Noisy takeoffs

[Smeech]

Noisy takeoffs in 1st gear

On takeoffs (in 1st of course) Unless I rev it up a bit (1500) my car will make a sound similiar to the one when you try do accelerate going 30~ in 5th gear... kinda a bogging/grinding sound. I tried some search keywords but couldn't find much regarding this issue. Is this normal? Or could it be a transmission/differential issue?

Thanks

 

[Route666]

The grinding is resonance through your car body of the torque spikes, since they are at high load and low frequency (low rpm) each firing cylinder is more discernable (these make torque spikes). Low frequency high energy waves tend to propogate well through anything, just like that ricer's sub thuds into your living room while you're trying to relax after work, except these spikes are most likely 50 000 Watts plus (the power your car is making at that rpm with a high load), and a bit higher frequency than music subs. There's nothing you can do about it, just rev it up a little. You could put dynamat or something similar all over the interior shell of your car, but this doesn't stop what is happening, just the noise. BTW 1500 rpm is not even revving up, that's a mild takeoff rpm. If you're worried about the guy in the 40 bazzilion horsepower car taking your normal driving as a challenge and blowing your doors off, don't worry about it, he/she is just very insecure.

 

[Smeech]

Wow, thanks.. I had no idea.

 

[Route666]

No worries, I probably could have explained everything in more detailed, but I'm a bit slack. Oh, and the 50 000 Watt thing, the spikes may be this much, but most of it will be used to power the wheels, so you'll probably get 10% or so in actually noise being transmitted through the car, but still, a 5000 Watt sub is still pretty powerful.

 

[01LaserRedCobra]

Gear roll over...