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  #41  
Old 10-23-2013, 09:49 PM
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GregWeld GregWeld is offline
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I started with Accel DFI stuff 15 years ago.... with the laptop and NO support... I've done Fast XFI... Back in the day - the weak link was the dual sync distributors.... They'd go gunnysack and nobody had one "in stock" so a car was dead until you could get some parts shipped out. The electronics just weren't that robust.... but once this EZ EFI stuff came out and you could just run a regular MSD distributor etc then everything was so much easier - I don't know why someone would go with anything else as long as they're just street cars/hot rods and not wound too tight. Big cams - forced air induction - they take the big stuff and lots of dyno and tuning time. I'm usually just messin' with somebody's hot rod.
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  #42  
Old 10-23-2013, 10:57 PM
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On IR stuff -- the syncing of the stacks is absolutely crucial. They should be balanced to within 1 number.... whatever that number is... and with the cross linkage hooked up - you can't get 'em dialed in. You've got to drop that linkage off then you end up with 4 "pairs" and there are adjustments to each one and then the second one in the pair is driven off the other..... So I get one pair to read the same number -- Let's just say 10.... then I go to the next set - and try to get those to each read 10 but as the motor runs better --- the idle climbs -- so now I go back to the first pair and turn them down -- match their number - lets say it's now 8 -- got to pair two - get them both to 8 or close - go back and measure pair 1 -- adjust them and try to get the one side of the motor "close" -- then just to the other side - try to get the pair matched - then back them down to close to 8 - all the while I'm checking the "set" side... then on to the last pair -- try to dial them in --- now maybe everything is running better and smoother and the idle has climbed again.... no ya go back and you should just be able to drop the idle adjustment screws and that pair should stay sync'd up -- now go around AGAIN ---- and they'll all be able to be brought into total sync - but it takes time and very small adjustments. Imagine Injections stacks use a linked "arm" and screw and spring set up ---- The Inglese air valves use a shaft linkage and set screws -- undo the set screws on the shaft and they become adjustable individually.


To me -- it's like a more complicated 4 corner idle adjustment... you can't just go around the carb once - ya got to go around maybe a couple times or more to get 'em all running sweet.


When I get the idle all set physically and in the the handheld -- THEN we go for a drive.... making sure to try to HOLD a speed... the computer HUNTS for the air fuel setting -- so it goes fat -- then goes lean - then comes back a little less fat - then a little less lean at a vacuum (load) and RPM.... so I just try to drive and hold and give the little bugger some time to settle in before I add a different throttle setting. Again trying to find a different RPM/LOAD and let it bring that in.... and I try to find a hill and hold steady up a hill even if it's pissing the other cars off.... then I hit the highway and try to find a couple different RPMs to run at and let that "come in".... by now she should be running pretty good. It's easy to just set idle and cruise at the same setting -- just pick one -- I use 13.8.... and set WOT at 12.5.... now I just drive around for awhile letting all the different throttle settings come in.... then get into it a bit and hold -- and then a little more and hold.

Only after it's running really well do I go back and watch the idle rpms and vacuum go up or down as I play with the idle AF numbers - jump it to 14 and see what happens -- if it likes it - I'll go to 14.2 --- give it some time to settle in and see what happens etc. If it doesn't like it -- I go the other way unitl I'm pretty happy with what I'm seeing and hearing. NO DIFFERENT THAN ADJUSTING A CARB! Highest vacuum and idle is telling you it likes it.... lower and it's telling you it doesn't.

The CRUISE is far harder to dial.... so I go bigger changes --- because at cruise I'd like to run as lean as possible and you need to find what that is... so from 13.8 I'm going to jump right to 14.7 and drive it awhile before I make any other changes --- the computer needs to relearn the new AF --- and has to go back and learn and set - and smooth.... but after awhile (15 or 20 minutes of driving) you're going to have a good idea if that's going to work... IR's like a FAT A/F.... but if the car isn't doing anything weird that I can feel --- like bucking etc with light throttle cruising -- I'll lean it out to 15 and see if I can get away with that -- USUALLY NOT.... and I come back to something in the mid to high 14's.... then depending on the motor -- I'll set WOT at 12.8 -- it's pretty safe -- and most guys aren't drag racing.....


