Never had, never been in a superchaged car.


I now have a all forged 4 bolt 355ci head cam LT1 9.1:1 CR and i put on a ATi prchager P!-SC with a 12# pully.

It has a wierd (to me, remember no blower experience) vibration. Kinda like holding a drimel or weed wacker.... very very high freqency i guess. makes a "hhuuuuummmm" as well (in addition to the blower wine)

please not i have not been over 2500 rpm and i know its not the motor, i ran it for a 100 miles with no belt and its smooth (cept for lopy cam)

just let me know if this is normal, how your feels etc... just concered cuz i spent alot on this

lastly, i dont know how tight to set the belt tension?? the ATI book is soo vague, how tight should it be? loose as you can with no slippage?

 

Mine doesnt make a humm but more of a whooshing sounds when im at certain rpms. I guess Im hearing the air coming from the byepass vlave b/c mine is vented to atmosephere.

 

Sounds like an external fuel pump in action to me
If you are running an external inline pump, pull the fuse and drive it to check (just don't get on it), if you're not running an inline pump, we'll have to go to plan B.

As far as belt tension goes, I used to use the old "less than 1" total deflection" across the edge of the largest setion of belt between the blower and crank pulley.

Marc

 

Im running and intank walbro 255


I think when i said "vibration" it made yall think the car was shaking or something....

I mean, its more like a high speed electric motor felling. I feel it when i rev the motor up holding the TB, or when im indside the car on the steering wheel/gas pedal....even the dash.

BTW i do have poly motor mounts, but no vibrations NA whatsoever.


Just seems odd to me, but i guess maybe thats just what they feel like ??? I mean it is spinning realy fast, even at idle (65,000 rpm at 6000 rpm? so 10,000 RPm at an idle of 1000?)

 

My blower never resulted in any such vibrations. All things considered, the car actually ran pretty smooth in most respects, unless you get suspension into the picture lol.

Btw... what did your car run with your old engine in it? The topend of that engine sounds interesting. Also, you have a very nice looking car!

 

I'm thinking those poly mounts may have something to do with your vibrations, but then again when ever I touch something on my engine when its running I don't get any high speed vibrations.

Disconnect the blower belt and see if the vibration goes away??

Give ATI a call about vibrations??

Hope this helps

LWM

 

Is the blower new or used?

 

Make sure the supercharger is not touching the ABS bracket on the DR side frame rail. This will make a bad vibration. With the belt tensioned, the SC bracket may flex & allow contact with the ABS bracket. Without the belt installed, it may just clear & act fine.

Hope this helps.

 

Before installing it i did clearance the sway bar bolt abd bracket...

couple house ago i took it back off(PITA) and clearance it more AND the ABS bracket...problem seems solved

wwhheheeeehwwwww


Thanks guys