2.5" v 3" Test Pipe Any torque losss?
08-24-2004, 06:53 AM
#16
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After reading all your interesting and wise words, it's better to get a 3" test pipe WITH a 3" cat back to gain the effect right.
The test pipe alone would cause problems.........what is the size of the stock system? 2.5" right?
The test pipe alone would cause problems.........what is the size of the stock system? 2.5" right?
08-24-2004, 06:58 AM
#17
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Hosrum,
Save your cash & just get a test pipe. Stock is 2.5 inches.
I would imagine that it would be cheap to get it done in
in Dubai. If yours is a 2 piece down pipe just remove that
section & get an exhaust shop to do a new one without the
cat.
Save your cash & just get a test pipe. Stock is 2.5 inches.
I would imagine that it would be cheap to get it done in
in Dubai. If yours is a 2 piece down pipe just remove that
section & get an exhaust shop to do a new one without the
cat.
08-24-2004, 08:08 AM
#18
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JChecn: I am sorry but i don't understand what you recommend.
What i have now is that the Cat is removed and i have the one piece X-over pipe and some cheap a$$ muffler with a crappy tip.
I was looking into the Lindsey exhaust system (they sell it as a Downpipe all the way till rear muffler tip) a 3" piece.
"If yours is a 2 piece down pipe just remove that
section & get an exhaust shop to do a new one without the
cat."
2 piece as in 2 piece X over right? do you think that they can do it here (i know two exhaust shops that specifically do custom exhaust systems for ALL cars).
I can show him the new 2 piece system and let him do it right?
Again, it should be a 2.5" system all the way through?
What i have now is that the Cat is removed and i have the one piece X-over pipe and some cheap a$$ muffler with a crappy tip.
I was looking into the Lindsey exhaust system (they sell it as a Downpipe all the way till rear muffler tip) a 3" piece.
"If yours is a 2 piece down pipe just remove that
section & get an exhaust shop to do a new one without the
cat."
2 piece as in 2 piece X over right? do you think that they can do it here (i know two exhaust shops that specifically do custom exhaust systems for ALL cars).
I can show him the new 2 piece system and let him do it right?
Again, it should be a 2.5" system all the way through?
08-24-2004, 08:21 AM
#19
Burning Brakes
Essential Styling in the uk do a nice system at a good price. It was designed by janspeed for them and is well made. My car was used for the design, the front section replaces the cat but keeps a silencer (it was noisy without it and the box offered no losses). The pipe that is 'squashed' on the standard car under the bulkhead is now round. It offers a slight performance increase (maybe more than the site says as I had a boost leak during those dyno runs) and a nice sound without being too loud. The 6x4 tailpipe puts some people off but they do a twin exit option.
Tony
Tony
08-24-2004, 02:10 PM
#20
Burning Brakes
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Originally Posted by J Chen
Hahaha Tommo,
You know what, you right about this. What I was trying
to say was that the savings made could have been used
on other upgrades as well.
BTW is your XJ12C the one that was publish in an auto
mag years ago ? Boy, wish I could afford a Countach. That's
my all time favorite. Had a chance to drive one once. Difficult
beast to maneuver on the street, claustrophobic too. But the
sound of the V12 behind your head & the ego when you're
driving one is just way above any other experiences.
You know what, you right about this. What I was trying
to say was that the savings made could have been used
on other upgrades as well.
BTW is your XJ12C the one that was publish in an auto
mag years ago ? Boy, wish I could afford a Countach. That's
my all time favorite. Had a chance to drive one once. Difficult
beast to maneuver on the street, claustrophobic too. But the
sound of the V12 behind your head & the ego when you're
driving one is just way above any other experiences.
The Countach is a total beast, the best example of 1980's Excess!
Its a total pig around town. But once you get onto a nice stretch of winding road it is quite rewarding but it takes time to get the confidence to throw the thing around a bit. 12 cylinders and 6 webbers is quite a sound especially with the Ansa sport exhaust. They are a bit claustrophobic as the windows only come down about 3 inches. Therefore you tend to make sure the A/C is in tip top condition!!!!
08-24-2004, 03:44 PM
#22
Burning Brakes
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Hi Tony
I thought it was the weekend that has just gone as a mate of mine stacked his 996 Cup there racing on Sunday! Its only 15 mins up the road from me. Are you sure there is something this weekend??