NOW ---- if the throttle acts dead off idle -- I'll go to the advanced settings and add ONE number in the accel fuel table --- see if that fixes it --- if not -- I add one more number... if that doesn't fix the flat spot I go the other way one number below what the base was.... sometimes the flat spot is lean - sometimes it might be too fat! You just don't know until you fuss with it just a bit. In the meantime I've done NO OTHER CHANGES.... I've got to let the ECU learn the fuel curve. And it needs a little time to makes it's adjustments because of the way it works (the too fat to too lean and back and forth a couple times before it settles in).

When I'm all done with that --- we go back to the manometer and check all of that and adjust if needed. SET the idle and tell the ECU what that is. By this time you should be done.

Now I go to the fan on settings and double check or adjust that... turn on usually 10* HIGHER than the thermostat... so a 180* thermostat I set the FAN ON at 190* or even 195* (some guys can't stand to see there temp fluctuate - it drives 'em crazy - so I get tighter on the setting for them). But I like to let the thermostat do what it's made to do -- it opens and it closes - slowly -- and it needs time to fully open and circulate some water... and I don't like the fans on continuously and I really don't want them on at all on the highway... And of course this all depends on how you're controlling the fans and A/C etc.


The key is to get the IR's dialed in FIRST --- because if they're off - you've got one cylinder running lean and another fat --- and the idle is all off which means the MAP is all over the place and the computer is load sensitive --- it's really using 3 criteria -- ECT -- MAP -- O2.... so the motor has to be warmed up (above 140* to start the self tune) and the load on the motor is critical to fueling --- and then it's reading and making adjustments to the fuel based on the smell test (the O2).... and if one of those is jumping around -- then getting her settled in is a bitch.

We know to adjust the idle bleeds on a carb first -- get it smooth -- adjust idle - check timing and adjust if needed. It's no different on a EFI application.

I'm no expert by the way --- I'm just writing this in an effort to help others that may be following or maybe thinking about an EFI install. The A/F's one motor needs can be completely different than another one... it depends on so many variables. If I'm asked BEFORE an engine is built -- I tell them to get some LSA in the cam -- like 112* or so..... these systems don't like lumpy jumpy 106* cams... for them you need a tunable version EFI.... but for a nice street rod/hot rod motor - with A/C etc --- then you want/need a fairly steady vacuum signal on the MAP sensor. A wider lobe separation angle (LSA) goes a long way to helping that. Modern LS3 engines use cams with 116* or more! So an LSA of 112* is still a bad ass sounding cam (other specs are important there too of course).


Timing and timing curve (advance) and total timing are far more critical to the power of the engine... With these systems the A/F only needs to be close. Without a dyno that's the best you can do is get 'er running nicely... and with the handheld - once you get it running really well -- you can fuss with A/F's all you want to! You only have the ability to change 3 numbers -- Idle AF -- Cruise AF and WOT AF. You'll really only hurt the motor with too lean of an WOT AF so I'd keep it safe in the 12.5 to 13 range and I wouldn't try to push it more than that unless you've got a dyno to run on and an experienced operator.

On my '32 I've messed with trying to get the cruise AF up near 15.5's but it doesn't like it -- and you know what -- the little bit it gets driven -- the difference between running it at 14.2 and 15 cruising isn't going to break the bank in fuel costs. It gets too lean at cruise and she starts bucking. It's noticeable in such a light little car. But the point is -- I can plug in the handheld and go driving and just change the one setting and she learns the new ratio and starts tuning to achieve that number... I know pretty soon if she's happy or not -- and if not -- it's so simple to just plug in a different number.

The Nomad or the '32 cold start within about half a rotation. I never have to touch the throttle... they just idle cold or hot... and they just fire off immediately hot or cold. They're both IR -- one is Inglese -- one is Imagine - both are EZ EFI. Both have healthy cams... one is a stick and one an automatic. One has one fan and no A/C and the other has dual fans and A/C... and the load on the motor is heavier when I turn on the stereo in the Nomad vs the A/C (HAHAHAHAHA - yeah it has some amps).

I've had more 'issues' tuning the simple little '32 with the stick because the SOB is so touchy. It's so light - the motor is 450hp -- and with the 8 stacks the throttle is INSTANT... which makes smooth take offs a bit of a trick... but that's not the fault of the EFI -- that's the fault of the 8 stacks instant response. That's why racers installed them in the first place! Instant throttle response! LOL
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  #43  
Old 10-23-2013, 11:42 PM
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David Pozzi David Pozzi is offline
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I've done two EzEfi installs, one standard throttle body, and one 8 injector retrofit system, we already had the intake and throttle body.

Things I've learned are:
If you are not using the supplied throttle body unit, make sure you are inputting the correct info on injector size and flow.

The EFI power leads MUST connect to the battery terminal. I tried running off the radiator support power terminal near the battery because that's how far the wires reached. The Throttle position sensor readings & idle speed readings fluctuated, & idle was poor, - after going direct, they stabilized.

An HEI distributor will KILL the little tach conditioner box. Mine died in a few hours. I've heard of them dying while cranking on initial startup. The best solution was to install an MSD HEI module which has a clean tach output wire. Regular HEI modules have such a dirty tach output they can damage electronics. Keep in mind your module may be a Chinese made knock off part which may have NO tach filtering at all.

Keep the tach and TPS signal wires away from spark plug wires. The tach signal and Throttle position sensor signal are critical and need to be as clean as possible.

For most of my life I've maintained farm equipment, much of which had bronze filters. They filter too well, the super fine dust particles they stop can be so small they can't be seen. I've had plugged bronze filters that looked clean but you couldn't blow through them. Stay away from them for carb or EFI use, they plug easily.

The external pump may work but it's marginal for performance use when the fuel level goes down to half tank, - unless the tank has special baffles. If the pump takes in small bubbles, the pump performance will drop off and the engine will sputter. Modern cars have the pump in a fuel bucket to protect it from sloshed fuel bubbles.

Properly setting fuel pressure is easy to do wrong, read the instructions carefully, then read 'em again.

Setting the base idle screw is important, I had better results setting IAC "counts" to 20.

Throttle response can sometimes be improved by changing "enrichment" settings. Read the instructions carefully.

Quote:
I've had more 'issues' tuning the simple little '32 with the stick because the SOB is so touchy. It's so light - the motor is 450hp -- and with the 8 stacks the throttle is INSTANT... which makes smooth take offs a bit of a trick... but that's not the fault of the EFI -- that's the fault of the 8 stacks instant response. That's why racers installed them in the first place! Instant throttle response! LOL
Greg, look at your throttle linkage ratios. A lot can be done to slow down the initial throttle opening ratio. All the early LS engines use a ramp system that has a slower initial opening for those huge single butterflies.
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Last edited by David Pozzi; 10-23-2013 at 11:53 PM.
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  #44  
Old 10-24-2013, 12:03 AM
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GregWeld GregWeld is offline
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Quote:
Originally Posted by David Pozzi View Post
Greg, look at your throttle linkage ratios. A lot can be done to slow down the initial throttle opening ratio. All the early LS engines use a ramp system that has a slower initial opening for those huge single butterflies.


Good post David!

Yes I'm aware of the linkage ratio - and in the '32 they're wrong.... I just haven't wanted to tear into it to make the necessary changes. So sometimes I squawk the tires accidentally... HAHAHAHAHAHA
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  #45  
Old 10-24-2013, 09:48 PM
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Great info here guys! Maybe even worth making a "sticky".
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  #46  
Old 10-27-2013, 10:07 PM
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IR systems are great for torque, but synchronizing the butterflies is absolutely critical to achieve driveability. The linkage must accommodate individual adjustment & the whole linkage has to "hang" on the throttle cable at idle the same way as when it's floored.
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Last edited by David Pozzi; 10-27-2013 at 10:16 PM.
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  #47  
Old 10-27-2013, 10:21 PM
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GregWeld GregWeld is offline
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Quote:
Originally Posted by David Pozzi View Post
IR systems are great for torque, but synchronizing the butterflies is absolutely critical to achieve driveability. The linkage must accommodate individual adjustment & the whole linkage has to "hang" on the throttle cable at idle the same way as when it's floored.



SPOT ON David!!


I just disconnect the cross linkage (driver side to passenger side)… otherwise if a guy tries to set the idle - it's opening or closing both sides BEFORE I have them all sync'd up. Once they're sync'd then I can use just the idle screw.
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  #48  
Old 10-31-2013, 09:00 AM
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On weber carb set ups, I sync the front carbs to the rear carbs on each side using spring loaded balance screws, THEN adjust the linkage hex rod between them to balance left bank to right.

If there is a vacuum difference between venturies of a carb, it usually indicates a twisted throttle brass throttle shaft. When screwing on linkage arms, they are easily twisted, the good news is you can tweak them back. All v8 webber set ups should have the linkage pull between the carbs, not pull on the front or rear ends.
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