[6D6GOAT]

juuust finished rebuilding and installing my ECU controlled Pontiac 301 turbo distributor. just wondering what you EFI guys are running in the way of advance/spark curves? what should i be shooting for?

Idle?
cruise?

also, i removed the MSD with boost retard but then i started to wonder if i can reinstall it, and if i get some bad gas or its really hot etc...i can simply retard the timing via the MSD on the fly. that would be so much easier than cracking out the laptop, booting it up and making changes but i will get the spark map as close as possible with out the MSD.

thanks

[TheMonkey]

Vic-

does your ECU have an intake air temp sensor to retard for hot intake? why would you have to do that by hand?

Scott.

[6D6GOAT]

it does have a MAT sensor but its really sluggish..moves slow, kind of like a water temp guage. i dont think it would do me any good. i have looked at datalogs and the MAT reading is pretty much flat WOT through a couple gears, i didnt see any spikes when the boost came in.

[Ollie]

Originally Posted by 6D6GOAT

it does have a MAT sensor but its really sluggish..moves slow, kind of like a water temp guage. i dont think it would do me any good. i have looked at datalogs and the MAT reading is pretty much flat WOT through a couple gears, i didnt see any spikes when the boost came in.

There are two different Sensors, One is interchacgable with the coolant sensor, the other is called an open sensor.

Turbocharged or Supercharged engines should use an open-element air temperature sensor for faster response time. Here are some reported part number equivalants for both coolant and air temperature sensors (verify before ordering)

Coolant Temperature sensors (CLT) Mushroom Key way.
GM#12146312, may have been replaced by #15326386, Standard TX3 GP Sorensen TSU81, AC Delco 213-928, Niehoff DR134AK, Wells SU109, MSD 2310 (includes connector)

The Mushroom pig tail connector part numbers.
Wells pn 254, NAPA ECHTSC 200, Autozone pn 047131.

Open air Temerature sensor Square Keyway.
GM # 25036751, Standard AX 1, GP Sorensen 799-1901, AC Delco 213-190 Niehoff Igniton TS83631 was DR-136W Wells SU 107, MSD 2320 (includes connector)
There is also an open air sensor that goes in the air filter housing, that is what Iam using. The one I have is from NAPA the number molded on the side is 12160244.

Connector Pig tail IAT Square Key Way.
Wells pn 235, NAPA pn ECHTSC300, Niehoff pn PS77421, Conductite Dorman pn 85110.


.

[Hammered]

My Accell Gen7 system came with an open sensor for the MAT and closed for the ECT. They are supposed to be standard sensors for late '90s GM V8s.

EFI will have the same total advance as a NA engine but you have much more latitude for what happens between idle and WOT. I wish I could help more, but I'm still optimizing mine.

[6D6GOAT]

yes, its idle and cruise setting that im trying to figure out whats ideal

[6D6GOAT]

amcmike hooked me up with a good spark map. i took it for a test drive last night...i noticed a pretty big difference accelerating. a lot more responsive. thanks mike

[TheMonkey]

Vic-

would you share the wealth a bit? i'd be interested to see what you came up with.

thx,
Scott.

[Hammered]

Me too!

[6D6GOAT]

but what if its amcmikes super secret supercharged street spark map?

id better check with him first.

[6D6GOAT]

here is the rough. i think im going to make some tweaks to it...see if i can squeek in a little more timing when the boost comes in. but first i want to hook up the MSD box.

thanks again mike!

[6D6GOAT]

hey, we dont you guys post your map aswell so we can compare notes..

[krisr]

I'll be able to on Tuesday when I get back to work, I left my laptop there over the easter long weekend.

[amcmike]

Originally Posted by 6D6GOAT

here is the rough. i think im going to make some tweaks to it...see if i can squeek in a little more timing when the boost comes in. but first i want to hook up the MSD box.

thanks again mike!

No problem! Thanks for the feedback.

I see a little fine tuning was done to the base map (as expected). Be careful about going more aggressive on the boosted areas. And definitely make sure your fuel map is close (lean plus too much advance at WOT is not good).

How do you like the idle and how low were you able to set it?

I should also mention this was done for Vic's particular setup, so results might not be good in other cases.

[6D6GOAT]

i have made a couple more tweaks to it and smoothed it out a little. also, the table you supplied me was only like 10x10 so i had to put what you sent me in the grid that best matched yours and then fill in the blanks.

im not going to go any higher when under boost. 30 degrees max i what i expected to see. as for idle (keep in mind im new at this). i thought that less advance at idle = running hotter. i can barely keep her cool at idle so i bumped up the idle spark advance to 28. do i have it backwards? she likes alot of advance at idle to begin with (18 deg initial is what i used to run with no vacuum advance).

im getting ready to put the top down and go for a cruise to the beach. i am going to datalog the cruise and check it out later.


thanks again

[amcmike]

Should be fine. I doubt you are seenig the 19 or 27 kPa of the MAP except at decel. anyway. I had it setup for 12x12, since it was intended for Megasquirt use.

[krisr]

This is what my spark map looks like, the 10*btdc dip at 100kpa/low RPM is because I have the ECU calculate the amount of advance for cranking because I'm using a 36-1 crank trigger. I should also add that this timing map hasn't been optimized since I swapped to a hydraulic roller cam plus I use inlet air temp compensation to remove some timing under hot air conditions but trying to work out how to put more timing back in when the air is colder, I dont think the current codeset in my megasquirt allows negative integers but it shouldn't be too hard.

[Hammered]

I will see about getting a screen shot of mine this weekend. It's a much courser table than what you guys have. I think it's 8x8.

[TheMonkey]

i used Kris's to start, and have not tuned for low load cruise, but my idle seemed to like a bit more advance than Kris's. i look forward to sharing some data when i do get a chance to tune while driving.

[amcmike]

TheMonkey, Hammered, and krisr:
Can you guys please pm me your email addresses? I'd like to get some information from you about your engine combinations. Thanks.