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Old 07-15-08, 11:44 AM   #1
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Default Kartboy 08 rear subframe bushings

Kartboy Rear Subframe Bushings

Install and impressions

The rear subframe bushings are the latest and greatest product from Kartboy specifically designed for the 08 Impreza chasis. These bushings are added to the lower portion of the four rear subframe mounts and are designed to help hold the subframe in place during acceleration or turning. The bushings are sandwiched between the lower metal flange/washer holding the subframe and bushings that isolate the subframe from the frame.
Install
The install is quite easy and should take no longer than 30 minutes to perform. It involves removing the large bolts and metal flange/washers one at a time from the subframe followed by inserting the new bushings and tightening down the large bolts. There are four bushings in total that need to be installed with the kit.
This first picture shows the location of the left rearward mount. You can see the large (19mm) bolt head that I am pointing to and the metal flange/washer above the bolt head. This large bolt needs to be removed. It is only torque to about 60 ftlbs and should be removed easily.


This is the large bolt and flange/washer removed from the car.

This shows the approximate location of the bushing on the large flange/washer.

You can see that the flange/washer and bolt have been removed in this picture. The bushing will go into the void area seen between the metal sleeve and outside ring of the stock bushing.


Here you can see the proper installation of the bushing in relation to the stock bushing and large flange/washer.

After installing the bushing, make sure you tighten the bolts back to around 100 ftlbs. That’s it for the first mount. The other three follow similarly. The fronts have a larger flange/washer that is also a chasis bracket. The front mounts have two 14mm headed bolts holding the front of the bracket along with the 19mm headed long bolt in the rear of the bracket.
This is the front portion of the mounts in the front.

And a picture of the mount removed from the car.





Tony


Last edited by Turninconcepts.com; 01-07-09 at 04:25 AM.
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Old 08-23-08, 11:35 AM   #2
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Default Re: Kartboy 08 rear subframe bushings

I put these bushing inserts on today. 30 minutes may even be overstating the amount of time install takes-- super easy. If you use ramps, like I do, every bolt you have to remove matters, so I suggest not completely removing the 14mm bolts on the front of the front rear subframe bracket as done in the 9th photo of this tutorial. I just loosened the 14mm bolts 5 turns or so, removed the rear 19mm bolt and flange washer completely, and had enough slack to pinch the bushing insert into the void under the 19mm rear bolt/flange washer (as shown).

I'll post street driving impressions next week some time (added NVH), but won't be hitting the autocross again til next month. By then I'll also have the harman front/rear sways & endlinks on, so any impression of performance enhancement caused by these bushings will probably be clouded all to hell.
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Old 10-28-08, 08:05 PM   #3
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Default Re: Kartboy 08 rear subframe bushings

^^ ping, still need to add impressions
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Old 10-29-08, 10:09 AM   #4
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Default Re: Kartboy 08 rear subframe bushings

Quote:
Originally Posted by sutter2k View Post
^^ ping, still need to add impressions

I installed these bushings with new sways/links, so after a few autocrosses without, and now a few with these mods, I can definitely say things are better. The car responds quicker to inputs through the slalom and seems more apt to oversteer when i'm off the throttle and starting my turn in. It never gets twitchy and seems more connected...

I haven't noticed any added noise after installing the bushings.

Downsides to the bushings and sways are probably caused by the otherwise stock suspension--i lift the inside rear tire whenever the car starts a slide and I get on the throttle. Good times.
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Old 10-29-08, 10:12 AM   #5
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Default Re: Kartboy 08 rear subframe bushings

well, not sure if it's a fair comparison... but i have the whiteline rear subframe and rear diff inserts.

... and THEY ARE SO WORTH IT the driveline in the rear doesn't feel like it's dancing around anymore, it's so much more solid and connected now.


anyway, i realize this is a different product, but the result should be somewhat the same


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Old 10-29-08, 10:23 AM   #6
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Default Re: Kartboy 08 rear subframe bushings

JPH:

I was wondering whether the Whiteline subframe inserts were more prone to added vibration noise than the Kartboy ones I installed? The Whitelines look like they are a harder material and also fill more area inside the stock bushing than the Kartboy inserts do. My assumption is that this may lead to the transfer of more vibration from the suspension into the cabin? I'm not knocking either product, just wondering if one may fit a finicky daily driver better than the other?
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Old 10-29-08, 12:13 PM   #7
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Default Re: Kartboy 08 rear subframe bushings

Quote:
Originally Posted by phowie50 View Post
JPH:

I was wondering whether the Whiteline subframe inserts were more prone to added vibration noise than the Kartboy ones I installed? The Whitelines look like they are a harder material and also fill more area inside the stock bushing than the Kartboy inserts do. My assumption is that this may lead to the transfer of more vibration from the suspension into the cabin? I'm not knocking either product, just wondering if one may fit a finicky daily driver better than the other?
well... in addition to that, i also have group-N hardened motor and transmission mounts, kartboy pitch stopper, other poly bushings and bracing, and yes... the total package adds a little more NVH, but i'm sure MOST of that is coming from the motor and tranny mounts, not the other bushings and inserts.

this is of course, just my opinion


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Old 10-29-08, 05:04 PM   #8
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Default Re: Kartboy 08 rear subframe bushings

Yeah, I've done solid motor mounts on previous cars. There was definitely noticeable associated vibration. Definitely. It shook the hulk hogan bobble-head off my dash.
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Old 02-08-09, 07:26 PM   #9
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Default Re: Kartboy 08 rear subframe bushings

Quote:
Originally Posted by phowie50 View Post
I put these bushing inserts on today. 30 minutes may even be overstating the amount of time install takes-- super easy. If you use ramps, like I do, every bolt you have to remove matters, so I suggest not completely removing the 14mm bolts on the front of the front rear subframe bracket as done in the 9th photo of this tutorial. I just loosened the 14mm bolts 5 turns or so, removed the rear 19mm bolt and flange washer completely, and had enough slack to pinch the bushing insert into the void under the 19mm rear bolt/flange washer (as shown).

I'll post street driving impressions next week some time (added NVH), but won't be hitting the autocross again til next month. By then I'll also have the harman front/rear sways & endlinks on, so any impression of performance enhancement caused by these bushings will probably be clouded all to hell.
1+ on easy install. followed your hint with ramps.
Little bit tighter in the rear. Don't notice any NVH.
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Old 03-02-09, 10:23 AM   #10
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Default Re: Kartboy 08 rear subframe bushings

+2 on the easy install. also only loosened the 2x14mm bolts and it worked out well, made it easy for the bushing to stay in there while i was tightening the bolt up.

haven't gotten to drive the car yet and it will be a while before i can give it a real test, 8+ inches of snow = taking it easy on the car for a few days.
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