Jay Cartay

iTrader: (3)

Curious one this, we were out road mapping my Blob and the mapper showed me it was basically running perfectly except on odd occasions it would pick up noise on the actual gearchange when gunning it. I think it was 3rd to 4th but can't remember clearly now.

What on earth could cause this? There was absolutely no knock while actually accelerating, so it's very very odd. It pulled a whole 12 degrees of timing on the occasions when the gearchange did upset it.

Anyone got any clues?

joe v3sti

iTrader: (8)

Who are you using to map it? What are thier thoughts on why it is happening?
Also what ecu?
can the sensitivity be adjusted

jazzyjembreaze

iTrader: (11)

Still in throttle as clutch de- pressed or engaging whilst car in neutral temp , ever so slightly ??

yabbadoo4

iTrader: (8)

12 degrees is a lot of timing to pull, i had a fuel and air leak on my bug which caused the ecu to pull around 7 deg. at higher rpms as it saw it running lean but thats a fair bit and id be wanting the mapper to have another look.

SmurfyBhoy

Could be gearbox mount or loose pipe in bay

I had my intercooler pipes cause faulse knock

Jay Cartay

iTrader: (3)

It was only on gearchange and even then it was only every once in a while. It was absolutely perfect the rest of the time. No det through the cans. Most times shifting 3rd to 4th it didn't cause an issue. It happened maybe three or four times in a good hour of driving about.

Joe, I ended up getting Tim to map it as I couldn't move the car to get it to Andy Carr so had to cancel with him. Tim helped me out a fair bit and helped me get up and running again and I've been very impressed with what he's done for some of the other lads I know. We didn't get chance to investigate further as the tweaking was done the night before competing at Harewood.

I'll go back to him soon to discuss it, just wanted to get a feel for what it could be.

The gearbox mount is an uprated Hardrace item, and that was only recently put on and everything torqued up to spec so I'd be quite surprised if that was at fault.

yabbadoo4

iTrader: (8)

an uprated item would be firmer im guessing so might actually be transmitting vibrations which the sensor is picking up.

joe v3sti

iTrader: (8)

Tim knows his onions so I'm sure it will get sorted. I had a similar issue at one point that seems to have gone away of it's own accord

Joe

Jay Cartay

iTrader: (3)

I thought this too, but just odd it's not all the time if that's the case. Who knows? The fact it doesn't pick up anything the rest of the time and there's no det coming through the cans is reassuring though.

Yeah I have been really impressed with him. He's good at explaining exactly what he's doing etc. too which I like.

The Rig

iTrader: (13)

I get the same on my esl, usually around engine load 40 just as full boost kicks in , ranging from 2800 rpm to around 3600 cells and usally around .5 or .75 degrees (so virtually nothing)

Ive tried all sorts and what cures it for some weeks then doesnt a month later, so if its known to be gearbox noise, live with it ha

yabbadoo4

iTrader: (8)

as the rig says probably nothing but 12 deg is an alarming amount of timing to pull so if it is just noise it must be a frequency that the knock sensor really doesnt like. id still want it checked out to be sure.