[JGT]

Hi all,



Just got the car back with the Tubistyle Sport exhaust installed. It changes only the rear mufflers. No mid-pipe, cats etc. are replaced. Only drove 10 miles with windows down. The sound is beautifull and I agree completely with earlier reports by M! and Avantgarde. But my 1st reaction is that it is a bit too loud. Especially under partial load at low revs it is really loud. So imposible to drive unoticed through a low speed street or car park.

Tubi has 2 exhausts for the 2005 Quattroporte: standard and sport. I took the sport as recommended by the sales guy since the standard is only slightly louder than stock according to him. Well I have to drive it a bit more and see people's reactions but I find it a bit loud. Perfect would be something in between the Tubi and stock.....

So now the objective data with a sound pressure meter A-weighted at 1meter behind the car:

Stock at idle 71dB(A) ; reved to 4000-5000rpm max. spl 86dB(A)
Tubi at idle 85dB(A) ; reved to 4000-5000rpm max. spl. 110dB(A) !!!!

so it is a very "decent" increase. As M! and Avantgarde already stated vibrations increase slightly. Now I have to convince my wife to take it for a spin me watching along the road to see if it is still a decent 4-door sport car or more a screamer.

M! / Avantgarde: does it become louder or does it settle down over time? If not I might look for ways to make it a bit more silent......any ideas for the latter are welcome (Glasspack?).

 

[willie]

Well I have to drive it a bit more and see people's reactions but I find it a bit loud.

Well,

you know what they say man, "If its too loud, you're too old."


hope you enjoy it, i have an appointment to get my exhaust removed and put in straight pipes.

I'll post some sound before and after.

-willie

 

[JGT]

yep maybe you are right!

Anyway took it for another spin but ended up in traffic. So I noticed that the car now stalls easier from a standstill....will have to monitor that. Finally it doesn't give you the occasional blop but it blobs all the time when you take your foot off the accelerator....it blops too much for my taste so maybe a glasspack is the solution for both reducing sound level and blops a bit....

 

[JGT]

Well accordig to german test data (auto motor sport) the ferrari 360, 360CS and 430 f.e. are louder. Data:

360 idle 97 dB(A)
360 CS idle 101 dB(A)
430 idle 98 db(A)
Maserati Gran Sport idle 86 dB(A)

but that is only at idle (outside the car) and the Ferrari's also have the motor in the back (adds to sound level).

they also have data passing by at several gears/speeds and the max. reached Spl. inside the car in 3rd gear. In the latter category the 360 CS is again the "winner" with 94 dB(A) while the F430 reaches 89 dB(A). The 360 84 dB(A).....GranSport 82 dB(A)

The stock QP accoring to their data idle 74 dB(A) and max. inside 78 dB(A).

I measured the max. spl inside in 3rd gear and get 85 dB(A).....but the QP is better insulated then above sport cars, doesn't have a window on the motor and I have the double-window pack....

 

[M!]

hi JGT! congrats!
i think mine settled a little (less vibration thru firewall !) and sound less loud. i could be my ears getting used to it??

my dealer has a Sport GT and the tech who installed my Tubi said that the Tubi sounded better than the Sport GT definitely.

 

[Avantgarde]

Many congrats on your marvellous purchase!
The objective data you have provided vis-a-vis the 360, 430 and gransport is spot on. As mentioned in my earlier postings, the idle sound level(outside the car) of the Tubied QP appears to be similar or a tad softer than the Gransport. However, the loudness >5000rpm is gloriously LOUD.
The loudness will begin to soften a little after driving a complete tank of fuel by going on slightly longer commute drives than usual. That's what my dealer said and its true. It will also sound 'smoother' as the ECU probably adapts to the improved flow.
I have received only compliments in the improved sound, more so in the already large presence it originally exudes, only better. I have ferried my associates and clients, and they honestly thought that the car sounded melodiously enchanting and looked great. Its probably just a matter of getting used to the evident increased in decibel levels as M! mentioned. The sport TUBI we have in our rides now does indeed sound better than the sport exhaust equipped in the new QP SportGT. Biologically speaking, our sense of hearing is the slowest to adapt in comparison to our other vital senses.
I have no stalling issues before or after, you should have that checked by your dealer.

 

[JGT]

Thanks guys,

Stalling issue only happened a few times yesterday evening and that has stopped now....car drives very well again.

Have done 80km so far. People watch much more (mostly admiration) and I wonder how loud it is hearing it pass by. Have to check that. Still think it is a bit too loud at very low revs....but maybe I am getting old indeed .....

Also it blops a bit too much to my liking. Hopefully that gets better after burn-in.

Although I am impressed, I am still not 100% convinced but if I would go back to stock now it wouldn't sound at all any longer since my ears already adapted a little bit......I love stock at WOT but it's soft under partial load and doesn't blop. The Tubi is even better at WOT but slightly too loud at partial load and blops too much. Guess you can't have the best of both worlds....

I'll drive it a while (have to go back to the dealer next week since some kid stole the Trident sign of the side of the car - luckily no scrathes only new Trident which is 9Euro) and if I ever decide to put it on eBay I'll let the board know 1st.

 

[JGT]

getting better. Did 250km so far with the Tubi part of it at top speed and it is getting less harch. Idle Spl is now around 83,5 dB(A) and it blops slightly less. So lets see if I empty the full tank as said by Avantgarde what happened..... For now still a bit too loud at partial load between 2000-3000 rpm.... I really am wondering how a straight through would sound. Looking forward to those sound files Willie....you feel obviously much younger then I...

