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Discussion Starter · #1 ·
well i know matt has one coming out and pasetter has one... but the question i have is, is an exhaust what i need? i used to drive a 88egt and now that i have my 95 lx i have noticed the lx has more torque in 1st and second than the gt. this is what i want to keep. if i put a gt header on, will i loose low end torque because of less backpressure? also... if i put on a cat-back system will i gain more torque and horsepower if i keep the stock header? thanks guys.
 

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i don't know too much about the header, but if you keep the exhaust piping to 2.25 inches you'll have the best gain without loss in torque. LX 108 ftlb torque stock is a beautiful thing :)
 

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I'd think you wouldn't notice too much loss of torque with the GT header.. if any at all. The small shrouded valves in the LX head are going to keep the low RPM tumble and high flow velocities. My best guess is that the header may broaden the torque curve just a little further up the RPM range without much lower end loss at all. Just don't port out the header or exhaust ports :wink:

I'm with Jugg, keep to a 2.25" (or 2.0") diameter piping and you'll end up maximizing hp and torque.

Remember, you can have the best exhaust in the world, but if the intake can't flow enough to match it you won't get anywhere. (of course, you're lucky enough to have the larger MAF already :x )
 

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Discussion Starter · #7 ·
heres another question.... say i put a 1st gen gt header on, take out the resonator, 2.25" mandrel bent pipping, and a glass-pack muffler.... will i need to reset the computer? does this sound like a good system? thanks.
 

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Just don't port out the header or exhaust ports


Why not? isn't it supposed to increase the flow in the exhaust system? always though it was a great improvement to do this kind of work on your system....

would be nice if you could clarify this for me :) Tanks mec
 

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Electronikal said:
Just don't port out the header or exhaust ports

Why not? isn't it supposed to increase the flow in the exhaust system? always though it was a great improvement to do this kind of work on your system....

would be nice if you could clarify this for me :) Tanks mec
I'll clarify.. I said that kinda wrong. What I should have said was, "Just don't port out the header or port match the exhaust ports."

In other words, the GT header primaries are probably plenty big enough for the SEFI 1.9L from the 2nd gen, and you're probably only going to be shooting yourself in the foot if you were to try to make them any larger. I'd imagine a little honing (polishing) wouldn't hurt though.

Yes, porting the heads (and in this case, installing larger valves and cam) is a great idea.. port matching the exhaust ports to the header is not. Having the exhaust ports smaller than the primaries has shown to help on the dyno. That's what I meant to say :oops:
 

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Yeah, port matching on the way in is good.. keeps the flow nice and smooth (sometimes a tiny lip to spill over will help).

I've read that the spill-over from the exhaust port to the primaries may help to block reverse pulses and give them something to bounce back off of. It's apparently better to leave the ledge at the outside of the curve for some reason. Smoothing out flow on the inside of the curve seems to be an over-ridding theme in head design. (I've been reading A. Graham Bell - Four-Stroke Performance Tuning in Theory and Practice the past week.. interesting stuff)
 

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Hi pplz,

My muffler cracked yesterday and i now have to replace it...but then, since my whole exhaust line is screwed...

Picture on my cardomain page

i should get the whole thing fixed for good....

1) I'd like to do it myself..not really to save some bucks, but mostly for the fun of doing it by myself :)

2) I don't know what is on the market right now.... I've heard about the pacesetter catback, but i'm not sure about the quality of their products...so i might think about doing it the hard way, which is the custom way :)

So i'd appreciate it alot if you could give me some tips about the products available and the appropriate material that i should use for the piping..

Tanx dudes
[/img]
 

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Hi pplz ! Hope your doing fine after isabelle's bash in your country... him doing fine cauz i got lucky and that b*a**h didn't make it through where i live...

I went to my local metal shop this morning cauz i needed to buy some piping to custom build the exhaust system on my 1.9 sefi escort by myself ( hope it will end up fine hehe) ...
as you already know, the stock diameter of the piping is 2 1/4 inchs...but they don't have this kind of piping for sale at the shop..they have 2'' and 2 3/8''....so what should i do ?

So should i go 2'' , 2 3/8 '' or 2,5 '' ? Is there any good or bad points in choosing one of these sizes ? I know you previously wrote in this post that you should stay with the 2 1/4 or the 2'' piping...but why ? Wouldn't it flow better with a bigger exhaust piping?
Tanks for your help !
 

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Check out the article: Build Your Own Exhaust

Some great info there.

[edit]

Of note.. the pipe diameters listed for each approx. engine size are not for max power, they're for best midrange and low end for street cars. Go up one size if you want max top end power.

[/edit]
 

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not really. What you want is to keep the temp and velocity of the exhaust gases as high as possible. This obvioulsy expels them as quickly as possible. If the gas cools/slows down it sort of blocks the gas behind it.

If you are wanting to weld up your own system I can supply you with the materials (including hangers etc). If you want just let me know and I'll get you a price.

Also We are almost done with TRashknights cat-back system. All I should need is some detailed measurements and we should be able to produce the LX version as the routing should be the same.
 

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Ok i see...so a hotter gas will expand itself more and then will rush faster to the nearest point of expulsion... ok i see...and a small diameter pipe will allow a bigger pressure on the gas...so it will be expelled faster too..ok... guess i should not have studied french litterature ahahha physic rocks better :)

Tanks Beaver and Egt dudes, you gave me some very usefull informations...and I'll check out what i need to build my system and i'll reply to you later EGT ...tanks

Max
 
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