Im looking to put a de-cat on my MY96 sti import.
Ive been told to get the most power to remove both cats. If i just remove the rear cat what would the benifit of this do?

Is there any thing that i should know about before getting this done?
MOTs are not problem!!!

What about the sensors?
If any one can help it would be great.

 

Go for a full TSL system with there Firestorm backbox, you'll love it.
Pops and bangs all the time.

Kevin

 

im not positive but i dont think your car will have a centre cat , just the downpipe one .......correct me if im wrong anyone

 

Wiggy, I can't confirm whether or not there is a centre cat, as I don't think I've ever seen a standard exhaust on an early scooby.

As for what to change... Figures I've heard are 5-15 BHP for removing the centre cat, and 15-25 BHP for removing the downpipe cat. - Most dealers quote upto 35 BHP for a full de-cat system.

Apart from BHP increases there will also be a torque increase, exactly what can differ hugely. The torque will normally peak lower in the rev range, and the turbo will spool up quicker.

As an example...

I had a blitz induction kit, standard boost, blitz centre and back box. When I removed the front cat (for a magnex twin dump), I gained 23 BHP, and somehow got another 36 ftlb of torque (although my original reading seemed a bit low)

My friend also had 305 BHP on his STi as standard, and when fitting a Blitz NUR Spec exhaust with a Scoobysport downpipe, gained exactly 35 BHP taking it up to 340BHP With no other mods, recorded on the same day I think.

And as Kevin says:

 

Been told i need to re map my ecu??
Any truth behind this?

 

You won't actually "NEED" to, as the ECU is quite a clever piece of kit, and tend to compensate for a lot of changes.

 

Cool.
Been quoted £250 for both cats and a replacement fiting for the Lambda sensor by Powerflow. They can have it done in an afternoon. Thot that was rather good.