R500 owners HELP! - BTB noise levels

[GetCarter]

Hi chaps,

 

I guess you'll hear from me a few times over the next month or two. Thanks in advance.

 

I've just taken delivery of a shiny new R500 ( www.R500.com )- and went straight down to BTB to get a big silencer fitted so that I can do all the track days I've booked in for later this month. BTB told me that the car now reads 101.8db @ .5 metre @ 6000 rpm.... which is fine. However, I'd seen that Bookatrack were hiring out noise meters, which I hired, and that reads 107db - are noise meters that useless?

 

Three further questions:

 

1. The R500 seems to 'pop' and backfire like a mad thing till 6000 revs then evens out... do they all do that? (I think it's marginally quieter @ 7000)

 

2. Am I missing something here? - I believe several of you have followed the BTB path and got to 100 db. How?

 

3. Lastly (not exhaust related). When I drive on 'neutral throttle' - through traffic etc... I'm getting massive 'bunny hops' - proably look like a first timer. Is that normal?

I have to accelerate then brake to stop the lurching. I'm thinking perhaps the engine management system is not quite set up right... hence popping and indecent throttle behavior?

 

Any ideas would be appreciated

 

Thanks

 

Steve

 

Edited by - GetCarter on 9 Aug 2002 18:02:44

[jerrypike]

yes, noise meters are very variable, as are the conditions for testing

engine needs to be hot, make sure nothing in the exhaust exit line to reflect sound, build revs gradually to just reach the requested 5,000 rpm (red-line must be 7,500 surely?!)

my slr used to pop and bang horribly on part throttle/overrun but change of ecu and remapping has cured this and driveability. see you're already on the upgrade trail:

e-mail me if you want the details of the man who fitted/mapped my motec, v.happy

jerry

[Howard Dawson]

Steve

 

I still run the standard exhaust so I can't help there. However, the car should be smooth throughout the rev range. There are many different maps and a special one to get the car through SVA I believe. Check with Caterham/Minister that you have the correct map.

 

Howard