Can An Bigger Exhaust Be Bad?

[96GTRman]

I am aware that fitting say a 3.5 inch exaust and airfilters to my stock GTR will increase power, and most likely fuel economy..

however will this increase in power be potentially damaging to the engine or is it just a good thing all round.

[race_snooze]

good thing all round

[nissan_280zx]

Its a good thing. you are not really putting anymore stress on the motor, just freeing it up and making its job easier

[96GTRman]

thanks guys,

just wanted to make sure, dont really need the extra performance although it would be nice, just thought it would be better to improve the economy and dont want it to blow up on me.

i drive the GTR for work every so i put alot of miles on it.

thanks for the info.

[benl1981]

I didn't really get any better economy. If you do a lot of kms make sure you select a quiet exhaust...I have a kakimoto which is pretty quiet. Good to free up the exhaust though otherwise any other performance bits or boost increase you are not getting the full benefit of.

[ebola]

It my understanding that a bigger exhaust is better for top end, but can lose power at low revs (no backpressure).

So just don't go sticking a 5in exhaust on, and you should be fine. 3.5in should be dandy

[foznice]

I heard that with turbo's you don't need to worry about backpressure? I don't understand how or why? or even what the deal is with backpressure.. maybe someone could explain that... but that's what i've heard

[ebola]

I heard that with turbo's you don't need to worry about backpressure? I don't understand how or why? or even what the deal is with backpressure.. maybe someone could explain that... but that's what i've heard

<{POST_SNAPBACK}>

Good point.

*now* I remember, the less restriction after the turbo the better.

but as low rpm, would the turbos provide enough of a restriction? Or it is just that as soon as boost starts to kick in, there is more than enough exhaust...

ideas?

[Dee 33]

Pretty sure back pressure is only an issue in n/a cars.

... and old people...

[blind_elk]

Gasses only flow because of pressure differentials. If you have too much back pressure in the exhaust system, then the exhaust gasses aren't going to flow as readily through the turbine. Then the turbine doesn't spin as fast, and you don't get as much boost pressure.

[96GTRman]

I have also heard that the turbos provide enough backpressure.

but would not the increase in boost pressure create more chance of something going wrong with the engine.

[ferni]

the engine is pretty strong by itself, will last a long time on low power if looked after. Be More worried about the turbos letting go, if you want to be safe .8bar should be fine, if you want a bit more power a lot of guys run std turbos on 1bar fine.

Remember, the candle that burns twice as bright, burns half as long.