SC kit for 308/328/Mondial

The air/fuel sneaking up a tad in the direction of lean and THEN responding down to rich is unique to the KE-Jetronic system that your Ferrari is using, and different than the standard K-Jetronic that Porsche used. What you are seeing is the enhanced Control Regulator of the KE system react to the WOT position, and come in with the fuel.

The Mondial we supercharged did the same thing.... we even thought that Ferrari may have tuned the system to hit close to Stoich in a particular RPM band they knew that the US market would test emissions at, yet run richer than Stoich in other rpm's for maximum power. (Max power is generally believed to be at about 12.5:1 AF ratio, where maximum efficiency is generally best at 14.7:1 AF ratio)

Anyway - not a problem.

 

the 308qv does not use KE-jet but K-jet basic with lambda, the KE wasn't in use until the Testarossa. the 308qv is the same setup as the 924T & 930T.

 

That's not what i meant to say. Yes, the torque and horsepower are higher at lower revs, but it's a heck of a lot more fun when you push it all the way to redline!

 

Congraz on the new supercharger.. looks great. I installed a turbo over the winter... makes the car so much fun to drive!! You are going to love it!!! What boost level are you running? I am running 9psi with a single turbo on my car and making around 304 hp and 260 ft/lbs of torque at the wheels. Again.. Congratz on a great job. Can't wait to here more!


Oh... btw here is the information about my turbo upgrade I posted a while back.

http://www.ferrarichat.com/forum/showthread.php?t=131709&highlight=308+turbo

 

Got it back on the dyno today, new cooler range plugs, .24 gap, better results. Still looks like ignition issues are there, and A/F begins to spike up @ around 6000. Input appreciated. We will see what Carl has to say.
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A really great chart - with a wonderful and flat air/fuel delivery.

I am working with Lou now to see what's happening to his ignition at 5800.

 

Lou,

Looks good.

260 and there's more room?? Nice

 

Agree - the K-jet fuel delivery curve looks well adapted;

I know this is a bit silly, but it's something I might do - did you disconnect the vacuum line from the ecu? - the combination of positive manifold pressure and rpm might shut the ecu down.

best

rt

 

Good thought !!! might be an out of bounds advance retard issue caused by positive pressure vs vacuum,.... HMMM. Carl and I are also exploring the vacuum connections on the WUR .The placement/inlet locations on my Euro car are both before and after throttle butterfly. Here again applying boost rather than the expected vacuum or neutral pressure may be goofing the fuel delivery control ability of the WUR. I am going to get an onboard AF guage and boost guage ASAP to dial in whats going on on the road, repeated dyno runs are a waste of time and money until the details of fuel delivery and ignition are close to sorted out. What do you guys think the consequences of zero vacuum information to the ECU would be?

-LouGaudio

 

I thought about the fuel delivery and the WUR, but I would have expected the curve to progressively lean then cut out; instead, it drifts off rich as you would expect it to do losing ignition.

I am on travel and away from my books, but the ignition charts are posted here somewhere for your car - would look at the high ambient pressure graphs - the clue of losing it at approxomately the same place in combination that you may have kept the vacuum line on, the ECU may be brought into parameters for which it was not designed.

Good luck - these are valuable lessons for us all.

rt

<< EDIT>>
Clamp off the ignition vacuum line and take for a drive and re-simulate the dyno run in 3rd or 4th - I bet it runs up to redline.

 

Bosch has few variations on the WUR, the one ferrari uses is vacuum controlled full load enrichment, based on the section cut and WSM I get this...
the WUR has two nipples, the upper one is connected to the TB before the throttle plate. the lower one after for vacuum/load pressure, that one needs to be connected to the plenum, the upper one is before the TB to read atmosphere but in this case it'll do both.

this is if you still have the OEM unit, some others look the same but the chambers are reversed and will cause the opposite of what you want.

don't remove the vacuum line to the ignition you'll default to map 8 and it will run bad, retarded ignition and just plain bad. that's whats happening now when you hit boost, the maps will go to the highest pressure. when I wrote the new maps for the tec4 we had the benefit of a 2bar sensor so I could write new maps above atmosphere. the current setup can not adjust for boost correctly.

 

according to the maps the advance drops from 35* @4k to a flat 25* @6k which is what is showing up on the dyno.

