7427 5.7 Performance Spark table from 7747.

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09-06-2019
Unorthodox122

7427 5.7 Performance Spark table from 7747.

Hi everyone,

I was reading the thread http://www.gearhead-efi.com/Fuel-Inj...BI-ECM-1227747
and yes, I know Ill still need to modify ve and the table itself, I just figured it would be a good starting point.

my question is before I go ahead and flash it, in the discussion mark says
"First is "SA - Max RPM for Spark Slope" which adds timing after the 3600 RPM because that is as high as the Spark Advance table goes in these 7747 $42 ECM. So say a stock ADSU chip adds 5.05 degreees per thousand but it only adds to "SA - Max RPM for Spark Slope" 4200 RPM so that's about 2.5* which it no longer needs with a table like this.
Then there's "SA - PE Spark Added" which will add up to 4.92* which is no longer needed... or can be played with.

What I'm getting at is with Dave Spark Advance table total at WOT of 31.99 + the Spark Slope of 2.5 + the PE spark of 4.92 you could end up with 39.41 total advance by 4200 RPM! Which is to much for any street vehicle on pump gas!"

Okay, so I do not see a spark slope in the 7427,
I Did zero out the pe spark added, Do I need to worry about zero'ing all the bias's out?
How would i go about putting this in the 427 (options wise, not the table).

Wanted to make sure I did everything before I tried, so I wouldnt end up in bad territory. Sorry if this has been discussed, and thank you for the help.

It's a mostly stock 350tbi, maf 0D, 2.5 headers, 3wire 02, 3.73 gear awd, just wanted a tiny bit more kick out of it.
09-06-2019
Fast355

Quote:

Originally Posted by Unorthodox122

Hi everyone,

I was reading the thread http://www.gearhead-efi.com/Fuel-Inj...BI-ECM-1227747
and yes, I know Ill still need to modify ve and the table itself, I just figured it would be a good starting point.

my question is before I go ahead and flash it, in the discussion mark says
"First is "SA - Max RPM for Spark Slope" which adds timing after the 3600 RPM because that is as high as the Spark Advance table goes in these 7747 $42 ECM. So say a stock ADSU chip adds 5.05 degreees per thousand but it only adds to "SA - Max RPM for Spark Slope" 4200 RPM so that's about 2.5* which it no longer needs with a table like this.
Then there's "SA - PE Spark Added" which will add up to 4.92* which is no longer needed... or can be played with.

What I'm getting at is with Dave Spark Advance table total at WOT of 31.99 + the Spark Slope of 2.5 + the PE spark of 4.92 you could end up with 39.41 total advance by 4200 RPM! Which is to much for any street vehicle on pump gas!"

Okay, so I do not see a spark slope in the 7427,
I Did zero out the pe spark added, Do I need to worry about zero'ing all the bias's out?
How would i go about putting this in the 427 (options wise, not the table).

Wanted to make sure I did everything before I tried, so I wouldnt end up in bad territory. Sorry if this has been discussed, and thank you for the help.

It's a mostly stock 350tbi, maf 0D, 2.5 headers, 3wire 02, 3.73 gear awd, just wanted a tiny bit more kick out of it.

The only time I ever messed with spark bias in that PCM was to add in IAT functionality. I copied the stuff over from a 4.3 CPI to start with. The only bias I ever changed was IAT Bias. I also never zero out the PE spark. I use atleast 4* from 3,200 up. You need less timing when the engine is at heavy load and stoichiometric to keep the engine from spark knocking, but need more timing when you are in PE with the richer mixture. That being said why switch to the MAF setup and leave the pathetic stock cam in the engine? I had a 8.75:1 18cc dished piston 350 TBI in my G20 van that I put a set of ZZ4 heads and the ZZ4 cam in. Had stock drivability but made ALOT more power. I used a performer rpm intake, mercruiser 454 to square bore carb adapter and the 2" bore marine TBI. I used factory GM 0.028" composite head gaskets rather than the 0.051" ZZ4 gaskets. With the compression around 9.3:1 and aluminum heads it ran on 87 octane all day long at 34° of timing from 2,600 rpm on. Lots of low-midrange torque, good top-end power and no knock retard.
09-06-2019
Fast355

I ran that same 350 for a while with the ZZ4 cam, ported 081 TPI 305 heads, an edelbrock 3704 intake bored to 2" and the marine 2" TBI as well. The aluminum heads with their larger valves and performer rpm intake made ALOT more HP. Probably close to 40 hp more judging off the airflow increase. Went from 240 gms/sec to 280 gms/sec. In the 5,500 rpm range the prior setup was down around 220 gms/sec and the later still in the 280 range. Knocked nearly 1/2 second off my 1/8 mile time and gained about 4 mph. From 68 up to 72 mph. I think it went from a 9.80 to a 9.30. The stock heads and cam did a 10.6 @ 62.
09-06-2019
Fast355

From the best of my memory of 13 years ago, lol.

