gemellocattivo.com

Which means "Evil Twin". Lets see your projects where you change boring into fun or create the fun from scratch.
It is currently Fri Sep 19, 2025 9:27 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 1670 posts ]  Go to page Previous  1 ... 48, 49, 50, 51, 52, 53, 54 ... 167  Next
Author Message
PostPosted: Mon Apr 20, 2015 8:59 pm 
Offline

Joined: Sat Jan 03, 2015 10:13 pm
Posts: 794
mk e wrote:
The other thing that's been troubling me for some time is what to do with the tips. I roughed up a dual 3" that I think looks 3/4 decent and fits the stock opening in the cover pan.......I'm thinking this will look good if I TIG the seam, sand and polish it.

Thoughts?


The conjoined outlets look a lot like the modern Porsche Turbo design... You can't put Porsche pipes on your Ferrari :-P


Top
 Profile Send private message  
 
PostPosted: Mon Apr 20, 2015 9:03 pm 
Offline

Joined: Sat Jan 03, 2015 10:13 pm
Posts: 794
mk e wrote:
TheDarkSideOfWill wrote:
I wish I knew that!... I'd have posted one a long time ago. I used FOUR of those and less than 36" of straight pipe in the Fiero's exhaust, which is duals with an X-pipe.


How did you manage and x-pipe with a transverse engine? Way back when burns did the exhaust design for me they said an x would help a little but not to worry if i couldn't do it in the transverse layout....so that came off the list almost instantly once I looked at what I was dealing with space wise.


First, I have four fewer cylinders! :-P
Also, I haven't built long tube headers (yet).

Here's the system:

Image

Image

Image


Top
 Profile Send private message  
 
PostPosted: Tue Apr 21, 2015 11:25 am 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4687
Very neat. I have a bad habit of full welding piece by piece so it's REALLY hard to change my mind....which I guess in some ways is a good thing :)

I have a bunch of tubing on order that should be here by the weekend so hopefully in another week or so I can get the exhaust project wrapped up....spring is slipping away fast!


Top
 Profile Send private message  
 
PostPosted: Tue Apr 21, 2015 11:58 am 
Offline

Joined: Tue Jan 06, 2015 6:56 pm
Posts: 26
TheDarkSideOfWill wrote:
mk e wrote:
The other thing that's been troubling me for some time is what to do with the tips. I roughed up a dual 3" that I think looks 3/4 decent and fits the stock opening in the cover pan.......I'm thinking this will look good if I TIG the seam, sand and polish it.

Thoughts?


The conjoined outlets look a lot like the modern Porsche Turbo design... You can't put Porsche pipes on your Ferrari :-P


Thats exactly what I thought. Looks like Porsche.


Top
 Profile Send private message  
 
PostPosted: Tue Apr 21, 2015 12:03 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4687
TheDarkSideOfWill wrote:

The conjoined outlets look a lot like the modern Porsche Turbo design... You can't put Porsche pipes on your Ferrari :-P


A little I guess.....that's actually may biggest issue with ovals, no ovals in the 80's.

round 2 or 4 tips = 80s
Flat top & bottom with rounded side = 80s ish
conjoined rounds = 80's

True ovals though..... ovals came into vogue late 90s early 2000s. I remember the 2000 taurus (I think it was) and "lets count the ovals!" jokes, so I want to steer clear of true ovals I think


Top
 Profile Send private message  
 
PostPosted: Tue Apr 21, 2015 5:49 pm 
Offline

Joined: Sun Jan 11, 2015 4:07 pm
Posts: 26
Non round exhaust pipes look like a bucket of horse poo, even the Porsche fancy ones.

Why? Because unless it is round it never, ever, ever, ever, and I mean ever, looks straight. There will be a view point somewhere where it looks wrong.

So if you need bigger pipes (I don't actually understand why your computer calcs called for a smaller size and you immediately stepped up. Surely you needed to step up after a certain length of pipe at the correct size? That was what the calcs showed for my last exhaust system and the step up is to simulate the end of the pipe where size is important for flow) put a bigger single round tail pipe poking out each side and modify the "nappy" so that it fits perfectly.

