[Irace86.2.0]

I finished working out the vibration issues: it is the engine. It isn't the exhaust. It isn't the shifter. It isn't any rubbing points. It is simply the engine.

There are some noises that I have that are new from the old setup that aren't ideal. The sole, high-flow cat creates some drone at certain rpms, but overall, it isn't terrible, and it isn't there on the highway or in any way that can't be easily overcome with my stereo. There is some hollow noise that resonates on decel at certain rpms, which I can't tell if it is from the IC pipes, the exhaust, the skid plate or what, but it isn't loud enough, nor does it happen often enough to matter much, and again, it can be easily overcome with music, which I listen to loud most of the time.

There are several noises that I liked that are there still and possibly slightly louder, but not obnoxious. My Exedy Stage 1 clutch is sprung, but it does create some noise on decel. The Whiteline transmission bushing creates a mechanical friction noise that makes the transmission sound more mechanical, so I like that.

I don't think I am getting any driveshaft vibration. Such vibration would be there independent of rpms or accelerator input, but I really haven't detected anything consistently, but I'll keep checking. Overall, I don't think it is that.

It seems to be the engine at idle and in motion that is the problem, and I am certain it is mostly losing the balancing shafts in the oil pump. Certain conditions will cause an engine to vibrate. On a normal car, high-load low-rpm situations, low-load high-situations and on decel are times when an engine will typically vibrate more, so I think it is just slightly worse. Some of that could possibly get tuned out, and some of that could get smoother over time, as the Haltech makes adjustments, but I don't think there is really much else that can be done because race car. I drove the car around, and with the music on, the car seems to do fine. There seems to be less vibrations, so maybe the Haltech is figuring things out, and maybe the music is my best bandaid.

Here is what I did:

--I removed the under trays. Nothing appears to be touching them, and removing them did nothing to change the vibrations or noise.

--I detached the exhaust from the hanger. I turned on the car. It still had the same vibration.

--I felt the rod going to the bottom of the shifter. It was vibrating on the transmission end, but it was barely vibrating on the shifter end, and it became more obvious that the shifter is not transmitting anything to the car. It being hard mounted makes no difference at all, but I will say that the shifter on this setup is pretty awesome. I had the Perrin shift bushing, MTEC springs, and I had shortened the shifter, but this takes the feeling up a notch. It is lower, it is very solid feeling, and the shifts are very bolt action, which is great. I wouldn't want to change the shifter at all.

--Then I checked the chassis. The exhaust has about a centimeter gap. The AC lines has maybe 3-4mm from the head. The oil pan is about 1.5mm (confirmed with the feeler gauge) away from the steering rack, but it wasn't touching. The transmission is about 5-10mm away from the transmission tunnel at the closest point. I really couldn't find anything that is touching the chassis.

--I then decided to remove the transmission bushing. Instead of doing that, I just jacked up the transmission with some wood under it. At this point, the transmission mount was entirely removed, and the transmission was jacked up high enough that the gap by the oil pan and steering rack was 3-5mm, yet the vibration was still there, and I confirmed there was no chassis touching still, so I realized at this point, it was all the engine.

The vibrations pretty much disappear at 1400 rpms, and the resonance returns above or below. I could probably raise the rpms, but I took the car on a drive, and it just wasn't really that obnoxious with some music, and the shaking seems to smooth out some after cruising around. I think I can live with it for now.