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Discussion Starter · #1 ·
Hi, does a anyone have any data/numbers on how much power just a Y Pipe does?

Thanks
Mark:cool:
 

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I didn't think it did anything powerwise, was just for audible benefits, and didn't void your warranty.
Stage1 typically just consists of remap and a y-pipe..
 

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IT won't really add anything power wise but have heard that it needs a remap ideally as the car will run really rich with just a pipe swap
 

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Discussion Starter · #7 ·
There are so many conflicting figures on the www about this topic.
My head said it would make no difference, but might slightly increase spool - this is based on testing I have done on other cars.

I have spoken to other GTR owners and they have quoted anywhere between "I don't know" to "100 BHP".

Can I also check where the mantra of "it won't affect your warranty" comes from?

Mark:)
 

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Can I also check where the mantra of "it won't affect your warranty" comes from?
Sure, it was an option available from all NHPCs, unresonated y-pipe was the only slight modification allowed. Other than M16 Middlehurst (NHPC) special edition with a nismo ecu and few other fancy bits. Was offered one fitted for £600 when I first bought my car from nhpc. (which I politely declined;)

(I think it was a milltek version - not 100% sure though).
 

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I seem to remember that a Y pipe with a remap would add about 5 BHP although some people claimed as high as 17 BHP but it was never proven. Obviously, removing the secondary CATS would improve spool but the real gains would be when you swap the downpipes for fully de-catted versions. More than anything, the Y pipe is/was a good route to take if you wanted to make mild modifications with Cobb/Ecutek etc. without major engine mods.

Re - Y pipes and warranties, this really has been discussed many, many times and there have always been some HPC's who were happy to fit them and said it didn't invalidate the warranty but others said it 'might do'.

How lucky do you feel?
 

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I would say it adds power even without a remap, but pretty much unnoticeable to the driver, although response should be noticeable, probably around 5-10 bhp.

It's not just about spool which should make the car feel slightly more responsive, but also the fact that exhaust gas can escape ever so slightly easier/quicker with less restriction (minus 2 secondary cats) which will allow slightly more gas to be expelled, and thus slightly more fresh air to be inducted, rather than reinducting exhaust gas, so basically less exhaust gas overlap.

I found that my car boosted around 0.5 ish psi higher too. I always assumed the GT-R had a built in automatic boost controller to keep boost the same no matter what restrictions were removed from the exhaust, but it appears not?
 

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Discussion Starter · #13 ·
Ok, well I slightly cheated when I posted my question... :flame:

I already had the results but I wanted to see what peoples views were before posting the graphs (Sorry!)

Here is the a true, back to back dyno test:





The tests are done in R Mode AND SAVE Mode for comparision.
 

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I love all this stuff nice one nemesis, the flow increase is really aparant when coming on boost showing good gains upto 3700 rpm after there I guess the extra flow is diminished by so much gas trying to escape, id love to see a run with downpipes and a full 102mm system to see any gains/losses.

peak figures mean nothing, higher longer curves mean everything ;)
 

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Discussion Starter · #19 ·
Not sure I will be going as far as a 102 system as I use the GTR as my back up car in Time Attack so it needs to past the sound checks (Marc Kemp couldn't run his at Snetterton due to the excessive DBs).

Treg, yes it's Eurospec in Guildford. You sound surprised?
 
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