You really only notice it (negatively) when decelerating from 40/30mph down to a stop...but there is NO missing it when it does. On the upside, while cruising on the highways & backroads this weekend, it was great. There were so many sections of two-lane roads where i needed to pass someone (usually a semi or something, kicking up cinders at my hood/windshield (good'ole Pennsylvania snow removal system)) and i'd just press the pedal and GO! No lag at all...you WENT!
It's going to take some time getting used to the vibration at stops, mainly b/c that's all i drive in the city, so there's a LOT of stopping going on. I'd like to keep it...we'll see if the wife gets too annoyed with it. For something with minimal performance gain, i don't know that she'll (want to) put up with it much longer. She's already noticed it...just a matter of time LOL. If i do revert back to stock, i'll definitely spin the bushing again...that would be a nice compromise.
Also, i don't know if it has anything to do with it, but the poly mount from ZZP needs to be trimmed to fit properly in our mounts...and i didn't do that. I posted a pic somewhere (here it is again). The raised parts of the poly mount hits the triangular part of the mount itself and needs to be trimmed. It is possible that the bushing is not seated properly and causing excessive vibration. It's also possible that the vibrations is what it will be forever and the fact that it's "squeezed" in there makes no difference. I'll make it a point to trim the edges this week and see if that helps.
I'm assuming that the older 3800 mounts are squared off, without the triangular bracing. Also assuming it needed to be triangular to offer the support that the 5.3L needs. Regardless, b/c these were designed for the 3800s, fitment with all 5.3s might be an issue.
I paid more attention to the vibration this morning and yesterday evening and it's not at 30-40mph...it really kicks in at 23-24mph when slowing...while it downshifted into 2nd gear, i believe. It's very pronounced when in reverse, too, but for a short while. I back into my driveway every night and can feel it there.
I'm real close to City Hall...West Side....but the rest of my family, 'cept the parents, are in West Seneca, OP and Hamburg (or So.Carolina )
I'll definitely need to get to a few meets in the NorthTowns this summer. I can't wait to get to the track, though...haven't been yet, though. Do you drag? By your sig it looks like it. Where do you go? Lancaster is just an 1/8mi and i don't want to waste time there.
Yeah, i sold it. Trimming didn't help any. However, it may have been the extreme cold causing the issues b/c yesterday, when it was 50* out, i didn't notice the vibration as much. Regardless...i don't want it in there...so it's going to corny, mount and all.
When i install the new OEM mount, i'm gonna spin it and live with that.