LittleBlueGT Posted December 23, 2007 Share Posted December 23, 2007 Haven't I said before it is the whole drivetrain slack? Motor mounts help. The bushings are just part of the problem, but by the looks of them they are the worst part. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
TRS Posted December 24, 2007 Share Posted December 24, 2007 The inserts I made out of some sway bar bushings have tamed the noise for me. I planned to fab up some poly inserts to replace the rubber ones I put in but the noise is all but gone so I've stuck with the original ones for now. Link to comment Share on other sites More sharing options...
Gmachine Posted February 10, 2008 Share Posted February 10, 2008 Bumping for any updates. I can reproduce this vibration/noise at will. My car has full suspension mods; coilovers etc. This problem never surfaced when running stock engine tune. Once the car went stage 2+ it has become an issue. Cruise in 5th ,get into boost and the vibration gets louder as the revs/load increases. One strange thing i do notice is,if i do a 1st gear accel run mid way thru 5th gear. The vibration / noise does not occur. Thinking the loads must be different for the drivetrain dependant on the RPM / Gearing / Torque levels. Pretty picture of JDM Spec B diff support unclemat posted about,we all like pretty pictures right:lol:. Link to comment Share on other sites More sharing options...
Guest Posted February 10, 2008 Share Posted February 10, 2008 ^ what exhaust is this? And I see you painted STI lateral links silver to match alu components Link to comment Share on other sites More sharing options...
Gmachine Posted February 10, 2008 Share Posted February 10, 2008 Easy uncle, Not a picture of my car. I think those are the actual STi lateral link set. The exhaust looks like the K2 system. Possibly same system that was on a west coast members car "Legacy Otaku" can't remember his name right now. Pic of my actual car:). Link to comment Share on other sites More sharing options...
Guest Posted February 10, 2008 Share Posted February 10, 2008 I see. I have STI lateral links and they are black like the stockers. Link to comment Share on other sites More sharing options...
Leonardo Posted March 12, 2008 Share Posted March 12, 2008 Sean, any updates?? Link to comment Share on other sites More sharing options...
Mr. Ed Posted March 12, 2008 Share Posted March 12, 2008 I've actually upgraded my bushings but still ahve the sound....someone suggested that the vibrations may be coming from the exhaust hangers... anyone try replacing them?? Link to comment Share on other sites More sharing options...
Guest Posted March 12, 2008 Share Posted March 12, 2008 Upgraded with what? Link to comment Share on other sites More sharing options...
Gmachine Posted March 13, 2008 Share Posted March 13, 2008 I do not think it has anything to do with any exhaust related parts. Something in the driveline is loading up. 5th gear cruising @60mph if i stomp on it, boost will come up and the car will shudder and make a rumbling noise underneath. The engine pulls nice and smooth but something between the flywheel and rear tires is causing this. 4th gear cruising @60mph if it stomp on it,boost hits and the car takes off fast and smooth with no vibrations from the chassis or body. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted March 13, 2008 Share Posted March 13, 2008 Upgraded with what? Yea, did you invent your own? Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
Leonardo Posted March 13, 2008 Share Posted March 13, 2008 I've actually upgraded my bushings but still ahve the sound....someone suggested that the vibrations may be coming from the exhaust hangers... anyone try replacing them?? As above: Replaced with what? Also, I have Kartboy hangers an that isn't it. Link to comment Share on other sites More sharing options...
Leonardo Posted March 13, 2008 Share Posted March 13, 2008 Also, it happens on both 5EAT and 5MT so it has to be something aft of the tranny and even rear Diff housings are different. Link to comment Share on other sites More sharing options...
Mr. Ed Posted March 13, 2008 Share Posted March 13, 2008 Yea, did you invent your own? no, I bought some at an autoparts store... they are designed for a truck, but fit nicely after some trimming to the mounting hardware with the dremel. didn't solve the problem though.... I may have posted on the wrong post here...but at one point in time we had a post going on the same subject where we thought it might be the swaybar bushings... after a refresher reading here I see the focus has been on a different set of bushings so my bad. those of you that have replaced hangars...did you replace all three? The dealership first thought mine was my exhaust (it was really loud) and then with stock cans diagnosed it as being hot spots on my flywheel.. changed out the clutch and flywheel and I still have the same problem... flywheel was burned up pretty bad tho. Car was on coilovers..switched back to stock suspension bcause of a blown strut...same problem dealer again said they have had numerous complaints of vibration that were solved with new exhaust hangers... but what do they know???? Link to comment Share on other sites More sharing options...
