What are your 944 turbo Afr readings whilst driving ect?

[Dan944t]

hi guys

I’m preparing my car for a long 4 hour drive to get it tunned and just finished fitting a long awaited afr gauge/kit to see what’s what.

ive managed to get the car up to temp and idle at 14.43 , and want Out for my first drive last night in a while.

Ive got the boost low maybe 8psi for now as engines just been freshly built , and the car drove very well all be it, keeping it under 4000rpm. My question is what readings should I be seeing If all is well?

max On boost
off boost ect

at one point I was doing maybe 30mph in 4th hardly touching throttle more rolling maybe and it went to max lean I think 28 then the 3 lines ... crapped myself for a minute then it came back

just not sure what I should be looking at. By time I got home and opened my garage it had settled to 14.33 ticking over nicely.

I understand every cars different with different tunes and mods ect just wondered what sort of numbers of numbers to be alarmed at ect.

thanks
Daniel ??

 

[PSH]

Hi Dan

AFR at normal will be 14.7, this will fluctuate but should be around that mark when cruising. Currently, at 14.34 you are running a little rich, if that's the highest it gets, but not by much. When you back off it will lean out, this is normal as no fuel is being used. Don't worry if when you close the throttle after driving at a speed that the AFR goes wild, if like my Innovate gauge it will flash at a brighter level, even just showing '02' when leaned right out. What is important is what the gauge reads under acceleration (load)....this will depend on your tune and mods installed but I would have thought you should be seeing at least 12 for your setup, difficult to tell as each engine setup if different. Can you tell us what it read under load, don't worry about the revs, it's the load that counts, open her up a little and note what the AFR shows, if it's not into the 12's at least, back straight off and take it easy until Wayne does his magic. The AFR should go richer immediately you apply more power/load.

 

[blade7]

I wouldn't sweat idle starting with a 14 on these old engines. Not much point in chasing 14.7 stoich on an anything modified on a standard AFM. Years ago my MOT man used to wait while I turned my Cosworth down to pass emissions, it hunted at idle until I turned it back up. As for AFR on boost, that depends entirely on how much boost you intend to run.

 

[Dan944t]

I was on 18 before the build and now once it gets tuned I will leave it up to Wayne..... what ever he decides I’ll stick with it?

Daniel ??

 

[blade7]

Were you running a 3bar FPR?

 

[Dan944t]

I have also installed the adjustable FPR and set it to 3bar once engine was at temp yes.

my boost gauge did something I’ve not noticed before but maybe becuase I don’t often notice unless I’m given it the beans. It idles at about -20 which is what it started at then it dropped to around 24 which I’ve never noticed, then after driving a bit went and stayed back at -20 on idle.

i also noticed the adjustable fuel preasure reg is set and starts at shy of 3 bar but sometimes notice when hot drops a bit to 2.7 bar? Wasn’t sure if it was the spring bedding in or a slight leak somewhere which I can’t see yet

 

[Dan944t]

I took The car out for a little run tonight, all be it i dragged my dad who just came over in the car with me for bit so I could try test it.

I found it hard to get a good under load reading becuase of the fact I’m still in the bedding in stage and not going over 4000rpm which doesn’t really leave me allot of time to build any boost. I could only get a reading of 18.09 before I had to quickly change gear so I don’t know if it is going to be good enough of a realistic reading seeing also that I’ve turns the BC all the way down to maybe 8-10 psi ?

car felt great though and I’d say although it cranks a few more times than it did before I fiddled with stuff trying to lean the mixture out to above 14 on idle , it deffinately feels like it drives smoother as I had a few pops and bangs last month when I accidentally took it over 4000 with my foot down , but now it’s not so rich it feels way smoother, and sits happy after a run.

 

[Eldavo]

AFR at idle will be off stoich due to the lack of flow so I wouldn’t worry about that. Also, when you completely lift off from the throttle, the injectors switch off so a - - - reading of full lean is completely normal. Under full boost, 11.7 is my target but better to be slightly above than slightly below if there is going to be any variance.

