Downpipe techie help needed

[oz *sti*]

Hi all,

Looking for a bit of advice fitted a de-cat downpipe to my V3 sti today took it out for a drive afterwards and if I give it a bit of a boot in 3rd or 4th gear then take my foot of the gas letting the car slow down the car develops a strong vibration coming from the engine which I can feel and hear whilst driving wondering what this could be.

The car has de-cat centre section afterburner back box and mugen headers and with the downpipe  it now has no cats in it at all, as yet it has not been remapped could this be the reason? I am planning on getting it remapped. Was not sure if it is safe to drive it without the re-map?

Any thoughts or advice has anyone drove there scooby with a full decat and not had a remap?

 

[Guest]

hi there,

 

do you have a boost gauge fitted ? as far as i can remember running a full decat it could over boost - easier to see what the boost is - 0.9 bar standard ( could be diff in a v3).

as for the vibration no idea - all bolts fully secure? mountings secure?

im sure someone will come along and advise better.

 

[oz *sti*]

yeh got a boost gauge it's running at 1 bar - no sign of over boost.

[drb5]

Do you mean to say, that since you've had all the work done, including the headers, you haven't had it remapped? If so and unless you can watch the AFR and turn up/down the fuel pressure, to add more/less fuel, i seriously suggest you don't cane it.

The standard ECU is good, but you still need to work with it, to make it safe/powerful.

[oz *sti*]

o.k. the story now gets interesting regarding the downpipe when I fitted it the other day as above took it out for a run and there was a vibration when I got home did not have enough time to look under the car.

So yesterday I went down to the car a notice that by fitting the downpipe it had moved the angle of the rest of the exhaust so the back box had no moved left and up touching the bumper which in turn started to melt it!!??!! not happy (mind you don't know if it was something I done wrong?) I went under the car to look again at the downpipe and noticed it was resting against the bolt that you can see in the below pic's; 

 

I had to use all of my weight to pull to from the bolt but when I let it go it would just spring back up and rest on the bolt above - so if I'm thinking right the vibration would be coming from touching the bolt and also because of this it has thrown the line of the rest of the exhaust out causing the problem with the back box.

For the mo I have just put the standard downpipe back on.

Question is the downpipe I bought is for a 93-00 classic and mine is a 96 sti V3 so I thought it should fit without any probs?? is there something I could be missing or have done wrong?? should the downpipe come anywhere near that bolt??

Thanks in advance. [Y]

[Guest]

hi

whos downpipe did you get i have heard of horror stories where they have been made wrong.

the 'classic' is the same for all models as far as i know.

[oz *sti*]

I bought it from ebay dare I say from a seller by the name of 2fast2cool2 here's a link to the same sort that I got but mine did not come with the the bracket that goes into the gear box.

The downpipe does have a make on it of japspeed??

http://cgi.ebay.co.uk/SUBARU-IMPREZA-WRX-S...1QQcmdZViewItem

[fai17]

Oh no the dreaded ebay again.......

Do it right and buy the right things from a reputable is what i'm saying.

Hope you get it sort Alan.....Meercat is only down the road you know.