jpar196

hey all, just curious of the sound of my engine when Im accelerating hard, the car is V7 STI running 1.1 bar low and 1.4 bar high. I know that STI panel filters sound like ripped piece of paper so its sort of chittery if you know wat I mean. but when I put my foot down I seem to hear this chitty chatty sort of noise. Is this detonation ? or is detonation really loud ? I can only just hear it, but its definately there. So Im confused to weather its the sound of the airfilter or detonation. Is there a way of seeing if its detonation rather than the sound ?
thx in advance

jjones

invest in a knocklink and see what that shows.

Moray

your crazy ! just drive it

Delboy2

As above - fit a Knocklink or get someone to listen to the engine with DET cans

Cheers

Turbo_Steve

DEFINITELY get a second opinion if you aren't sure.

dij

Definately get a knock link, and dont thrash it untill youre monitoring it (ie the kl is fitted).

Dark Blue Mark

Its quite hard to hear det while driving, without det cans. I think there are a few on hear with a well tuned ear though At worst it can be described like the sound of a drill!

Why's it running 1.4 bar??? Presumably its been fiddled with?

MB

easyrider

Is it at high revs?-if so,it could be your boost gauge rattling.Try it with the gauge disconnected.

jpar196

hey thx all for the replies, I have a electronic boost gauge atm so I dont think it could be the bg rattling, and as for running 1.4 bar it's been set as high boost with a manual boost controller. I run it at 1.1 bar most of the time.
sorry to sound so ignorant but wat is a det can ?

Dark Blue Mark

Why have you upped the boost?! That madness without adjusting the fuelling, and of course you will get det!

Det cans are basically headphones that allow you to listen for detonation.

MB

john banks

Knocklink will teach you to hear det if your car is doing it because you'll start to associate the noise it makes when it hits a big red, it isn't that loud but quite distinctive, then it is surprisingly easy to hear moderately severe det in the cabin, even on a new age with better sound insulation. But even then you can get less severe det that you would never know about without det cans or knocklink. For example I did what I thought was a final map on my car two weeks ago and it hasn't shown anything above 2nd green at 7000 RPM since. Another tank of fuel and there was a patch poking through at 5200-5800 RPM - just a spike to first orange on the knocklink, but not normal, ECU had found a bit at 3000 RPM. Just a degree out of these two areas and hopefully it will tolerate bad fuel a bit better. Getting a nice map takes a while of driving in different conditions and tanks of fuel. You keep pulling it down with a little safety margin, and then one day it never dets again for months or as long as you don't fiddle with it, unless something goes wrong.

From what I saw of new age STi maps, without octane booster you really do need to retard the ignition to run more than standard boost.

john banks

Some people describe det as a pin dropped in a tin, it can sound like a metallic click or thunk as well. Or a pneumatic drill that is really loud and doesn't stop until you lift off or even after that if you've really over done it