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2L motors should only ever go 3inch if theyre charged (whether turbo or super). you dont get any gain above a 2.5 in small n/a motors, you can even loose power by going to big. this is what ive been told by multiple exhaust guys that have been doing custom setups all theyre life
it will be interesting to see the dyno results - nice work though
I doubt these exhaust folks would have had much experience with k-series race cars... The results speak for themselves really. In fact, all the sub 13 second k-series hondas i know of are running 3" exhausts.Quote:
Originally Posted by EUR003act
3 inch FTW , As Slim said - results speaks for themselves :thumbsup:Quote:
Originally Posted by ginganggooly
Tried 2.5 and 3 inch on our k20a eg already. We dont lose power at all running 3 inch
You don't lose power but do you lose low-mid rpm torque?
One would assume the 3 inch is great for high end power at the sacrifice of low rpm grunt. If you'll be revving to 9500-100k rpm I guess 3 inch is better.
?
100k rpm, wow that's a high reving engine ;)
excellent point there... and as said later on, im guessing you lose alot of low end power/ torgue? and as for noise, im guessing constant drone while cruising?Quote:
Originally Posted by ginganggooly
Yeah sorry I couldnt count lol. Should have read 10K RPM you cheeky boy :PQuote:
Originally Posted by BiLL|z0r
Quote:
Originally Posted by EUR003act
I don't know for sure as i've never seen the two graphs overlaid. I would assume that you would sacrifice some low end power. Sometimes the drop is quite small- I went from a 2.25" to a 2.5" on my b18c and had solid gains from 3k rpm onwards with a negligible drop below that point...
In terms of noise- not really, I've been in a few vehicles with 3" systems that have been reasonable, and i've been in a few cars with 2" systems that were absolute barry crockers... I think the choice of mufflers, resonators, lengths etc have a huge bearing on this.
But pls remember 2.25 inch to 2.5 inch is a much less significant jump compared to 2.5 inch to 3 inch piping.
The piping area of 2.25 is only 4 square inches smaller than 2.5 inch.
The 2.5 inch jump to 3 inch piping is 8.8 square inches more, or 12.8 squre inches more than a 2.25 diameter piping.
In other words, the jump from 2.5 to 3 inch has increase the pipe area by more than 200% than the jump from 2.25 to 2.5 inch. and that's not taking into consideration the difference between 2.25 to 3 inch!
So there is most probably going to be a much more significant loss in low-mid-range power going from 2.5 to 3 inch than 2.25 to 2.5 inch!
You need to take into consideration that I'm comparing a 1.8L b-series to a 2.4L k-series. The k-series heads have much better flow, and the bottom end has an additional 600cc...Quote:
Originally Posted by Omotesando
If i were to fit an aftermarket exhaust to the euro, i'd fit a 3". I imagine you'd need to be going a little further than just bolt-ons to really get a decent benefit from a 3" exhaust.
all good points, and as i said at the start, i wanted a very quiet exhaust when not driving hard (i do alot of 3+ hour driving). and yes i definately agree, if you went 3" you'd definately have to do more than cat-back (extractors would be a must) if you wanted high power gains...
i suppose my questions will be answered on sunday when i see my dyno results! :D