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I Neeed A reply!! Please someone respond to this thread( Decat and losing torque) 3rd time posted

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Hi all I had a decat on my p reg VR6 obd2. when I fitted the pipe it felt like I lost torque but he car was really good on the m-way over 60. having looked at other posts on the forum I wanted to know If I will have the same problem if I put one on my new VR 97 model obd2. as Not sure if the problem was with my old car in terms of torque. Any response is much appreciated cos I hear lots of different things. I have even been told to chip the car to get the torque back if its lost. This all leaves me very confused?X2£$ Just want a little extra power with the sweet sound and no problems!

Thanks

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iv heard different things also...im in two minds of doing it myself tihnk vr6rich off here says you can lose torque obd1 or 2...il ask him agian. i know some one who de-cat'd a late highline and only got 184 on the rolling road with full exhaust wich i dont think is amazing really...same for torque i think

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hi i went for a test run in my friends std vr6 and the decatted the car ,the car pulles better up in mid engine range on the revs,with the cat removed,,,if ur vechical is loseing engine torque after u have removed ur cat box removed have u done a engine compression test to see ,as a cat box box will make backpressure in the exhaust and restrict gasses passing thow ,,just remmenber ull still need the cat for mot emmisions

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thank you for your posts (mike)+(powernut) I love the sound more than anything. makes me fell like I got an R32 (till I can afford a real one). But on a serious note my last car felt flat after change over and dont want to go through that again just need to know if I can do without chipping the car as I have been told

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I have found it seems to depend on what exhaust you run with the decat i had a miltek on 1 with a decat and it was great but ive had a scorpion 1 with a decat and it was crap both using raceland decats well thats my opinion anyway its exhaust dependent.

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Just had a Milltek Cat-back and De-cat fitted and noticed a slight reduction in torque low down but once you get over 4krpm and on the motorway the difference is awesome. Much more poke.

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Ok,

So basically you loose pressure in the pipe and thus will loose some torque low down...

Some basics for all exhausts. ..... There is a balance between flow and an amount of pressure required. Varies from car to car and engine type to engine type. If you take a pea shooter zorst off then the car can breath more easilly. You get better performance higher up but poorer lower down.. It's a trade off!

If you're wanting to do the whole thing correctly. Spend the money on a made to measure where you can manipulate the profile as you need.

The manifold in a standard VR6 is pretty good as they had a design issue and couldn't use the audi one. So it performs well as standard.

In simple terms but not exactly like this.....Single box will give you lots of flow so if you live on the red line then enjoy. If you're a city driver go three box as it helps retain some of the pressure.

Failing that get a 2 or 3 box system with or with out CAT and charge it to get back to where you want to be. :)

The losses are not huge - but enough to be noticed. You will notice them more on systems which are not as well "Designed" or designed for something else such as all out track options!

Finally, if you are going to mess with the flow rates then you really need to start to think about a remap. Remember it will map differently with or with out the CAT so your emmissions may be (only may be) an issue come MOT time.

Remember the different Zorsts are trying to do different things so read the print and get what you want... Street/Sports/Race.....

I hope this helps..

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I hate this kind of thing, So know one realy knows for sure if a decats better than a cat, Raceland manifold better than standard manifold? K&N style induction is better than a airbox!!!

Im going for a scorpian backbox (which ive just hurd arnt that great for power :@ lol but already got it) Stardard vw suitcase large middel box (retain back pressure and toruge?) and strate pipe going from that to a raceland manifold. Hope this will give me more flow better sound yet retain enuff back pressure to keep my toruge.

Supersprint are ment to be very good putting all systems on dynos making sure they perform but there maifolds are £500

All I know for sure is that Chargers and turbos defo increase BHP and tourge and exhaust and induction are there to make it sound like a beast

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imho it comes down to difrent engines mine had no cat on no boxes apart from the backbox when i bought it it wasnt down on midrange torque it sounded awesome and went pretty well too killokilla aill back that up

ps it made 198 bhp and 187 lb ft with no remap

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