 

I think that's the full vacuum number on a US 2v. this is a swiss 4v if I recall, so it looks like 32.5 from 4100 up.....if I'm reading the graph right. They have it charted as deltaP in mm hg, so I think WOT would be line 1. But if it's an absolute value deltaP, that could really be screwing things up with the timing and putting it on one of the vacuum curves.

 

Mark,
i'm going off the std 4valve not the 2v maps from the WSM. and yes it's absolute pressure, so it starts from line 1 at idle to line 8 WOT, the US and CH map is worse it'll transition from 32* to 20* between 4k & 5k

 

Any of you ignition Gurus want to comment on this sparkplug. I pulled it and photographed just after the last dyno pull. It is, of course showing whitish/lean and a little evidence of detonation (tiny "ball" deposits), but beyond that, the stripe on the electrode etc.
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too lean and too hot,
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

prolonged use will destroy the engine.

 

here's a quick explanation...

Porcelain = the porcelain shows up preignition/detonation, it will not accurately reveal jetting/air/fuel ratios. To look for the first/beginning signs of detonation, search the white porcelain for tiny black specks or shiny specks of aluminum that have fused to the porcelain. When detonation occurs, part of the air/fuel mixture explodes instead of burning, the explosion is heard as a "metallic knock", this audible knock is the result of a sound shock-wave, this shock wave travels back and forth across the clearance volume "disrupting" the cooler boundary layer gases that cover the entire clearance volume area. This disruption allows "more" heat to be transferred into parts, especially, domes/piston tops,...along with the very rapid rise in pressure like a hammer blow, pistons can get torched with melted sides and holes !!! With the early signs of detonation, the shock-wave will also rattle rings causing the tiny amounts of oil that now gets by rings, to be fused to the white porcelain as tiny black specks, also fused as specks are soot that was clinging to clearance volume surfaces in the relatively "still-air" of the boundary layer. One step beyond the black specks, will be tiny specks/balls of aluminum coming off the pistons that will be fused to white porcelin,....the next step to be reached is occasional pieces of the porcelain being broken-off as detonation gets worse, ETC. Soon after that are holes, blown head gaskets, broken connecting rods, ETC.

 

That is the coolest heat range plug that I could find for the car (Champion N6YC) any suggestions for another ? Air fuel lean out @ high rpm will have to be addressed pronto of course !

 

Scott, the WSM is labled delta P, not P or Pa.....I'm pretty sure you have the number reversed and 1 is WOT

 

Bosch and NGK make colder plugs. I use NGK BPR9ES (ngk heat ranges are opposite the rest or the world, so higher number is a colder plug). I think I rember finding Bosch plugs with a heat range of 3 or 4, about the same as the NGK, but they were harder to find in stock anywhere.

 

when i had to convert the maps to Kpa for the tech4 the conversion shows that 70mmHg is .09bar where 490mmHg is .65bar, 70mm is less pressure hence more 'vacuum' and 490 is greater pressure or less 'vacuum'. the system can't read vacuum as we understand it, there is no such thing as vacuum in scale but less pressure.

"delta P" only means 'change in pressure'

 

those 3's are ungodly expensive! Porsche used them in some of the turbo racing 911's back in the 70's. I use the 5's and paid $10 a pop thru a wholesaler. so far I've had great results with them, they're also silver.

 

Not to get off the main subject, but that chart in the WSM had me scratching my head when I first looked at it. I ended up assuming that "8" was WOT, and that the mmHg Delta started at 0 mmHg for "1" and ended with 490 mmHg at "8". "Tell me it ain't so Joe".

 

that's about it, the map reads from 0 up (assuming zero to be complete vacuum which it couldn't or the engine wouldn't run) to 490 at WOT. convert the 490mmHG to bar and it's about 1/2 bar. I tried the map the other way around and the car would not run right, flipped the values and it runs right.

 

I'll corraborate that the delta P readings in the WSM advance tables are the difference in pressure sensed by the ECU as compared to the ambient air pressure. The early Marelli ECU sensor is unable to assess absolute pressures,
i.e. the lower the delta P and the nearer the manifold pressure is to atmospheric (MAP proportional to throttle opening - more throttle, then the nearer the plenum is to atmospheric therefore lower delta P).