Ducati Monster Forum

Moto Board => Tech => Topic started by: hackers2r on March 27, 2009, 02:03:16 PM

Title: Exhaust Pros and Cons
Post by: hackers2r on March 27, 2009, 02:03:16 PM
Well...my venture for an HPE exhaust has come to an end as the one I was interested in is not produced any longer.  In any case, I have set my focus on the Quat-D Ex-Box.  My question to everyone is the following: is there any downside to cutting the exhaust system so short?  Am I losing backpressure as opposed to a "traditional" (i.e. termignoni) high mount exhaust?  I am planning on doing a Nemesis 2 to even out everything.  The bike is a 2007 S2R 800.  Thanks.
Title: Re: Exhaust Pros and Cons
Post by: needtorque on March 27, 2009, 04:00:44 PM
Actually the e-box is the only system that needs no fueling changes.  It will run the same as a stock system pretty much.  Which means no real performance gain but it will sound (and look IMO) much better.
Title: Re: Exhaust Pros and Cons
Post by: hackers2r on March 27, 2009, 09:36:12 PM
So let me get something straight...the exbox offers NO gains?  I don't understand...The piping is the same diameter as stock?  I was told that they had a removable restrictor, the pipes are 1/2 the length, how do they make no power.  On quat-d's site, they clame a power gain for the system.  Someone please explain.  Also, does anyone know of a nice system that uses titanium cans that REPLACES OEM header pipes on S2R 800 if they will gain power?  Thanks.
Title: Re: Exhaust Pros and Cons
Post by: hackers2r on March 28, 2009, 12:11:52 AM
To get an accurate idea of what I am dealing with, can someone with a Quat-D ExBox chime in with pipe diameter possibly?  And can someone else with an Arrow system let us know the piping diameter?  Thank you.
Title: Re: Exhaust Pros and Cons
Post by: stopintime on March 28, 2009, 01:41:06 AM
As far as I know there is no Nemesis for the '07 - only for '06. Of course, without me knowing how, it could work on your bike too.

The impression I'm getting from this board is: no gain (same back pressure), sound not even close to Termignoni, little or no fuel adjustments required. My guess is that the Nemesis, should it fit, will be a waste - if it's not really needed it can't improve performance much.

All that money will be better spent on upgrading the suspension and brakes, which is where our 800s REALLY need it.
Title: Re: Exhaust Pros and Cons
Post by: rockaduc on March 28, 2009, 02:25:35 AM
I am pretty sure that the full Termi system pipes are 7mm larger than stock.  Noticeable difference.
Title: Re: Exhaust Pros and Cons
Post by: hackers2r on March 28, 2009, 05:26:59 AM
I have spoken directly to MM Compsystems, they do make a system for the 2007 S2R 800.  Now does the Ex Box have the same backpressure with or without the baffle?  Also, as far as I know, the Termi full syste uses 45mm, this is what the dealer told me.  If all above are true, here is my plan:  I prefer a titanium muffler to a carbon one so I am looking at the titanium Arrow race system.  In my opinion, these pipes look better than the termi system while presenting the same, if not better performance gains.  So am I supposed to understand the following:  Doing full termi or arrow system REQUIRES ECU modification, but running Ex Box w/o baffle can use factory ECU settings?
Title: Re: Exhaust Pros and Cons
Post by: amcloud on March 28, 2009, 08:39:58 AM
backpressure really isn't much of a concern with 4 stroke engines...it is more of an issue with 2 cycles. 
Title: Re: Exhaust Pros and Cons
Post by: corndog67 on March 28, 2009, 09:34:35 AM
I used to work for a guy that was the distributor for Sato pipes, specifically for RC-51's, and on the dyno, the low pipes made more power than the high pipes, with basically the same mufflers, not really sure if this applies to Ducs or not, but there it is. 
Title: Re: Exhaust Pros and Cons
Post by: needtorque on March 28, 2009, 09:52:49 AM
The big thing with the ducs is what they call "equi-length" exhaust where the length of the headers is the same for both cylinders.  The x-box home site even states for you that no fueling changes will be necessary with their system.  It is mainly for sound and looks.  If you want performance gains then go with Arrow, Termi, Sil full systems and an ecu of other fuel system change with a dyno tune.  The DP ECU with Termis will not require dyno tuning and is probably the best bolt on and go system out there but you pay out the ass for it. 

As was previously stated backpressure is not really a concern on 4 strokes that is more of a 2 stroke engine concern.  4 strokers like more airflow in and out.  The more air and fuel you can squeeze into those cyclinders and get out through the exhaust the better they run.  (with is why turbos and superchargers are such a massive power gain for 4 strokers)
Title: Re: Exhaust Pros and Cons
Post by: hackers2r on March 28, 2009, 02:49:20 PM
Ok...so here is what I have gathered so far:  power wise, it is either the Termignoni or Arrow setup, ex box=sound.  However, due to my preference for Titanium, I am leaning towards the Arrow.  Will the S2R 1000 Arrow header fit S2R 800?  I really want to get rid of the small header pipe.  I know that other companies make systems for the S2R in general, so will this work?  Also, is it true that I can run a full Arrow system with factory ECU?  If so, why can you not run a full Termignoni system with factory ECU?  Thanks.
Title: Re: Exhaust Pros and Cons
Post by: stopintime on March 28, 2009, 03:11:17 PM
You're going to feel the frustration which ever route you choose, IMO.

