Will a decat pipe, centre section and backbox from a PPP MY01 WRX fit on to my STI7? I assume they are the same connections and diameter etc?

 

Hello Mate.

Can't speak for the centre section but the PPP backbox for WRX MY01 is the one thats on mine so that definately fits.

If you're partially decatting, are you going to get a remap done?

The STI suffers from boost spikes (apparently)

Cheers

Matt

 

Hello Matt, basically buying a decat centre pipe and Prodrive rear box off someone tonight and was just gonna swap them over. A remap is on the cards but not for a while? What are boost spikes?! Do you think I should just get the backbox for now?

 

Should fit fine, centre included.

Boost spikes are when the turbo "overshoots" and produces too much boost, typically at around 4000rpm on an STi, this can cause det and engine failure.

Having said that, I believe the problems with boost spikes on STi7s normally come from changing the downpipe without remapping. Even with a downpipe change, it can be made safe with a very cheap modification to the diameter of the restrictor in the pipe to the boost solenoid. Check with someone who does mapping, like Scoobysport/Xtreme Scoobies/Bob Rawle/John Banks or whoever.

 

Yep, as Hades says

The backbox alone should be fine. If you start decatting, I would speak with someone who knows a bit about it (TSL?)

As I understand it, there is a risk of boost spiking and without a boost gauge you can't keep an eye on it. TSL would know what to do to keep things safe.

Will sound nice

Matt

 

Cheers for advice guys. Picked up the backbox and decat last night. I'll take some advice off someone like TSL before fitting though. Cheers.

Simon

 

For anyone interested....just spoke to Gavin at TSL and he says the Decat Centre Pipe and backbox will go on fine without a remap or anything. Boost spikes shouldn't occur either due to the cat that exists in the downpipe. I'm leaving that pipe as it is. Booked in for next weekend.

 

You learn something new everyday

What BHP gains then ?

 

He didn't say, I'd expect 5-6 bhp gain at a guess from when I've done it in the past. Just hope it sounds nice with a new found deeper burble with the new backbox on! He said if I'd changed the downpipe too then that 'may' produce the boost spikes but not necessarily.