AFR FIGURES?????????
Turbo Mini Forums

Right got fed up with me car going out of tune so much, as i've said about before, so not need to going into that now.

But i've bought an AFR gauge to give me some idea of what the tune is doing and i might be able to keep it nearer to in tune.

Anyway I can tell you a good Co2 fig for power and safety, but when it comes to air fuel ratio it's all very new to me, so does any one know what sort of figures i should be getting for safe power at the top end and economy at part throttle.

Thanking you.

MW

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

I still can't undertsand why your car goes out of tune so often??

Team Racing

never mind, it's only after a really hard boot, but there you go. at least this might help me under stand why. that's the plan.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

Full power 12:1

cruise 14.7:1

light acel 13:1

over run 15+:1

They are very rough guides and lots of people use diffferent figures.

richer than 9:1 and it will miss fire lots!

Rember lean on boost = no pistons :)

Alex

AlexF

Cheers Alex, yes that's some thing I have to think about that the lower the figure ISN'T meaning it going lean but rich, It's the opposite to the C02 readings in that sense.

MW

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

What gauge have you gone for?

Alex

AlexF

It's an aem.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

oooh, Good choice!

Just bought two myself.

you gready git dave wasnt one enough lol.

ill wait and see how it pans out willie before i get one ( another suffolk guinea pig in the making).

always looking for them bigger bunches of bannanas

On 23/05/2006 02:13:35 TurboDave said:

oooh, Good choice!

Just bought two myself.

Team Racing

not wanting to hi-jack the thread but staying on topic, a feeind has a AFR guage in his punto turbo and its not a verry steady at all it never holds one place for longet than a second other than when decelrating, is this just becouse of the ECU or is it becouse its a cheep guage? i am unsure what make it was but iirc it was about £60.

thanks. Dan

at about £60 itll be a narrow band gauge. there slow and not accurat unless you want to know where an afr of 14.7 is. (better than nothing mind you)

if i set my wideband to do real time output, the gauge flickeres so fast i swear i can see the AFR of each idividual cylinder at idle. this confised the std ecu though, but tehre is an option to slow down the outputs to "emulate" a narrow band sensor.

my wideband was teh cheapest avaliable at teh time, cost about£ 150 ish to my door, and didnt come with a gauge. but came with laptop software and datalogging stuff. and i made a guage. with a gauge i remember it being a sniff over 200.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

In my N%%% and astra the AFR showed 14.7 all the time except when decelerating

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

so is a narrowband one not really worth the hassel?
would an EGT guage be of more use? how fast are they to react tho? i imagine them to be quite slow at telling you its running lean?

thanks, Dan - should i start a new thread so i dont get told off for hi-jacking?

I think i know the answer to this but here goes.
And the answer might be no you can't but.....

if Full power setting is 12:1, is there any way (apart from going to the rolling road and seeing what the mixture is running)

Can the AFR figs / lamba readings be converted in to a close CO reading, as i no my car likes to have 5%-6% CO at tickover, my gauge may be reading in the rich setting but what is the fig, for all i know it could be 10% CO, i hope i'm making sense.

MW

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

On 26/05/2006 11:47:51 pot_dan said:

so is a narrowband one not really worth the hassel?
would an EGT guage be of more use? how fast are they to react tho? i imagine them to be quite slow at telling you its running lean?

thanks, Dan - should i start a new thread so i dont get told off for hi-jacking?

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.