Convert V6 Netres To V8

[festy]

For V6 to V8 just cut the leg, no need to add any resistors.
And no, LHM (limp home mode) won't work, and there's no easy fix (other than getting hold of a v8 memcal)

[VX L67 Getrag]

Ahh cool thought as much, thanks Festy!

[MrWillys]

On V6 to V8 conversions I just solder a jumper as shown, because I'm already there upgrading the 28 pin chip, and it's easier than trying to cut under the esc unit. the other is a 4 cylinder with the appropriate 7.5 ohm resistor.

[VX L67 Getrag]

The Photo is a little blurry but looks pretty cool, the knock filter wouldn't be to suit 4cyl would it?

[MrWillys]

The memcal on the left is a 4 cylinder without knock filter. The one on the right is a 6 cylinder with knock filter with jumper (paper clip) soldered in. I run each one I do in my vehicle prior to shipping. I haven't logged one yet, but notice no difference in driving vs a standard V8 memcal. Right now I have over 50 memcals of 4, 6, and 8 cylinder flavors.

The V6 conversions will run the vehicle even if the burn doesn't take with the SES light on. I'll go in and reburn and she'll fire off without an SES. I assumed it was running in limp home? Does jumping the 15 ohm pin to ground do something different than cutting it?

[Holden202T]

not sure how jumping the resistor to ground effects it, cutting the leg basically stops the resistor doing anything.

with the 6 cylinder one being converted to V8 it will work fine with the knock board still on it as most all V8 tunes have the knock disabled, just as long as the recipient knows that!

[MrWillys]

Each time I do this I burn my bin to it with the knock intact. I have not set a code. I need to log and watch what is occurring, but I've loaned my logging stuff out. I deal mainly with $8D, and $6E. I've noticed yours appear different than here. I assume this is Holden driven?

[Daviero]

Great thread and good info!
What I gather from several reads:
To get the knock retard to function using $12P/1227165 with NVRAM on a V8 one needs a V8 memcal from a '7165 pcm. (LHM will be close if running a similar engine)
or
Using a pcm from a 4 or 6 cyl and using the '7165 NVRAM will run the V8 but not be capable of knock retard, and the LHM "will run like poo"

The latter is my case now and it runs pretty well now but I want the knock retard functional.
I am using a $12POSE '165 NVRAM to run a stock Cadillac 4.6L Northstar.
The car is a 88 Pontiac Fiero GT.

I have not found any info about mounting a knock filter board directly on the NVRAM adaptor board though.....
Anybody done this?
What are the requirements of the knock filter for doing this - does it have to be a '7165 V8 board or can it be a V8 knock board from another pcm, say a '7730, or is it something else altogether?

[delcowizzid]

as long as its a knock filter of the same style and is tuned to suit the cylinder bore size it will more than likely work ok
i think some people are also using external filters input into the esc pin of the ecu but im not sure .we didnt get external filters so havnt messed with it

[Daviero]

"knock filter of the same style".....so for the '7165 pcm then, the V8 knock filter needs to be off a '7165 V8 too?
V8 '7165 memcals are getting hard to find now, or pretty pricey. ( '7730 are plentiful and cheap)
As for bore size, I'll have to be satisfied with close enough. The Northstar I am running is 4.6L, and the smallest V8 GM used the '7165 (or the 7730) on is a 5L (305 CI).