Leonardo Posted March 13, 2008 Share Posted March 13, 2008 I replaced 4 hangers (2 per muffler). Link to comment Share on other sites More sharing options...
Nighthawk CL9 Posted March 13, 2008 Share Posted March 13, 2008 when i had my legacy i also replaced by exhaust hangers and they didnt do anything to the noise. They were the KartBoy Hangers. ps o had the long version. http://www.daddysscp.com/dcart4/product.php?productid=21 Ex '05 Legacy GT Link to comment Share on other sites More sharing options...
rony Posted March 13, 2008 Share Posted March 13, 2008 I was thinking about this yesterday and was wondering if there was any progress on this item. This is not the exhaust, it is the drive train. There are bushings on the rear diff that connect to the cross member. These have been identified as the culprit. No one currently has an after market replacement for these bushings. I'm honestly thinking of making my own inserts to, if not solve, but at least dampen the issue. I have STI tranny mount and lowered car. Nothing else has been altered, other than Stage 2+ power levels. My Car vBGarage Link to comment Share on other sites More sharing options...
LittleBlueGT Posted March 13, 2008 Share Posted March 13, 2008 The rear diff bushings are the main culprit, yes. I don't think they are the absolute cause though. It seems to be a harmonic hibrations along the drivetrain, of which those bushings contribute the most to allowing it. By swapping my motor mounts for GroupN ones the noise was diminshed by a good 60-70%. Not that it is 60-70% quieter, but takes significantly more torque to acheive the noise now. I think the rear diff bushings, whenever they get made, will solve most of the problem. But, the whole slop in the drivetrain ultimately has to be addressed for a complete solution. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
praedet Posted March 13, 2008 Share Posted March 13, 2008 Any NVH increase from the Group-N mounts LBGT? You got them from Rallitek, right? Link to comment Share on other sites More sharing options...
whitetiger Posted March 13, 2008 Share Posted March 13, 2008 i agree that the rear diff bushings are the problem. I also think the driveshaft center support bushings suck as well. Link to comment Share on other sites More sharing options...
Mr. Ed Posted March 13, 2008 Share Posted March 13, 2008 those of you that have replaced hangars...did you replace all three? Exhaust hangers= 5...or three locations. Each of the mufflers with two on each and the center y pipe hanger... not saying it would fix anything, but curious if anyone had replaced that center hanger... Link to comment Share on other sites More sharing options...
LittleBlueGT Posted March 13, 2008 Share Posted March 13, 2008 Any NVH increase from the Group-N mounts LBGT? You got them from Rallitek, right? Got them from PDX. Anything over about 900-1000 rpms and it is not noticeable, not at all! Once the car warms up and the idle gets down to 750rpm you notice a little more shaking at idle. So, yes, it is noticeable, but IMO totally liveable for a DD. The same way that the KW2s are totally lieable (although the engine mounts are less noticeable then the coil-overs). Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
Leonardo Posted March 13, 2008 Share Posted March 13, 2008 Exhaust hangers= 5...or three locations. Each of the mufflers with two on each and the center y pipe hanger... not saying it would fix anything, but curious if anyone had replaced that center hanger... Didn't do it and I think the system is stiff enough with only the ones on the mufflers. I try to move the tip with my foot and end up moving the car. Link to comment Share on other sites More sharing options...
nismoz Posted April 2, 2008 Share Posted April 2, 2008 Any updates on the insert product Sean? After reading thru all the posts, I am very scared to even go Stage 1. I'd rather live with slower car than a faster car that sounds like its gonna break apart. Link to comment Share on other sites More sharing options...
Levisimpreza Posted April 2, 2008 Share Posted April 2, 2008 Yeah I read all 30 pages, i'm board. If it is any constellation guys I had the same prob in my Impreza in first (launch) second (hard acc) and sometimes third if it was a chilly or cold day. I replaced my struts all around (AGX/KYB) and the problem went away. AWESOME thread BTW, very informative. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now