Best compromise for performance exhaust without any drone

Hello guys,

Previously on my '96 R, I had a 16T with angled housing, a 3" home-made downpipe with 200 cel cat and genuine catback : there wasn't any drone, but backpressure.

Currently, I changed my genuine catback for TME one (wishing better response, better exhaust gas flow, less consumption...), and it's droning (not a big drone, but there is one) between 2200 and 2600 revs.

So I need your help : what's the best solution for upgrading exhaust without any drone, please ?



May I get back to 3" downpipe with genuine catback (no drone but backpressure)

or

go with OEM 16T with straight housing and OEM downpipe + TME catback (no backpressure, but I never tested this way, so I hope it would be drone-free), please ?

What do give best performances, please ? 3" DP or 2,5" "straight design" catback ?

(also got a 4.4 remap, blue injectors, R manifold, JR panel air filter, iPd CBV and iPd TCV, iPd Phenolic Intake Manifold Spacer...)

Thanking you in anticipation.

Best regards.

I shouldn't get hung up on back pressure too much, as the cat will be causing back pressure, as that's the most restrictive part of the system.

Sorry to hear that JP. It was me who said there was no/little drone on my T5 auto (16T straight outlet, 70 mm TME down pipe). That was a saloon though, being an estate can't help

Maybe it’s the downpipe making the difference, although that is not a good answer as to go back to 70 mm / standard it’s money and time for less power etc

200 cell cat shouldn’t be very restrictive

I've got a bsr cat back and there's no drone whatsoever.

I had a TME too on my 850, but I had it without the centre box. (silly me) it sounded ace but I did drone, I ve just had a new box put in where the old suitcase one was and its super quiet now until you nail it.

I've had a GWE cat back on ours, lovely sound and hardly any drone, sorry to hijack your thread Neal (stunning car btw ) does a sports cat and DP make a noticeable difference on the R..

Cheers

Quote:

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Originally Posted by Red850Restate

I've had a GWE cat back on ours, lovely sound and hardly any drone, sorry to hijack your thread Neal (stunning car btw ) does a sports cat and DP make a noticeable difference on the R..

Cheers

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I'm sure it does, it was more vocal, the rollers showed a 4 bhp increase but it felt quicker than that.

The TME downpipe has a 100 cell or 200 cell cat?

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Originally Posted by Ric@rdo

The TME downpipe has a 100 cell or 200 cell cat?

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100 cell I believe

http://www.tme.se/e_main.htm

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Originally Posted by Svedish dudes

TME TURBO DOWNPIPE WITH METAL (RACING) CATALYST
A stainless steel downpipe with catalytic converter with rhodium and platinum coated stainless steel monolith as a complete unit. A very durable 100 cell catalyst, originally developed for racing use that will keep the emissions within the limits. FIA-certified for racing use. OEM quality 3-layer flex coupling. Will in combination with a TME sportexhaust reduce exhaust back pressure measured before the catalyst with up to 85% compared to the factory system. A standard type catalyst on a downpipe is basically useless and in some cases even worse than the original catalyst for high performance use.

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If it had 200 cell, would it reduce the drone or even make it go away?

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Originally Posted by Ric@rdo

If it had 200 cell, would it reduce the drone or even make it go away?

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Absolutely not!

When I had my exhaust full 3 "I had a 200cspi catalyst and the drone was there.
What makes the drone is the downpipe 3 "especially when stainless steel as the material resonates much more than steel.
The thickness of the pipe also plays ... If the thickness is too thin increases the drone!

First I'd like to thank you all (et salut Yann ;) )

Quote:

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Originally Posted by Saaamon

I've got a bsr cat back and there's no drone whatsoever.

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Hello Saaamon, do you have it installed with a genuine downpipe, please? Straight housing?

