I would much rather a 'real' timing value from the xede.

 

can any of the vishnu people confirm about the knock sensor buffer? does it in fact change the knock sensor signal to have a 0-5v output?

 

In the process of messing with my boost pressures, I noticed that the AFR is doing some pretty weird stuff. I have an Xede V3.2, Signature Exhaust (that doesn't fit!) and Vishnu Cam Gears. Running base Vishnu 93 Oct Stage 1 maps. I had to mess with the boost map to get rid of a fuel cut / overboost problem, but now I'm wondering if the problem is with the lean AFR? Any thoughts? Thanks.



This is my fuel map, which I haven't changed from Vishnu. As you can see, the AFR profile doesn't seem to be even loosely related to the fuel map! The peak lean value is just under 12:1 but it's hard to see on the graph. The rischest it ever gets is about 11.6. The Torque definately dips during the lean spike (lump!). Before I start richening up, I just wanted to get some thoughts on what might be causing this?

 

Hey, I want that software!
That loss of power may be the ECU pulling timing due to high knock count in the lean hump.

I would richen up that area 5k on by 2 points and check AFRs again.

 

I looked at the timing, but realized that the timing value from the Xede is only "before" the ECU gets it, so it doesn't really mean anything. You're probably right, the factory ECU is pulling timing, which explains the torque dip. What I don't get is why the lean "hump" is there at all? The Vishnu map is calling for "enleanment" (not sure that's a real word?) but the AFR reading seems to have a life of it's own?

I'm pretty new to this, so I appoligize if this sounds stupid, but of all the "dyno runs" I've seen on this site, they all start lean and progressively get richer, yet mine goes rich (sort of) then starts getting leaner at higher RPM? Is 12:1 too lean at high RPMS and high load?

By the way, this isn't a proper run on a dyno, this is on the street (oops, I meant to say "closed circuit with professional driver").

 

The off the shelf maps in my experience are richer. Is your wideband in calibration?

What is "Street Tune"?

 

What do you mean "it won't fit". Did you install the spaces for the tie bars?

My fitment was perfect on a used one and I'm a _moron_ when it comes to wrenches.

d

 

I'm pretty sure it's in calibration. It reads 14.7 at idle, plus/minus a few. I also did an "overnight" calibration before taking these readings. So I think the AFR readings are correct.

"Street Tune" is some crappy software I got off a friend in the UK with a FQ340MR (UK version of a hot EVO produced by Ralliart - very cool, by the way). I'm pretty sure he had a version of Xede straight from the land of OZ. I haven't been able to find out who wrote the software, it's "buggy" but great when it works. I think he got bored and quit half way through! Also (when it works!) it allows you to change the Xede maps online so you can do a pull and then mess with the maps and do another pull to see the difference (kind of like a 4WD dyno). Pretty cool for "Street" tuning! I don't think it even made it into the category of "freeware", more like "Experimental", but works for me :-).

 

software looks cool! Do you have a walbro fuel pump?

 

Yeah, I did the spacers and all. This is the 3rd one they've (Vishnu) sent me. The problem is with the clearance by the aft prop shaft. I even went to AMS in Chicago to have them make sure I wasn't a_moron_ but even they agreed. When it gets hot it actually expands and touches the drive shaft (sounds like an F-18 with full afterburner taking off, makes my teeth chatter!). Plus it can't be good for the aft prop shaft!. Anyway, I found a solution, thanks to a bent piece of coat hanger! I just bend it away from the prop shaft (do you Americans call it a prop shaft? Is it a "rear drive shaft"? Yes, I'm a "Limey").

 

Interesting as d hasn't been able to get ChipTorque to release the protocol that would permit updating the Xede's maps.

What gear was the pull taken in? First gear will be rather lean. In my experience with that map second gear will be no leaner than 11.2 to 10.8.

 

We call it a drive shaft. Prop shafts are on boats. But never fear we understand in any case...

I don't understand the pipe runs parallel to the shaft and then turns away to meet up with the muffler. Normally the exhaust system expands and touches (melts) the bumper cover.

 

No fuel pump mods so far. I know, I thought the same, but without fuel rail pressure monitoring it's hard to know what's going on? Is it poosible that the fuel pump is maxin' out and pressure is dropping?

Why do you mention "Walbro"? Are they bad?

 

I just swapped in a Walbro yesterday when I found a lean run condition on Friday for the first time with the stock pump. Knock was the give away that something had changed. Subsequent runs returned to reasonable AFR.

That said the Walbro pump is very (VERY) noisy. It's also low cost and a common addition.

On the other hand I ordered a Power Enterprises 210 LPH pump yesterday and will swap that in when I get it.

 

walbro is "good" just calling it by brand name ... not sure but the maps may well be made for a car having the upgraded fuel pump.