As some of you know I had my Spec C Verso re-tuned the other night, I also put up a thread on Rexnet.

I am getting interesting comments on the benefit of going to a 2.5inch pipe after the rear diff, also getting some negative comments on the dyno charts (Too Lumpy!!).

Here is the Rexnet link : http://www.rexnet.com.au/forum/index...howtopic=74338

Here is the PerthWRX link with the Maps :

http://www.perth-wrx.com/vb/general-subaru-discussion/13723-verso-re-tune-tonight.html

Anyone care to comment??

yeah. true. pretty lumpy. have you got a comparison graph against boost and AFRs?

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RS Liberty - Because WRX's are only good for parts...

rexnet'rs arent used to seeing plots from hub dynos, and usually have a bone to pick with them.

stick to a 3", or play with a 2.5" if your wanting to waste money.

the only credibility the 2.5" has is that your exhaust is cooling down by the time it reaches the muffler, so aslong as your exhaust is efficent (good dump, catless etc) then a 3" will be an improvement.

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Long live the WRC

What too lumpy. It's all scaling.

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[DBR]

sorry for the noob question but how can u tell if its lumpy or not?

What people are looking at are the waves in the dyno plot.

On the road you would not feel the 'lumpyness' and other dynos will not show this. OR you could do 1500rpm increment scaling like other dynos and it wont look lumpy.

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[DBR]

The Rexnet post by Michael South only proves to me that he knows rally cars and thats about it.

As Stace said a 2.5" would be a waste of money, so long as your 3" is effecient.

As for the lumpyness, its all to do with the scaling as mentioned. If the data points are closer together showing a true reflection of the car, it will always be lumpy. If the data points are spread further apart with some interpolation to guess the curve of best fit it will be smooth.

Anyone who plots a graph on excel would know all about these things. Its very easy to manipulate raw data to make a nice smooth curve. What does this mean... Diddly squat.

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]

ah i get ya thanks

HP scaling 50hp-600hp graph. It will look smoooth.

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[DBR]

I agree with the graph comments, as I have said on Rexnet the car is smooth to drive and to me that is where it counts, the trouble is Rexnet has so many experts who all inject their 2 cents worth (I don't wish to start a bash Rexnet thread by the way!!).

Michael South has done alot of R&D with the twin scrolls so his input on the 2.5inch sizing may have some credit..

cheers