Noise on back of car!

[B1G5I]

Hi guy's, what it is the car has been lowered 60mm on a full kit and since then whenever i go to pull away or apply any sort of gas to build speed i get like a creaking, vibrating, grinding kind of noise as if the spring is struggling to cope or something. Now i read a post before that the guys back box was catching, the person i got the car from has stupidly fitted a triangular 1.0 back box instead of the round 1.2 one, could this be the problem?


p.s. I am replacing the back box soon!

[mobiius]

It could be. Get a few fat mates to sit in the back and see if the exhaust catches or rattles.

[jimi12369]

i had the same prob with triangular backbox, especially when me big fat mother in law was in back, you have to get best best position for it not to knock on crossmember, or change it for a diff type, hope this helps.... jimi.

[B1G5I]

So where is it that it knocks? And is it gonna happen more when speeding up because of the increased airflow?

[B1G5I]

Got my Ashley back box on now and where the exhaust clamp is it's hitting the crossmember. The car is lowered 60mm all round, what can you do to get it to stop knocking????

[matty101]

put some pics up mate, its hard to tell what the problem is when its just someone explaining.

[B1G5I]

I will try and get some next week as am not at home. Basically if you look under the car you have the crossmember runnin from wheel to wheel then the exhaust system runnin down the middle of the car, where the back box connects to the middle pipe with the clamp it basicall sits on the crossmemeber when the car is lowered, so obviously it is knocking all the time and i dont know what to do to rectify the problem.

[matty101]

ah right mate got ya, i lowered mine 60mm+ and the clamp has more than enough clearence, where talking inches, cud you not stick a little extension piece in, or cut the pipe further back and clamp the back box on further back? or even heat itup and bend it a little

[B1G5I]

Gonna look into it when i have some more time like but at the moment the back box is sittin as far on as possible without blowing, think am gonna try twist the middle pipe and see if that makes any difference, if not i am gonna get a striaght through and see what that does. It's annoyin but for the performance gains it gives it's worth perservering!

[matty101]

is it a full exhaust system u've put on or just a back box, does it make much difference performence wise?

[B1G5I]

Just the back box but thinkin about full system now that it's being a right pain, there aint massive gains cause it's still a 1.2 but ya can def feel it pulls a bit better, picks up speed more comfotably i know that.

[matty101]

yeah mines just a 1.2 and ma brother is trying to get me 2 get one

[B1G5I]

It sounds really nice when accelerating threw the gears like, not very loud when ideling which is what i wanted because i dont like to sit at lights with something rumbeling away then nothing under the bonnet when it hits green ha ha

Am convertin next year though to a 'D'

[matty101]

haha yeah a dont want to look like a tit.

"D"?

[B1G5I]

Sorry mate a Corsa D, possibly either the 1.3cdti or the 1.7cdti, probably the 1.7cdti as it's 125bhp standard with ridiculous amount of torque!