S
Skant
Guest
Got my vette back with several mods installed (Transmission noise problem)
I'm very excited about it! My LT4 was previously totally stock..
4.11 ring and pinion (Tom's)
Borla cat-back exhaust
Breathless Air Rammer Intake
Lowered 1"
I'm nearing the end of the break-in process for the ring and pinion... it's sooo hard to baby her around and not cut loose to see what this new stuff will do.
The Borla exhaust sure growls nicely. I'm finding myself very pleased with its sound level. It has a huge resonance at 1500 RPM, but it goes away almost entirely by about 1800 RPM. Pretty quiet at 2000RPM cruise. It has the LT1 square exhaust tips on it which I'm trying to decide if I like or not... I think they look a little weird if you look inside them with two round exhaust pipes opening into the big rectangle. I might want to put the ZR1 tips on it instead. Dunno yet.
The shop was concerned that the tranmission was noisy when they took it for the break-in drives. To me, it does sound noisier than it did before. Which is odd because they didn't do anything with the tranny. My perception of it is that it's like the sound deadening material under the cup holder area has been removed. It makes the same sounds it ever did before, but it's like the barrier isn't there. If I just put a little towel over that cup holder panel, the extra sound is gone.
Now I know there's no insulation there that would have been removed, so that's kinda weird. A vague theory is that maybe the sound is being reflected by the new exhaust somehow... kind of like an echo...
But really, as I've been doing the break-in runs on the car, the gear sounds have been changing. The shop said that the new rear gears were quiet and I shouldn't hear them during break-in or afterward... but after a while I was hearing some sort of gear whine that was linked to road speed. It's a little hard to tell where it's coming from, but it sounds like the rear of the transmission. But then this and all the other sounds seem to be quietting down as it gets broken in. In fact, at this point, it seems to me like the car is sounding near normal again (or maybe I'm just getting used to the new sounds).
It's so hard to figure out if it's just me being hypersensitive or what. I know after I get a car back from the shop, I'm listening and watching so carefully for any sign of any trouble...
Anyway, I think it could be that the new ring and pinion actually is whining a bit and that's being transmitted down the drive shaft so it sounds to me like it's from the transmission. The nature of this is changing with heat level and time. And it seems like it's getting quieter. So hopefully that's just normal.
Of course, the first time I can cut loose with this thing, I suspect I'm not gonna care what it sounds like anymore. Even just babying it around, I can feel its greater desire to go... it's definately opened up.
The other part that's a little questionable right now is the lowering. The shop says they measured it as having dropped a little more than an inch. But I just measured it this morning, and it's at pretty much exactly the same height it was before. Now I expected it to be high for a few weeks since that's what happens when you pull the spring out. It needs time to settle again... and when I'd gotten a new spring before, it dropped 1.0 - 1.25 " from its initial height when I first got it back over the next weeks. So if it does that again, then that will be good. That will put it where I expect.
But the weird thing is... how is it the shop measured it as being an inch lower _now_? That's weird. Maybe because they'd already had it on the lift for a while so it was sitting high for their initial measurement or something.
So anyway... it looks like both of these quibbles are things that should settle and be fine after a while. Hopefully it will all be good. Just slightly nervous in the meantime... what if they _don't_ settle? But... this shop seems to be a real good place. So I'm not too worried yet.
I'm very excited about it! My LT4 was previously totally stock..
4.11 ring and pinion (Tom's)
Borla cat-back exhaust
Breathless Air Rammer Intake
Lowered 1"
I'm nearing the end of the break-in process for the ring and pinion... it's sooo hard to baby her around and not cut loose to see what this new stuff will do.
The Borla exhaust sure growls nicely. I'm finding myself very pleased with its sound level. It has a huge resonance at 1500 RPM, but it goes away almost entirely by about 1800 RPM. Pretty quiet at 2000RPM cruise. It has the LT1 square exhaust tips on it which I'm trying to decide if I like or not... I think they look a little weird if you look inside them with two round exhaust pipes opening into the big rectangle. I might want to put the ZR1 tips on it instead. Dunno yet.
The shop was concerned that the tranmission was noisy when they took it for the break-in drives. To me, it does sound noisier than it did before. Which is odd because they didn't do anything with the tranny. My perception of it is that it's like the sound deadening material under the cup holder area has been removed. It makes the same sounds it ever did before, but it's like the barrier isn't there. If I just put a little towel over that cup holder panel, the extra sound is gone.
Now I know there's no insulation there that would have been removed, so that's kinda weird. A vague theory is that maybe the sound is being reflected by the new exhaust somehow... kind of like an echo...
But really, as I've been doing the break-in runs on the car, the gear sounds have been changing. The shop said that the new rear gears were quiet and I shouldn't hear them during break-in or afterward... but after a while I was hearing some sort of gear whine that was linked to road speed. It's a little hard to tell where it's coming from, but it sounds like the rear of the transmission. But then this and all the other sounds seem to be quietting down as it gets broken in. In fact, at this point, it seems to me like the car is sounding near normal again (or maybe I'm just getting used to the new sounds).
It's so hard to figure out if it's just me being hypersensitive or what. I know after I get a car back from the shop, I'm listening and watching so carefully for any sign of any trouble...
Anyway, I think it could be that the new ring and pinion actually is whining a bit and that's being transmitted down the drive shaft so it sounds to me like it's from the transmission. The nature of this is changing with heat level and time. And it seems like it's getting quieter. So hopefully that's just normal.
Of course, the first time I can cut loose with this thing, I suspect I'm not gonna care what it sounds like anymore. Even just babying it around, I can feel its greater desire to go... it's definately opened up.
The other part that's a little questionable right now is the lowering. The shop says they measured it as having dropped a little more than an inch. But I just measured it this morning, and it's at pretty much exactly the same height it was before. Now I expected it to be high for a few weeks since that's what happens when you pull the spring out. It needs time to settle again... and when I'd gotten a new spring before, it dropped 1.0 - 1.25 " from its initial height when I first got it back over the next weeks. So if it does that again, then that will be good. That will put it where I expect.
But the weird thing is... how is it the shop measured it as being an inch lower _now_? That's weird. Maybe because they'd already had it on the lift for a while so it was sitting high for their initial measurement or something.
So anyway... it looks like both of these quibbles are things that should settle and be fine after a while. Hopefully it will all be good. Just slightly nervous in the meantime... what if they _don't_ settle? But... this shop seems to be a real good place. So I'm not too worried yet.