Fitting a Mongoose.. (properly)

[JamieG]

Guys,

I fitted my mongoose a few weeks about and have used the car for a couple of weekends. I went out in it tonight, whilst the weather was good, and its started badly vibrating again.

Something isn't quite right somewhere, there isnt enough mountings on the exhaust to the car & the exhaust, seems to bow a bit in the middle near the decat, how can i sort this.

If anyone has any advice/pictures to help, it would be greatly appreicated, as i can't be doing with adjusting it after every other drive!

[Wobba]

I've had the same problem for some time.

I sorted the bowing at the decat by turning half the adjustable decat, 180 degrees. For some reason this helps stop it going really low.

I also took the whole thing apart the other day and bent the hooks so they were more suitable for the hangars on the underside of the car.

I also cut the hanger off the back of the backbox as it was hitting the brake bias valve.

They also knock on the rear beam. You can help reduce or even sort this totally by using cable ties to raise the back end of the system up a little higher.

They are a pain in the arse, these Mongoose systems, but just get on your back and have a look at what's up, and you'll sort it.

I find when doing the bolts/clamps up, jacking the exhaust up at the mid section helps put it in place, and stiffer polybush exhaust rubbers help.

[chip]

If it helps motivate you, there were no blows or knocks or rattles from it on the car it came off (assuming its the one you got from me?), so its definately possible to get fitted right.

But as above, its a pain in the arse, "trial and error" is the key.

[fab]

and just to add a little more encouragement lol
ive been at mine for 2 years and it's a pain in the butt! sorted now but as the lads said you need to work at it.

Car must be on a ramp or all 4 wheels on the ground for the back box section.
Try TWIST the back box so that the bow is well clear of the beam. (should be able to stick your hand between box and beam for sufficient clearance)

Between cable ties, jubilee clips and exhaust mounts you will get it into place.

REMEMBER the keyword is TWIST the pipes at the rear so they keep the center section up!

[ThRaXaIR]

this the same as janspeed single box exhaust?

if it is mine was a right shit, in the end i do believe the mechanics warmed it up and bent it just a little so it hit nothing. works bang on now....when its not breaking my 4-2-1 manifold. :roll:

[JamieG]

Thanks for all the advice guys, i will play around with the adjustable decat too, as that could certainly help - is there a specific way it should be fitted, or you able to fit it both ways?

I will get some polybush mountings sorted for it too, as hopefully they'll take alot of the play out of the rubbish standard ones.

Yeah, i will have a good play around with the sections of exhaust, i initially fitted it on a 2 post ramp at work, but then re-fitted on a four post ramp at work, and it seemed to fit much better second time round.

Fab, its the same one as you supplied me - i have no qualms about the exhaust, just want it perfect!

[Yanoo_]

Although I have a Devil backbox but I hope this helps a bit: I put some heat-resistant o-rings on the back-box pipe where it goes above the rear beam and I clamped the polybush mountings by jubilee clips, it reduces the movement of the box. There is no knocking, only Devil sound :D. Fitting exhaust/backbox is really a nightmare, it took me 3 afternoons.

[fab]

I found the elbow part is the key to get right. Once you clamp it on to the center section I had it facing right up over the beam. Then stuck the back box on and twisted it anti-clockwise so it cleared the beam well enough.
Taking the spare wheel and heat shield out of the way helps set the back box right also.
If you have the car on it's four wheels using a jack under the center section to hold it up until you have it all clamped up also helped.

Just a thought though, should there be a little give/movement in it so that it does not stress out the manifold when the engine moves?

[JamieG]

I slackened the two clamps on the elbow off and adjusted it a tad higher over the rear axle, also used a 18-25mm jubilee clip on the bracket infront of the NSR wheel, and the knocking has all but dissappeared.

Going to swap the decat around, when i get chance to put it on a ramp, maybe tomorrow, if its quiet at work.

Thanks for the help everyone :)

Jamie

[Wobba]

Great! Mine is ok for now too...it does still knock if a passenger sits in the car though :(