Exhaust from the manifold back

Maximus · Post by **Maximus** » Sun Dec 28, 2003 3:25 pm

I two months time I will be doing my exhaust. I want to change everything from the manifold to the end. Everything will be made custom exactly for my car.

As I know the part from manifold to CAT has 50mm that?s 1,96 inch and from the CAT back it has 45mm that?s 1,77 inch. The custom manifold will be 4-2-1, and I want to make new pipes from the manifold back with 50mm (2?) diameter with one exhaust at the back (optionally with one more in the middle ? I am waiting for your opinions). The last exhaust will be exactly this one ŕ http://cgi.ebay.com/ebaymotors/ws/eBayI ... gory=33636 I won the auction and it is mine. But it has an 2,5? inlet so the exhaust guy will have to reweldit to 2? ? will it be ok ???

I?m waiting for your opinions guys

Post by **Efratech** » Sun Dec 28, 2003 4:02 pm

arent you going turbo?

Maximus · Post by **Maximus** » Sun Dec 28, 2003 4:13 pm

maniac16v wrote:arent you going turbo?

Not wright now

don't have enough money wright now, it is not only instaling the turbo, but also 15-20 liters of gasoline per 100km

i use my Lanos as a daily drier and I do quite a lot of milage...

Post by **Efratech** » Sun Dec 28, 2003 6:45 pm

thats a shame...

getting low MPG (miles per gallon) is the bad side of this lifestyle you should get used to it...

Post by **PrecisionBoost** » Sun Dec 28, 2003 7:20 pm

I'm sure 2" will be more than enough for your Lanos.

Most people think that "bigger is better" with exhaust but it isn't allways so.

The pipe diameter must be matched to your engine size for optimum efficency (and horsepower)

A smaller pipe make the exhaust flow faster so it has less time to cool down before it goes out the exhaust.... lower gas density = less resistance.

If on the other hand you had a 3" pipe the exhaust gas would cool down and become more dense which would cause a much larger restriction than if you had stayed with the 1.5" pipe. (especially when it comes time to go through the muffler)

So from a thermaldynamics point of view you need to take both flow rate and cooling rate into calculations on pipe diameter.

Having said all that.... if you had the 3" pipe wrapped in insulating tape it would outperform the 1.5" pipe every time. (that's part of the reason for ceramic coatings on exhaust components)

Maximus · Post by **Maximus** » Sun Dec 28, 2003 8:23 pm

Erfinder wrote:I'm sure 2" will be more than enough for your Lanos.

Most people think that "bigger is better" with exhaust but it isn't allways so.

The pipe diameter must be matched to your engine size for optimum efficency (and horsepower)

A smaller pipe make the exhaust flow faster so it has less time to cool down before it goes out the exhaust.... lower gas density = less resistance.

If on the other hand you had a 3" pipe the exhaust gas would cool down and become more dense which would cause a much larger restriction than if you had stayed with the 1.5" pipe. (especially when it comes time to go through the muffler)

So from a thermaldynamics point of view you need to take both flow rate and cooling rate into calculations on pipe diameter.

Having said all that.... if you had the 3" pipe wrapped in insulating tape it would outperform the 1.5" pipe every time. (that's part of the reason for ceramic coatings on exhaust components)

OK Erfinder, so 2" will be ok, I thought so

but tell me how many mufflers shall I put in ? one in the midlle and one at the end (both straight through) or just one at the end ? there will be no cat ofcours

Chas Wiggins · Post by **Chas Wiggins** » Sun Dec 28, 2003 8:42 pm

2'' exhaust should be plenty for almost any naturally aspirated engine under 2.0 liters. I say go with a resonator and a straight through muffler in the back. It may be a bit too loud at constant highway speeds just for one muffler. Good luck.

Post by **PrecisionBoost** » Sun Dec 28, 2003 11:57 pm

Chas Wiggins wrote: I say go with a resonator and a straight through muffler in the back.

