Hi,

In the future I may be looking at changing the exhaust on my STI. I've read that the PPP exhaust is still quite restrictive from the Sports Cat back.

I want to keep the Sports Cat, as it is highly rated. (plus I can't be ar*d with mot/decat problems)

I've heard good things about the Milltek system...

Any comments/suggestions ?

Cheers..

Mark.

 

anyone care to comment ?

Can the Sports Cat cope with higher power outputs ?

 

Mark,
Probs is the same old chestnut of PPP and Warranty. Exhaust mods are considered a No No and by-by Waranty


If your not worried by Warranty the PPP sports Cat is very good. Most of the original MY02 PPP's were soldered in chips in ECU, which would need to be removed if you were to reprogram TEK3. later MYO2's were remapped.


Saying that I have known people who have changed the rear sections and had no problem and some have making them slower

PPP is effectively an off the shelf ECU map, fits all and 3 year warranty(Ecuteck2 type ish). But no two engines/boost valves/sensors are exactly the same, so lager allowances windows are made. A Ecuteck3 map to take in account your cars Mods etc and window are narrowed.

So if a Ecuteck2 type, and your boost is running on low end of this set boost window and you fit mods you maybe lucky and get to the top end of the window. if your already at the top end of the window you get problems of overboost.

With exhaust mods the Engine can and will spool up quicker, the upside, making it quicker. Downside "Overboost" or boost "Spikes" if these go over ECU set "Limits" it can protect the engine by further reducing the Boost. The car will and was affectively slower.

This is probably not 100% Technically correct but it's how someone explained it to me in simple terms.

IIRC IMHO

 

Thanks. Don't get me wrong. I'm not looking at just bunging on an exhaust part and off I go.

This is a long term question (ie, after my warranty expires in March).

I know I will need a remap whatever I do. (I do have the newer PPP fitted, not the boost clamp).

I'm just trying to assertain that the Sports Cat can indeed cope with bigger power.

My long term plan (again after warranty expires) is to fit headers / tek3 / maybe a FSE fuel regulator.

Just wondering if chaging any exhaust parts will make a difference, whilst retaining the cat.

 

The WR1 must have a d/pipe cat in it - perhaps someone can confirm its the same Prodrive sports cat as on the STi PPP?
Mike Wood replied on a thread some weeks back, that the PPP sports cat was as good as a decat d/pipe in terms of low backpressure.

Nick