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01-17-2013, 05:08 PM | #155 | |
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The other thing I noticed is that there's less bucking when letting off the throttle. Before I had to let off the throttle somewhat gradually or the car would buck a little, now I can let go and it stabilizes much quicker.
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01-18-2013, 03:24 PM | #157 | |
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heres the info from the man himself.... Regarding stress cracking this is an interesting one. The stresses could come from two areas if the car is solid or near solid mounted. 1) A solid mounted engine will stiffen up the chassis by becoming a reinforcing member. This will increase the torsional stiffness of the car but by doing so you will potentially put massive forces into part of the car that are not designed to take it. 2) A solid or near solid mounted engine will transmit vibration from the engine to the chassis increasing local stresses in the mounting points. We measure vibration using the scale mm/s. This is an industry standard for vibration severity. An engine produces around 10mm/s at idle and up to around 20 to 30mm/s at high RPM. When we measure vibration we aim to get down to around 0.5 to 0.8mm/s in the cabin floor. Even our very stiffest mounts competition mounts would only give around 2 to 3mm/s in the cabin. To put this into perspective the threshold of human perception is around 0.4mm/s. In a building 10mm/s is enough to cause structural damage!. So if an engine were mounted solid there is enough vibration energy produced by the engine to put enormous stresses into the car structure. So in summary there is not enough vibration transmitted by our mounts to significantly increase the stress in the subframe either by chassis flexing or vibration transmission. I hope this helps. Now..... i have to say these mounts are rather impressive..... im PLEASED i have the competition units in the car and im happy with them, i would say however you WILL notice an increased almost like low resonance vibration almost @ idle... so in summary, these wont damage your mount points, they WILL increase idle NVH and so far from what i can tell the rest of the rev range theirs no real concern area Zub.... your car may be even smoother as mine has the imbalance of a whopping great s/c on one side, (it creates idle vibration) The mounts are a work of art..... The road versions are more than enough for 99% of the needs, for me i wanted as much motor movement control as im getting certain parts brushing the hood under the extremes of use.... Im almost certain that movement will be stopped with these mounts..... i Cant wait to get to the track with these on!!!! BTW they are lighter than the stock mount according to my scales..... i opened up one of the mounts also and their rubber piece is much more significant that you think from what you can see.... so i understand how the comp ones wont be causing stress issues...... they are simply not solid enough and can be slightly depressed with you finger even..... the fast road version can be squeezed pretty easily.... the stock ones feel like jelly compared to both!! my stock mounts had 11k miles and its pretty obvious the ast few ks worth of s/c power and track-time has really weakened them....... if you can chance to open one up they are a very nice design inside, their is no way they can completely come apart!! VT you killed it with these mounts!!!! phil has been a pleasure to deal with from the off.
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01-18-2013, 03:25 PM | #158 |
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niiiiiiiccceeeeeee just as i posted my review and you DONT need to worry about stress fractures with these!! read back :-) have you polished yours??? lol!!! they are gleaming???
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01-18-2013, 03:32 PM | #159 |
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Great follow up info Byron !
I wish I could try these things out. Until spring arrives, i just have to enjoy looking at them.
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01-18-2013, 03:36 PM | #160 |
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are yours polished like above or are they matt finish???
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01-18-2013, 03:49 PM | #161 |
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ZUB cant wait for your review......
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01-18-2013, 04:14 PM | #163 |
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they really are easy, even more so on my car with the smaller intake manifold and euro mani.... really was almost enjoyable!!!
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01-18-2013, 04:23 PM | #164 | |
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I have a couple of questions. 1. Did you have to modify the heat shield? 2. Can these mounts install one at a time? I wasn't sure by your write you. Engine mount bracket bolts was loosen to get the mount out. Do I have to loosen both side before lifting the engine? |
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01-18-2013, 05:33 PM | #165 |
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Polished.
.....not that they'll stay that way for very long where they're going.
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01-18-2013, 05:45 PM | #166 |
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Strangely this guy only talks about the vibration caused by the engine running, but those vibrations are almost negligible in force. (I also don't understand why he gives acceptable stress in buildings as an exemple, a car is much stronger)
I was worried about/my point being the engine jerking around in the engine bay, caused by bumps and turns. Especially the s54 is a relative heavy engine with it's cast iron block. Just like a very stiff shock absorber can damage the chassis with large bumps wheras a softer shock would have cushend the blow (resulting is less peak force). Those blows are much much harder than the max 30mm/s that the engine vibration @high rpm may produce (a nice bump can lift the chassis what.... 3cm? in 1/4 of a second? So that's 120mm/s (average; the movement is sinusoide, so peak is even higher), which is over 4(!) times the vibrations caused by the engine. And I don't know what balance shifts in short corners do, but it makes the engine wiggle around pretty much) Maybe he misunderstood or so. For the record: I'm not saying that it will be a problem, but the answer from that guy doesn't cover the load of the question imho All I know is that stiffening up your car usually comes at a price. Stiffer springs, stiffer antiroll bars, stiffer suspension bushings... they all put bigger strain on the chassis, and sometimes it cracks over time, so imho it's best to keep an eye on those mods to see if the future brings any of these effects. These things don't happen over night. Last edited by GuidoK; 01-18-2013 at 06:23 PM.. |
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01-18-2013, 06:09 PM | #167 | |
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2. One at a time. |
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01-18-2013, 07:45 PM | #169 | |
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Installed my mounts earlier today!! I also did the last two Motorsports bolts.