 

[M!]

i have not yet taken my QP to top speed

 

[JGT]

above 250 ity does start vibrating a bit.....but it sings a lovely tune....

 

[JGT]

I am going to disappoint several here but after driving 400km with the Tubi and having friends driving it me watching on the outside I am afraid it is too loud for me. Especially between 1800 and 3000 revs. So it is impossible to go slowly through a street or car park without being very noticed. A pity since stock is bit too silent. So I am selling a brand new Tubi for a 2005 QP. Price will be good especially for those living in the US (although with the $rate) since I bought it at a good price here in Europe. Will have to check transport costs but I have the original box. If anybody is interested send me a mail or private message..... M!, Avantgarde thanks for the reviews and your help. Enjoy yours. Willie good luck with the straight through.....

 

[M!]

oh no!!!!!
you know my reaction already!
i strongly suggest you give it a bit more time...
once you change back to stock, you will know what you missed...

on the side note, i briefly discussed with the maserati tech, and asked him about the Sport GT vs Tubi. he indicated that the Tubi is "WAY better", and the sport GT (from what i understand) is stock muffler minus the central resonator (or whatever you call it). may be you can consider something in the line to get something in between the Tubi and the stock.

 

[JGT]

I know what you were going to say M!.....
I was indeed thinking of the solution you propose. An other one would be to put a small glass-pack tube-muffler before the Tubi but then I need to cut the original pipes and that is not something I like.....Yet another solution would be to put resonated tips on the Tubi no? Anybody has any experience with any of this?

The Sport GT has a central resonator with a by-pass valve that opens when in Sport mode. I can't find if this is all the time or only above a certain rpm??? How does the Gransport exhaust work??? I can't find info on that neither. Some say the Gransport valve opens at 5000rpm??? WHat does it bypass? The central resonator? THe rear Mufflers? Any Gransport owner who knows?

The easiest/fastest would be to buy the Sport GT central resonator but this is also the most expensive. More hustle but cheaper would be to install a custom made central straight-through but then I need to leave the car 3/4 days with the shop. Would I need an x-straight through or are 2 direct pipe-conectins god also? The stock central resonator is an x one....But according to some websites the x design is to decrease sound levels. Any ideas?

According to some threads by-passing the central resonator increases volume by 20-30% and that is probably more what I am looking for. I will have to miss the beautifull Tubi idle though. Once I have prices of al options I let you guys know.....

 

[JGT]

Attached links with some info on x-pipe or H pipe design. Seems we need an X-pipe design..... http://www.carcraft.com/techarticles/69238/
http://www.advanceautoparts.com/english/youcan/html/pht/pht20011101xp.html

 

[JGT]

Found a few websites that state hat the Gransport exhaust valve opens ip at startup, above 4000rpm in normal mode and always in sport mode.....Can a Gransport owner confirm this? Found no info on hoe the QP SPort GT valve works but my guess is that it would be comparable to the GS one. Still not clear to me what the valve bypasses? Cenral resonator? Part of rear muffler like in an F430?

 

[JGT]

Attached pictures I found on an other board. The guy claims this are (maserati) tubi's opened up......In that case it would be just a nice looking straight-through...... not sure if he is telling the truth or not but the Italians are also known to buy cheap Spanish olive oil, put it in nice ottles and sell it for double the price....

Anyway nobody has the answer to my question on what the valve in The Gransport exhaust bypasses? The centre resonator? Part of the rear mufflers? Thanks

link http://ferrari101.com/forum/showthread.php?t=47551

 

[maserati of minneapolis]

We got our first couple Sport GT's last week, and I have to say the Tubi Sport exhaust sounds waaaay better. From my initial impressions the exhaust difference between standard QP and Sport GT are minimal, not nearly the same difference as between Coupe and GranSport.

- Mark

 

[JGT]

thanks Mark, appreciate it....looking forward to your full review.
Well the GS is tubied already some say and has the bypass valve. Do you have it clear how/when it works? I am afraid the Tubi (sport version) is a bit over the top for me but stock is a bit flat under normal driving especially with the double glass....maybe Sport GT is what I am looking for....

 

[maserati of minneapolis]

Definitive GranSport exhaust answer

Three pictures attached

First picture is looking at the right side tailpipes straight on, you will see a bracket on the bottom with 2775 stamped on it, and a bung welded on the top of the exhaust pipe directly above it. This is where the actuated exhaust baffle is located.

Picture two is looking through the mesh in the rear bumper, just to the left of where the pipes come out. I've highlighted the vacuum-actuator that turns the baffle in the tailpipe.

Third picture is looking down the tailpipe, and you will see the butterfly defaults to the open position. This is why it is on when you start, and then a valve at the front of the car controls whether it gets vacuum or not, with springing to open the default position, and with vacuum the baffle closes.

There is a mirrored system on the left side.

From what I have seen the Sport GT doesn't have a similar setup, but does have a reconfigured exhaust system. (I will post pics of this vs. standard QP in a moment)

- Mark

 

[maserati of minneapolis]

Sport GT exhaust vs. Base

Alright, some more pictures. I'm not entirely sure what other changes exist in the Sport GT exhaust system, however, I know they've eliminated an H pipe, and generally smoothed out the flow of the system. My ears tell me there aren't many differences aside from this...

Pic 1 - Base exhaust system
Pic 2 - Sport GT exhaust system

- Mark