[Kelvin1000]

The last incarnations of Procede V3 and JB3 1.4 that I tested did not variate at all from stock AFR (nothing like the GIAC or the Dinan which both run similar AFR curves)

However, I don't know about JB3 2.0 and Procede Rev4 as I have not dynoed either. Maybe others can chime in with their dynos!

[Former_Boosted_IS]

Originally Posted by Sniz

hmmm......so it looks like the JB3 is running WAY leaner than both your GIAC and the procede. Both the GIAC and the Procede are in the 12's at 4500rpm while the JB3 is over 14.1. Huge difference right there.

Sniz, be careful not to carry former A/F ratio logic for a traditional EFI motor to a DI motor. I have done a lot of testing on a lot of different A/F ratios and what you knew does not apply on the DI N54 motor. Here is my A/F on my JB3 for reference. The only reason I richened up my setup is to keep get things a bit fatter for the dry NO2 shot. You can see I am 12.5 at WOT to 11.5 at redline. Any JB3 can easily be modded within 10 minutes to make their A/F graph to look like mine.

[Mike@N54Tuning.com]

Originally Posted by Sniz

yeah I saw that and that really surprised me, those are 2 very different tunes for sure.

I'd like the richer tune myself, safer in a big way. I know the n54 has some great engine control but I dont see the reason for pushing it like that. I'll have to admit I dont know the limitations of DI, but if both GIAC and Vishnu are running much richer I have to question the reasoning behind the 14+ afr the JB3 is running there.

Actually all the piggybacks run around the same air/fuel ratio. The mistake you are making is comparing air/fuel ratios from a load dyno to those from a dynojet. I'd rather not get in to posting dyno charts but its easy for someone to search for dynojet charts to compare.

On the JB3 fuel resistors the standard ones are ~4.7k ohm and users often swap them to ~3.3k ohm for extra fuel or even ~2.2k ohm for use with nitrous. They are right on the board and easy to swap. The standard ones are fine though for most applications.

Also, Map 0 runs the factory air/fuel ratios for dyno comparisons and emissions testing.

Mike

[Sniz]

Originally Posted by jpsimon

yeah at that point kelvin has marked on his graph (4500rpm), my graph is at the same reading ~12.95

Originally Posted by Mike@N54Tuning.com

Actually all the piggybacks run around the same air/fuel ratio. The mistake you are making is comparing air/fuel ratios from a load dyno to those from a dynojet. I'd rather not get in to posting dyno charts but its easy for someone to search for dynojet charts to compare.

On the JB3 fuel resistors the standard ones are ~4.7k ohm and users often swap them to ~3.3k ohm for extra fuel or even ~2.2k ohm for use with nitrous. They are right on the board and easy to swap. The standard ones are fine though for most applications.

Also, Map 0 runs the factory air/fuel ratios for dyno comparisons and emissions testing.

Mike

gotcha, thats probably the variation we are seeing then, was wondering how different dyno's can change this. thanks for the info.

[a32guy]

I'll be on the same dyno this weekend and have removed my JB3 (my car is 100% stock). I'll overlay the three AFR curves and update this thread at some point this weekend. I'd be interested to see how much leaner the factory runs these cars.

[mwahlert]

Originally Posted by a32guy

I'll be on the same dyno this weekend and have removed my JB3 (my car is 100% stock). I'll overlay the three AFR curves and update this thread at some point this weekend. I'd be interested to see how much leaner the factory runs these cars.

oem tune is stoich at peak torque...

[a32guy]

Originally Posted by mwahlert

oem tune is stoich at peak torque...

k thx...

[Sniz]

Originally Posted by a32guy

I'll be on the same dyno this weekend and have removed my JB3 (my car is 100% stock). I'll overlay the three AFR curves and update this thread at some point this weekend. I'd be interested to see how much leaner the factory runs these cars.

I'll be interested in seeing that, same dyno, different tunes.

[jpsimon]

Nice, you're doing it this weekend? Do you know when yet? I'll try to come by

Originally Posted by a32guy

I'll be on the same dyno this weekend and have removed my JB3 (my car is 100% stock). I'll overlay the three AFR curves and update this thread at some point this weekend. I'd be interested to see how much leaner the factory runs these cars.

[Former_Boosted_IS]

Originally Posted by Sniz

I'll be interested in seeing that, same dyno, different tunes.

Sniz, you have to understand this is only limited by the safety features built into each tune like Shiv mentioned. By changing the resistors, you change simply change what 100% fuel means to the tune.

[jpsimon]

Sniz, here's a JB3 car (from 2009) on the same dyno, along with lots of complaints about it reading low :
http://www.e90post.com/forums/showth...light=EPL+dyno

[a32guy]

Unfortunately I won't have my tune in because I'm chasing a VANOS code, but it should give us a good evaluation for stock AFRs. Probably Saturday morning, I'll be there helping a buddy pull the engine on his S4. Stop down!

