Is a remap 100% needed after fitting a decat?
08 May 2008, 02:09 PM
#1
Is a remap 100% needed after fitting a decat?
As title, its just I can't afford a remap at the moment but I have the Decat already.
From what i've read the majority of people say you will need a remap, but they don't say why.
My guess is the car may overboost - If I do fit it what is a safe level of boost for a 93 wrx? Its about 1 bar isn't it?
Another guess is that I wouldn't be getting the full power potential out of the decat pipe as I would with a re-map.
Has anyone else fitted a decat without a remap? & how did you get on with spiking levels etc.
My car only has a 3" staighthrough pipe at the moment and an Apexi air filter, so do you think i'll be ok with these mods?
From what i've read the majority of people say you will need a remap, but they don't say why.
My guess is the car may overboost - If I do fit it what is a safe level of boost for a 93 wrx? Its about 1 bar isn't it?
Another guess is that I wouldn't be getting the full power potential out of the decat pipe as I would with a re-map.
Has anyone else fitted a decat without a remap? & how did you get on with spiking levels etc.
My car only has a 3" staighthrough pipe at the moment and an Apexi air filter, so do you think i'll be ok with these mods?
08 May 2008, 05:54 PM
#3
Scooby Regular
iTrader: (1)
Join Date: Dec 2006
Location: Central Scotland
Posts: 3,687
Likes: 0
Received 0 Likes
on
0 Posts
As tidgy said you might or might not. personally i saved for the remap because i felt it was cheaper than a new engine if i was unlucky. Basically, you pays your money (or not) and takes your chance. I didn't risk it.
5t.
5t.
08 May 2008, 08:10 PM
#4
Former Sponsor
Join Date: Dec 2005
Location: 10.68 QT mile in 2007 2.33 Type R ** Current 2002 Spec C 2.33 Track prepped.
Posts: 1,658
Likes: 0
Received 0 Likes
on
0 Posts
Alternatively you can fit a boost controller to address and over boost that “Might” by caused by the decat.
09 May 2008, 09:11 AM
#6
Scooby Regular
Join Date: Aug 2005
Location: Andover
Posts: 354
Likes: 0
Received 0 Likes
on
0 Posts
for some reason the early wrx and most of the classic seems to take to a decat quite well without the remap. The biigest culprits for decat overboost seem to be the buyeye on.
my wife's MY95 has a decat and induction kit with no overboost and still runs a little rich so all seems well at present, give it a go and see if it works for you
my wife's MY95 has a decat and induction kit with no overboost and still runs a little rich so all seems well at present, give it a go and see if it works for you
09 May 2008, 09:46 AM
#7
Moderator
iTrader: (4)
Join Date: Jul 2004
Location: The Terry Crews of moderation. P P P P P P POWER!!
Posts: 18,687
Likes: 0
Received 0 Likes
on
0 Posts
As title, its just I can't afford a remap at the moment but I have the Decat already.
From what i've read the majority of people say you will need a remap, but they don't say why.
My guess is the car may overboost - If I do fit it what is a safe level of boost for a 93 wrx? Its about 1 bar isn't it?
Another guess is that I wouldn't be getting the full power potential out of the decat pipe as I would with a re-map.
Has anyone else fitted a decat without a remap? & how did you get on with spiking levels etc.
My car only has a 3" staighthrough pipe at the moment and an Apexi air filter, so do you think i'll be ok with these mods?
From what i've read the majority of people say you will need a remap, but they don't say why.
My guess is the car may overboost - If I do fit it what is a safe level of boost for a 93 wrx? Its about 1 bar isn't it?
Another guess is that I wouldn't be getting the full power potential out of the decat pipe as I would with a re-map.
Has anyone else fitted a decat without a remap? & how did you get on with spiking levels etc.
My car only has a 3" staighthrough pipe at the moment and an Apexi air filter, so do you think i'll be ok with these mods?
As said, some models run it without issue UK non-STis seem to be fine with it, certainly wouldn't do it on a 99/00 STi though!
Ns04
Trending Topics
09 May 2008, 10:23 AM
#8
my93 wrx has run a decat and Apexi IK for the last 2 years and is fine (has been checked on a rolling road to check fuelling etc).
i did get overboost on the standard ecu during cold weather went for a Z4 (94-96 wrx ecu) and cured it as the fuelling map is lot better then the standard early ecu.
Before putting the boost up check the fuelling is ok
i did get overboost on the standard ecu during cold weather went for a Z4 (94-96 wrx ecu) and cured it as the fuelling map is lot better then the standard early ecu.
Before putting the boost up check the fuelling is ok
09 May 2008, 11:43 AM
#9
Scooby Regular
Join Date: Aug 2005
Posts: 121
Likes: 0
Received 0 Likes
on
0 Posts
As already mentioned, not always necessary, but well worth it!
