stock.
6. Will not hurt the engine under normal street use.
7. Will increse the amount of oil avalible to the main and rod bearings
8. The JWT kit will improve oil control, reduce windage and reduce oil starvation under cornering.

Whether or not this has any value to the consumer is up toi the consumer, anything else is just opinion.

Mike
 
1 - 20 of 89 Posts
Status
Not open for further replies.
Top