[jpsimon]

awesome, I'm really interested to see what a completely stock car puts down on this dyno

[Sniz]

Originally Posted by Former_Boosted_IS

Sniz, you have to understand this is only limited by the safety features built into each tune like Shiv mentioned. By changing the resistors, you change simply change what 100% fuel means to the tune.

gotcha

[Sniz]

Originally Posted by jpsimon

Sniz, here's a JB3 car (from 2009) on the same dyno:
http://www.e90post.com/forums/showth...light=EPL+dyno

looks like you are putting down around 50whp more than that guys car, impressive.

his dyno does not show afr though.

[Former_Boosted_IS]

Originally Posted by Sniz

looks like you are putting down around 50whp more than that guys car, impressive.

his dyno does not show afr though.

I have plenty of AFR runs with multiple setups on the JB3 if you guys want them. Remember I have the FJO wideband.

[a32guy]

Originally Posted by Former_Boosted_IS

I have plenty of AFR runs with multiple setups on the JB3 if you guys want them. Remember I have the FJO wideband.

While this is great and all, I'm more interested to see results on the same dyno, with the same wideband and sensor, and all scaled on the same graph.

[OpenFlash]

Originally Posted by a32guy

While this is great and all, I'm more interested to see results on the same dyno, with the wideband and sensor, and all scaled on the same graph.

If the dyno is reading AFR from the tailpipe, it's going to be very inaccurate for the first few thousand RPM of the run. And somewhat inaccurate for the rest. If you want to do proper testing, log AFR further upstread in the exhaust, preferably before the cats.

[Prince ///M]

Very interesting topic...and I hope someone can help me for a check of the following logs performed on a 135i with IC, BMW performance kit and AA processor on top of it.

As you probably know the AA processor can not bias the wideband sensor, so that the A/F ratios are the same in stock and tuned configuration (very, very bad IMHO)

In the first graph you can find the TARGET lambda value (lambda 1 = stoich = 14.7:1 A/f) versus rpm. In particular the DME asks for 12.3:1 @ 6500rpm and 13.5:1 at max torque.



The second graph shows the VOLTAGE value of the stock wideband O2 sensor (vs rpm). Sadly I don't know the exact coversion table needed for the passage from V to Lambda.



In the third graph there is a comparison between target and lambda reconstructed from wideband voltage (using the following formula that seems to be the best fit):

Lambda actual = (O2voltage+3)/5

The result is not so bad, but I would like to be sure about the conversion factors used.



Mikerry/Shiv, do you know the BMW sensor specifications (I hope so, 'cause you use it )?

P.S.
Shiv, is the A/F ratio of RevI maps the same implemented in V4?
Can the A/F be read on RevI through the Procede datalog?

P.P.S.
The tests performed without AA processor confirm that BMW Pk software is a total waste of money! Unbelievable how badly the boost is controlled... Slow and with hell of an overshoot all the way up to 5000rpm (in accelerations from 2000 rpm this causes for several seconds a HUGE throttle closure up to 20 deg residual).

[mwahlert]

Originally Posted by shiv@vishnu

If the dyno is reading AFR from the tailpipe, it's going to be very inaccurate for the first few thousand RPM of the run. And somewhat inaccurate for the rest. If you want to do proper testing, log AFR further upstread in the exhaust, preferably before the cats.

when i took my efi tuning class - the instructor (greg banish) said that as long as you first let the cats stabilize or saturate, the run would be accurate...

he was showing us on the dyno that if you loaded the engine up for a few seconds the lambda reading would stabilize and be accurate for the run if this was done first.

he was explaining that the cats are basically "air capacitors" - and that once they are saturated they don't do much to effect AFR.

i'm sure however though, that measuring so far downstream also has its fallbacks..

[Sniz]

lol at Mikerry

[OpenFlash]

Originally Posted by mwahlert

when i took my efi tuning class - the instructor (greg banish) said that as long as you first let the cats stabilize or saturate, the run would be accurate...

he was showing us on the dyno that if you loaded the engine up for a few seconds the lambda reading would stabilize and be accurate for the run if this was done first.

he was explaining that the cats are basically "air capacitors" - and that once they are saturated they don't do much to effect AFR.

i'm sure however though, that measuring so far downstream also has its fallbacks..

Hi Mark,
That would very well be true. But what I was referring to is signal contamination from non-exhaust gas (air) at the sensor. This is common when a widegand sensor is just clamped to the exhaust tip. It needs to be completely isolated in the exhaust stream with no access to air. Or just subject to enough exhaust flow velocity that there is no free air mixture anywhere near the sensing element. So this means upstream in the exhaust pipe.