Mrmerlin

Ken for post 28 can the pins be switched to disable fuel cut off with the S300 chipset

PorKen

With any stock LH2.2 chip, and my 'standard' chipset, yes. On my 'racing' version, it is already disabled.


I'm going to disable the injector cutoff on both of my chipsets from now on, though.

Mrmerlin

Thanks Ken, I swapped the connector pin from 19 to slot 15 and connected the wires not sure if i like it, but it needs more drive time

PorKen

After getting back into my '86.5 auto after it being down for a few months (dead wiper motor, leaky PS rack, junk battery), I was dismayed with the performance compared to my '85 manual. (Duh, you might say. ) After some experiments, I was surprised by an easy adjustment that seems to make but better use of the S3 torque peak.

Tighten/shorten the auto trans bowden cable, one turn at a time, until a part throttle 2 to 3 shift happens at 2500 rpm. This lets the engine rev a little higher for more torque before shifting (closer to how you might drive in a 5-speed). At medium throttle it will shift nicely, just past the torque peak at ~2800. It will also kick down more readily for better performance.

Notes:
- Part throttle 1-2 always happens at a lower rpm than the 2-3.
- Stock adjustment for the cable is to be able to drop the socket straight on the ball.
- Too tight, with a part throttle 2-3 shift closer to 3000, and the 3-4 shift on the highway may only happen if you let off the throttle, which is annoying.

Rob Edwards

Duh.

porsche 928 RI

do you need to run 91 gas as well as the NGK's for the race version? or can you run 89 with the NGK's?

PorKen

I have consolidated the two versions of the chips into the V3 chipset. There is just a choice of 89 or 92 octane EZ chip. You can use the stock resistor or non-resistor plugs with either. (The S300s website always has the latest info.)

PorKen

With more testing I'm finding the V3 LH chip may not be rich enough for X-pipe and true dual ('86.5) exhaust, especially w/o cats.


So...I think I've figured out the 'holy grail' of chips - end user adjustable WOT fueling. I have some more testing to do, but so far it works!

The WOT input into the LH2.2 is variable resistance capable, for a proper TPS. I put a 14-turn potentiometer inline to the WOT switch, and figured out the code to make the amount of resistance add to the WOT fueling. (The wiring is fairly easy, and reversible. Just have to disassemble the LH connector.)


I was worried that even though the WOT input goes through an A/D converter, that it may not be wired properly on the board for it to register anything other than on/off. Without making more extensive code changes, there is a limited range, but there is enough to add quite a bit of fuel if needed.

No, I don't know if LH2.3 (S4-up) has a variable input, but I'd guess that it does.

Don Carter

Ken,

Should those of us with v3.x chips, X-pipe and 86.5 exhaust go easy on WOT driving for now? or not lean enough to be a concern?

PorKen

Don - It's lean enough that you could hear pinging. If you do, then go easy!

The S3 is most efficient/requires the least advance around 2700, and 5000 rpm. These areas are where you'd hear knocking. I tune for no knock sensor detected knocks, so you should never hear audible knocking!

I'm still testing the wired input, and then I have to make a procedure for making them in 'bulk', take pictures for instructions, etc. So it will be a few days before it will be available, if it works. If all else fails, I will add a non-adjustable richer chip option for 'duelies'.

BC

Ken - when you say on your site that the green, LH board is required for no-lift-**** - what sort of green do you mean?

My board looks green in some areas and brown in others?

https://rennlist.com/forums/928-foru...-3-27-a-3.html

PorKen

The late '86.5 boards are all yellow. They appear to be computer designed (or designed w/better software) and have a more logical layout. They also have room for a 28 pin EPROM socket, although only a 24 pin is fitted. These boards have the capability for the pin 15 input (T1->8048) that I use for the clutch switch, but the electronic components were not installed for it.

I'll post a pic on your thread. (It looks like your board is 'yellow'.)

BC

So if I get your chips I do or do not order the no-lift-shift.

stolarzj

I'm in that boat also, 86.5 with X and not cats. So I eagerly await this new upgrade..

PorKen

You find a green board LH, and order the no-lift-shift.