tuning my sr

Discussions concerning the M7790 cpu

Moderator: Matt

PL
 

Posts: 957
Joined: Fri Feb 03, 2006 3:29 pm
Location: Adelaide, South Oz
Contact:

Post by PL »

Hmmm. That ain't good. Check the plug. Other than that I'd just keep driving it until it starts to play up. I've never seen an intermittent CAS fault. They've either been dead or alive.

PL
Matt
Site Admin
 

Posts: 8961
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Post by Matt »

Does it come back immediately?

I've seen intermittent CAS faults on my R31 before swappnig it over. On the RB30 they are positioned too close to the exhaust manifold and suffer from heat eventually
Josh K.
 

Posts: 42
Joined: Fri Nov 16, 2007 3:30 am
Location: Makawao, Maui, Hawaii.

Post by Josh K. »

nope, its just random. I think I have a wiring issue, I'll trace it this weekend.

Matt, have you had any time to work on the afr auto tune?

what is the "Knock" box for on the fuel and ignition maps?
Matt
Site Admin
 

Posts: 8961
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Post by Matt »

No time yet. I just got a some boards out last night, finishing off the base image programmer tonight

I can try for tomorrow night to get the next stage of coding done. Testing is going to be the fun part...

Knock box is for when knock signal is detected it marks the cells red. This has only been started but only for R32/Z32/CA18 at this stage
Josh K.
 

Posts: 42
Joined: Fri Nov 16, 2007 3:30 am
Location: Makawao, Maui, Hawaii.

Post by Josh K. »

it would be nice to take the txs knocklite and use the bulb signal in place of the factory knock sensor input to the ecu. that way we could map trace with a more refined signal.
Matt
Site Admin
 

Posts: 8961
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Post by Matt »

I definately like the look of that TXS knocklite unit

What you could do is instead of feeding that bulb into the ECU that we feed it into the DLP A/D converter which is already supported
http://www.dlpdesign.com/usb/io8.shtml

This would then feed into NIStune for the knock detection currently in the software and is a very simple addition to make since all the code is there

Currently that unit uses channel 1 for AFR, channels 2-7 for Aux and channel 8 is spare

Channel 8 can be configured as a 0-5 volt Analogue input or 0/5 volt digital input

We could connect the light from the knocklight and put this straight into the A/D converter

If anyone is interested in this, let me know and I can add the code changes within an hour
PL
 

Posts: 957
Joined: Fri Feb 03, 2006 3:29 pm
Location: Adelaide, South Oz
Contact:

Post by PL »

He he he - I ordered a Knocklite 10 minutes ago. So we shall see!! :)

PL
Matt
Site Admin
 

Posts: 8961
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Post by Matt »

Okay we are in business... :D
Josh K.
 

Posts: 42
Joined: Fri Nov 16, 2007 3:30 am
Location: Makawao, Maui, Hawaii.

Post by Josh K. »

I'm glad all my stupid questions have been beneficial!!

I'm ordering mine today along with that DLP Converter.

Can we still run a light with the converter? I would like to wire in a big bright light in my gauge cluster to alert me to knock if i get bad gas.
PL
 

Posts: 957
Joined: Fri Feb 03, 2006 3:29 pm
Location: Adelaide, South Oz
Contact:

Post by PL »

Should be fine. I'll let you know the story once I pull the Knocklite apart.

I'm thinking that if you wanted to, you could actually remove the LED from the Knocklite and build it into your dash. You'd need to set up the knock threshold and overall gain using the buttons on the Knocklite first of course.

I guess you could even build the buttons into your dash if you wanted.

PL
Josh K.
 

Posts: 42
Joined: Fri Nov 16, 2007 3:30 am
Location: Makawao, Maui, Hawaii.

Post by Josh K. »

thats what i want, a big light in my dash. living on Maui I don't have alot of fuel choices so you never know what your getting.
Josh K.
 

Posts: 42
Joined: Fri Nov 16, 2007 3:30 am
Location: Makawao, Maui, Hawaii.

Post by Josh K. »

finally ordered the knocklite and dlp converter. any update on yours Pete?

I have 2 questions.

sometimes when warm i start my car and it dies, have to give a few blips of the throttle. also when i let of the throttle and go to neutral it dips to 500rpm then comes back. could this be the result of my tranny harness and neutral switch not being connected?

When i adjust timing with the knocklite do I make pulls and advance timing from low rpm all the way to redline, once knock is deteced back off 2 deg? does advancing timing only benefit under boost?

Matt, can I download the new rev of nistune with the knock flags?

Josh
PL
 

Posts: 957
Joined: Fri Feb 03, 2006 3:29 pm
Location: Adelaide, South Oz
Contact:

Post by PL »

Hey Josh,

Yes, I have the Knocklite. Haven't had a chance to try it yet. Things have been conspiring against me. I tuned 2 SR's in the last week. The first one had the knock sensor missing! And the second one had a non-functional cigarette lighter! I'd just wired up the power for the Knocklite to a cigarette lighter socket! We didn't have time to mess with wiring for it so I just used the well proven "add timing until torque stops rising" technique to find the detonation threshold.

I also employed another technique that works quite well. The guys at the dyno place were having their morning smoko when I was doing my final runs. The smoko room adjoins the dyno cell. This effectively blocks out all the engine noise - allowing them to hear detonation quite clearly. I've had them come running into the dyno cell telling me that they could hear detonation when it was only just on the detonation threshold.

Regarding your idle issues. Firstly you need to have your speed sensor hooked up. And you may need to adjust the K constant a bit to get you idle mixtures just right. They can be quite touchy.

Yeah, back it off at least 2 degrees from the knock threshold. I tend to only do timing adjustments in the high load area (usually the last 3 or 4 colums from 3000 rpm onwards). Increasing timing in the load load areas can pay dividends but you'll find that I've already done this in the map I gave you. :)

PL
Josh K.
 

Posts: 42
Joined: Fri Nov 16, 2007 3:30 am
Location: Makawao, Maui, Hawaii.

Post by Josh K. »

I've heard timing affects turbo spool, any truth to this?
kenbam
 

Posts: 131
Joined: Sat Sep 15, 2007 9:46 am

Post by kenbam »

I beleive retarded timing with a richer mixture in the lag areas can cause quicker spool, but only because some combustion is happening in the exhaust manifold, which obviously produces more heat for the turbo to deal with. Will aid spool but can also shorten turbo life.
Post Reply