Spiky

iTrader: (1)

the lotus exige's suffer from noice due to induction (sean bicknell is one)

i've heard some gti6's with ITB and carbs, and they not THAT loud, but some are louder than others

i heard the chosen cam can affect the noise level???

just my two pence worth

JTECH James

iTrader: (13)

im 99% sure martin did have an induction noise issue when the new car was first used,

Rab

I love these informative passionford threads

richard_syko

The only way to reduce induction noise would be to use an airbox like on a production car. The volume of the box will effect the frequency and the volume of induction noise.

Big cams can also actually increase induction noise alot as the pressure difference between the manifold and the engine changes quicker as the valve is opening faster.

Stavros

Bloodyhell

Everyone im sure is mentally able enough to work out HOW to reduce induction noise, the question is, at what level does your usual turbo and cone filter cause so much fucking noise it trips the noise meter.

StephTell

I might be way off here but didn't Mike used to wind the boost down to a certain level to decrease the noise?

JTECH James

iTrader: (13)

thats hard to answer as it will depend on so many things,

what is a usual turbo? what is a usual cone filter, and where is it placed, what engine spec and boost does a usual car have?

only you can find out how noisey yours is

richard_syko

Well it is a bit of an open ended question to which your getting open end replies

markk

iTrader: (2)

i would say that a cosworth variety'd turbo engine unless someone has done something totally ridiculous with it will not be able to produce anywhere near 100db on pure intake noise alone, especially not on driveby, in fact i would place a safe bet on that, having to deal with noise on a regular basis and having been noise tested on a regular basis.

alot of the biggest issue related to INDUCTION, is that when a restriction is placed in the inatke the noise of the air trying to be pulled through this can be very loud at full boost/high revs.

wildheart

iTrader: (4)

I got black flagged after a few laps at national day in my 3dr.

T4 running 2 bar boost and i had a restictor in the exhaust and the bloke that pulled me in said it was down to induction noise,I tripped the meter at 99.1db

Stavros

only if you are a retard.

anyone with experience of this will know when they tripped it due to what they think or was told was noise, and will know the rough spec of their own cars.

Porkie

iTrader: (1)

Sierra did. Bedford and Donno.

Deffo induction... my own fault really. Silly metal thingy cone filter unboxed...

Would have been something that was definately modded if I had kept it.

Mike Rainbird

iTrader: (3)

Stav,
I believe my car was black flagged for induction, as I cut the front of my airbox away even further a few weeks ago, and I have never had problems before. I only "just" tripped the noise meter at 2.0 bar of boost as well, with 98.7dB, so my exhaust works and I believe that 1.8 bar would have sorted it, but I had to drop it down to the lowest setting, as I was already on position 2 (of 4), which equates to 1.4 bar creaping to 1.6, as the boost curves with the roller-bearing turbo have gone to rat-shit and need adjusting, so I have my 1.4, 1.6 1.8 and 2.2 bar boost settings.

Incidentally, CSLs have huge problems with induction noise over exhaust noise.

StephTell

Go tell Lee and Mike lol

Markb_s1

at the risk of getting completely cunted off for being no help whatsoever...

not sure if this is of any use as i'm nto sure how the noise levels are tested at trackdays but i've seen a golf with an audi turbo engine penalised at lydden due to induction noise. i believe the basis for it being stated as induction rather than exhaust was that it passed the static test when revved to whatever rpm it was (despite being fuck off loud) but was caught out whilst racing by a trackside mic. presumably the induction bit comes from the fact that it was fine on static?

was running a turbo about gt30 (not a lot of use i know - sorry!) sized with an induction kit (kind of like those old viper things you used to be able to buy, and maybe still can) with the cold air feed out the front headlight.

Tim

iTrader: (1)

I was for induction noise on the t34

wildheart

iTrader: (4)

How did you overcome the noise Tim?

Dingy

Got black flagged at dono for induction in the morning at 25psi.....

In the SO turned it down to 18...

Last sessions i turned it up to 2 bar and never got black flagged.

Wind affects dono in a big way....

Ran the time before at full boost no issues.


Cone filter - no airbox.


Bedford - 2 laps on 15psi - off - worse track in the uk bar none.

Croft, brands, silverstone, cadwell and oulton - never had any issues with induction.