Is this a mod worth doing if dealer agrees to keep warranty? For example decat downpipe and HKS or Blitz power filter?

 

You'll suffer probably from overboost/oscillation but decat downpipe gives the best low down response.

 

Jim

That'll be why a decatted WR1 produced less boost than a number of 'std' WR1s and what boost it did produce started 300 rpm higher up the rev range then It did overboost as well though

Alan
Decatting an STi PPP is not the same as decatting a std car. The catalyst we use is not restrictive in any way and the design of the downpipe means that it flows better than a straight pipe with the same header design. Neither mod will retain your warranty as that is not something the dealer has much control over. In the unlikely event of a warranty claim, Subaru WILL inspect the car.

Mike

 

I think Mike has said it all
The free flowing cat is a blessing really, the only way your going to get more power is from a remap, but then that will invalidate your warranty.....
I also believe that Prodrive have done tests on panel filters and found no real gains with them on the PPP'd cars.

Tony

 

Thanks Guys