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3" or 2.5" Scoobysport Downpipe???

Old Mar 28, 2002 | 07:35 PM
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Hi folks,

I have my current SS downpipe off of my old girl, ready for transplantation to the new beast shortly, but have a question or 2....
The old girl has a Nur Spec R system fitted to the ss downpipe. The nur was 3" all the way along. My downpipe tapers from 3" down to 2.5" where she joins the centre. Me being a bit of a perfectionist thinks that I should buy the custom 3" SS downpipe now. What are your views on this folks???

If I do go for a new pipe, then unfortunatly I am looking at about £800+ for the downpipe and a new Nur Spec R system, as the silly girl that wrote off my old scoob gave the backbox a bit of a beating too [img]images/smilies/mad.gif[/img]

Thanks in advance,

Nick

P.S. Are there any alternatives to the Scoobysport that work even better?
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Old Mar 28, 2002 | 09:40 PM
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A 2.5" system will give you more low down torque, a 3" more top end power. I've noticed this since going from a 2.5" SS BB and centre to a BPM 3". This is with a 2.5" SS DP.

So I guess it depends on whether you want a little bit more torque or more power top end. You choose

DaveW
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Old Mar 28, 2002 | 09:48 PM
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Why does a smaller pipe give more low down torque? I ask this because surely the significant torque of an Impreza turbo is produced by the turbo and if a larger pipe allows the turbo to spool up more quickly, how can it porduce less torque low town? Unless you're talking before the turbo comes into play in which case who really cares about that insignificant part of the torque very low down the rev range...?
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Old Mar 28, 2002 | 10:41 PM
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Well, I think that due to having an older, bigger turbo and a 3" system already, that I might as well take away that little restriction at the end of the downpipe as well. Any other thoughts?

Cheers,

Nick
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Old Mar 28, 2002 | 11:28 PM
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do you have the blitz mid section for sale?
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Old Mar 28, 2002 | 11:32 PM
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That is debatable depending on what type of Nur Spec back box or other you have first off. I have been led to believe from more than 1 source that the R system uses slightly different length pipes than normal, so if you were trying to mate it to a normal Nur spec exhaust, then both ends might not meet. I am actually going to ask on here about if anyone knows if my backbox can be professionally repaired first.

Cheers,

Nick
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Old Mar 29, 2002 | 09:44 AM
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when I was looking for downpipes I was told that as my system (center and backbox) was 3" and I have an early car (94 WRX Wagon) that I'd benefit from a 3" downpipe, eventually went for a BPM Twindump as a few guys had suggested it.

Very happy with it.
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Old Mar 29, 2002 | 05:55 PM
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i have the backbox only, however, i modified the flange to fit a 3'' custom mid section, that is my current set up. no problem mate,
when you make your mind just let me know
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