Using Vacuum Advance With FiTech Controlled Timing
Quote from bdhulderman on November 7, 2019, 2:36 pmI had to put an electronic speedometer where the clock used to be on my '66 Sting Ray, since I built a motor for it that redlines at 8000 rpm. As soon as I wound it up the first time, I blew out something in my mechanical tach. I take that tach signal directly from where the fitech gets its signal with no issues.
Could have broke the cable inside. Spinning a mech. tach that high seems to me something should break. I hope it's just the cable. Myself I still use the mechanical tach and the Fitech tach. I like using my mech. tach when driving and the fitech tach when tuning. My stock mech drive dist. is stored under my workbench. I'm using an MSD tach drive 8762. It comes with a pin that you stick in tach drive hole then the cable inserts into this. This is just an assumption that your running an MSD tach drive then this could be your problem with your mechanical tach.
Wayne
Yes, it probably was, but not going to use it now since I'll be racing it on the track soon.
https://www.youtube.com/watch?v=vLw4LBvwfBk
Here's when I was just starting to tune my small block with fitech 800 hp EFI unit for my previously engine dyno tested 700 Hp N/A powerplant using quick fuel carb on pump gas with only 10:1 compression. No nitrous, turbo, or supercharger yet.
Brandt
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OK I've looked at your build sheet and I watched the video and I'm impressed. Sounds real sweet, luv it. I like a lot of what you have in the 454 cu. in.sm. block. I have some similar pieces in my engine. But what really stood out to me was your IAC count after releasing the throttle it came down to 0 as mine does as well but hovered at 0-1 til the end of the video. I'm guessing this is not the correct setting - the video was too short for the IAC motor to stabilize. What is your setting at if you don't mind me asking. I played with mine quite a bit but now she drops to zero when off the gas then quickly resolves itself to sit at 5, 6 or 7.
I need to know more about that Chevrolet racing tach drive dizzy. Tell me a few things about it. I may have to look into one. I'm guessing no vacuum advance canister.
I read that whole build sheet. Even though there's similarities between ours the HP your putting out is beyond my 550HP. I run a comp cams solid roller as well, I don't remember my exact numbers but somewhere greater than 0.650" lift In. and Ex. and duration at .05 @246*/252*. Lash is at .016 I. and .018 E.
How do you like that single plane manifold w/ EFI - is it easy street driving or harder i.e. having to give it more gas to start off. Been thinking about upgrading that as well. I have more questions about your engine but let's start there.
Wayne
65-StingRay
The video of the IAC setting was before I had corrected that "just starting to tune". It liked about 20 for IAC steps at operating temp when I finally got it set at idle, then it never went down to 0 after hitting the throttle and letting settle. The AFR 235 heads I have on my engine are monsters! Compare those with what you have online for flow numbers. That coupled with nearly .8 lift and 268/284 duration at .05 helps also. Big inch small blocks like an extra bit of exhaust duration to help in removing spent gases, since the valves are so small. I used my software I wrote to fine tune my engine parts for power, and it's estimate was within 3% of what the engine dynoed at. Plus it told me what the clearances were for the 50 mm core camshaft and rotating assembly for piston to valve clearance, and connecting rod to camshaft clearance, to make sure it fit before purchasing the parts. The software is now free.
http://www.enginebuilderprofessional.com
I love my new distributor from Performance Distributors. I needed it for my higher rpm. It's a HEI with easy tach signal output to fitech, but won't allow for timing control. My engine likes 30 deg intial idle timing and I pegged it at 42 above 3500, so I just let the distributor handle that. The one I have has no vacuum advance, not sure if they can provide that.
https://performancedistributors.com/product/chevrolet-racing-dui-distributors/
I love the single plane manifold at higher rpm, but it seems to also work nice and smooth on the street.
Hugger 1, Rick do you ever check this thread.
Since the last time I was here which was 8 months ago I had ring gear problems similar to you. Fixed and finally ready to start her up and pick up where I left off with the tuning using full manifold vacuum.