Stock 8.75:1 350 with the 3704 intake, stock exhaust manifolds, stock Y-pipe, high flow 3" cat, single in/dual out flow master 40. 700r4 with a stock 1,600 rpm converter and 3.08 gears. Had Impala SS wheels with like a P275/50R17.
Went 11.40 @ 60 mph with the shifts at 5,000 rpm.

Stock 8.75:1 350 with a 3704 bored to 2", Marine 2" TBI, Open Center TBI spacer, Thorley Tri-Ys into a dual 2.5" exhaust with dual cats, X-pipe and Magnaflow mufflers. Stock cam and 1.6 full roller rockers. Same trans, gears and tires.
Went 10.60 @ 62 mph shifting at 5,000.

Swapped in a 96 LT4 cam and upgraded the springs. Everything else unchanged. Went 10.40 @ 68 mph shifting at 5,500.

I put a Weiand 177 on it for about 6 months. It was pullied to make 10 psi @ 5,500 rpm. Went through 3 well built 700r4s and a 10-bolt rear in less than 10K miles. Not before running an 8.60 @ 82.

After I got tired of changing driveline parts I figured I would get some cheap compression and maybe better flow. Swapped out the TBI heads for the ported 305 TPI heads. Also swapped in the ZZ4 cam. Probably would have been quicker with more stall speed. Ran a 9.80 @ 68.

Picked up the L98 Aluminum ZZ4 heads from a friend that put Fastburns on the ZZ4 in his C10. Same engine the ZZ4 cam came from that had been previously upgraded to the LT4 Hotcam, lol. I like having friends that throw out good used parts. I put them on with the performer rpm and the marine TBI adapter. Went 9.30 @ 72 mph.

I pulled the engine apart yet again after losing a roller lifter and damaging the ZZ4 cam. I put a set of ported Vortecs with 2.05/1.60 valves, the LT4 cam and an edelbrock performer vortec intake. Went 9.10 @ 74 shifting at 6,000 rpm

Then I decided to play with a single plane victor jr 2bbl intake. I put a Reed custom grind cam into it. IiRC it was 214/218 @ 0.050, .520/.540 lift, 114 LSA, 110 ICL. Idled like the stock cam and pulled like a freight train.
Went 8.80s @ 79 mph shifting at 6,400-6,600 rpm.

Then I decided to swap on a ported TPI with SLP runners. 8.70 @ 77 shifting at 6,000. Added alot of torque and lost alot of RPM. Probably saved the factory TBI rotating assembly. Except for the fact I somehow managed to mix a 3.4 17 lb/hr injector into the mix with the 26 lb/hr LT4 injectors. I cooked a piston on a 500 mile trip pulling a trailer. So I built a 10.5:1 383. It ate another 700r4 and two 4L60Es with the TPI 383.

None of these setups ever ran under a 2.1s 60' time. Thanks to 5,300 lbs, a stock 1,600 stall and 3.08 gears lol.
09-06-2019
Fast355

I will say that the Weiand blower was definately the most fun to drive. Instant torque. I could not even go WOT without knocking the tires off at a 20 mph roll. 700r4 did not like that kind of torque in the heavy van though. That was a WOT hit followed by alot of pedaling trying to regain traction. In an AWD truck you might be able to plant it and a well built 700r4 would probably last a lot longer in the lightweight truck. I tried all the tricks I could to try to make the 700r4 last too. I even had a spring on the TV cable that aggressively pulled the TV valve in the transmission open to build line pressure by preloading the TV cable in the idle position by roughly 1/4"..

https://youtu.be/DPIaLtE_U1I
09-06-2019
Unorthodox122

Quote:

Originally Posted by Fast355

The only time I ever messed with spark bias in that PCM was to add in IAT functionality. I copied the stuff over from a 4.3 CPI to start with. The only bias I ever changed was IAT Bias. I also never zero out the PE spark. I use atleast 4* from 3,200 up. You need less timing when the engine is at heavy load and stoichiometric to keep the engine from spark knocking, but need more timing when you are in PE with the richer mixture. That being said why switch to the MAF setup and leave the pathetic stock cam in the engine? I had a 8.75:1 18cc dished piston 350 TBI in my G20 van that I put a set of ZZ4 heads and the ZZ4 cam in. Had stock drivability but made ALOT more power. I used a performer rpm intake, mercruiser 454 to square bore carb adapter and the 2" bore marine TBI. I used factory GM 0.028" composite head gaskets rather than the 0.051" ZZ4 gaskets. With the compression around 9.3:1 and aluminum heads it ran on 87 octane all day long at 34° of timing from 2,600 rpm on. Lots of low-midrange torque, good top-end power and no knock retard.

