full decat turbo back

will it cause problems / knacker the engine? without a remap

1998 STi Type R (standard car run on VPower + booster)

 

I hope not or mine is on the way out.

There are a number of people running Subarus with full decats and no changes to the oe map. Power gains are to be had as well but ultimately, to get more and better driveability from the mods, then a remap is necessary.

Quite a few tend to run full decats, induction kits, with great success, it's when you move onto larger turbos, bigger injectors/more fueling, fmics' etc that a remap is a must; the car simply wont run properly with these mods.

 

I always thought it was bad news to start removing cats without Remap????

 

It can lead to overboosting spikes causing fuel cut to kick in. I've put a manual boost controller on and reduced the boost down to prevent this. I don't think I've decreased the power out put that much but the car now overtakes rather than getting alongside the car then fuel cut slowing you down!

Like I said, you can gain some good bhp and more importantly, torque from the relatively simple mods without mapping. To overcome the fuel cut, boost spikes and release the true potential of the free flowing exhaust, a remap is the best way (possibly electronic boost controller as well set up by a competant tuner).

 

Im thinking about fitting mine and then getting remapped at a later date (few weeks later) will it be safe if I drive easy until mapped?

 

This is the crux of it. You might be ok (most are) but if you are unlucky you'll kick yourself for saving £500 on a remap when you are shelling out several grand for a new engine.

I decided not to take the risk and went straight to AndyF...

5t.

 

Clarkie i would never run the car with mods unless it had been mapped accordingly. only for peace of mind dude

 

I've owned 3 imprezas that I've decatted and not remapped, no problems. Another has been mapped and the last one wasn't de catted.

No doubt the doom mongers will be recomending a remap, especially the ones making money out of the process

 

There's a lot of confusion over this and it is mainly generated by the fact that the newer Imprezas (2.5ltr is particular?) will very likely have problems if decatted and not remapped. I know a few people with classics that have not had issues.

It is always a risk though and I'd recommend a remap for both piece of mind and to get the most out of the modifications.

 

Doom mongers LOL - Driven mine for a year and no issues not sure how much longer it has been decatted as ive only had her for a year.

Save your money.

 

Ill definately be getting it mapped, it may just be a few weeks later thats all. I can fit the decat etc myself saving money so I was thinking of doing this just before its booked in for a remap. It could be a day or it could be a couple of weeks. Im getting a date for the remap tomorrow

 

Did mine in the morning before the map. All well and good laughing at 'doomongers' but as said some are lucky some aren't. Pay your money (or not) and take your chance. For me, with the car as a daily driver, it just wasn't worth it. Now have an STi fast WRX that still passes MOT emissions test.

5t.