JIM THEO

Which is safest for the engine regarding reliability and longevity PPP or full decat?
As PPP brings the pressure slightly up is theoritically worse for our very hot climate (40C degrees/the summer) if you push often the car but it also includes ECU remap that alters fuelling etc and is good whichever way you look at this, while decat as far as I know lowers EGT significantly and gives some horses due to increased volumetric efficiency.
My car is MY03 Impreza and warranty isn't an issue (for some personal reasons).
I really wonder what professional’s opinions are.
Thanks
JIM

Just to add in the above that Australian MY03 owners(MRT forum) "complain" that even with full decat their cars after few milles drive as before cause the ECU adapts parameters to the previous level! How can this be true when all MY01-2 owners agree that have seen significant changes when decat their cars? Worth to mention here that Australian MY03 is different from European models due to AVCS, increased compression ratio etc


[Edited by JIM THEO - 6/15/2003 10:06:51 PM]

Nick200

I'm not having that m8, if you decat then you will notice I dont care where you live.

Also is your car a ringer? (no warranty?)
Only joking m8.

A full decat is awsome m8 everyone will tell you (more experienced people)

But as you say remap or ppp, just do what your pocket allows.

JIM THEO

Thanks Nick, I had before few months a MY00 PPP full decatted with "some" more modifications on it and I know first hand what difference catless exhaust does but wonder if the new model "responds" the same to this modification and more importantly if PPP is better regarding reliability as this is by far my first priority! There are no WRX03 cars dynomited on Scoobynet so I can't compare the final power outputs, if someone has a catless WRX03 dynomited please post or send me your results.
By the way 59 views and only one answer...the professionals don't care or don't want to comment as they have to prove their words?
JIM

[Edited by JIM THEO - 6/16/2003 3:01:41 PM]

blachie

hi jim!
are you planning to use your vf29 as well with the ppp or decat,or with the std tdo4?

Pete Croney

Jim

All options that you have mentioned should be as reliable as each other. A full decat will produce the same power as a PPP and is well within the ECU's range, in standard form. The parts in the engine are more than capable of much more power than this and any safety issues will be down to further mapping suiting your set up.

The question is, will this be enough or will you want more? That's the question which should decide which you choose... PPP or Decat.

JIM THEO

Thanks Pete, I just wonder if the ECU retards (pulls some timing) after few miles with full decat as all the overseas WRX03 owners claim (an example) and I have seen myself from dyno plotts in MRT forums.
Will this happens on European models with standard ECU as there is no one with dynoed decated "03 so far?
Basically I am thinking for downpipe/centre/back box(+CEL fix) and intercooler hose and my target power is 255/260ps, I like more torque/driveability rather huge horsepower, is this realistic with the above changes?
Thanks
JIM

[Edited by JIM THEO - 6/17/2003 11:23:18 AM]

Pete Croney

Jim

The ECU is always optimising things, rather than reducing them. I suspect its people getting used to the performance, nothing else.

The 03 ecu is basically the same as the 01-02 and these owners get 260+bhp with a full system including up pipe. In your climate, a front mount IC will help keep the charge cool and you should see similar figures.

WREXY

Hi Jim,

You already thinking of doing mods ay? Back in Greece on Friday m8.

JIM THEO

Simple modifications George like the above... I believe a PPP or full decat doesn't affect reliability, I just want some more torque low to mid and better spool-up, with one word driveability, what do you think?
By the way how easy is for you to bring me an MRT front upper strut tower brace mate as I can't find it here?
JIM

WREXY

Hi Jim,

Didn't get to see the rest of this thread whilst in OZ. I'm back in Greece now. I would not have been able to get you the strut brace. I was only allowed 20kg in baggage for the plane. I had 46kg. Lucky the check in girl, after some sweet talking, let me off, otherwise I would of had to pay 25AUD per kilo for the extra weight. They let you off up to 30kg, but anymore and you usually have to pay. I was very lucky. The only thing I could bring for my car was a Samco silicon Y pipe kit, which only cost me 250AUD. That was family friends price.

A few mods for your car won't hurt I suppose.

Cheers,

George.

[Edited by WREXY - 20/06/2003 16:50:18]