In the end all engines only need a single tail pipe, anything else is for visual masturbation. In your case because it is a v12 yeah 2 pipes would make sense, but Ferraris 4 tail pipes is if we are honest typical Ferrari being a poser (like the 24 thousand Ferrari and horsey badges all over their cars).

There I've said it ;)
Pete


Top
 Profile Send private message  
 
PostPosted: Tue Apr 21, 2015 8:38 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4687
A little progress tonight. The valves are on and the one out pipe mostly done....and very straight ;)


Attachments:
2015-04-21 001.JPG
2015-04-21 001.JPG [ 250.8 KiB | Viewed 9765 times ]
2015-04-21 002.JPG
2015-04-21 002.JPG [ 232.77 KiB | Viewed 9765 times ]
2015-04-21 003.JPG
2015-04-21 003.JPG [ 285.68 KiB | Viewed 9765 times ]
2015-04-21 004.JPG
2015-04-21 004.JPG [ 205.46 KiB | Viewed 9765 times ]
2015-04-21 005.JPG
2015-04-21 005.JPG [ 196.28 KiB | Viewed 9765 times ]
2015-04-21 006.JPG
2015-04-21 006.JPG [ 189.58 KiB | Viewed 9765 times ]
2015-04-21 007.JPG
2015-04-21 007.JPG [ 212.07 KiB | Viewed 9765 times ]
2015-04-21 008.JPG
2015-04-21 008.JPG [ 205.36 KiB | Viewed 9765 times ]
Top
 Profile Send private message  
 
PostPosted: Tue Apr 21, 2015 8:51 pm 
Offline

Joined: Thu Jan 01, 2015 6:47 pm
Posts: 4687
PSk wrote:
Non round exhaust pipes look like a bucket of horse poo, even the Porsche fancy ones.

Why? Because unless it is round it never, ever, ever, ever, and I mean ever, looks straight. There will be a view point somewhere where it looks wrong.

So if you need bigger pipes (I don't actually understand why your computer calcs called for a smaller size and you immediately stepped up. Surely you needed to step up after a certain length of pipe at the correct size? That was what the calcs showed for my last exhaust system and the step up is to simulate the end of the pipe where size is important for flow) put a bigger single round tail pipe poking out each side and modify the "nappy" so that it fits perfectly.

In the end all engines only need a single tail pipe, anything else is for visual masturbation. In your case because it is a v12 yeah 2 pipes would make sense, but Ferraris 4 tail pipes is if we are honest typical Ferrari being a poser (like the 24 thousand Ferrari and horsey badges all over their cars).

There I've said it ;)
Pete


Yes you have and I wish it were that simple. There is a lot going on at the headers and pipe sizes are more about wave tuning than flow. The upper primary header tubes are a pretty big flow restriction with the gas moving at something like 0.7 mach, but the flow low pays off with much stronger waves helping draw in new intake charge. The last ID on the last collector is called the choke and it's main mission is to effectively reflect/terminate the waves before they head into the main exhaust pipes.

To flow 900+hp of exhaust in a dual system without big losses I need at least 3.5" pipes
http://www.exhaustvideos.com/faq/how-to ... -diameter/

so that's why it steps up after the choke, the wave tuning is done and the goal is to prevent simple flow losses.

The tips.....well that's a preference. you're exactly right that there is no need for 4, Ferrari put resonators in them on the US 308s, not sure about euros?, which do help dampen drone a bit and smaller diameter is better...so 4 small instead of 2 big. I NEED 3 big or 2 HUGE which I'm afraid will have awful drone on the highway so the smaller primary on quietish mufflers will make driving for more than a few minutes more pleasant. It might not work for sh*t though.....he'll find out in a couple months :)


Top
 Profile Send private message  
 
PostPosted: Wed Apr 22, 2015 8:37 pm 
Offline

Joined: Sat Jan 03, 2015 10:13 pm
Posts: 794
mk e wrote:
conjoined rounds = 80's



What applications had this in the '80's?


Top
 Profile Send private message  
 
PostPosted: Wed Apr 22, 2015 9:42 pm 
Offline

Joined: Sat Jan 03, 2015 10:49 pm
Posts: 83
euroqv oem have resonator tips,4.9inch,,long


Top
 Profile Send private message  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1670 posts ]  Go to page Previous  1 ... 48, 49, 50, 51, 52, 53, 54 ... 167  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 384 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group