Cheers
Tom
I thought it was the weekend that has just gone as a mate of mine stacked his 996 Cup there racing on Sunday! Its only 15 mins up the road from me. Are you sure there is something this weekend??
Cheers
Tom
08-25-2004, 12:55 AM
#24
Rennlist Junkie Forever
From experience...
You won't gain anything over a simple 2.5" test pipe, stock down pipe, and stock cat-back exhaust (including stock muffler) under somewhere around 360RWHP.
Above that, you'll pick up additional power especially if your top end supports a HP peak above 6600-6700+ rpms.
And.. to have a top end that supports HP peaks above 6700rpms though 7100rpms and above requires big bucks. Also.. the turbine outlet size would be much larger than the stock downpipe ID.... thus considering using the stock downpipe/exhaust at that point... would be mute.
TonyG
You won't gain anything over a simple 2.5" test pipe, stock down pipe, and stock cat-back exhaust (including stock muffler) under somewhere around 360RWHP.
Above that, you'll pick up additional power especially if your top end supports a HP peak above 6600-6700+ rpms.
And.. to have a top end that supports HP peaks above 6700rpms though 7100rpms and above requires big bucks. Also.. the turbine outlet size would be much larger than the stock downpipe ID.... thus considering using the stock downpipe/exhaust at that point... would be mute.
TonyG
08-25-2004, 07:12 AM
#25
Burning Brakes
Arriving saturday evening staying sunday and Monday. Will be hanging around the 944 register area, my car will be on the stand Monday (dont look too close at the paintwork 
). Will be driving round the track Monday as well behind a carrera GT.
Should be a good event, Monday morning 8.00 there is a record attempt at getting the most porches moving on a race track at one time.
Bring a camera!
Tony
). Will be driving round the track Monday as well behind a carrera GT.Should be a good event, Monday morning 8.00 there is a record attempt at getting the most porches moving on a race track at one time.
Bring a camera!
Tony
08-25-2004, 08:00 AM
#26
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Ok, now i am totally lost........
What i understood is either go for a full 3" system (Test pipe and cat back)
And just a test pipe would not have gains........right?
I need to tell my 'exhaust guy' what i need, also if they can somehow do a two piece cross-over pipe custom made, sounds like a big job?
What i understood is either go for a full 3" system (Test pipe and cat back)
And just a test pipe would not have gains........right?
I need to tell my 'exhaust guy' what i need, also if they can somehow do a two piece cross-over pipe custom made, sounds like a big job?
08-25-2004, 11:47 AM
#27
Burning Brakes
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Originally Posted by TonyG
From experience...
You won't gain anything over a simple 2.5" test pipe, stock down pipe, and stock cat-back exhaust (including stock muffler) under somewhere around 360RWHP.
Above that, you'll pick up additional power especially if your top end supports a HP peak above 6600-6700+ rpms.
And.. to have a top end that supports HP peaks above 6700rpms though 7100rpms and above requires big bucks. Also.. the turbine outlet size would be much larger than the stock downpipe ID.... thus considering using the stock downpipe/exhaust at that point... would be mute.
TonyG
You won't gain anything over a simple 2.5" test pipe, stock down pipe, and stock cat-back exhaust (including stock muffler) under somewhere around 360RWHP.
Above that, you'll pick up additional power especially if your top end supports a HP peak above 6600-6700+ rpms.
And.. to have a top end that supports HP peaks above 6700rpms though 7100rpms and above requires big bucks. Also.. the turbine outlet size would be much larger than the stock downpipe ID.... thus considering using the stock downpipe/exhaust at that point... would be mute.
TonyG
this confirms my thoughts, with a full blown race engine that is designed to breathe at high RPM with trick cams there would be an advantage. But on a standard engine albeit with MAP, uprated Turbo, wastegate etc there would be no advantage of going over 2.5"
My requirement is drivability with a wide torque band not something that is totally numb below 5,000 revs then turns into a scalded cat over 5,250.
Great for the track but useless for the road
08-25-2004, 01:14 PM
#28
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Hey Hosrum,
You've already gotten rid of the cat which
means it's like going over to a test pipe.
Unless the double wall part of the down
pipe has collapse, theres no need to do
any other exhaust mods.
You've already gotten rid of the cat which
means it's like going over to a test pipe.
Unless the double wall part of the down
pipe has collapse, theres no need to do
any other exhaust mods.
08-25-2004, 01:23 PM
#29
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We got way over 400rwhp with the 2.5" test pipe, stock downpipe and 3" cat-back.