 

[scam75]

High 11's/low 12's on WOT is pretty safe and to be expected. I'm running about 19psi boost and only use Shell V-Power. Mine idles around the 14 mark and is same on cruise. I'm using Promax L2 chips and rest of spec is on signature below.

Stuart

 

[blade7]

Any turbo car I've had has always been run on super unleaded. It's probably a bit late after 10 years, but I've started using BP recently as they don't add Ethanol to their super. I think it's only BP and Esso that state that now.

 

[Diver944]

How did it go at Waynes?

 

[Dan944t]

How did it go at Waynes?

Hi mate,

well it started off a bit of a mission as we had a really annoying boost leak from the dual port wastegate I bought from JMG the lines were maybe 3 mm too large for the banging fittings and were leaking bad under even blowing through by mouth, so we went to the nearest hardware car shop and bought some better lines than the silicone ones that weren’t really adequte.

then I ended up taking the top part of the engine apart 3 times off and on ie fuel rain/ injectors / boost hard intercooler pipes, manifold just to get under where we could hear and see air leak which was a couple of original and hard rubber hoses going to the idle controll valve.

oncr all those were fixed it must have been near on 5pm I dont think Wayne was expecting me to be so hands on! ?? I brought a boot full of tools and spares luckily and whipped it all off and on quickly but still took allot of time as the preasure testing for boost systems is the only thing I ran out of time to do myself as I didn’t have the kit for the bings yet.

anyhow once that was sorted the car was beginning to do really well and Wayne started to get somewhere doing stronger and stronger pulls untill he said the engine wants allot more but the fuel pump isn’t supplying anymore fuel past the point he was at. I had a quick look on the screen and it said 370bhp

i was frustrated as I had upgraded to a Bosch motorsport pump from JMG which they say is good for 450bhp but we tested It in-line from the tank with separate fuel preasure gauge and sure enough it stopped delivering enough fuel , so it’s ratger the filter on the tank is slightly blocked as we checked all lines which are new and no blockages , or the pump is dodgy or possible a fake? Which Wayne says there are quite a few company’s that do sell them so I’m hoping it’s the filter ? His going to drain and check the tank and then buy a proper motor sports Bosch pump which his not sure on price but thinks near the £400 for genuine but his got to find out still from his catalogue? JMG only charge £189 I think ??

so so I ended up having a really expensive train and cab journey home on virgin

left the car in his hands and now have to wait and see what he finds ??

I was deflated but happy at same time becuSe the engine was coping well ??

 

[blade7]

Remind me what turbo and intake you're using now?

 

[Dan944t]

Intake manifold is porsche original with ceramic coated and honed out inside, stage 2 intercooler and rebuilt 220 kkk26 I think turbo

 

[blade7]

It's definitely not a standard 944 turbocharger if it made 370 bhp.

 

[Dan944t]

It's definitely not a standard 944 turbocharger if it made 370 bhp.

im fairly sure it was the standard unit. When I rebuilt it And ordered the bits.

im not sure iether if the car was actually making it will make that figure when it’s finished only time will tell but I deffinately saw that on the screen on the last run before he realised the pump could keep up with the engines demand.

I don’t know if they do a math with that figure and take something away like the tension of the rollers ect ? This is my first live mapping so I’m no expert at these things.

What would you say I can expect at a maximum BHP with a standard 220 turbo?

He did say one thing and that was with the mods I’ve done, the only thing stopping me making massive figures is the turbo, but I much prefere a faster spool then a bigger boost mid range so for now I reckon I’ll be happy with a quicker pick up of boost. Maybe after a good few years of dusting up on the bushes and handling I may treat myself to a larger turbo and another session with Wayne.

Daniel ??

 

[blade7]

AFAIK max BHP with the K26/6 is around 290.

 

[Dan944t]

Cheers blade!

What does this mean mate ?”AFAlK”

id have hoped that I’d make at least 330+ with the way the engine had been built but when Wayne’s finished with her I will report back and let people know what it made if anyone is interested?

atb
Daniel ??

 

[Waylander]

That means

"As Far As I Know"

 

[Dan944t]

Cheers Martin ??