Could someone explain the lambda reading on this power graph for me

Thanks in advance

 

yup....its good

ok its not an explaination as such....

 

The good bit i like

for the explanation

 

I’m guessing here but……….the scale on the right is the average voltage output of the lambda sensor ie 0.2v = Lean, 1.2v = Rich. Your readout shows it leaner at the lower revs, a fairly steep climb between 3200 and 4000 (which I’m guessing is where boost really starts to kick in), and a nice steady rich reading at the higher revs. If you were to have any negative spikes anywhere along that line I’d say it was probably a bad reading. – But yours looks good (methinks).

If you can be arsed to read it, this should tell you some more about lambda sensors…..

http://www.picotech.com/auto/lambda_sensor.html

I’m going to be checking mine soon.

HTH

 

I think lambda = 1 means stoich, which is an AFR of 14.7:1

So lambda of 0.8 is 80% of stoich, as in 14.7 x 0.8 = 11.8:1

Your graph shows 0.7 = 10.3:1, which means a nice safe AFR when on boost

I stand to be corrected though, but thats how I see it

 

Cheers for that

 

Jay m A is correct in his description of lambda, but that looks quite rich to me, I would expect a mapped car to be in the 0.76-0.78 range.

 

i think on the road youll find that the lambda reading would be closer to 0.78 as described above, on the rollers though the strange loads help to bring that figure down slightly lower....

I think my graph read around 0.72 or 0.73 on the dyno.

 

They do tend to read a bit richer on the rollers.
One of the factors being that the boost achieved on the rollers is normally a little lower.

what's your spec now then Granby, to get 333BHP ?

 

Better to run a little rich than lean

 

Cool, similar to me then, except my headers are still on the garage floor half ported (waiting for some carbide burrs to arrive).
I guess thats running about 1.4bar then.

 

Peaks at 1.45bar then dropping to about 1.3bar

 

Does it still spit flames, as it was when I was behind you at brands in Keiths Classic Wagon.

Are they real or is it a flamer kit ??

 

Yes it does still spit flames but they aren't real , just opened up the plug gap on it recently and it seems to be flaming some more , think i scared a few people in Blackwall tunnel last Saturday coming back from the rolling road day

 

Effective mods these, I have similar on my MY99 (VF35 rather than 34) and ugraded fuel pump and hoses. After some attention from Mr Rawle ....

http://img.photobucket.com/albums/v683/ns04/cc60eb74.jpg

Ns04

 

oh yes i forgot to put down uprated fuel pump

 

ian, i keep forgetting to ask what the VF34 is like compared to the old TD04...do you notice any more lag or has that all been sorted by Mr Rawl?

 

The VF34 spools up later than the TD04 but you get a bigger hit when it does kick in, now with the ported headers and the remap it almost spools up like the TD04 , you could always try one of Andy Forrests hybrid TD04's which are good for about 330bhp

 

its the only thing thats making me drag my heals at present, my car almost feels like its NA at the mo which is lovely to drive but bad on the juice consumption...330 pah <petulant child voice> I WANT AT LEAST 350

 

Hi mate,

I hope Ian will excuse me for jumping in with a reply, I have a VF35 (very similar to the VF34). In terms of the threshold at which the boost kicks in, it's like a TD04 before you get a decat etc i.e. it really starts to go from about 3000rpm (this is with ported headers though) at that point I have the torque I used to have at peak with the Td04 and from there it never looks back! The response below 3000 rpm is better than the TD04 after the remap and it feels beefier! In terms of the lag, i.e. the delay in response to the throttle being pressed, its not really discernably different TBH- it spools quickly. It punches considerably harder and longer though.

Ns04

 

Well if you want 350 i'm going for 400

 

is that all?

 

thnkas ns04, i also have harvey's headers so not a problem there...sounds as though a VF35 is the way to go...i'll also be upgrading to one of harvey fmic's so i expect quite a change in the way it drives

ian (another one!)

 

OK maybe 401

 

pmsl, yeah you will need it for lugging around that lardy blob-eye

 

330 would be "sufficient" as the folks at RR always used to say!*

Ns04

*For the moment!

 

BTW There's not much in it, but I believe the VF35 is the slightly quicker spooling turbo owing to the smaller exhaust housing (?), I think the flipside is that it's not quite as strong right at the top end, but -again, there is very little in it! The mapper will make the biggest difference by far I suspect.

Ns04

 

Meow

 

(only joking )

 

get yourself to a track, ill show you how slow it is if you like