Fitted a sports cat (Scoobyworld) a few weeks ago, then a H&S centre de-cat and back box. Had a remap done at Power Engineering on Tuesday this week, and what a difference! Not only up to about 270bhp from 215bhp (will get it dyno'd next week or following as their dyno was broken), but smoother drive, and improved fuel economy too by the looks of my fuel gauge.
Get saving!
Slim
Fitted a sports cat (Scoobyworld) a few weeks ago, then a H&S centre de-cat and back box. Had a remap done at Power Engineering on Tuesday this week, and what a difference! Not only up to about 270bhp from 215bhp (will get it dyno'd next week or following as their dyno was broken), but smoother drive, and improved fuel economy too by the looks of my fuel gauge.
Get saving!
Slim
15 June 2008, 08:42 PM
#10
This just apply to 99/00 sti in particular, or just 99/00 general?
I've just got myself a straight through 2.5inch turbo back today and was wondering the same questions. I've heard LOTS and LOTS from both sides of the argument.
Oh, mines a MY99 (UK)
I've just got myself a straight through 2.5inch turbo back today and was wondering the same questions. I've heard LOTS and LOTS from both sides of the argument.
Oh, mines a MY99 (UK)
15 June 2008, 10:19 PM
#11
Moderator
iTrader: (4)
Join Date: Jul 2004
Location: The Terry Crews of moderation. P P P P P P POWER!!
Posts: 18,687
Likes: 0
Received 0 Likes
on
0 Posts
UK MY99 run on SUL will be ok with a decat; it's the STi's that won't like it. you could always get a knocklink to check for any det; better safe than sorry
BUT, you will need a remap to get the best out of the exhaust mods, as the ECU will be trying to maintain the status quo.
Ns04
16 June 2008, 09:26 AM
#13
UK MY99 run on SUL will be ok with a decat; it's the STi's that won't like it. you could always get a knocklink to check for any det; better safe than sorry
BUT, you will need a remap to get the best out of the exhaust mods, as the ECU will be trying to maintain the status quo.
Ns04
BUT, you will need a remap to get the best out of the exhaust mods, as the ECU will be trying to maintain the status quo.
Ns04
Remap is planned, but bit skint at mo - plus other mods planned so thought would wait until everything all done before remap.
Cheers
16 June 2008, 10:07 AM
#14
Scooby Regular
iTrader: (1)
Join Date: Dec 2006
Location: Central Scotland
Posts: 3,687
Likes: 0
Received 0 Likes
on
0 Posts
Personally i wouldn't want to fiddle about with any car without checking fuelling. The fact is you are taking the car outside expected performance so if something goes wrong you'll always be wondering if it was because you didn't get the map done.
5t.
16 June 2008, 10:07 AM
#15
Get a knocklink fitted and try it, if it dets either change it back or adjust your spec to suit.
16 June 2008, 12:11 PM
#16
Moderator
iTrader: (4)
Join Date: Jul 2004
Location: The Terry Crews of moderation. P P P P P P POWER!!
Posts: 18,687
Likes: 0
Received 0 Likes
on
0 Posts
While I agree with the knocklink comment I disagree with the 99 sti bit. I did it on mine and it took it no problem. I had it dyno'd the week after and made a solid 320 bhp and the only other mods were a 3" exhaust and a walbro fuel pump. The dyno operator commented that the fuelling was spot on and the run was totally det free.
Get a knocklink fitted and try it, if it dets either change it back or adjust your spec to suit.
Get a knocklink fitted and try it, if it dets either change it back or adjust your spec to suit.
ns04
16 June 2008, 02:32 PM
#19
Moderator
iTrader: (4)
Join Date: Jul 2004
Location: The Terry Crews of moderation. P P P P P P POWER!!
Posts: 18,687
Likes: 0
Received 0 Likes
on
0 Posts
Ah, the millers octane booster explains it.
Sti 5s are marginal in safety terms on less than 100RON on the std map, and a decat would make things worse. SUL plus a splash of octane booster should keep things safe though, as it appears to have done in your case.
Ns04
Sti 5s are marginal in safety terms on less than 100RON on the std map, and a decat would make things worse. SUL plus a splash of octane booster should keep things safe though, as it appears to have done in your case.
Ns04
Thread
Thread Starter
Forum
Replies
Last Post
ossett2k2
Engine Management and ECU Remapping
15
23 September 2015 09:11 AM
robbie1988
Wanted
2
13 September 2015 09:25 AM
Scooby-Doo 2
Wheels And Tyres For Sale
1
09 September 2015 06:51 PM