Proflo 3550 496

[jaslamp]

I'm looking for some tuning help if anyone has anything close to my engine combo. 496 BBC, edelbrock alum. heads, crane cam Dur. Int 228 Dur. Exh 284 Lift Int:544, Lift Exh:544 , proflo 3550, Hooker 2"primary headers Dual 3" exhaust. If someone could let me know what they are using for their calibration settings that would be great. Thanks

[moms-toy]

i just finished mine 496 with specs very close to yours, i have the 3550 system and a 3554 chip in it and found it very difficult to tune right , so i added a wideband oxygen sensor kit, with both led and digital reading, and that changed everything

after that it felt like i added another motor, i am not finished tuning it but many changes have been made everywhere, but basicly i am running about

global fuel 10+ and a lot of work around 1000 rpm to make it smooth from idle and up, also with that chip i have more than 20 + on idle fuel

also i took out 20- fuel from cold start to prevent the plugs getting black

looks like it makes most hp around 12.5 afr, and with the one led on the
display module it just stays green

i have not tuched the spark mods at all yet

my motor are in a 57 chevy with cast exhaust manifolds and 2.5 exhaust
compression are 10.7 heads are procomp 320

my computer says 550 horses and it puls really hard, drives really smooth and nice, it is vinter here now in denmark so i guess i have to wait until spring to finish it, i leave for 3 weeks vacation in orlando in 3 days

good luck with your projekt, let me know how you progress

soren
denmark

[jaslamp]

where did you get your wideband sensor kit? what kind of problems were you having tuning your 496 gefore installing? I haven't gotten to the point of being able to drive my camaro yet, it still needs to much work, but the engine is running and i am only able to mess with it sitting in the garage. As far as i know, I got the timing correct, but it is to hard to tell exactly. I can't keep the engine running smoothly with base timing on, it surges way to much to get an accurate reading. It seems to run fine at idle now, but I can't seem to get a green or amber reading. I'm only getting red. I am runnning 38 on global fuel and 10 onTransient. This is all that i have changed so far. Everything else is still set on the base cal. of 0. I have turned the fuel setting all the way up in an attemp to rid the lean issue, but still no change. That is where I am at so far. Thanks

[moms-toy]

its still lean at idle , go to misch modifiers and put like 30 + on the idle fuel

i bet it will run then back of on the global, i did the same thing, i live in denmark and bought the wide band kit here, but you can get it on ebay for
270 usd, mine are a plx

t
just search for wide band kit on ebay and the will come up

soren

[jaslamp]

That didn't seem to help much, still red. How is your fuel pressure? Do you have a gauge? With key on, engine off, I am getting 44. With engine running around 1200 rpm, I am getting only 38. Do you think, this is an issue or are you getting around the same. Thanks, Jason

[S. Armish]

where did you get your wideband sensor kit? what kind of problems were you having tuning your 496 gefore installing? I haven't gotten to the point of being able to drive my camaro yet, it still needs to much work, but the engine is running and i am only able to mess with it sitting in the garage. As far as i know, I got the timing correct, but it is to hard to tell exactly. I can't keep the engine running smoothly with base timing on, it surges way to much to get an accurate reading. It seems to run fine at idle now, but I can't seem to get a green or amber reading. I'm only getting red. I am runnning 38 on global fuel and 10 onTransient. This is all that i have changed so far. Everything else is still set on the base cal. of 0. I have turned the fuel setting all the way up in an attemp to rid the lean issue, but still no change. That is where I am at so far. Thanks

Chances are the red indication is due to either reversion, where large overlap causes spent exhaust to be pulled back into the combustion chamber, or exhaust leaks. Both of which will create a false lean condition. When we tune engines at Edelbrock that have relatively large cams (more than 240 deg of intake duration at 0.050" lift), we usually ignore the O2 indication and tune the engine until it makes the best vacuum. We usually have to do this at idle and cruise conditions where engine vacuum is the highest and reversion is most likely to happen. Give it a try. Ignore the rich lean indicator and adjust your fuel modifiers until you maximize the engine vacuum reading. It's a lot like tuning a carburetor at that point. The information in this post may help also:

http://forums.edelbrock.com/forums/showthread.php?t=66

[jaslamp]

Thats some nice info, and I appreciate the reply, however, I will be running the edelbrock Nitrous kit designed for the proflo manifold. It still makes me a little nervous about using it when I have a big red lean indicator. I bought my cam after the recommendation from an Edelbrock tech for my engine combo with the proflo. You would just think that with that recommendation, the edelbrock efi system, edelbrock heads, edelbrock nitrous, and a chip that was supposed to be tuned for my application, that maybe the parts would work together as they should. I will give it a try, but regardless of how the engine is running, I will still not be happy with a system that cost $2500 that can't even tell the difference between rich and lean. I have got $10,000 tied up in my engine and I don't believe I should just ignore the indicator. Would you? I don't mean to be sore about this, but the system was not supposed to be this big of a pain to get running right. I had always used Holley carbs in the past and just got tired of all the BS that came with them. So far this doesn't seem to be any better. thanks, Jason

[jaslamp]

Besides, my int., duration is 228 as stated, not larger than 240, and there are no exhaust leaks.

[S. Armish]

Thats some nice info, and I appreciate the reply, however, I will be running the edelbrock Nitrous kit designed for the proflo manifold. It still makes me a little nervous about using it when I have a big red lean indicator. I bought my cam after the recommendation from an Edelbrock tech for my engine combo with the proflo. You would just think that with that recommendation, the edelbrock efi system, edelbrock heads, edelbrock nitrous, and a chip that was supposed to be tuned for my application, that maybe the parts would work together as they should. I will give it a try, but regardless of how the engine is running, I will still not be happy with a system that cost $2500 that can't even tell the difference between rich and lean. I have got $10,000 tied up in my engine and I don't believe I should just ignore the indicator. Would you? I don't mean to be sore about this, but the system was not supposed to be this big of a pain to get running right. I had always used Holley carbs in the past and just got tired of all the BS that came with them. So far this doesn't seem to be any better. thanks, Jason

First of all, if you are talking about a nitrous combo I would NOT trust a narrow band O2 sensor that is essentially a switch that tells you if you are either richer or leaner than 14.7 to 1 and nothing else. I would invest in a wideband sensor setup to know EXACTLY what the air/fuel ratio is all the time. Second, you stated you were having problems with the indicator. I was only suggesting that you might watch engine vacuum and let the engine to tell you what it wants at LIGHT LOAD (cruise) and IDLE...not wide open throttle. I never said the indicator wasn't doing what it is supposed to do. I also never said the system won't work with your combination. I apologize if my reply was not clear. We never ignore O2 indications from any kind of sensor at wide open throttle. Just thought I'd share some experiences that might be helpful. One other thing...open unrestrictive exhaust systems sometimes don't create enough heat AT LOWER ENGINE SPEEDS for the narrow band sensor to work properly. This can also cause a false lean reading.