My question to you is: Are you still running full manifold vacuum? Has any thing else changed in your set-up?
Did you find 10* to be the number for initial timing?
I've got to eliminate that starter "kick-back" before I burn another ring gear.
65-StingRay/Wayne
Another update: I decided to put a relay on the solenoid switch to help with the power getting to the starter.
I am waiting on one part to come back from the powder coater's so I can start my car. The piece is my 5 blade fan. Should be ready this week some time.
65-StingRay/Wayne
OK, Today she started with the new MSD starter. What I like about it: 3.4 HP; 25% increase in cranking speed; can be clocked to fit better; blueprinted solenoid; lastly, I added a relay to the solenoid circuit _ this also made a difference. She cranks over very fast and starts well also. Something that was severely lacking last fall. MSD DynaForce Starter # 50952.
Here are my settings from last year: Dist. Base Timing - 12*; VR - 7.5; Idle - 12*; 1100@45kpa - 15*; 3000@45kpa - 36*; 6000@45kpa - 36*; WOT 1100@95kpa - 18*; WOT 3000@95kpa - 36*; WOT 6000@95kpa - 36*.
As it sits right now everything is working good. Tonight I'm going to do some tuning runs - not really going to change anything just observe the settings. Tomorrow or later I'm going to change my RPM breakpoints - move the 3000 rpm down to 2300, and the 6000 rpm down to 5600-5800 and see how that does.
Again I've never downloaded any of the new software since I've owned my FiTech 600 hp.
Last year I ended up shielding and adding ferrite chokes to much of my EFI wiring to help kill some of the codes I was getting and this seemed to help.
65-StingRay/Wayne
My car is running decently. The only real glitch is a little popping on shifts in 1st, 2nd and 3rd at 3000 rpm. Unburned gases igniting in the hot exhaust. Turned the timing down at both 3000@45 & 95 kpa to 34.2* and 35* respectively.
Tomorrow in the breakpoints I'm going to adjust these two parameters down to 2200-2500 range from 3000@45 & 95 kpa.
65-StingRay/Wayne
My Last Post on this subject.
For the last few days after getting back on the road - I've pulled the plug on running both fuel and ignition. My engine just will not tolerate any rotor misalignment of any kind. On start up it will still kick back when cold - that's only going to lead to another broken ring gear tooth.
I've played with moving the rotor all around to try and find a good place - there isn't any for me.
Trying to run without manifold vacuum keeps the engine to hot and does not accelerate as good. Without vacuum advance on full manifold vacuum I'm only pulling between minus 5" - minus 7" at idle. With it hooked up I pull minus 12".
Today I returned everything back to no ignition control. With just a little tuning she's now running the way I like - 'full power straight away'. There's hardly anymore popping out of the sidepipes, pulls strong and hard when the rotor is aligned with the cap terminals all the way through the rpm range. Drives easier at low speeds as well.
No more error codes showing up. Especially that code 36 - spark error.
I've learned some hard lessons over this series of events.
I don't know if I should say this but I'm removing my FiTech system and installing the Holley Sniper Stealth in a couple of weeks.
They just have better support. FiTech should have improved their support by now it's been 3.5 years since I bought mine. I still feel like a BETA tester for their products. With the Holley system I can play with a 30X30 fuel tables and spark ignition tables. Plus my stock air cleaner base will work again with the Holley Stealth.
65-StingRay/Wayne
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Thank you for sharing your experience. I am in the process of going towards ignition control and if find too many issues I will revert. This brings back memories of a very early phone call to Fitech perhaps 4 years ago and I asked them about ignition control. Their response was "Why would you want to do that?". I was kind of baffled by his response given the fact that it is one of the capabilities of the system. Then he explained that I should take one step at a time. That once I have the fuel settings working then I can try ignition control. And that's where I am now. My fuel settings are working pretty good right now so I will give it a go over the winter break.
From all of your experience, is there a rotor phasing that works better? Should I phase the rotor to be slightly before center at initial advance?