After-market motor/engine mounts are a nice upgrade over your stock mounts and they can be used either if you have added more power to your engine... or not.
Overall, motor mounts are basically stiffer mounts than stock and they help keeping the engine more stable inside the engine bay. They remove or drastically reduce, the engine's movement when doing some "spirited driving" :).
By reducing the engine's movement under harsher driving conditions, you actually help the engine to put more usable power to the wheels, improve the shifting experience and reduce the stress on transmission and other moving parts inside the engine bay - like drive-shafts, pipes (exhaust or intake), etc.
Also, by keeping the engine's movement to the minimum, you improve the car's balance and it should be more predictable during hard cornering.
Some people even go as far as saying that it helps with eliminating the "wheel-hop" on the car - not entirely true (but that's another topic to discuss).
What actually happens (depending on the bushings on your control arms and your drive-shafts), is that the "point" where you get the wheel-hop gets "shifted" NOT "removed/eliminated".
By adding more power on your car, the wheel-hop will be back in no time :).
Before jumping on these though, you need to know the one small down-side that for some of you might be a deal-breaker...
Stock mounts are softer for a reason... they are designed to absorb the engine's vibrations and keep them away from the body of the car. By installing "stiffer" mounts you will transfer some of those vibrations to the body... the stiffer the mounts the stronger the vibrations.
This for you will translate as shaky steering wheel and rattle inside the car when idling, first gear launches or using the AC. So yes... you will give up on some of the ride-comfort. If you have a cruiser, keep it stock mounts.
As far as the mounts go, well, you have a few options to consider... the brand and the stiffness of the urethane used for the mount.
There are 3 major brands that are building motor mounts for the 8th gen Si (that I know of): Boomba Racing, HaSport and Innovative.
Each brand offers a 3 mount set with a wide variety for the grade of urethane stiffness. Keep in mind that less stiffer = less noise/rattle inside the car. Choose wisely :).
Also, be aware that each brand offers a different combo for their sets and they are quite different looking as well. So do a little bit of homework and choose whatever you think is better suited for your taste and application.
One thing is for sure... whatever brand or grade you choose, it will outperform the stock mounts (even the softer ones).
Personally, after doing some research on what others have done, I decided to go with a combination between Innovative's 3 piece set and HaSport.
Innovative is offering the upper mounts for the passenger and driver side, plus the lower-front mount. And since my car is mostly track dedicated, I got the 95A urethane stiffness - "Extreme racing".
From HaSport, I've only purchased the lower-back mount with the softest urethane they are offering.
The upper-driver side and the lower-front / back mounts might be a little bit difficult to replace; however, the upper-passenger side should be considerable easier.
Jack-up the front of the car and make sure it sits securely on jack-stands - please do not work under your car without jack-stands! And also make sure the hand-brake is on and the back wheels are blocked - better safe than sorry (hand-brakes DO fail from time to time)!
I would even go as far as having wheels under the car as a back-up safety in case the jack-stands fail (they DO fail as well from time to time...).
OR (as I have), put the car on portable ramps and have jack-stands as a fail safe - but still block the back wheels.
Once the safety issue is taken care of, we can move on with the work... sooo... take a very deep breath... you are about to enter the world of frustration where swearing, bitching and moaning are a requirement :).
Depending on what you are selecting for your application, the installation process might be slightly different than mine, but the removal process should be the same!
I've went ahead and started with replacing the lower mounts first; specifically with the lower-back mount (the extra one that I have purchased from HaSport).
This thing in theory is not very hard to replace; however, practice teach me differently :).
Others that have done this before me suggests the use of a jack and a piece of wood to support the engine's weight. Sounded like a good idea and I give it a try... give up on it in the first 5 minutes.
It was taking too much space under the car limiting my movements and as it turns out, if you tackle each mount separately, there's nothing really that you need to support...
What I did was to first remove the 2 bolts that connects the mount to the brackets. Then, I realized that the space is too tight to just simply slide the mount out without rocking / moving the engine (as others have done) so, I've decided to remove the bracket from the engine as well in order to have some space to easily slide the old mount out and also have some space when installing the new one.
