AFR at idle, first startup

chally72 · 09-15-2010, 04:45 PM

Hey guys, I've got her running permanently now, but before I start her up again, I wanted to confirm what AFR numbers should be like at idle. I'm concerned about the AFR, and have the following factors: large turbo, stock injectors, stock chip, 3bar FPR.

She varies between 14.7 and 15.8 at idle-2500rpm on my new wideband gage. Up and down every few seconds.

Is this ok? I haven't even put the car in gear and moved it, just started it up in the workshop for a couple minutes, and revved it while it's sitting. Haven't gone beyond 3000 yet, and I won't until I'm sure I'm not hurting it.

Thanks!

minho78 · minho78's Garage

Can you post a video. If you are revving at 2500 at it shows a constant AFR of 15.8 then no good, 14.7 at 2500 it's OK, after that 2500 rpm it should go richer.

chally72 · 09-16-2010, 05:01 AM

I will try to do so tonight, thanks.

running_cold924 · running_cold924's Garage

mine did the same with the max chip set especially when it was cold. after warmed up, it was from 14.4-15.2 at idle and while driving without boost

redscare5 · 09-16-2010, 08:28 AM

Mine sits at 14.6 to 14.7 at idle. When I get into it it rapidly drops down to around a 12. You might want to go with bigger injectors if your 15+. The Vitesse stuff is very pricey, but worth every penny in my opinion. I used to have lindsey racing aftermarket chips. Once I went with Vitesse I was much happier. He has the maps perfect in my opinion. Better power ban, will not run lean, and my car idles better than any of the previous 5 944s that I have owned. Just food for thought....

'86 951
'88 Turbo S motor
3 Bar FPR
55 Lb injectors
Vitesse MAF
Vitesse Maps

choinga · 09-16-2010, 11:40 AM

ideally, you want to be at 14.7 of course, but your car is going to start up rich (mine is in the 12's) until it warms up and then will stabilize. I have the full Vitesse MAF w/ piggyback so I was able to dial mine in so that it stays at 14.7 at idle and will stay there all the way up through 2500RPM. I had to do this because that's how they do emissions testing in TX - it's a two stage idle process.

chally72 · 09-16-2010, 02:24 PM

Thanks for the input, all. I talked with Vic at Pauertuning just to confirm that what I was running was too lean. It is. I just couldn't get away with things with stock chips, even just for break-in. My own fault.

minho78 · minho78's Garage

Quote:

Originally Posted by chally72

Thanks for the input, all. I talked with Vic at Pauertuning just to confirm that what I was running was too lean. It is. I just couldn't get away with things with stock chips, even just for break-in. My own fault.

Absolutely not, I just saw you have Vics BB turbo. Yup you definately need fore fuel for that puppy(Injectors also).

Like others said Lindsey, and Vitesse has good stuff. I run Russell Berry chips and this guy Knows 951's software. I'll attach my Dyno from the last meet we had at Van's house. Mine is the Manny Fernandes

running_cold924 · running_cold924's Garage

x2 on the vitesse stuff, couldn't be happier

chally72 · 09-17-2010, 03:41 PM

I actually went the DIY route and got the Ostrich 2.0, currently trying to get a working tune using TunerPro with the help of Rogue and Vic. I'm impressed by the options the TunerPro software offers, and for anyone with even middlin' computer skills, a wideband O2, and some time, I think I'd recommend this. Very cool stuff, very versatile. And I've never done this before in my life.

Me a year ago if asked about injectors: "Injectors? What the **** is wrong with jets?"