Exhaust query?

[M.Habs]

whats the difference between a straight through system and a normal system? is there a difference in power BHP and sound?

[skip113]

yes to all 3. because the exhaust gas clears quicker it allows the engine to breath better thus giving more power.

[SeanSmith]

I know I'm replying to old threads, but hopefully other newbies here like me will find things in my posts useful

Ok, as said above, a straight through system (or freeflow system) will clear the exhaust gases more quickly, this means less resistance getting the gases out of the cylinders and hence gives more power as the engine has less work to do.

You have to be careful however as having too big an exhaust and too little resistance will rob your engine of torque.

Obviously if you are building a car purely for the quarter mile or for sprints then this is no problem, but if it is your daily driver and you live in hilly country, it will make the car harder to drive on hills etc and you'll have to work your engine harder.

Looking around, for a 1.8 - 2litre normally aspirated engine, a 2 1/4" to 2 1/2 inch system works well and for a turbo engine a 2 1/2" to 3" system works best.

Hope this helps.

-=Sean=-

[blue4917]

Originally Posted by skip113

yes to all 3. because the exhaust gas clears quicker it allows the engine to breath better thus giving more power.

hi there
forgive me if i have posted this in the wrong forum,
i am having a few problems with my exhaust my car is 94/95 primera eGT
and i have just recently had hair like material coming from the exhaust this has happened on a few occasions now and allso the noise from it is getting louder,
i realise that something is not rite and it's not a head of hair up there can you tell me what it is and how much it would be for me to get it fixed
ip.s and allso if this would be the reason my engine check light is staying on at all times thanks
carl

[SeanSmith]

It sounds very much as though it is the fibreglass stuffing that is in your silencer. What sometimes happens is the piping inside the silencer (muffler) rusts out and then the stuffing starts to blow out of the back.

If you knock on the silencer you'll probably find that parts of it sound hollow.

It's not a problem with your engine and isn't terminal. You just need to replace your silencer.

You can replace it with a standard unit from an exhaust shop or otherwise if you want to keep the car for some time and wouldn't mind a bit more power then you could go for a stainless steel freeflow system.

If you go for a freeflow system then tell the exhaust shop exactly what you want and they will give you a system to suit. For example you can have a bigbore system which is loud and has a large tailpipe, or if you want to keep your car quiet you can go for standard sized piping (or just replace the silencer itself) and have a normal size tailpipe. I've seen stainless systems that give good performance improvements but sound almost standard and aren't loud, so just let them know what you want.

Hope this helps.

-=Sean=-

[blue4917]

thanks
thats brilliant info pal thankyou very much
carll

[SeanSmith]

No problem, always glad to help where I can.

My sad news is that I'm probably moving back to South Africa within the next year so I'm going to have to say goodbye to my P11-144 Sport+ (sob sob).

On the good side is that once I get settled and back on my feet over there I'll be looking for another Nissan and at least there I have all my contacts etc for head skimming and gas-flowing etc, so I suppose that is something to look forward to

-=Sean=-

[blue4917]

good luck over there pal
carl