There are 4 bolts on the engine bracket. The 2 that are on the passenger side can be easier to work on if you remove the passenger wheel and the plastics from the wheel-well (just like you would do when changing the oil filter).
The other 2 bolts can be accessed from under the car.
All 4 of them might require some persuasion but they will come out nicely.
Once all the bolts are out, put them aside because we will re-use them. You will have to move the parts around and they will eventually come out easily - hold the bracket and watch your face :).
When you put back the parts, start first with the HaSport mount - slide it in the frame bracket as far as possible. You need to apply a little bit of "swartz" - a hammer and a piece of wood to bang on it will do the job nicely - don't hit your oil pan with the hammer, pay attention.
Once that is done, you should be able to put the engine bracket back in without any issues. Get the bracket bolts, put some red lock-tight on the threads and then bolt them all by hand - don't tighten them down until all are in. Once they are all in, your bracket is aligned and now you can tighten them down without any issues - use a cross pattern when tightening.
Once the engine bracket is back in and tighten down, you can start moving the mount back in its place - again you need to apply some "swarts" to get it moving in the right spot.
First, align the holes of the mount with the frame bracket. After you align the holes, put some lock-tight on the bolt and put it back in - you can tap it with the hammer lightly if it needs some convincing. Don't tighten it down yet!
Now, align the holes of the mount with the ones from the engine bracket - you might need to use a sturdy piece of wood as a pry-bar to align the holes. Once is done, use some lock-tight on the bolt and back in it goes - again you can use the hammer to lightly tap the bolt to get it in.
Tighten everything down!
That's about it for the lower-back motor mount... as an advice, double check to make sure everything is tighten down and then we can move on the the next mount.
This lower-front mount is slightly easier to replace than the lower-back mount.
It brings on the table 4 bolts that needs to be removed and a puzzle :). Keep the bolts because we will be re-using them.
The bolts, are pretty much straight forward but not a breeze... you have to find your own way around with your tools to reach them and remove them.
The more difficult part comes when you have to slide it out :). The trick here is that you HAVE to remove the bracket for the coolant hose that is in that area or else you will have a bad time removing that motor mount...
Once the coolant hose bracket is out, as you are sitting on your back under the car, push the motor mount up until it clears its bracket (you will have to push on the coolant hose as well), rotate it clock-wise 90 degree and then sort-of flip it upside-down while slowly moving to the left - still pushing up. After that it will come off easily.
To put the new mount in, I followed the same steps but in reverse.
When I got down to installing the bolts, I first mounted the 3 small bolts by hand and then placed the larger bolt that goes trough the bracket and mount. You will have to wiggle the mount around in order to make sure each bolt gets in properly!
Once all the bolts were put in by hand, I tighten down everything starting with the 3 small bolts. Once those were nice and tight I tighten down the big bolt that goes trough the mount and frame bracket.
Double check everything again and make sure you don't forget to put back the bracket for the coolant hose (like I did :| - had to lift the car back up :( ).
As always, if you want to, is a good idea to use lock-tight on your bolts when re-installing them
At this point you can put the car back-down on the ground if you wish... but I would recommend to keep it up on the stands / ramps because it will make things easier when working on the top mounts - you won't have to bend too much and also in case you forgot something (like the bracket for the coolant hose :) ) you can easily go back under.
Take a break, have a beer... things MIGHT get easier from here on...
I know I said that things might get easier from here on, but for those of you that still have the stock intake system and the battery in the engine compartment... I lied... :(.
Yes, as you probably guessed already, you need to make some working space in the engine bay and the intake system, battery and battery bracket will have to go out!
I won't be covering how to do this since I have already replaced my intake and moved the battery in the trunk some time ago... and I honestly do not remember all the steps :(.
