My upgrades are almost finished. Ported Tb's, Ported intake runners, ported plenum, new injectors, no screens in MAF's, straightened intake hoses, twin air boxes, headers, no cats, magnaflow custom exhaust. Will this car run with stock chips ?
Try it and see. Low rpm and cold start may be a problem. May run lean as you go up but bigger injectors may counter that. No real clue just 'guesstrapolating" It would be better with OBD2 telemetry. Hopefully O2 sensors will measure and adjust mixture properly.
The 02's on these cars really leave a lot to be desired Mine runs nice and rich when I unplug them. When plugged in they really dial the AFR back to 1.0 that equals 14.7 to 1. Working on another solution besides tuning the MAF
Simple fix is to relocated them out of the exhaust stream. Seems illogical, but they will read less accurately, which is what you are looking for (you want them to richen up it sounds) plus they will offer less exhaust restriction. Goth does this on his cats.
In a nutshell yes A lot of guys I been playing with run strictly off the tables and not the 02's Lambda value is 1.00 for a 14.7 AFR. I want to be at 12.5 to 1 so my lambda would value would need to be 0.85, 12.5 divided by 14.7 is 0.85 or there aboutski. 12.5 afr most likey will eat these old 02's alive so for that reason I may be running without them strictly from the tables, not to mention how it will make the cats glow red. Then adjust fuel afr with injector size and use the tables to set fuel and advance curves. The hunt is to find all the spots in the ECU that checks lambda. We found several so far and still more hiding. Once we find those it's a hard core party or we blow up the ECUs hehehe I am really have a fun time playing with it
I wish I could remember. I had it done in Glen Burnie at a Trick Truck place where the owner owned a Ferrari. Look in the threads for muffler and you will find him. Good guy and not thet expensice.
Yep 12.5 to 1 at idle rules hehehehe Just showing an example how this ecu works, I never tell my real numbers. I think the 358 was running about 8 to 1 that one day at the track when it was getting 3 laps per tankfull , that was cool
8:1 is perfectly fine for an AF ratio.... As long as you are running E85. Fuel A/F Lambda Pure Gasoline Stoichiometric 14.7 1.000 Pure Gasoline Max Power Rich 12.5 0.8503 Pure Gasoline Max Power Lean 13.23 0.900 E10 Stoichiometric 14.08 1.000 E10 Max Power Rich 12.0 0.8523 E10 Max Power Lean 12.7008 0.9020 E15 Stoichiometric 13.79 1.000 E15 Max Power Rich 11.75 0.8521 E15 Max Power Lean 12.4362 0.9018 E85 Stoichiometric 9.765 1.000 E85 Max Power Rich 6.975 0.7143 E85 Max Power Lean 8.469 0.8673 Ethanol Stoichiometric 9.0078 1.000 Ethanol Max Power Rich 6.429 0.7137 Ethanol Max Power Lean 7.8 0.8659 Methanol Stoichiometric 6.45 1.000 Methanol Max Power Rich 4.0 0.620 Propane Stoichiometric 15.7 1.000 Propane Max Power Rich 13.18 0.8395
Is there a reason people don't run an electrically switched cat bypass? Racers used to open up an exhaust that way for drag racing. Then you could run a clean map and fast map. You really want to run clean 99% of the time. At 12.5 AFR there is so much unburnt fuel your eyes sting and clothes stink by the time you get out of the car.
Yes sure can butt in the end they would still glow red and start fires. Remember in 1975 or 76 when cats were phased in, they were setting fires whenever they parked if the carb was running rich. And the lovely rotten egg small Cats tend not to live at anything below 14-1. New standards are saying 15.5 to 1. It sure is changing in the frindge
Nope I'm talking bypass the cats with more plumbing so the cats don't see any exhaust when running under 14/1 and both ECU maps Image Unavailable, Please Login
Yes I remember those LOL You could but lots of work and extra plumbing then you need a stand alone ecu. I rather just pull off the cats if I go to the track, less filling taste great
To protect cat's auto makers enrich to keep the brick cool. Excess fuel and excess oxygen (say a dead cyl) will raise cat temp (quickly!) but just running rich does not raise the cat temp, it cools it.
Sized correctly cats aren't taking much if any power. (And there's no benefit to constantly run richer than stoich if its not under load)