I'd agree, although some people like loud exhaust I only like it when accelerating and at idle... I have straight through dual glass pack resonators (no mufflers) on my 83 GMC Truck and it gets really annoying after an hour or two on the highway. ( I have to crank the stereo to max just to overcome the exhaust noise)

I have some 4-2-1 headers with the glass pack resonators so it sounds like a real high horsepower muscle car engine at idle and accelerating (even though it's really not that powerfull )

My other car is an Acura 3.5RL and it uses a two stage muffler..... you can't even tell the car is on when its running and during light accelation you just barely make make out the sound of the engine.

But at fast acceleration the VTEC kicks in and a secondary valve in the muffler opens to give the exhaust a less restrictive path which engine more power.... and you can really hear it as it winds up into the 6000RPM + range.

I was also thinking about this for street application since you could design a muffler that has a secondary chamber for when high performance is not required. (such as driving to work at 6:00am )

Normally the exhaust valve would be totally closed so the exhaust has to go through the secondary chamber which muffles the sound really good.

Then you flick a switch and the valve opens up to allow for straight through flow with no restrictions.

Here is a diagram..... http://ca.f1.pg.photos.yahoo.com/ph/erf ... xhaust.jpg

It would be great for sleeper cars....nobody would suspect a thing until you switch it to wide open....it would go from a quiet purr to a harley davidson sounding exhaust.

Alternately you could have it based upon and adjustable accelerator position sensor ( you could set it to open up the valve at 80% throttle )

Sorry to get off topic.....I have to damned many ideas and not enough time.

anesTHEtic34 · Post by **anesTHEtic34** » Mon Dec 29, 2003 3:28 am

i bought that same muffler. i was misled thinking i was getting a deal on a tanabe, which it isn't, but it's not a bad muffler for the price. oh yeah, the silencer they sent me doesn't fit. i wasn't planning on using it anyhow, but none the less somebody else might care.

Chas Wiggins · Post by **Chas Wiggins** » Mon Dec 29, 2003 4:22 am

They should call this forum "Daewoo-indepth". Very interesting shyt.

Post by **PrecisionBoost** » Mon Dec 29, 2003 6:18 am

Is that to say you don't like the "indepth" info??

I could post it elsewhere or we could make a "Technical issue" forum index for me to post in.

I'm not sure how to take what you've said....I'm a technical kind of guy and I teach classes here and there so I tend to ramble on about details to help those who are interested in learning.

Let me know what you think.... would technical details be better off in their own forum index???

Chas Wiggins · Post by **Chas Wiggins** » Mon Dec 29, 2003 6:59 am

Oh God no, I love this kinda stuff. Sorry I kinda came off as sarcastic, I too have all sorts of plans for several types of cars and no time and no resources. This forum has opened a new door for me in the automotive field as far as I'm concerned.

Be as in depth as you want Erfinder. I soke up all this discussion like a sponge.

Maximus · Post by **Maximus** » Mon Dec 29, 2003 9:04 am

anesTHEtic34 wrote:i bought that same muffler. i was misled thinking i was getting a deal on a tanabe, which it isn't, but it's not a bad muffler for the price. oh yeah, the silencer they sent me doesn't fit. i wasn't planning on using it anyhow, but none the less somebody else might care.

Could yoy elaborate on this please ? what didn't fit ? I know I will have to make custom mountings and that the inlet pipe is wider, but what about oather things ?

Maximus · Post by **Maximus** » Mon Dec 29, 2003 9:07 am

Erfinder wrote:
Chas Wiggins wrote: I say go with a resonator and a straight through muffler in the back.
I'd agree, although some people like loud exhaust I only like it when accelerating and at idle...

I don't want it very loud, I mean that it has to be sporty sound but not to loud...

Am I right thinking that Lanos midlle muffler is a resonator ? But If I want to stay with resonator and one muffler at the end I will have to buy a resonator with 2" inlet/outlet.

anesTHEtic34 · Post by **anesTHEtic34** » Mon Dec 29, 2003 10:18 am

the silencer was too wide for the muffler. it would have been nice to have, but not nessesary. the muffler is made for a 2 1/4 inch pipe, and seems to perform exactly the same as the tanabe medallion, but it's not a tanabe, just a damn good knock off.

don't get me wrong. this muffler was very well worth the $30 i paid for it. the only disappointment for me was i thought i was getting a tanabe like the headline said.