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Two lines of thought for me.1. Reduce the Immediate fuel charge on acceleration. Like reducing he accelerator pump shot on a carb.( I have reduced mine by about 15% on mine so far )
2 . is the fuel enrichment for the TPS. Since full open throttle is pretty useless with these little engines. Next time I play with mine I may try flat lining enrichment above 60% or even 50% TPS since Very little TPS reading is required to get full vacuum 95 to 100 MKa. So 80% TPS may be flooding the engine if only 20 or 30 TSP gets the same air flow. The 800 CFM EFI is not the limiting factor on these engines. LOL.
Could potentially adjust the throttle cable too to not open the secondaries all the way either to prevent flooding. More of a bandaid than an actual solution though.
[QUOTE=fbse7en;12555116]You really NEED to input it as 160 cu. in.
I was one of the first people to do this system and we put in 80ci for 12a and it works great! 1000 rpm idle, I move mine to 2000 when racing for quicker response. You can play around with "cam" setting. I am getting close to reinstalling mine as the car has been in rebuild mode for a couple years. But as far as cubic inches, 80 worked just fine for me.
I have installed a 550-850 Sniper on a 1980 12A installed in a 1984 B2000 truck. I used a early distributor set up. This unit is a 2300 two barrel type. I have a Racing Beat 4 barrel intake and use an adjustable carb adapter that is tapered and hand ported the intake to flow better with the adapter. I had to install and external fuel pressure regulator as the on in the throttle body malfunctioned on start up and it took a while find the issue. I recommend installing a fuel pressure gauge when you put it all together. As for oil, my client really wanted the OMP to work but we wanted a stand alone tank. I modified the OMP with a fitting on the side to feed 2 stroke oil. I found the OMP would allow the oil to seep into the engine from the shaft. I machined the housing and installed a double lip seal on the OMP and have no oil loss anymore. It clearly is pumping oil through the lines. I used brass tube that I put a barb on the end of for hose retention. That tube was pressed into the adapter plate to feed the oil. I used a mower coolant tank for the oil tank. So far it works great. Very happy so far. The OMP was a big hurtle, my client was vert firm on not wanting to premix. He said "You have all those machines, make it work." I used a race car air filter base with K&N filter and that lets the original Mazda hat to fit. Had to drill a hole for the stud, but it looks pretty cool. I used 100 ci but it would probably work with 80 ci as well.
I am new here, I will get some pictures loaded and post them. In the shop. After the fire up and test drive in the lot. In the lathe OMP seal install Before the seal Intake after porting Adapter for the intake OMP port plugged with a small set screw Custom inlet tube on the OMP Modified OMP
Re-did sniper @80cc and idle at 1500. Won't idle but drives pretty good. It will fall on its face and die when coasting to a stop, and will struggle to idle while sitting. Not perfect but getting there.
I did that and several other things, happy to say it idles pretty decently now at 1000 and pulls pretty hard when laying down the hammer.
Now I just need to keep it from dying right after a cold start, currently adding time to the afterstart enrichment chart in hopes that it runs long enough to figure itself out.
A few things to look at:
1. Lengthen the return to idle up from the stock 2 seconds to 8 to 10 seconds has fixed my dying on the coast down with a manual Transmation.
2. Lengthen the return to idle after start up
3. Juggle the Coolant Temp enrichment to get good AFR numbers.
I set the idle at 1400 with a full street port engine with Racebeat intake. can go lower but this is very stabile and I have no problems at this number.
Off beat question to people who know more on this than I do. Replaced my alternator with a stock 56 amp for the 12A but my electric cooling fans use most of this. Was wondering how a 130 amp chevy v-belt alternator would work or what wiring changes I would need to make to convert it to the more powerful version. Any insights could be helpful.
This is possible! Ignoring the alternator that you specified, as I have no specifications on it, the process is quite straightforward. I don't have a ton of free time at the moment to get into it so I'll post a few sources for you to take a gander at. Please note: there may be data in these sources that are outside of the scope.
Wiring something more modern ie: an alternator governed by ECU is likely doable but I have no experience with such. I assume it's just as easily doable but slightly different.
Now that wiring is more or less settled you now need to sort out your belts, making sure the rotational direction of the replacement alternator is clockwise and mounting.
For mounting if you are not using a saddle mount alt you'll be required to fabricate an adaptor. Probably need to fabricate something regardless.
Off beat question to people who know more on this than I do. Replaced my alternator with a stock 56 amp for the 12A but my electric cooling fans use most of this. Was wondering how a 130 amp chevy v-belt alternator would work or what wiring changes I would need to make to convert it to the more powerful version. Any insights could be helpful.
This is what I’m using on my 82 GSL. Haven’t had any issues at all. I only changed the spacer that slides on the bolt.
Last edited by shadyj26; 10-19-23 at 09:49 PM.
Reason: Missed spelled word
Will not have an external ECU but could wire in an external voltage regulator. But the high output 130 amp may be my best bet and is over twice what I have now. Too much voltage drop effects the Sniper EFI so trying to keep voltage at least 13. plus volts while running. Running all of the cooling fans and the headlights and fog lights is too much draw for what I have now.
Finally got the 120 Amp alternator in. Require a 120 mm long 10 mm By 1.25 pitch threads not included. 1/2" spacer trimmed to 0.4" to fit. $gauge battery wire and Working great. Have not added the extra fans yet, but should work great. Adding 4 gauge (10 foot )wire from the battery in the back of the car to the multiple fans in the front. Thank you guys for all the help. Looking to be able to run the ported 12Aharder with the temp climbing. This should be it.
I run it a little rich. A like13.3 to 13.8. for normal and cruising with 12.3 for full throttle. The problem on the videos with the 2300 was actually a spark issue. &0 cu. in. and this will adjust pretty easily if everything else is good. I increased the ramp down time from 2 seconds to 8 which avoiding it dying with manual Transmation deceleration. Loving mine.
What do u have for cubic inches? For a 13b I had it at 80cid stock cam. Think it's the same for 12a or a little lower like 79cid.
When I try 70-80ci the car wont run. I ended up bumping the ci to 110 and it seems to operate better. However, it idles at 2k rpm and cant seem to get it any lower. Also, the car drives ok up until you start to rev it out. Attempting to go past 5k rpm while driving will not happen. It just sputters. I might have just meet the limits of the self tune.
Again I went with the four barrel and the lower numbers worked for me. The Idle is controlled by the air in. So either IAC is too high or the Idle screw is too far in or a vacuum leak. These are the only sources of air. What is your AFR at idle. and Kpa? Double check your Timing that can make a big difference as well.. Also has it gotten to 160 degrees to self tune. Just the normal things on the sniper Facebook group stuff.
04-11-23, 10:38 PM