I have no idea if a 1000 system will fit the 800, probably not?

The '07 EURO3 800 engines are very sensitive to changes - emissions requirements = very lean. I never heard of anyone doing anything without the
DP ECU and getting away with it. Power Commander, open/closed airbox, O2 sensor on/off, cat eliminating mid pipes, slip ons only, whatever, without some unwanted issues - backfiring, surging, lean, rich ...... (Ex box maybe not included).

I'm not saying it can't be done, but my impression is that the trouble, the cost of tuning, added parts besides the cheaper non-Termi/ECU systems will bring the total cost close to a full Termi/DP ECU system.

I got the slip ons and DP ECU when I bought my bike, added the midpipes later and haven't had ANY issues what so ever.
It performs perfectly at all times and just keeps me smiling. Bonus: soundwise open Termis will eat Ex boxes for lunch.
Title: Re: Exhaust Pros and Cons
Post by: hackers2r on March 28, 2009, 05:58:18 PM
Regardless, I am planning on doing the Nemesis 2...this question was basically for arguments puposes.  If you have to change ECU with both systems, it would be assumed that both systems offer performance gains.  I am really trying to avoid the termis for the material choice, and the fact that I have a CW fender eliminator and I think it will look absurd considering how far the termis stick out.  Biggest questions here are:  will 1000 header fit 800, and can you run either system without ECU?  I can't imagine that the Termi full system performs that much better than the Arrow that it requires ECU mods and the Arrow doesn't.
Title: Re: Exhaust Pros and Cons
Post by: stopintime on March 28, 2009, 07:41:34 PM
Quote from: hackers2r on March 28, 2009, 05:58:18 PM
.............................
  I can't imagine that the Termi full system performs that much better than the Arrow that it requires ECU mods and the Arrow doesn't.

They probably both require work on the ECU/new/other(Nemesis?)
Title: Re: Exhaust Pros and Cons
Post by: Monstermash on March 29, 2009, 02:18:19 PM
Quote from: amcloud on March 28, 2009, 08:39:58 AM
backpressure really isn't much of a concern with 4 stroke engines...it is more of an issue with 2 cycles. 

Not true. When I had my custom shortie exhaust on last year, I lost power becasue the baffles were too close to the heads.

Here is a pic in case you missed it.

(http://i236.photobucket.com/albums/ff176/MonstermashS2R/S2R1K%20for%20sale/RimStripe.jpg)

The baffles extended into the header about 2-3".

Quote from: needtorque on March 27, 2009, 04:00:44 PM
Actually the e-box is the only system that needs no fueling changes.  It will run the same as a stock system pretty much.  Which means no real performance gain but it will sound (and look IMO) much better.

I'm sure that the bike wasn't perfect from the factory but when Jewcati installed his Ex-box on his S2R800 he had to do a PCIII (and custom map) to get it to run right. So there has to be some fuel change needed no?
Title: Re: Exhaust Pros and Cons
Post by: Buckethead on March 29, 2009, 02:47:03 PM
Quote from: hackers2r on March 28, 2009, 05:58:18 PM
Biggest questions here are:  will 1000 header fit 800, and can you run either system without ECU?  I can't imagine that the Termi full system performs that much better than the Arrow that it requires ECU mods and the Arrow doesn't.

AFAIK, it is POSSIBLE to run any aftermarket system without changing the fueling AS LONG AS you don't change the intake.

Same amount of air in + same fueling + free-flowing exhaust = you can get away with it.

If you look at a DP accessories catalog, every exhaust system that comes with an ECU also includes a new airbox lid/filter.

More air in + same fueling + free flowing exhaust = dangerously lean mixture.

Your power gains from JUST an exhaust system will be minimal. In fact, freeing up the exhaust with the same fueling, while it does increase top-end HP slightly due to increased flow ability, has also been shown to LOWER low-midrange torque.

The Arrow and Termi full systems are comparable. Neither one flows decidedly more than the other. Where the Termi system comes out ahead is that the guys who designed your bike figured out how your bike would behave with the system installed and made a factory ECU optimized for that system.

You can get comparable, possibly even better, results from the Arrow system, but it will require an aftermarket fuel-management system (nemesis, etc) and will require tuning.

As far as the headers, I couldn't tell you. I'd say PM ducvet.
Title: Re: Exhaust Pros and Cons
Post by: Howie on March 29, 2009, 03:58:45 PM
Slip-ons made little difference on the bikes with the narrow crossover and no cat.  Tom's bike is a much different case, big drop in back pressure and little space for expansion.

Someone I know has a 900 with a full system.  Big difference. 
Title: Re: Exhaust Pros and Cons
Post by: Ivan on March 30, 2009, 11:58:13 AM
Quote from: Monstermash on March 29, 2009, 02:18:19 PM
Not true. When I had my custom shortie exhaust on last year, I lost power becasue the baffles were too close to the heads.


That has little to do with back pressure in absolute terms, and a lot to do with the timing of the pulses that are reflected back to the exhaust port on the head.  If the pressure reflection hits the exhaust port when the valve is open and the engine is trying to push the exhaust gasses out, you end up with reversion.  I once had a Sportster with wild cams that provided a lot of overlap (intake and exhaust valves open at the same time).  With short pipes, the reversion was so bad you could actually see a fog of fuel/air being pushed back out of the carburetor.  For the most part, short pipes suck when it comes to performance.