3 inch exhaust and fuel economy

hey guys, ive read a fair bit that 2.5 or 3 inch exhaust increases torque, and gains approx 10-15kw.
Now ive decided on getting myself a 3 inch exhaust with Hi-Flow Cat.
Just wondering.... apart from the performance gain, will the fuel ecomony be greater, (more km's less fuel)??

i seriously doubt the 10-15kw increase. by the seat of the pants i would say its far far less than that.

economy does improve, however you have to also factor in that the more power you have the more you tend to use it which increases fuel consumption. ie you use the same fuel but you get there a bit quicker.
one time its more economical is when your doing the same speed as before ie driving at 100km/h on flat road.

jap55s said:

hey guys, ive read a fair bit that 2.5 or 3 inch exhaust increases torque, and gains approx 10-15kw.
Now ive decided on getting myself a 3 inch exhaust with Hi-Flow Cat.
Just wondering.... apart from the performance gain, will the fuel ecomony be greater, (more km's less fuel)??

Click to expand...

.

http://www.diesel-tec.com.au/pdf/Stage 2 Navara 3.0 power.pdf

http://www.diesel-tec.com.au/pdf/Stage 2 Navara 3.0 torque.pdf

20% with chip + exhaust at peak power

BUT - 45% more power @ 90km/k (~3000rpm)
- Over 50% more torque @ 70km/h (2-2500rpm)

Gains are prob around the 10% mark with just the exhaust.
But very noticiable in the mid range and helps to reduce the turbo lag time

I put a D'tronic chip and a 3" exhaust on at roughly the same time. Uses exactly the same (10.4l per 100km) before and after the mods.

I agree with Tweak's, I've recently fitted a full 3" including dump pipe. Power gained? maybe but it would take a dyno to prove it, doesn't seem any different to drive. Probably the most disappointing mod I've made so far dollar for dollar.

I just put on a 2 3/4 inch beaudesert exhaust on monday and I think it's great. The power rolls on alot smoother, more like a petrol. When the revs hit around 2000 it pulls alot harder. Very very happy with it, not sure how many kw it added but I'm guessing around 8-10? Next is the chip, looking forward to that one.

As for fuel economy I can't comment, haven't had to fuel up yet

tommy222220_0 said:

.

http://www.diesel-tec.com.au/pdf/Stage 2 Navara 3.0 power.pdf

http://www.diesel-tec.com.au/pdf/Stage 2 Navara 3.0 torque.pdf

20% with chip + exhaust at peak power

BUT - 45% more power @ 90km/k (~3000rpm)
- Over 50% more torque @ 70km/h (2-2500rpm)

Gains are prob around the 10% mark with just the exhaust.
But very noticiable in the mid range and helps to reduce the turbo lag time

I put a D'tronic chip and a 3" exhaust on at roughly the same time. Uses exactly the same (10.4l per 100km) before and after the mods.

Click to expand...

im from near your way, im from jindabyne. where abouts did you get your chip from?

jap55s said:

im from near your way, im from jindabyne. where abouts did you get your chip from?

Click to expand...

2nd Hand, 4wd forums

Just be patient and 1 will pop up, (well thats what i did)

Guys Girls and others, 2 things - 1/ Is it just my computter (windows 7 ) or is this Nav Forum a slow site.......(Take a priest to tears waiting for screen changes etc ) - 2/ Had a 3" exh + dump pipe fitted with Hi flow cat / resonator by Windsor Exhaust NSW and WOW - no one could say " little or no difference " - The diff is absolutely amazing. Absolute minimum turbo lag - lovely turbo whistle!!!! - cooler EGTs - petrol like acceleration and excellent torque - felt in seat of the pants. ........Then added a DP chip set on 5 out of 7 ......its now actually SAFE to drive-----you can ACTUALLY pull out into a line of traffic and know when you tickle the accelerator......it WILL respond.....Yes mine is a 2:5ltr 09 Cosmic Black STr not STX.

Nope, Nav Forum always nice and snappy for me, loads nice and quick. Is it just this site that has that issue for you?

(Vista64)

Hoo Roo

Thanx guys. What's a reasonable price for a 3" plus hi flow cat?

i paid $800... 3' turbo back, high flow stainless cat and no muffler, curved up around the back axle so now water can get in unless it sinks.....