Hi fast, thanks for your replies. The MAF setup was actually one of the first things I did after switching to the 427 ecu a couple years ago now, much better cold starts, and smoother transitions then I was able to ever get with the Tbi tables . I remember reading through a lot of different threads by you, and dimented and both of you basically pioneered the way for it, even stock I hate going back to the regular tables ha.

From all the cars Ive done swaps in my s10 is the one that kind of got neglected, one ive had the longest, but never really worried too much about it. It was the first v8 swap in a mini truck I did when I was 19, and also the first truck that got me so interested in the tuning world here. Now Im back to driving it daily and wondered IF I could make it any more fun to drive atm.

Yes, it is the pathetic stock cam, The engine is only a 2-bolt main, and no provisions for the roller cam unfortunately, I guess i could have them drilled out bit I'm also using it as a daily driver for this winter until I do an ls swap (yes another ls swap guy) in a few months in somewhere in that time frame, so I really don't want to throw too much at it anymore, just wanted a slight more kick for merging than the stock timing table for a little while.

So when I came across that thread I was happy to see he said for most stock setups, and made this thread seeing what else I would have to do to run that particular table.

Must be nice to have friends throw away nice engine parts to experiment with, lol.

Anyway thank you for taking the time to reply to my thread, I appreciate it.
09-07-2019
Fast355

Quote:

Originally Posted by Unorthodox122

Hi fast, thanks for your replies. The MAF setup was actually one of the first things I did after switching to the 427 ecu a couple years ago now, much better cold starts, and smoother transitions then I was able to ever get with the Tbi tables . I remember reading through a lot of different threads by you, and dimented and both of you basically pioneered the way for it, even stock I hate going back to the regular tables ha.

From all the cars Ive done swaps in my s10 is the one that kind of got neglected, one ive had the longest, but never really worried too much about it. It was the first v8 swap in a mini truck I did when I was 19, and also the first truck that got me so interested in the tuning world here. Now Im back to driving it daily and wondered IF I could make it any more fun to drive atm.

Yes, it is the pathetic stock cam, The engine is only a 2-bolt main, and no provisions for the roller cam unfortunately, I guess i could have them drilled out bit I'm also using it as a daily driver for this winter until I do an ls swap (yes another ls swap guy) in a few months in somewhere in that time frame, so I really don't want to throw too much at it anymore, just wanted a slight more kick for merging than the stock timing table for a little while.

So when I came across that thread I was happy to see he said for most stock setups, and made this thread seeing what else I would have to do to run that particular table.

Must be nice to have friends throw away nice engine parts to experiment with, lol.

Anyway thank you for taking the time to reply to my thread, I appreciate it.

A set of underdrive pulleys, 1.6:1 full roller rockers and an edelbrock torquer 2 intake would perk it right up if you have headers and a decent exhaust. To make the older intake fit all you have to do is get the Weiand washers and elongate the 4 center bolt holes.
09-07-2019
Fast355

Quote:

Originally Posted by Fast355

A set of underdrive pulleys, 1.6:1 full roller rockers and an edelbrock torquer 2 intake would perk it right up if you have headers and a decent exhaust. To make the older intake fit all you have to do is get the Weiand washers and elongate the 4 center bolt holes.

Actually just noticed professional products offers some for 1/10th the cost that might work too. Especially if you were to use one of their intakes.

https://www.summitracing.com/parts/pfs-52110/
09-07-2019
Unorthodox122

Quote:

Originally Posted by Fast355

A set of underdrive pulleys, 1.6:1 full roller rockers and an edelbrock torquer 2 intake would perk it right up if you have headers and a decent exhaust. To make the older intake fit all you have to do is get the Weiand washers and elongate the 4 center bolt holes.

I have a set of 1.5 tube shortie headers into a 2.5 inch collector, and a dual 2.5 inch exhaust into a dual in dual out muffler.

That sounds like a decent plan, I saw recently a torquer 2 for sale for 80 recently maybe I'll go pick that up.

Thanks for that Fast.

Also, a bit off topic and I dont know if you remember or not about the definition files, but im using the maf 0d file, and I want to add knock counts to it, I tried copying over the hex from a different one, but the knocks portray like thousands in the log files, and when I run just plain TBI and the v250.adx file I get regular readings.:innocent: