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308 Weber to TWM throttle body and electromotive

Discussion in 'Technical Q&A' started by cavallo_nero, Feb 22, 2008.

  1. mk e

    mk e F1 World Champ

    Oct 31, 2003
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    The Holley is a bolt-on package....you use the sensors they supply and ONLY the senors they supply so its not a good choice for what you're describing, you want/need a more universe setup. Link, haltch, AEM, enginelab, motec.....something like those.
     
  2. cavallo_nero

    cavallo_nero Formula 3

    Nov 3, 2003
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    Giovanni Pasquale
    Update. The car fired up about 3 weeks ago. I had to use Holleys coils (I found a discontinued set on ebay that was new in box). Everything seems to be working fantastic. I took it for a drive in LEARN mode (a little AI action from Holley). Based on feedback from the O2 sensor, the fuel map 3D table is updated automatically by the computer if there is a discrepancy between the reading and good ol 14.6 stoi.
    I created the fuel map table as best I could on my laptop, but in learn mode, this all gets updated, verified, recompared, re updated,
    compared and so on until the number is pretty stable. Fuel map table is a 3D table based on RPM, MAP and amount of fuel.
    Based on the Wideband O2 readings, I am running very clean and pretty much at the desired A/F ratio, except in open loop (accelerating). The car has NEVER run so good, accelerating, cruising and WOT are very impressive.
    gonna hit the dyno this spring and report back.
    I am very happy with this system, holley has their **** together, they were always on the forefront of aftermarket FI - way to go!!
    I don't know why duplicate pics are showing up, sorry bout that, I cant seem to edit them out either.

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  3. Ferraripilot

    Ferraripilot F1 World Champ
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    May 10, 2006
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    Looks really clean. Glad this setup is working well! I really dig AEM Infinity ECU, which I'm running in an ITB 911 hot rod. Runs good, but has no self-learning mode :/
     
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  4. cavallo_nero

    cavallo_nero Formula 3

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    It is super clean, you can hardly see the wiring harness from the engine compartment. Considering this was a universal harness for a new ford truck, it came out great with only a few mods. I wouldn't go any other way than with this learn mode tech, simply amazing.
     
  5. cavallo_nero

    cavallo_nero Formula 3

    Nov 3, 2003
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    To get the tach to work, I had to use a programmable tach 'splitter', coupled with the tach adapter. Since my ignition uses a batch waste fire system, the tach in the 308 was seeing double rpms. So I programmed the tach splitter to 16 inputs and 8 outputs, and ran that output to the input of the MSD tach adapter.. I am still getting used to all the parameters that can be used in Learn mode.
    Looking at the engine it still looks kind of stock, not many visible wires to sensors. The throttle bodies look like webers - sorta. This lil euro 308 runs superb and incredible clean!!
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  6. cavallo_nero

    cavallo_nero Formula 3

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  7. cavallo_nero

    cavallo_nero Formula 3

    Nov 3, 2003
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    Heres a result of the Dyno Jet run, at 5500 feet. Numbers seem low for HP, great for Torque, the car pulls like never before, and my cylinder head temps are around 1050 at the header tube an inch from the head, up a good 150 - 200 degrees from before - this car never ran cleaner, spot on at 14.6 stoi everywhere, except for deceleration cutoff - which provides better breaking!
    Not sure why the squiggly output after 6000 RPM??? Not running as much timing as before, I think the max is 32 deg. thoughts on that?? And why the dip in torque at 4500?. Thanks in advance.
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  8. mk e

    mk e F1 World Champ

    Oct 31, 2003
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    If my math is right, you're at about 270-280 crank at sea level....did you expect more than that?

    Form there there are a few things you said that struck me odd and maybe warrants more dyno time.

    Peak hp normal wants the mixture closer to 13....like 12.5-13.5 so that is something to play with on the dyno and see what you engine likes.

    Timing, I'm not sure on a 2v but hotter exhaust pipes usually mean less hp. With an EGT setting timing to the lowest temp should get you close to max hp but again I normally let the dyno tell me when its right.

    The dip at 4500 is most likely exhaust related but mixture or timing could also be in play.

    The noise on the curve I'm not sure.......your kind of lean so minor detonation would be my first guess. I'd re-tune to get to the mixture that yields max hp and see if that goes away. Then play with timing....then start looking harder at the data logs to see if anything looks odd. Could just be dyno settings too, they always do some smoothing, maybe just not enough that way way its set up, but looking at other car dyno pulls from that dyno should answer this question.
     
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  9. Aircon

    Aircon Eight Time F1 World Champ

    Jun 23, 2003
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  10. cavallo_nero

    cavallo_nero Formula 3

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    I was mainly talking driveability, cruise and idle for 14.6, didn't mean to mislead on that, I am just psyched I will finally pass emissions for the idle test. It gets a rich mixture when needed - I can see it on my W/B A/F guage.. Yes, I remember thinking a crossover pipe in the dual exhaust would take care of that dip. I think my curve is already normalized for sea level - in the notes at the bottom of graph, it says SAE 1.23, does that mean it is normalized for sea level already?, then what would the crank HP be? I think around 17%. otherwise I can surely live with the hp of 270 on my 78 euro, its like a completely different car either way. Got about 500 miles on this new ECU, and it has been incredible.
     
  11. mk e

    mk e F1 World Champ

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    hmmm...I don't think there is any such thing as SAE 1.23hp? Lets say it is corrected then your at like 225 crank. If this was a stock US car I'd say thats good....any chance part of getting the car registered in the US included installing the 78 US cams?
     
  12. cavallo_nero

    cavallo_nero Formula 3

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    The car has been in the US all its life since imported new in 1978.. The last 21 being here in Colorado at 7000 ft above sea level with me. It has borgo pistons, and still has its stock Euro Cams. was rebuilt in 1990 due to a dropped valve, has SS valves now.
     
  13. mk e

    mk e F1 World Champ

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    Playing with the timing and mixture could easily add another 10-20 if you didn't spent any dyno time optimizing them, that could be the missing hp then.
     
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  14. cavallo_nero

    cavallo_nero Formula 3

    Nov 3, 2003
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    Yes, I can easily load a new timing curve, Here is a snapshot of the current timing vs Map vs rpm table. WOT is generally greater than 60 kpa for reference, putting me around 30 - 32 ish degrees of advance. Also, all my timing doesnt come in til around 4500 rpm (which I think should come in sooner, like around 3500??). Also is a snapshot of my desired AFR. pics are taking forever to load...
    The car still pulls like never before
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  15. Aircon

    Aircon Eight Time F1 World Champ

    Jun 23, 2003
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    You've put in a lot of timing advance on light throttle. What sort of result did you get by doing that? I added about 5 degrees and didn't get any benefit after that.

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  16. mk e

    mk e F1 World Champ

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    I think the better question is what MAP [valve does it idle at and what MAP value on the highway?

    Adding time at very low cylinder pressure often helps keep the engine smooth and iirc 45 is what the factory QV curve does at high vacuum.

    The full throttle timing numbers look suspicious. Again, iirc the QV timing above about 3500 is 32 degrees. I would expect the 2v to need more and the fact that you said your EGT is now higher I think confirms that, I just can't imagine 30 is enough. I would say open up a 2Vi owners manual and set your timing to match that as a baseline. for the QV they have 8 ignition curves at 8 MAP values and when I was dyno testing they seemed about exactly right so I'd assume the same is true for the 2v engines. But, becasue you have ITBs you may need to adjust a bit for the lower power curves....but I'm sure just copying will get you close.

    Then on the AFR tables....I come back to the what are the idle and highway MAP readings? You want you be in your 14.6 or 14.7 on the highway and 12.5 is probably close at WOT although 13-13.5 is more likely the winner, hard to say though without dyno numbers. Anyway, once you have the highway at 14.6-14.7 and WOT at whatever it likes, I interpolate between the 2 for the intermediate points, or really I set like north of about 90kpa to the MAX HP mixture which is about what you did. The one that concerns me is the jump from 14.6 to 13.6 going from 56 to 63 kPa...that seems a big jump over a small pressure change, not wrong but probably more than you need.
     
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  17. cavallo_nero

    cavallo_nero Formula 3

    Nov 3, 2003
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    heres the timing curve out of my carby manual. looks like I can go as high as 34 degrees (using the plus, minus tolerance). and you think I should dial all that timing in at around 3500 RPM? I have not seen a 2Vi timing curve, I can look and compare. I can start at degrees at wot and see if I notice anything. I probably wont get to the dyno for some time, maybe next year. I will gather data for map readings at idle and cruise, compare it to the tables. I can try for a leaner wot mixture like you say, around 13 and see how that works too. I am running non ethynol gas too.
    thanks for all the help so far!!
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  18. mk e

    mk e F1 World Champ

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    I found the info for a 1980 2vi and its 37.5 degress at 5000, so 34 is probably plenty safe abd full time by 1/3 redline is pretty typical so yes to 3500 rpm as your manual seems to say...but going to 37 at 5000 might also be good....on the dyn to see. I again though I normally use these as guidance for things to try on dyno day. I do a pull that is safe, like your 30deg, then try 32, 34, 36, 38....keep going up until it stops helping. Then look at the fuel...try more first, if hp drops try less and keep going until the changes stop helping, then spark again as it does change with mixture...then fuel ones more and its tuned. It takes about 20 pulls to get it perfect.....you might get there in 10 pulls. I usually rent the dyno for 1/2 day and after I have the WOT good I do some 1/4, 1/2, 3/4 throttle stuff.....but this is for driveability and it sounds like you have it driving pretty well already so you might be good with just the WOT tuning. The important thing is though, there is no magic numbers that work for every engine.....you need to let the engine tell you what it likes but I'd guess it will like 13-13.5 better than it likes 12.5, but its guess a guess.

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  19. Aircon

    Aircon Eight Time F1 World Champ

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    That's 5000rpm in neutral, right?

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  20. mk e

    mk e F1 World Champ

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    Yes, but with the vacuum disconnected so the ignition system thinks its at WOT...and 34-38 seems about right for the 2v style chamber design, but only the dyno knows for sure.

    For sure it will tolerate more timing at 5500ft than sea level so it may want even more....I don't know enough about that particular ECU to know if the MAP axis is the actual reading or a corrected reading that is really a % of local baro reading so I would like to know what What MAP was reading...100ish or 83ish as at a true 100ish 34-37 is probably right, at 83ish, 40-44 is probably closer......some for fuel, the table values look right for sea level or corrected MAP but not absolute MAP (83ish at WOT).

    In my ECU fuel uses a correct number as WOT wants a fuel power mixture, but spark an absolute since its related to cylinder pressure.
     
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  21. Aircon

    Aircon Eight Time F1 World Champ

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    I always thought vacuum was another source of advance, not the only source. Will there you go. Live and learn.

    FWIW mines at 32. My car got nothing extra after that.
     
  22. mk e

    mk e F1 World Champ

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    QV? 32 is the number for a 4V, at least it was for mine. The QV has a bit more compact combustion chamber so it tends to need less advance at any given CR...but as CR goes up, advance goes down and mine was the stock 8.6.

    On an old mechanical distributor there was usually a centrifugal and a vacuum advance.

    The centrifugal change advance with rpm and is usually at full advance at about 1/2 redline. This is the timing curve the engine follows at WOT.

    Then there is a vacuum advance. This add advance as manifold vacuum goes up (MAP goes down) because the cylinder pressure is dropping and without additional advance the engine is less efficient and will surge a bit.

    Today with the fancy electronic stuff you can do whatever you want, but generally the curves the old distributors produced were about right. Boost redard is kind of the opposite, as boost goes up cylinder pressure goes up so it needs less advance.

    The reason I do 1/4, 1/2, 3/4 throttle pulls is to get the timing right....with increasing vacuum it needs more timing. Nobody really care about hp at 1/4 throttle but getting the timing right helps it run smoother, cooler and burn less fuel so I think its worth checking.....but on the QV the factory timing curves I plugged in as the baseline pretty much spot on. I also like to set the fuel to about stoich below about 1/2 throttle so I mess with that on the part throttle pulls then interpolate up tho the WOT throttle number from there.....it seems to work well but again no magic in it, just preference.

    Anyway, a data log to show what cells were in use on the dyno pull would be helpful in figuring out the tuning :)
     
  23. Aircon

    Aircon Eight Time F1 World Champ

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    Mine's a '76 2 valve.

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