As far the mount goes, there are 2 things that needs to be removed - a bracket and the mount - sitting on top of each other. Locate and remove all the nuts and bolts that are connecting it to the engine and frame. Some of the bolts will go trough both parts.
When removing the mount and bracket on the driver side, there are 4 "tricky" things...
From here on we will have to use the bolts, nuts and washers included in the Innovative kit (I think earlier sets did not had these included either...).
Also, if your kit was put together by a bunch of trained monkeys (like mine), you will have no instructions and you will have to figure out what bracket and mount you have to use on either side.
Simple solution... match the holes from the provided brackets with the holes where it suppose to connect and this will clear any doubts - also see images below for reference.
On this side, the bracket will be mounted on the frame and the mount itself is going on the engine.
As far as bolts goes, for the bracket, you will have to use the 3 short bolts provided plus one of the longer bolts to connect the bracket to the mount. Make sure you use washers on all the bolts provided by Innovative. And if you haven't used lock-tight so far, I would recommend to use it on the bolts and nuts provided.
When tightening the mount to the engine, you will have to use the tall spacer provided - reuse the stock bolt.
Make sure you first install the mount and then the bracket - you won't have space to insert the mount if bracket is installed first.
Place all the nuts and bolts in their place loosely and then start tightening them down. Start with the bracket that connects to the frame, then the nuts and bolt that connects the mount to the engine and lastly, the bolt that goes trough the mount and bracket.
Make sure you double-check all the bolts and nuts before you put everything back in (intake system, battery bracket, battery, etc...).
I think this was the easiest mount to install from all of them...
Mind you it will still take a little bit of time since there are a few bolts and nuts, but nothing as the other ones...
Unlike the driver-side mount, this mount has about 4 components to it.
The mount itself, one bracket with bushing that connects to the bottom frame, one solid bracket that connects to the side frame (we will be re-using this side bracket) and another small solid bracket that connects the mount, side bracket and bottom bracket.
A LOT of brackets on this side... don't worry too much about them though... just remove the bolts and nuts and only keep the side bracket - and the bolts and nuts since we will be re-using some of them.
As with the other mounts... locate all the bolts and nuts for the brackets and mount and remove them. Once they are removed, everything will come apart very easily.
Before you install the remaining bracket and mount from Innovative, make sure you first loosely connect them using the last long bolt and nut provided (use the washers as well).
Slide the mount in its place on the engine and loosely connect the bottom bracket to the bottom frame using the bolts from the old bracket. Also, loosely re-install the side bracket to the side frame (the bracket I mentioned before that we will be re-using).
The side bracket will connect to the bottom bracket with 2 bolts (use the ones that you removed).
Once everything is connected, start tightening them down like this: tighten down the bolt and nut for the mount on the engine... tighten down the bolts for the side bracket... tighten down the bottom bracket to the bottom frame... and lastly tighten down the bolt that goes trough the mount and bottom bracket.
The only thing remaining is to relocate the ground wire.
It can be easily moved to the back of the engine - connect it to the top cover.
Check, double-check, re-install whatever else you might of disconnected, pat yourself on the back and then go out for a test.
Considering that the mounts I've got are having the urethane stiffness 95A, the ride comfort is not that bad.
There are some noises and shaking around 1000 - 1500 rpms when leaving from a stop (I also have an upgraded clutch kit).
Yes, the whine from the transmission while accelerating is also noticeable... but is all normal (the whine was there before but you didn't hear it - the mounts are amplifying the noise inside the car).
If you are daily-driving your car and is more of a cruiser, stick with the OEM mounts OR if you do want to upgrade your car, go for the lowest stiffness for the urethane.
And that's a wrap... :).
If you have any questions, corrections or anything that you want to add, please feel free to leave a comment at the bottom of this page.
You can also send me an email via "Contact me" form.
I am NOT a professional mechanic. Everything I do I gathered from my experience and from other car enthusiasts.
While what I advise and recommend is one way of doing things, please understand that you take your own chances following my DIYs and I cannot be held responsible if you damage your car or hurt yourself by not following the "proper procedures".