Sequential Vs. Batch - Idle Quality

[TheMonkey]

does anyone have any real experience about how much idle quality can improve when going from batch to sequential? my example is 462 motor 230/236/112 HR cam. 10.25:1 CR. about 13-14" vac. idle sounds lumpy but not like a race car. uses MAP speed density.



i'm wondering what an upgrade to sequential will do to idle quality? on a scale of 'noticeablity'?

[parsonsj]

I just made that switch on FAST setup. Once I realized that the original problem with sequential mode was an invalid firing order, I fixed it and swapped over.

My idle is smoother, and part throttle acceleration is better too. Power is exactly the same at WOT.

jp

[TheMonkey]

thx... i've heard that it makes idle smoother, but how noticeable is it? i know that is kind of hard to articulate, but let's say that on a 1-10 scale....

1 = your buddy that helps you under the hood might ask while it is idling "is it set on sequential or batch right now?"

3 = when you have it on sequential, that same buddy says "man, sequential is smoother idle"

5 = when you pull into work, a car guy at work asks you if you changed something on your car

7 = that same guy at work asked if you got a smaller cam

10 = even your wife noticed

[parsonsj]

Awesome question!

I'd say 2. Absolutely better than 1, and certainly no more than 3.

jp

[DeltaT]

11 = So smooth and emissions-free that you have ruined 3 starters trying to start an already running motor ;)

Good scale!

Jim

[MonzaRacer]

Honestly UNLESS the engine has a super choppy idle I have never had much difference in idle quality between the two.
Now if you have a very mild cam your going to notice it being a little smoother but in all hhonesty I havent seen anything pushing me to sequential unless it doesnt cost a lot more.
I have helped tune and install a few older Fast systems and good stuff but way over priced, some like BigSquirt3 but that was way out of several peoples range.
what i have been doing lately was buying FI wiring from say Fbodies or aftermarket replacements and simply wiring them into Megasquirt systems.
I am going with a LT1 intake soon and it will run by MegasquirtII and I am building my own DIS and will have no distributor even.
I figure the DIS set at the back of the carb with wires loomed neatly and it would look sweet and very custom.
It really depends and I infact have wired many cars so that the wiring is there to go sequential later on and simply have the wiring ganged into a small box AND it gives great place to diagnose injectors and wiring without pulling harness apart all the time.
I had the gang block that ties all the injectors together with fuses to the batch fire wiring.
With holes in the block it is simple to push in a test probe from DMM and check each injector.
also if you have a single wire giving issues you can plug in a dummy bridge at the injector and tada you can diagnose any injector wiring independant.
After having several people come back with custom harness that had issues I started building my own and doing it this way.and the plug at the gang block can be unplugged and the sequential harnes plugged right back in and never get near the engine.