Trashman

Right, pretty well decided on a Scoobysport back box as a good balance for sound etc. after reading Buzzer's review (lucky git, though congrats on winning ).

The dilemma is this: my insurance company consider I have "Exhaust/Manifold - non standard" which basically means anything from a back box up to a full system & headers! Now, I'm not planning on going that far but just thinking is it worth going for a centre de-cat and backbox and take advantage of the premium I'm paying?

I'm not wanting to get loads of other kit (will soon have Boost, Oil Press & Temp gauges) and not after massive power or huge noise either. Main concern is if there will be any negative impact on the engine? I've read that replacing the downpipe means a remap to avoid detting/overboost etc etc. Can anyone categorically say it will be 'safe' with nothing more than centre decat & backbox? And is it really worth doing?

Car is a MY02 STi otherwise standard. Alternative thought is just get backbox for now and PPP it in 6 months or so but retain the Scoobysport backbox with the PPP (yes I know I'm wasting the cost of the PPP backbox) but then same compatibility issue?

Only benchmark I have on sound is a bugeye wagon WRX with WR Sport exhaust that I test drove a couplke of years ago. I'm after something deeper and more Scoobyburblier and a touch louder.

Many thanks in advance.

Trashman

So anyone got any idea? Any problems for a MY02 STi & Centre decat as well as back box? And is the centre decat actually worthwhile?

RLE

iTrader: (2)

Trashman,

I have a UK97 Classic. The decat was one of the first modifications I made and immediately noticed the power difference with a Jnaspeed S1 back box. This was later changed to the TSL Firestorm but my god it was way too loud for me. I too have now gone for the Scoobysport box. Torque seems to be much better, smoother power delivery and response seems to have been improved.

Was a bit of a shock looking at the rear going from 5" tail pipe to 3.5" but slowly adapting. Only criticism thus far is its seems very quiet and not too burbly. That said I mailed Buzzer off line before making my decision and he said it would be rather quiet for the first week or so and would free up.

Jap Innovations fitted the back box and a few other bits and pieces for me. Dont know about the sti etc but no remap has been necessary throughtout my tuning process and I'm now seeing over 300bhp! Invested in a few safety gauges etc and run booster but its been very very reliable.

Rob

RLE

iTrader: (2)

Forgot to add if your paying for it on your insurance premium its certainly worthehile going for the decat and taking advantage.

Trashman

Cheers for that. I have to admit I would like a 4"+ tail pipe, but don't want to set off alarms as I drive down the road .

Anyone else? If it's 'safe' I'm going to go for it, but a few more opinions would be useful. Think it's more like a PPP'd STi that suffers with overboost/spiking with decat but I can't find anything reliable when searching.

RLE

iTrader: (2)

I thought you'd have had a more techical opinion from some of the "experts". Sure they'll be along soon to give some sound advice. Come on guys....

Good luck with whatever you decide.

Trashman

Thanks again, hopefully I'll catch the morning rush

Trashman

OK, evening rush

The Fixer

As a general rule, any modifications that makes the engine breathe more either on the inlet side or the exhaust side requires a remap to add the extra fuel / ignition etc to be 100% safe.

PPP is a combination of parts & remap

I also dont believe you can get the PPP done with other non Prodrive parts like a different backbox fitted but dont quote me on that and its has to be a UK car as well

Trashman

Cheers Conrad,


I'd settle for 99% safe


I think I'll just get a backbox (dealer is OK with that as well). Just as long as it wont sound like a wet fart on its own!