Individual Cylinder Tuning

[TheMonkey]

seems that with TPI, the VE tables should be very similar for each individual cylinder, as the runner profiles are symmetrical.

but, with either an open plenum box with TB fed from the front, or with a carburetor 4150 manifold retrofit with 4bbl style TB (my case), it seems that the VE tables could be quite different.

i have a single plane carb manifold with MPFI & 4bbl TB and the ability to tune individual cylinders will be there, but would require A LOT of time & testing (as well as o2 bungs in each exhaust) to dial it in.

just wondering how much of a benefit anyone has found by doing this?

[Karch]

Anyone?

[TheMonkey]

thx for the bump. i thought it was an interesting question, but i think most EFI guys here must be tuned port?

i tossed a similar question out at PY, and Tom Vaught has a bunch of experience testing this and said that air volume can be dramatically different between cylinders with traditional manifolds. mentioned some cases of 40% difference. the advantage of carb or TBI on these manifolds is mixing the AFR before the air gets split up unevenly; carb or TBI would carry the same AFR through the ports, where MPFI without individual tuning would squirt the same amount of fuel into each port that may have different air volumes. hmmm....

i'm getting started on batch fire using Kris's tune, but MS will support sequential imminently. i just need to find a set of headers with o2 bungs in each cylinder to do the tuning when the ECU can support it.

[Karch]

Wouldn't egt be easier to measure (much cheaper), though not quite as accurate?

Did you ever get a 36-1 wheel?

[TheMonkey]

...

Did you ever get a 36-1 wheel?

yes, i'm using a motorcycle sprocket for the wheel. jury is still out on how it will work. i still need the VR sensor. new motor was broken in with a carb, now i'm tying up some finishing stuff on getting all the EFI on. i'm plumbing fuel right now. hopefully fire up the EFI on the break-in stand in the next few weeks.

[TheMonkey]

Wouldn't egt be easier to measure (much cheaper), though not quite as accurate?
...

yes, if i was going to monitor it on an ongoing basis, that would prob be the best route. however, i don't want to cut into my exhaust manifolds or have all the extra equipment wired up. i'd like to just get some correction variables and tuning done with a one time dyno session.Tom suggested that VE differences between cylinders are the same throughout different loads & RPMs, so it might come down to just having one correction variable for each cylinder.

[Karch]

Congrats on the progress. Mine has stalled, totally stalled.

I did p/u a tank and modified a pickup. The tank is out of an Impala RWD. I got a sending unit from both a TBI and TPI, so I can use either the A1000 pump I have, or get an in-tank pump (quiet).

Let me know how the sprocket works. I have a friend who may be able to make some wheels.

[TheMonkey]

i'm almost certain that the A1000 pump can be submerged in the tank. thought i read in one of their advertisements that all of their pumps can be either in or out of tank.