This video will show you the reason silicone TB adapters are preferred for intakes, and why rubber is too stiff:

http://www.williamwren.com/flex.mpg

Rubber doesn't give enough, which allows the intake to be forced into the hood. Silicone dampens this force.

Holy macorini Will . Are your engine mounts all in good shape, and if so is that a normal amount of movement???

Looks like a great arguement in favour of adapting the Grand Prix style double 'dog bones' to keep engine torque to a minimum.

Cheers,

Motor mounts are in good shape. That'* in gear, foot on brake, 3500-4000 rpm'*. Just to show a point. SC 92-95 use a totally different mount setup than other years/models. All mounts were inspected last month

your talk about your cai mounts??

He'* showing why he thinks the Intake tube needs a silicone mount to the Throttle Body, I use a hard Rubber/Metal mount, and angle it downward more, but something tells me Will actually researched this.....

I know Will does a ton of great research for us, but for some reason I still get the mental image of:

Will'* research = Drink beer, rev engine, stare..........

LOL, he does more research on a single project than I will on every project this car receives the entire time I own it, Combined.

Yes mine had that much flex also before I replaced that front rubber damper mount with a solid urethane donut. Now there is no visible movement and it reacts very positively. The only compromise, and there are always compromises to every mod, is a slight vibration felt through the steering wheel, but it'* barely noticeable.

Hector and I discussed this very problem way back 'in the day'. This is why silicone reducers are worth their money. Now imagine this:

You have a Non-Supercharged car. Your intake moves with the engine as you saw a little in my video, but in this case, you're running a rubber (much less flexible) coupler to the TB. So when your engine torques over, the intake pipe raises, and presses the underside of the hood. It resists this rocking motion. Your TB is mounted to a plastic upper intake.

Get it?

Something I've been thinking about more and more as we're all working on intake projects. Just keep this in mind. Mine is actually impressing itself on the under side of the hood insulator, but I have a silicone reducer, so If I hold the intake down with my hand while a friend revs it, my coupler takes out the motion by flexing. Rubber plumbing couplers won't do this.

Yes, the front motor mount is filled with hydraulic oil because it is a shock absorber that is designed to move about 3/4". That translates to a lot more movement up top. It'* for that luxury no feel experience.