Airbox resonator removed - few Q's

15th October 2014, 08:07

Hi guys,

Sorry for another airbox resonator removal thread, I am sure you get it far to often! Bare with me though...

I bought the car with the resonator box removed, which explained all that induction noise when driving it home! Sounds lovely mind!

I'm happy to keep it like this for the time being and maybe at some point run a cold airfeed pipe to it. At the moment it is left open.

The car drives lovely, pulls very well and performs as it should. However in town last night, stuck in traffic (gridlocked) I noticed at idle the revs would vary a bit after I blipped the throttle. Is this the ECU trying to find a steady idle? The car was hot, fan kicking in.

Would having the hole left open cause this?

Any ideas?

Thanks

15th October 2014, 13:04

Quote:

Originally Posted by Daniel_Saxo_VTR

Hi guys,

Sorry for another airbox resonator removal thread, I am sure you get it far to often! Bare with me though...

I bought the car with the resonator box removed, which explained all that induction noise when driving it home! Sounds lovely mind!

I'm happy to keep it like this for the time being and maybe at some point run a cold airfeed pipe to it. At the moment it is left open.

The car drives lovely, pulls very well and performs as it should. However in town last night, stuck in traffic (gridlocked) I noticed at idle the revs would vary a bit after I blipped the throttle. Is this the ECU trying to find a steady idle? The car was hot, fan kicking in.

Would having the hole left open cause this?

Any ideas?

Thanks

i dont think it would cause such a problem, keep an eye on all the usual sensors, it could be one of them starting to play up on you.

only thing i can think of, is with it just drawing hot air in from the engine bay, that hot air (bring stuck in traffic will have the hot air build up under the bonnet) isn't doing too well for the combustion process, maybe inducing a bit of knock which the ECU is fighting off now and again, and with it fiddling with the timing to keep knock away, would more than likely vary the idle a little bit (years ago idle speed could be minutely changed by fiddling with the timing...back in the days of dizzy's) but i dont think that it would cause that much bother unless the air going in is proper hot.

stick a bit of pipe on it to draw air from the front of the car and see if it makes any difference. if it behaves then you know she was sucking some really hot air and not liking it.

also, FWIW, relocate the IAT to the air feed pipe if you fancy a fiddle, i found when the throttle body got hot from the engine warming up, it was reading the air coming in as a fair bit hotter than what it actually was, and relocating it to the air feed pipe i found the car pulled a bit harder when it warmed up, and on a cold night, it pulled like a train compared to daytime.

15th October 2014, 21:43

Mi5terSIR Thanks for the reply! I agree with you, the car was hot (fan kicking in) sitting in a bastard of the traffic jam! (bloody Cambridge!). Sucking in hot air from the engine bay and the ECU trying to find a steady idle. I think a good idea would be to run a CAF to it.

Many thanks!