What have I done now?

[mr2haz]

Ever since i fitted a decat pipe my car has been over boosting, upto around 1.2bar and it used to hit 0.8bar. Having not got it fixed yet i thought i should just take it easy.

That is until earlier when i got bored stuck behind and O.A.P and decided to floor it and drive round. As i past the car stopped pulling like it usually does and the engine light lit up on the dash board. I pulled over, the light turned of and the engine sounded like it should. My peak hold boost gauge showed at 1.25bar which.

I drove home only trying to floor it once which again gave the same result.

About half hour later i drove the car again not booting it too hard, around 0.6bar and all was well.

What has caused this and should i be worried, what should i do? Apart from bin the decat that is.

[steve---o]

howdy fella,

had a similar problem with mine when the de-cat was first put on, started boosting at 19psi instead of the usual 10-12.

mine sorted itself out but you could put a mbc and turn it down to a more desired setting.

hope this helps.

steve

[Spittinflames]

Fuel cut maybe... you just need a fuel cut defender.

Also i belive that an mbc wont turn the boost down.

The de-cats doin what it should and giving you slightly more boost due to less restriction... enjoy it

[mr2haz]

Could i turn down the boost with an electronic boost controller?

I have bought a blitz i-d sbc which i will be fitting soon

[greeny]

Surely a downpipe will only increse boost by 1-2psi max??

Michael

[MegatronUK]

Could i turn down the boost with an electronic boost controller?

I have bought a blitz i-d sbc which i will be fitting soon

No, an EBC will also only increase boost.

[Rory]

1.25bar is just over 18psi. Thats too much for a rev 1 or 2 without supporting mods (cooling/fueling) and probably a little too much for everyday driving on a rev3+. I wouldnt boost it that high. You should certainly get it sorted before the weather starts to warm up!

Rory

[mr2haz]

So is my only answer to either replace the decat which i got on ebay (unknown make) with a better one e.g from rogue systems or to just put back on the cat again or is there another way around this?

Would it also be a good idea if i get a fcd which I could set around 1.1bar?

[Peter Gidden]

A decat will only increase boost by around 1psi.

I might be wrong, but i am wondering whether your ebay decat is restricting the opening of the wastegate. I've seen this several times - unlike the better quality items, they haven't been ground out inside the flange.

Take it off, and grind out around where the wastegate opens.

[mr2haz]

Would it be a good idea to grind it down? wouldn't that make it weak?

[hicks]

if youve bought a cheap downpipe from ebay it will be an xspower. i have one on mine and have had wastegate problems ever since. ive had mine off 5 times now and will be six after today. get some grinding stones from machine mart (the small ones that fit into a drill) and grind the flange down so there is no lip around the wastegate area and it should be cured.

im in a situation where i have a spare turbo so as pete suggested to me i can spread some blue tack on the inside of the downpipe fit it to my old ct26 and manually open the waste. then i can see where the wastegate is making contact and grind that area down.