A nice little intake mod AU. + horsepower

[HULK_I6T]

I have a au series 3 4.0L i6 auto.

It has the following mods, 2.5 inch cat back exhaust and panel filter, plus xr6t snorkel. I also have an air deflector fitted behind grill.

Anyhow under WOT I noticed the car would change up at just before 5000rpm, to me it felt like it was a little too soon. Surely I was giving up a few kW up top.

So I did this mod as a test.

1. Replaced the pipe from airbox to rest of intake with a straight piece of 3inch aluminium pipe. Removed fitting from airbox lid to get it in.

2. Flicked the panel filter and Grabbed a 45 degrees 3 inch pipe and fitted up a 3 inch pod filter inside the stock airbox. Used a 3 inch piece of silicone hose to join the two pipes.

RESULT:

There is a noticeable difference in off the line, mid range and top end power. It now is happy to rev out to 5200-5300rpm before changing up and feels more powerful in doing so. There is a little bit more induction noise from the pod but it's enclosed in the stock airbox. Great mod... Under $100 all parts.

The stock intake pipe that I removed closes up to about 2 inches at the point of the airbox, it must be restricting the power. There is probably going to be a fuel economy advantage as well.

To compliment this mod, I'd grab a xr6t snorkel and also the air deflector you can make yourself with a bit of aluminium sheet.

If your AU is changing up before 5000rpm @WOT try this intake mod and enjoy the benefits.

[Grippy]

Nice one Hulk, where did you get the new alloy pipe from? Any pics?

[HULK_I6T]

Originally Posted by Grippy

Nice one Hulk, where did you get the new alloy pipe from? Any pics?

$29 from autobarn. Silicone hose was $11, 45degree pipe $19, 2 extra hose clamps. I had a 3A racing 3 inch pod in the garage.

Definite power increase

[auIILTD]

Originally Posted by HULK_I6T

Anyhow under WOT I noticed the car would change up at just before 5000rpm, to me it felt like it was a little too soon. Surely I was giving up a few kW up top.

Hulk, just to let you and others know, shift points for your trans have nothing to do with the power the engine is making. In the tune, shift points are a function defined by throttle percentage vs tailshaft rpm.

Cheers
Stu

[JC]

Originally Posted by HULK_I6T

$29 from autobarn. Silicone hose was $11, 45degree pipe $19, 2 extra hose clamps. I had a 3A racing 3 inch pod in the garage.

Definite power increase

Years ago on our AU XR6, we did a dyno comparison between no filter, stock airbox and 3" pod, and the pod only increased power by 1rwkw over stock airbox. No filter was the same result as the pod. That's it.....

I doubt therefore that peak power has changed, but it is likely that more air is being sucked into the engine at high rpm with the restriction removed.

[HULK_I6T]

Originally Posted by auIILTD

Hulk, just to let you and others know, shift points for your trans have nothing to do with the power the engine is making. In the tune, shift points are a function defined by throttle percentage vs tailshaft rpm.

Cheers
Stu

Well it's added a few extra hundred rpm at the top.. Possibly just revving out quicker with the better breathing.

I've tested it plenty times, it's definitely true.

[HULK_I6T]

Originally Posted by JC

Years ago on our AU XR6, we did a dyno comparison between no filter, stock airbox and 3" pod, and the pod only increased power by 1rwkw over stock airbox. No filter was the same result as the pod. That's it.....

I doubt therefore that peak power has changed, but it is likely that more air is being sucked into the engine at high rpm with the restriction removed.

Well in my example I also changed the pipe from airbox to rest of intake as well as a pod, the stock pipe it's about 2 inches at one point, I changed it to a 3 inch pipe right through eliminating this restriction. Maybe it's not the pod adding the power... It's the pipe. Did your test include the pipe?

It's definitely feeling more powerful, car just pulls harder everywhere. I'd be happy if I'd done a full exhaust and it made such a change as it's done.