After driving around for a while....I've come the the conclusion that it is like having a NEW car. At idle, NVH may be subtly higher. Not enough to make any new squeaks in the cabin. I almost don't want to write that because the change is almost imperceptible. Maybe I'll have to go with very stock like NVH. Shifting from 1st to 2nd drastically improved!! It's only slightly notchier than from 3rd to 4th. I can shift into 1st with no problem rolling to a stop. I can shift at any RPM (from 2500 to 7000) feels almost like 3rd/4th shifts. This completely transforms the car!! The car is definitely smoother under acceleration, deceleration than ever before. This mod is as good as (if not better than) the AS SSK. That's saying a lot. Here's some pics.. First the old mounts (left side)... The right side... Comparing new to old... Here's the Tab on the heat shield that Beta mentioned. New right mount (top bolt not added yet). New left mount. Quote:
1. The only heat shield that needs modified is the one on top of the right mount. There's a pic above. Just hammer it down. 2. I did one at a time, however I removed all the bolts from both so that the engine could move. Something that I noticed when jacking up my engine is that the left side will clear the mount bolt before the right side. I put my jack under the front right corner of the oil pan to lift being careful not to disrupt that circular filter and oil level sensor. You could do both at the same time. When lowering the engine the right side engaged the mount bolt before the left, so that makes it easy to keep an eye on them. I ended up temporarily shimming my right mount a little with some cardboard so it would better line up with the mount bracket while I was lowering the engine. Make sure you have a u-joint socket adapter and a long extension. You need the u-joint for the right side. I used an 18" extension for the right and a 24" extension for the left. The super long extensions are probably not needed, but nice. |
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01-19-2013, 12:34 AM | #172 | ||
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As more people install their mounts and try it out we'll get a better picture (especially those with uprated transmission mounts). I'm still hoping a transmission crossmember provides a complete solution.
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Last edited by beta; 01-19-2013 at 12:58 AM.. |
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01-19-2013, 01:35 AM | #173 |
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i opened my vibra package at the shop so i could see the pretty things before they were installed and hidden for good. droool...they are gorgeous and scream precision. the shop guys were all pretty impressed. one of the guys wanted to take them apart lol.
the stockers. ehhh i put about 50 miles on the new mounts today. i'm not sure what phil was warning us about, but the competition mounts are not bad at all. i have a rattle here and there while the car is idling, and this verrry mild echoing resonance in the cabin when i get going in low rpm first gear from a stop. but apart from idle and low rpm instances, the noise and vibration is not to the level i was expecting. standing outside of the car while it's idling you can tell the motor is giving off a more pronounced noise...less muffled if that makes any sense. kind of how your motor might sound on a very cold start, but all the time. these mounts definitely serve their purpose. i cannot WAIT to take these to the track. if any of you are familiar with VIR, there's a sharp right hander (the turn is called oaktree) which i have been around countless times and get denied 3rd-2nd often. i got less denial with the A/S SSK, but i'm willing to bet that the motor mounts may help in that area based on how precise and crisp the relationship between motor and gear feel now. i think that's the best way to describe it - crisp. i think the mounts got rid of some throttle slop as well. maybe this is just placebo or my car was just running fantastic on this 40 degree day, but the motor responds cleaner and more instantaneously to my throttle inputs than i last remember. you do feel a lot more of the road with the mounts in. i love that it's more like a racecar, but it may not be the ideal mounts for those who regularly bluetooth or enjoy drives with a tall cup of coffee/tea. it makes imperfections in the road more dramatic, but that's in no way a deal breaker or deterrent to me. cliffs: they're awesome town.
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01-19-2013, 01:39 AM | #174 |
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also, funny thing. while i was driving home from the shop i was thinking to myself 'i hope phil/vibra got my note that i wanted the competition ones and not the fast road ones' because of how civil they were. they're not like butter, but they're also not like loose change symphony either lol. when i got home and saw the packaging, i saw that they were in fact the 362 competition mounts.
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01-19-2013, 02:22 AM | #175 | |
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Tbh I wanted then for a specific reason tho, to control my motor lifting as much as it does. If the car wasn't running the extra power I'd have gone fast road no doubt. Really glad to read ur review :-) They feel awesome!!!!
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01-19-2013, 02:43 AM | #176 |
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Zub what did you Tq the bolts to...... i was thinking,,,maybe we should be guided by VT on the Tq spec for the mounts as they use different fastening hardware....... i.e nylocks.
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