djc1

01 bugeye ,decat ,some are saying the car will NEED remapping to prevent it going bang and some are saying not ??

whats the truth ?

daz1968

iTrader: (13)

I think a wrx on tdo4 will run ok with a decat, but you won't be getting the best from the car at all, a remap will maximise the benefits you can gain from a decat, I wouldn't waste time decatting a car if I wasn't going to spend a little more and get it running at its best, at the least you will get a cel permanantly on, but the car will likely run worse than with the std downpipe on.

Billet

iTrader: (60)

It all depends on how lucky you are, to be safe you will need a remap, however so many people on here, me included, have run without a remap for ages, yours could blow up the day you put it on, or could be fine for years, it depends on whether you want to risk a engine rebuild. To be honest there isn't much point of putting one on if your not going to get it mapped as there is no noticeable gain in power, and i only gained a tiny bit of sound from mine.

tony de wonderful

I don't see how it could go bang unless you max out your injectors or fuel pump.

If you are not close to those limits with a cat it can't happen (I think).

dynamix

iTrader: (3)

Easily happen without either of those two events happening.

The std map on the car is designed and tested for it to reach certain boost levels at certain rpm points. When decated it will hit different boost levels and much earlier so it will be in untested areas.

Also by changing the amount of back pressure in the exhaust system it can have a massive effect on how well exhaust gases are extracted and subsequently what AFR is actually being seen by the engine. These combined can have a bad effect.

Having said that bug eye wrx's seem to cope ok with a decat but wont even get close to seeing the benefits of a decat without a remap. Blob and Hawkeye wrx's need remap for 1005 when decating.

tony de wonderful

I've never heard of a factory map going lean, more like R&R when in doubt.

That sounds debatable.

Luckyscoob

iTrader: (2)

Why risk it. And as Duncan said, you wil have a much better and safer car when mapped. A friend of mine has just had his decatted, and within 40 miles its gone bang. Whether its directly because of the map or it already had an existing problem, who knows, but to me it aint woth the risk.

pimmo2000

iTrader: (6)

Agree with Lucky .. whats the point in risking it for the sake of a remap ... the remap is going to give you a better car too..

djc1

dont get me wrong i am defiantely getting it remaped next year ,but ive got an exhaust here and im itching to put it on now .
just looking for a definitive answer as to whether im ok putting it on now .

lucky ,what year car was your mates ?

my mate blew his classic up by decating but ive heard the classic ecu can run lean but not new age?

dynamix

iTrader: (3)

It isn't nec running lean that is the problem.

Although quite a lot of bug wrxs run into that with weak fuel pumps or tired mafs.

How lucky do you feel ?

djc1

not very lucky at all lol

TINO.wrx

iTrader: (5)

i had run a decat on my MY03wrx for quite a while and didnt get any problems, i eventually got it mapped when i upgraded the turbo. the only things i noticed with the decat were, a slightly louder exhaust, and due to the lack of back pressure when i released the throttle the car would jerk slightly(even when it was mapped it did this)

what bug do you have ? wrx/sti?? if wrx and will be wanting more power etc why dont you get the upgraded turbo, (intercooler/injectors maybe?) then go for the mapping session. for your peice of mind. my exhaust was if it blows it blows! and a good time to save and get a forged engine ;-)

steve

Midlife......

iTrader: (2)

The Bugeye STi didn't like being decatted at all........... boost spikes and the like. Look back at posts by John Banks when he did his (about 8 years ago LOL)

Shaun

Myles

iTrader: (40)

You stick to Islam Tony, let Dynamix talk about what he knows.

dunx

iTrader: (3)

The de-cat makes the car feel quicker as it's less restrictive, mine had a sports cat and felt better... no unusual problems except a CEL on the motorway, due to cat efficiency out of "spec".

But after mapping it gained 70 bhp ( STI ) and the fuel consumption was unaffected.

Mapping is the important part.

IMHO.

dunx

Terminator X

iTrader: (7)

You know more than Dynamix then

TX.

Edit - when I decatted my Spec C along with an induction kit etc Bob Rawle advised me to take it straight from the garage to him driving v slowly off boost ... I took him at his word

Myles

iTrader: (40)

To be fair, at least Tony hasnt littered the post with his e-intelligent findings, like ad hom fallacy, or victimhood which seem to be his phrases of the week.

f4la k

iTrader: (1)

It needs mapped. But its up to you.

f4la k

iTrader: (1)

[quote=tony de wonderful;9698704]I've never heard of a factory map going lean, more like R&R when in doubt.



Youve never been in a hatch then.. took one to a rolling rd and they ended up not running it as halfway through the run it was showing lean afr's. Totally standard car.

djc1

if theres a risk then i wont chance it .just wanted to know for sure really .

i understand i wont get the full benefits till i remap but just wanted to know if it will or wont go bang in the mean time

midlife,i know that youve mentioned before that the bug ecu can cope with decat ,without sounding patronising how do you know this ?
cheers

mit

iTrader: (10)

As far as i see it, for the sake of a few months you'd be kicking yourself if you fit it now, and it did go pop. And, as winter is hear, do will you really need the extra power? It'll also give you a bigger grin when you get it fitted and mapped at the same time next year.
Listen to Dynamix, there's a reason he maps cars for a living, he knows what he's talking about, not just an uninformed opinion of ' my mate did it and it was fine' . If it leans out, which it could, and causes det, then this can cause damage now which may not show itself for a while, but could cause problems in the long run.
This is just my opinion.

xdave

if i was itching that much id just fit it cat back !!!! for now !!!