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Discussion Starter #1
Hi Guys
Here,s my next question for you.
After welding my exhaust for the 10th time i,ve thought about making one.My plan is this.
Remove the cat ,fit straight piece of pipe + fit lambda probe

Remove 1 or possibly 2 boxes and run the pipe to the back box.

Connect it all together using flanges so i can refit the cat at mot time.

Will this work,will it be too loud,how legal is it.

I recon that if i stripped a box i could make one out of stainless.

You might think i,m mad to do this instead of buying an exhaust but i like to play around with the car and it,s a challange to see if i can do it.
Check out air filters part 4 to see my next plan :confused:
 
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Discussion Starter #2
Hiya Shug

After welding my exhaust up for the tenth time I bought a new one!!!!

Exhausts are a bit of a science, they need to be made to the proper proportions and lengths (ask Henry!). You can gain or lose power!

You won't need to remove and re-fit the oxygen sensor as it's placed before the CAT.

I once made an exhaust for a bloke when I worked in engineering. It was for an Opel Manta! He smashed it up before we had chance to check it out:)

Go for it and let us know wink It'll be loud!

wrinx
 
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I have done a system once,it was for my 33 1,7 16v,and in stainless steel.I used "Simons" boxes,there not are in stainless steel,but very cheep,and lasts for aprox 2 years.I'ved made them with flanges,so they were easy to change/unfit.

It can work (mine did),but it takes time.Good luck.
 
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And by the way,do the system with at least 1 backbox(ofcource),and 1 in the middle!!Atleast!!I drive with only a middle and a rear box (no cat),and it's noisy,-alot.
 
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Discussion Starter #5
i thing PC Mc plod will be right behind you first trip out i think the law is 86db at 6 feet or something like that, you can shout louder than the legal limit if that helps.
 
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Discussion Starter #6
Thanks for the advice guys.
First things first.The lambda probe is on the cat on my 155 so i was going to drill a hole and weld a boss on the pipe.The cars a 92 k reg so does it need a cat .If not can i by pass the probe.
I,m planning on using the middle box and back box cause they,re in resonably good nick and joining by flanges so there easy to change
Regards Shug
 
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Shug

You will need the cat. Jimybob posted the exact month and year but basically any '92 car must have one to pass the MOT.

As far as I understand the system is known as a "closed loop" (no alterations possible) which means you must also have the probe to control the fuel/air mixture, even without the cat.

wrinx
 
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What are the dimensions (diameters etc.) of the exhaust systems that seem to be working the best? Like Supersprint, which seem to be good. Where are the boxes placed? In my country we don't have any aftermarket complete systems available, everything must be custom made. I'd like to plan my next exhaust a bit better than my current one, which is 63 mm al the way after the lambda probe (2l 16v). The 63 mm is good for top end, but bottom end power is down under 2000 rpm.
Maybe a complete system of 60mm would be better?

Jacques
 
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That's 2.5 inches isn't it Jacques. I'm going to do the same, just get the local exhaust place to weld in new pipes. I'm going for 2 inch (around 50mm) all through though. On my last car I used 2.5 inch and learnt that if i used a filter I might start getting problems with lean burn and valve damage. This needs to be rectified with an aftermarket chip, fuel controller or fuel pressure riser in order to increase the amount of fuel to match the air. I was informed that the factory ECU will compensate and adjust up to a certain limit for either one of the other (i.e. intake or exhaust) but once you get both you will need some form of extra fuelling. I have gone for 2" as I believe this will give me more flexibility with future tuning mods. I know a guy with a 164 with a 2" and it sounds pretty good so I just need to see what boxes he still has left before I go wild and cut mine out. There seems to be at least four under my car. Another good thing is we do not legally require cats. He he.. how will I handle my guilt about destroying the environment?!?!?
 
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Justin,

2" is too small for the V6. try 2.25". I now have 2.5" from the cat all the way to the stock rear muffler. No center silencers, just pure mandrel bent (no crush bends) 2.5" fat pipes. No loss of torque. I also have a squadra chip and a k&N panel filter.

Next is to get a bigger cat and equal length 2" downpipes with a good merge collector.

The stock rearbox makes a nice sound. I'll keep it that way.
 
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Justin,
I agree with evo75, 50 mm is too small for the V6. I won't go smaller than 60 mm or 63 mm on the V6. On (heavily) modified V6's 75 mm could probably be used.
With 50mm the back pressure might be too high and can result in loss of power, lost mpg and burning valves.

So what about the TS 16V 2L? The factory systems seem to be about 57 mm in the front, then tapering to a 50 mm at the back.
What I am looking for is a uniform diameter system that produces better mid range and top end power, but without sacrificing bottom end.
I remember reading somewhere that Henry Yorke did a bit of development in this regard on his car. How about some advice Henry?

Kind regards
Jacques
 
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Discussion Starter #12
Justin,
I agree with evo75, 50 mm is too small for the V6. I won't go smaller than 60 mm or 63 mm on the V6. On (heavily) modified V6's 75 mm could probably be used.
With 50mm the back pressure might be too high and can result in loss of power, lost mpg and burning valves.

So what about the TS 16V 2L? The factory systems seem to be about 57 mm in the front, then tapering to a 50 mm at the back.
What I am looking for is a uniform diameter system that produces better mid range and top end power, but without sacrificing bottom end.
I remember reading somewhere that Henry Yorke did a bit of development in this regard on his car. How about some advice Henry?

Kind regards
Jacques
 
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