| Author |
Message |
Mechanized Engineering Systems, Inc (Mensi)
New member
Username: Mensi
Post Number: 3
Registered: 7-2003
| | Posted on Wednesday, August 06, 2003 - 3:35 pm: | |
Stephen, the other factor affecting the cats's degree of restriction is the actual condition of the cats themselves. That throws another curve to the whole theory. There are a lot of cats on the market that offer better gas flow and still marginally do their job. Tubi also makes cats for the 360 and other recent cars; they are far less restrictive. There is always the often-overlooked "only-tube-silencer" that Tubi offers for recent F cars. Manu will attest to the awesome sound of a 550 with "tube-only" mufflers, a little louder but very racy.
Nick, I'm afraid the little savings in weight are not noticeable by simple mortals like us especially on the road. At the track with a stop watch, maybe... |
Nick Berry (Nickb)
Junior Member
Username: Nickb
Post Number: 127
Registered: 8-2002
| | Posted on Wednesday, August 06, 2003 - 3:10 pm: | |
Very doubtful. If it was that simple Ferrari would have done and charged a hell of lot more for the car!
Tubi exhaust is lighter than OEM by about one half. That may account for the feeling for more speed. |
P. Thomas (Ferrari_fanatic)
Member
Username: Ferrari_fanatic
Post Number: 499
Registered: 4-2003
| | Posted on Wednesday, August 06, 2003 - 9:53 am: | |
Due to design, it was the 348 cats that were more restrictive. The 355 cats are far less restrictive and/or a Tubi plus test pipes would show a very nominal increase in HP.
The 348 actually did see an increase with the test pipes.
|
neal (95spiderneal)
Junior Member
Username: 95spiderneal
Post Number: 219
Registered: 3-2002
| | Posted on Wednesday, August 06, 2003 - 9:50 am: | |
forza has report of a 308 rebuild by caribu that dynos just these type of changes. dont recall exactly but i think filter had decrease in hp while tubi had increase among other things
i think getting an in car analyzer like www.tazzo and using before and after each mod can be of huge help |
stephen winter (355f)
New member
Username: 355f
Post Number: 26
Registered: 6-2003
| | Posted on Wednesday, August 06, 2003 - 3:32 am: | |
well my expereinces with my 355f1 with the benfit of a rolling road were that airfilters made NO difference, a tubi exhaust sounded better(which is why I bought it) and it gained 5 bhp.
When we removed the cats it made no difference apart from loosing torque accross the intermediate rev band.
Mensi might be able to confirm this, but these days cats are not restrictive in the way that they used to be, in fact manufacturers build in more backpressure to the exhaust the other side on the cat so it warms up quicker, so its not the cats being restrictive themselves! and the idea that the 'less restriction the better does not hold up today.
I have tubi headers and yes they made a small difference but it was too late in the day to test how much and ambient conditions had changed so we could not guess on a correction factor!! |
Patrick Denonville (Arizonaguy)
Member
Username: Arizonaguy
Post Number: 476
Registered: 4-2003
| | Posted on Wednesday, August 06, 2003 - 1:12 am: | |
Dave, that's what I was refering to, Thanks! |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1516
Registered: 5-2001
| | Posted on Wednesday, August 06, 2003 - 12:18 am: | |
Patrick, I think you are confusing the Tubi exhaust with the "cat bypass" pipes. Tubi's are not a problem, removing emission controls is... |
Mechanized Engineering Systems, Inc (Mensi)
New member
Username: Mensi
Post Number: 2
Registered: 7-2003
| | Posted on Tuesday, August 05, 2003 - 11:55 pm: | |
All tales of big HP increase are falacies ! We've dynoed on the same day, in the (almost)same atmospheric conditions, on the same car...etc. We've done it on many sports cars and have found that cat-back replacements will do at best 2-3% increase (or decrease) in RWHP. An intake filter has never added anything to it. On the other hand, headers (manifolds) coupled with cat-back improved gas flow will significantly increase RWHP (4-7% of RWHP). The real bottleneck are the cats themselves. Tubi makes air filter elements for the 348, 355,456,550,360 and F50 only. I have them on my 360, they look like K&N filters and much more reassuring than the paper OEM filters. |
Patrick Denonville (Arizonaguy)
Member
Username: Arizonaguy
Post Number: 475
Registered: 4-2003
| | Posted on Tuesday, August 05, 2003 - 11:46 pm: | |
I thought dealers wouldn't install Tubi exhaust on cars because of liability reasons? |
Michael C. James (Mjames)
Junior Member
Username: Mjames
Post Number: 75
Registered: 6-2003
| | Posted on Tuesday, August 05, 2003 - 11:37 pm: | |
Didn't know Tubi made air filters...K&N, maybe, but not Tubi.
Now, Tube makes a Cat-Bypass pipe along with their line of mufflers. Cat-Bypass pipes are cheap compared to their stock muffler line, and the combo would probably net the HP gains you are looking for. |
Mitchel DeFrancis (4re308)
Intermediate Member
Username: 4re308
Post Number: 1010
Registered: 6-2001
| | Posted on Tuesday, August 05, 2003 - 11:20 pm: | |
Maybe more along the lines of 10-20 HP gain. |
Jason W (Pristines4)
Member
Username: Pristines4
Post Number: 573
Registered: 12-2002
| | Posted on Tuesday, August 05, 2003 - 10:45 pm: | |
I don't think it will be THAT much of an increase. |
Mark S G Murphy (Msgm1)
New member
Username: Msgm1
Post Number: 38
Registered: 2-2003
| | Posted on Tuesday, August 05, 2003 - 10:26 pm: | |
My local dealer has suggested that if I were to replace the stock exhaust & air filters on my 360 with a Tubi exhaust & Tubi Air filters, then this would increase the air flow, into & out of the engine, and that this would result in and extra 30-40bhp. Has anyone due the above and dynoed the car before and after to see if indeed there is any increase in power? |