Question to all 7A flywheel users

[hermanio]

resonating sound around 1500 rpm ?, had the same problem is torsen diff rattling

[A80Avant]

hang on... torsen is the middle one, isnt it? you mean it was out of position? or the diff itself had a problem?

[hermanio]

i had a lot of problems with this rattling sound in my 80q sedan 7a. tried out an new trosen diff but didn't help. the diff begins to rattle due to vibrations from the flywheel. i now placed a double mass flywheel and now i have no rattles at all

[A80Avant]

thanks for that info.

the sounds im hearing come from the front of the car,so it could not be the diff.

[A80Avant]

small update..

i remember now why i initially thought this was exhaust related. There is absolutelly no extra vibration involved, it is only coming on from 1200-1400, sometimes 1600 and gets a bit louder with more load(bigger pedal change). I can reproduce it more on 3d and 4th gear, but i suspect if i had an uphill it would be easier to reproduce as the smaller the speed, the easier to produce the sound.

It seems to be a louder version of the actual engine noise, rather than virbration/metal noise/judder. So i dont know... ill try and look under the car after work anyway.

[GazzaG60]

it it at a certain load at say 2k then goes away.

my system does this as its blowing a little at the join to the mid section. its not like a blow sound though more a metalic rattle. its the gasket.

[A80Avant]

yes something like that, but at lower revs

[GazzaG60]

also under the middle of the car the bracket that the system bolts to. if this is a lttle loose or not fully up or the rubber dampers are broken then the resonance of SS makes a tinny noise . low RPM only.

[A80Avant]

just got back from the exhaust place. we fiddled around with a few things, loose bolts and shields.

its better now,but the rest of it that is still there seems to be just normal engine noise.Obviously some things are close together, like the cats springs/rubber mounts and could be making a bit of noise, but after having spoken to various different people, i doubt that this is flywheel related/or any major engine problem.

so mapping is as scheduled this weekend!

[GazzaG60]

what oyu doing with the map vas

[A80Avant]

taking it up to 1.9-2bar hopefully(its already around 1.65 anyway. I have to put the old spring back in as it tends to want to go higher than what i want, and put the knock cable in for fine tuning..