Pre-Cat / Downpipe?

.Longshanks.

This might be a stupid question but anyways....

I have a corsa opc and have read that by putting in a new downpipe it will make the exhaust bang and pop a bit louder when changing up. It also gives 2-3 extra bhp as lets the turbo work more efficient, but its the extra bang and pop i'm after. In the UK they can do this as the pre-cat is a requirement on all new cars but in the later MOT.

How does this work over here? I really don't think i'll still have the car when it comes around to needing an NCT - but would like know anyways

p-nut

your on the ball with what you've said already mate, lets the turbo work more effeciently increasing power and throttle response, and will pop and bang as a result. A friend of mine used to own an OPC corsa with the courteny (spelling?) downpipe. I drove it a few times and it was a different animal, and sounded amazing aswel. I dont't exactly know how the exhaust system is assembled on an OPC corsa, but if the catalytic converter is in the downpipe, and you replace it with an aftermarket one, removing the catalytic converter, it wont pass an NCT due to emissions, but thats fixed by keeping the standard downpipe and changing it back in come NCT time:)

.Longshanks.

Cheers for that! I think i'll email thorney motorsport who sell it in the UK just to be sure

Gumbo

get the downpipe/decat, then fit a good recommended panel filter instead of the standard item (it wont affect noise) and then get the car remapped.

they will adjust the fuel/air mixture, and boost levels and give you about an extra 20-30bhp.

the remap should only cost about 300euro or there abouts.
filter about 50-60 euro
downpipe + decat about 200-250 euro

increase in performance and increased smile on your face is priceless LOL

put up some pics of the car, also a guy over on www.dtdirl.com had an OPC corsa for a while and carried out a few mods, it may be worth investigating that and seeing where he got the parts, and what he would recommend, not recommend etc etc
think his user name is kearney if you do a search over there.

.Longshanks.

kceire wrote: »

get the downpipe/decat, then fit a good recommended panel filter instead of the standard item (it wont affect noise) and then get the car remapped.

they will adjust the fuel/air mixture, and boost levels and give you about an extra 20-30bhp.

the remap should only cost about 300euro or there abouts.
filter about 50-60 euro
downpipe + decat about 200-250 euro

increase in performance and increased smile on your face is priceless LOL

put up some pics of the car, also a guy over on www.dtdire.com had an OPC corsa for a while and carried out a few mods, it may be worth investigating that and seeing where he got the parts, and what he would recommend, not recommend etc etc
think his user name is kearney if you do a search over there.

Cheers for that!

I been told from a different site that;

The main catalytic converter is required to reach a certain temperature in order to do it's job. On turbo cars, the turbine is absorbing much of the heat that should otherwise go into the main cat... which means, that it takes far longer for the main cat to reach it's ideal working temperature.
By adding a smaller (and less restrictive) cat right after the turbo, the exhaust gasses are cleaned just a tad more before hitting the main cat.

I have the exact same MOT-like test when my car reaches it's 4th year. I think as long as the engine (and hence the main cat) is hot, they won't be able to measure it.

I'm hesitant about changing the air filter. A few lads from the UK have been having problems with the air mass meter failing with after market filters. Its sends the car into limp mode . Its only a few people but puts a doubt in the back your mind. Have been pricing a remap. 210-215bhp easily achievable.

I will have a look out for kearney www.dtdire.com later this evening.

Heres is a pic from a few weeks ago after some messing around on the computer!

Gumbo

sorry, should be www.dtdirl.com

nice car btw