vibration

[jmwilso2]

Hi everyone I just got my gryphon a week ago and have been on a road trip half way accross canada since then I've been trying out the different canned performance tunes and am finding that the 87 towing gives me the best over all driveablility and fuel economy but both it and the 93 performance have a small but very noticable vibration when in 4th gear and under load. For example when accelerating gently, it occurs immediately after shifting to 4th. Or if going up hill at lower speed like 35-45 mph. Once I get up to highway speed the vibration goes away. It feels like it is coming from the tranny but I cant be certain. Has anyone else experienced this and if so did it go away when you got your custom tunes?

Thanks

Joe

[jmwilso2]

Hi everyone. I just installed an S&B cold air intake this morning. I started the truck up and everything seemed fine until I took it for a test drive. The intake does seem to add a little extra oomph and my average fuel economy is .8 better than before but the vibration I described in the previous post is 10times louder. It happens under the same conditions but at first I didnt even realize it was the same noise because it is so loud. I assumed it was the intake drone that I have heard the S&B has sometimes and was trying to think of a way to deaden the vibration in the air intake when I got thinking about the vibration I was already experiencing. I set my gryphon back to stock and all the vibration/droning went away. So now I am wondering if the noise I felt/heard in the original post was coming from the factory intake and the larger more resonance prone cai tube just amplifies it. I really dont know. Tomorow I will try two things first is to rev the engine while in park with the gryphon set to 87 tow and see if it makes the noise and then I'll try test driving it in tranny only. If anyone has any suggestions I could sure use the input. I'd like to make sure I'm going to keep this intake before I send in my hex code.

[Longshot270]

If the vibrations go away when tuned back to stock then it sounds like a tuning issue. I'll try to get Bill's attention to see what he thinks.

[jmwilso2]

Ok, thanks, its sure got me puzzled, if its just a tuning issue that is great because when I get my custom tunes it should eliminate the problem.

Thanks again

Joe

[Longshot270]

I'm not completely sure what it is but it sounds like a tuning issue. Normally the canned tunes dont cause any trouble.

[jmwilso2]

I did some playing around with it today. With the truck in neutral there is no vibration regardless of rpm and programmer level. When driving though there is only normal intake noise with the gryphon set to stock and a slightly louder with it set to tranny only, but in 87 tow it howls whenever there is load on the engine. Cruising along there is no abnormal noise but if you accelerate or even go up a small hill with the cruise control on it makes enough noise that you have to raise your voice to talk. Im still not sure if it is coming from the intake though i think it must be because the noise was very subtle until I installed the cai.