G-pipe or Cup Pipe ?

[Guest]

Hi,

I would like to no the opinion of other members concerning exhaust alterations. I have already decided to have the cat bypass fitted but not sure as whether to fit g-pipe or cup pipe[8|] they both replace the rear box but apparently the g-pipe is better for turbo's & the cup pipe for 964's. I want an increase in sound and bhp if poss.

Thanks as always for any advice

Pete[]
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1991 Guards Red 964 C2

 

[Dave Wilkinson]

Pete,

There are all sorts of options on the exhaust but, just to clarify, the Cup pipe replaces the primary silencer, i..e. the one across the back of the car under the rear bumper, whereas the G pipe is a much shorter pipe (in the shape of a "G") which replaces the final silencer mounted behind the right rear wheel.

I don't have either on my car (I've got a Fabspeed dual outlet silencer with Dansk cat bypass) so I'm sure you'll get some more meaningful replies from others but I think the G pipe has more affect on the sound and certainly offers a huge reduction in weight since that final silencer is really HEAVY. I think the Cup pipe does more for you in the power delivery (hence it's use in the race cars).

If you are interested in doing any track days you need to be careful of the noise issues too.

Regards


Dave

 

[Guest]

Hi Dave,

Thanks for the info I thought that both of the pipes removed the same silencer i.e the one across the back under the bumper[8|] as I was told that this was the heaviest one obviously this is not the case. I dare say that the power increase is un-noticeable anyway but the increase in sound and reduction in rear weight would be better so I think the g-pipe wins[]

Thanks

Pete

 

[kevin]

Anyone behind me in the Rouen tunnel will certainly testify as to how good/noisey the G pipe is, I like it, though after hearing the Le mans guys, I'm not sure that it's loud enough..


kevin

 

[Guest]

My car is fitted with the Cup Pipe and won the 964 Sound Off Competition last year! The competition was strong with a couple of after market brands there - but to my surprise the Cup Pipe was judged to have the best sound! []

I'm not sure about the performance gains as I've never driven the car with an original one.

The weight of the secondary silencer is considerable but I'd guess that the primary one weighs a lot too. I'm not sure what the difference in weight loss between the two would be.

At many track days the noise limit is 105dba. My car measured 104.9dba at 5000rpm with the Cup Pipe.

Hope that helps.

Steve

 

[Guest]

Steve

Does yours have a cat replacement pipe fitted.

I'm interested in both noise and performance to be honest but am not interested with having noise without the performance enhancement of removing the cat.

Which way would you go if you were me?

Cheers

Matthew

 

[Andy Roe]

Matthew,

I've just had a CAT & Cup by-pass put on. Lots more noise! Just replacing the CAT did not make any difference to the exhaust note. With the stock exhaust, I managed a 0-60 sprint of 5.3secs according to my G-Tech. I'll try to have another run on Thursday with my current set-up to see if it's any better, or worse...!

From what I've read, the Cup pipe produces more BHP, and the G-Pipe more Torque. Not sure what effect the CAT By-Pass has. Perhaps someone has some dyno results they'd like to share?

Andy

 

[PhilRS]

I have had both. I bought an RS with the cup set-up and then changed it to the G set up after one year (this involved re-installing the central silencer). About noise: the G set up produces more dB than the cup set up at all revs. The cup set up produces a sound closer to the old mechanical injection cars (the famous howling at higher rmps). I preferred the latter. About power: I did not compare the two set ups but always had the impression (though COMPLETELY subjective) that the G set up produced more back pressures than the cup set up: the engine felt less lively at higher rpms with the G pipe.

 

[Guest]

Mathew
It's a tough decision on which way to go. I love the sound from mine and would thoroughly recommend it but I can't say much about the G-Pipe as I've never had one. A G-pipe is quite a bit cheaper if thats any help []

Steve

 

[Martin Perry]

At quite a few track days (Castle Combe ordinary days, several 'airfield' days) it's 100dba, so most 964 exhaust mods would seem to put you over the limit.

 

[kevin]

Do a Rennlist search, I believe GregL had some small clips posted a time back which compared all variations we had at that time, no Dyno comps, just the noise.