Before you ask no I'm not a sad baseball cap wearing boy racer. Some guys here at work want to record the sound of my car for a rally game we're doing. I'm assuming that they're going to want the sound of the car at different revs low and high. Not sure how long it will take before they get the sounds they want but in doing this will it be bad for my car. For some reason I swear I heard once that this is a bad thing to do with Turbo cars.

 

Come on guys someone must know.

 

I assume you mean while not on the move. I'm not sure if it's bad for it or not - can't see why it would be (as long as the engine's warm). However, you won't get the proper sound unless you record it on the move anyway, as otherwise there will be no turbo sound and no decent exhaust sound. Trouble is now find out how to record it while on the move

Richard

 

They test the engines endurance by leaving them on the redline for 24 hours. If it doesnt go bang its ok.

So a bit of redlining if the engines warmed properly shouldn't make the slightest difference!!!!

Jza

 

Stick it on a rolling road and record it, if you're worried about staticly running the engine

 

Make sure you warm it up well.
Trashing the nuts of it from cold would indeed damage it.
Cheers.
Ian.

 

Jza - idumb *** question : is that the engine you get or just test them randomly and bin them after?

 

Cheers guys, I might see if the company will pay for me to take it on a rolling road. That way I can get BHP figures as well . I imagine it's going to be difficult to get the sound right but I'm not working on that game so I'm not to bothered if it sounds good or not.

 

I wonder if you even need to do that.

Surely a games developer will sample 1-2 seconds of the engine and then progmatically adjust the frequencey of the sound on playback to simulate increase/decrease in RPM. MS DirectSound has support for this stuff. Otherwise you'll have a hugely inefficient sample in your game and eat even more memory

Go ask your techies

Ian.

[Edited by igratton - 2/20/2002 1:42:03 PM]

 

My mate wanted to record his VR6, so he put a mike under the bonnet, brought the lead in the window and attached it to his laptop. worked a treat. he then hooked up a camera to the laptop as well. Unfortunately he was looking at the laptop when he should have been looking at the road and stuffed the car through a hedge -moral of the story is to get a mate to record while you drive.

 

To get a good sound for use in a 'rally' game they you have got a lot of different sources to think, not just the engine!

The Engine (induction noises, turbo spooling and dumping etc),
The Exhaust (under accelleration and braking, up & downshifts)
The Transmission (based on gear selection and road speed - not engine RPM).

Then you've got the sound created by running over gravel, tarmac and snow to think about, and wind noise!!!

Just try listening to Colin McRae Rally 2!

Good luck.

 

Cheers guys, I'm an artist so don't know much about the sound side of things. I know that they usually only grab a few frames worth of stuff and then work with the frequency but that's about as much as I know. But I'm assuming they'll want as much as they can to give them more freedom of choice. I'll leave it to them to decide what to do, I'll just stick to making sure the car doesn't blow up.

 

Engine needs to be on a rolling road to get proper wide open throttle sound, I think high rpm with no load is not so good for the engine. Trouble is with the Scooby you need 4WD rolling road. If you have one local and the company pays that would be ideal

Some manufacturers do tailpipe noise work on vehicle test track, you can set up a bracket to hold a microphone ~ 250 mm away from the tailpipe and record from that.

 

Reving your engine above 5k when not under load is not something
you do unless you have to!!!!!..

 

Sorry guys, I have to disagree with you.

Putting a car on a rolling road is probably one of the most stressful things you can do to an engine. Loads of load, minimal airflow to keep the engine cool when compared to real road driving.

This guy was concerned about revving the engine, no load. I don't have an issue with this at all, providing the engine is properly warmed.

Have I got this all mixed up or are you saying that lots of load is much less stressful than none? I really dont think so. Please justify your claims.

Al

 

Pob, due to tolerances in the drive and valve trains etc reving an engine under no-load is not recommended as the mechanical train will be subject to ****** and chatter. When under load everything is pulling hard in the same direction and this phenomenon is less likely to occur.

When performing power curves or back pressure testing on vehicle dyno it is potentialy hazardous for the engine. Mainly due to excessive temperatures being reached, so fire hazard more than anything. Particularly for large engine with cramped engine bays. We use large fans to simulate driving air flow. We also have an undert bonnet fire extinguisher system and emergeency remote engine stop facility. Also the driver has an oxygen pack and protective gear in case of the (unlikely ) event of needing to exit the test cell during a fire.

So yes it is hazardous but in a different way

Mick