AFR's who's running what

16bit · Postby **16bit** » Tue Feb 12, 2008 9:42 am

I am really interested to see what afr's people are running - in particular forced cars. I am running 12.5 atm but it could apparently go leaner.

Steampunk · Postby **Steampunk** » Tue Feb 12, 2008 10:30 am

On the dyno day last saturday that you piked on :mrgreen:

, the Mazda3MPS'ses and a Holden Astra HSV VX-R were showing up between 12.5 to and 11.5 on average.

The VX-R got all the way down to 10 nearing redline.

I think all of them had standard EMS tuning, and the power @ wheels they were making match their claimed power at the flywheel.

Why would you go leaner? The most powerful 3MPS (152kw@wheels) had the richest mixture out of the lot.

GP · Postby GP » Tue Feb 12, 2008 10:49 am

I think we need a FAQ for all these abreviations

16bit · Postby **16bit** » Tue Feb 12, 2008 11:36 am

thats funny

Well leaner generally means more power. But if I go too lean i will definitly need to upgrade my rad. I spose when it gets that tensioner thing sorted i will have more then enough power for no lsd.

Juffa · Postby **Juffa** » Tue Feb 12, 2008 11:43 am

As some of you know I'm running a FM/Link ECU. I'm using the AFR targets as set in the FM install manual. These may be adjusted when I finally get her on a dyno.

My current targets are:

140Kpa - AFR=12.5

180Kpa - AFR=11.5

227Kpa - AFR=10.5

The above boost levels are the centres of my ECU pressure tables while under boost. My wastegate currently opens at 160Kpa.

J

16bit · Postby **16bit** » Tue Feb 12, 2008 12:01 pm

so would you be running 23 psi?

Juffa · Postby **Juffa** » Tue Feb 12, 2008 1:31 pm

16bit wrote:so would you be running 23 psi?

No

....around 9 pounds, on stock internals....

J

16bit · Postby **16bit** » Tue Feb 12, 2008 2:42 pm

how come the internets conversion dooies said that it was 23psi at 160kpa?

blackster · Postby **blackster** » Tue Feb 12, 2008 3:40 pm

AFR = Can of worms.

For what its worth 11.8 under full throttle.

Juffa · Postby **Juffa** » Tue Feb 12, 2008 3:43 pm

16bit wrote:how come the internets conversion dooies said that it was 23psi at 160kpa?

Don't know the answer to the question...but I know that when my boost gauge is showing 9 pounds, the ECU display is showing 162Kpa and there is a conversion table in the FM tuning guide that shows 162Kpa as being 9 pounds.

According to the same table 227Kpa is about 18.5 pounds.

J

16bit · Postby **16bit** » Tue Feb 12, 2008 3:50 pm

cool - i think i will be around that 9 psi once the tensioner is sorted.

Matty · Postby **Matty** » Tue Feb 12, 2008 7:27 pm

Juffa wrote:
16bit wrote:how come the internets conversion dooies said that it was 23psi at 160kpa?

Don't know the answer to the question...but I know that when my boost gauge is showing 9 pounds, the ECU display is showing 162Kpa and there is a conversion table in the FM tuning guide that shows 162Kpa as being 9 pounds.

According to the same table 227Kpa is about 18.5 pounds.

J

absolute vs gauge pressure.