Quote:

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Originally Posted by jamesy12345

Sorry to hear that JP. It was me who said there was no/little drone on my T5 auto (16T straight outlet, 70 mm TME down pipe). That was a saloon though, being an estate can't help

Maybe it’s the downpipe making the difference, although that is not a good answer as to go back to 70 mm / standard it’s money and time for less power etc

200 cell cat shouldn’t be very restrictive

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Hello, James !

Don't blame yourself : your advice was the best I got, and I'm still sure it was the best way to prevent from drone. I'm now believing the best solution for me would be to add a TME downpipe for straight outlet (Thomas from TME said his was 2,75", up to 400 HP). Another French forum member told me his car became extremly noisy when he changed his 18T6 (straight outlet) for a 19T7 (angled outlet). But what a price ! I don't know if there's an alternative solution (2,75" at the most, straight housing, better form for better flow, 200 cat or 100 CPSI racecat).
The only way to get a TME one in Europe is to buy it at the TME German distributor, but price increases about 42 % incl. taxes but excl. shipping... About 910 € /w shipping...

James, where did you get your complete TME system, please ?

Excuse my ignorance, but I was under the impression that back pressure wasn't relevant for a turbo charged car.

Quote:

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Originally Posted by JeanPete

First I'd like to thank you all (et salut Yann ;) )



Hello Saaamon, do you have it installed with a genuine downpipe, please? Straight housing?




Hello, James !

Don't blame yourself : your advice was the best I got, and I'm still sure it was the best way to prevent from drone. I'm now believing the best solution for me would be to add a TME downpipe for straight outlet (Thomas from TME said his was 2,75", up to 400 HP). Another French forum member told me his car became extremly noisy when he changed his 18T6 (straight outlet) for a 19T7 (angled outlet). But what a price ! I don't know if there's an alternative solution (2,75" at the most, straight housing, better form for better flow, 200 cat or 100 CPSI racecat).
The only way to get a TME one in Europe is to buy it at the TME German distributor, but price increases about 42 % incl. taxes but excl. shipping... About 910 € /w shipping...

James, where did you get your complete TME system, please ?

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Direct from Thomas at TME, JP. If you email him he will quote you including delivery

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Originally Posted by JUDGENINJA

Excuse my ignorance, but I was under the impression that back pressure wasn't relevant for a turbo charged car.

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Eh? u sure?? Jan Woth disagrees...

http://www.wothrline.com/Cars_engine...rbocharger.htm

Quote: Don't mistake boost pressure as the same as power - even if the boost pressure is raised, the power may still be unchanged or only slightly increased. If the exhaust back pressure is too high the boost pressure may be very high with enormous heat and high turbine speed in the turbocharger as a result instead of increased power. Extreme heat in the exhaust and excessive turbine speed in the turbocharger is most often the cause to turbocharger breakdown. Extreme heat in the exhaust system due to exhaust back pressure and increased boost pressure is dangerous and the heat can travel back into the cylinder room with risk of damaging both catalytic converter, turbo, exhaust manifold, valves and pistons with a total breakdown as a result.

Thanks again, James. I wrote to TME European distributor (polar-parts.de). It's about 790 € + shipping... Gotta find a note tree.

I'll write to Thomas, as I'd like to know if outlet types can modify or add a drone...

Quote:

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Originally Posted by JeanPete

Thanks again, James. I wrote to TME European distributor (polar-parts.de). It's about 790 € + shipping... Gotta find a note tree.

I'll write to Thomas, as I'd like to know if outlet types can modify or add a drone...

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OK JP, good luck. If you need contact for Thomas let me know, he was very helpful & knowledgeable when I spoke with him, and ready to arrange delivery to just about any country

Just for information I now have a V70R AWD auto 1998, with a non-standard dual exhaust fitted - BSR/Jetex from the cat backwards

Attachment 27783

Without looking underneath I know that the downpipe is not 3", as the car is RHD and large downpipe will not fit

There is no drone at all at motorway speeds - I am guessing that the original downpipe with cat is installed & original turbo hot side (straight outlet)