Lance Cheney
SHO Member
Hi everyone,
I just attended a Dyno day with the Baysho group yesterday and had a chance to sit down for about 75 minutes to do some tuning on my car. The rest of the group was doing 3 pulls for $50 (with A/F monitoring). I learned some very cool stuff about my car and the software and the tuning time allowed me to get a good level of additional performance as well as get the curve for my 80mm MAF to something a lot more correct than I got on the original mail-order chip.
First, mods on the engine so people have an idea of what I'm doing.
I have a 3.2L block; internals from an ATX inside of a bored-out 3.0L engine with 3.0L heads that had new seals, guides, and valve springs put on them when it was rebuilt (~20k ago). No performance porting or anything. I also machined out the fuel rails and dropped in a set of Ford Motorsports 30lb injectors (only come in sets of 8, doh!).
I like top-end power so I dropped stage II cams into the motor and installed ShoNut's adjustable cam sprockets. They're setup up with 3 degrees of overlap reduction (exhaust advanced vs. 0 timing) and the baseline runs had 2 degrees of overall timing retard (I believe his markings are in cam degrees but I may be wrong). The intake manifold has been extrude honed and port-matched to the heads and to the surge tanks (I had a writeup about this earlier -- I was surprised how much material needed to be removed from the surge tanks to mate to the long runners). I have Sho Shop BBs installed as well.
The exhaust is a Sho-Shop Y pipe (old style), modified for a 3" catback, which consists of one 4" Dynomax bullet muffler and one 5x11x22" SS Magnaflow in the tail.
The intake has stock airbox with the outer removed and a 3 or 4" PVC pipe to the fender well and a 80mm MAF (in some runs) and a K&N (in some runs).
The engine runs pretty well but has suffered the same fate my other engines have though I'm not sure if it's for the same reason. I'm burning about a quart of oil every 500 miles, no matter what my driving style. I haven't checked the compression, so I can't assume it's a little on the low side, though it probably is.
I have my own tuning software that I developed from some documents I found online vs. the original code in the chip. I have a LPM with a removable 32-pin DIP byte-wide EPROM/flash/EEPROM, which makes do-it-yourself tuning possible (vs. the black Autologic plastic modules which one of the other SHO attendees had)
The first thing to do was to make sure that my fuel injector setting was right. I installed the 55mm factory MAF and made a LPM program with the larger injector value (300cc/min) and the stock MAF curve. This would give me a baseline A/F curve to compare against what the computer was programmed to give.
First two runs were this way (first run on a lot people's dynos seems to be a little low -- not sure why):
The A/F ratio was basically about what the factory computer was programmed for (11.4 @ 6800 RPM). I was pretty sure that the 300cc injector sizing was about right. Next order of business was to attach the 80mm MAF and optimize the curve in the LPM.
When I first got the chip the car didn't really run that well and seemed to learn some pretty wierd habits. A simple voltmeter-on-O2-sensor-lead test showed it was pretty lean at WOT, so I added MAF in the LPM until I got something that felt better. My last dyno (Nov 2002) was all based off of this type of tuning, and yielded 233whp (no EH intake at the time, and a 2.5" exhaust -- cam timing was the same).
This chart has the first two passes with the bigger meter. The first pass was pretty lean so I upped the MAF curve for the second pass and it's now fairly close to correct, at least for relatively high flows.
It's hard to tell exactly how close it is to the right curve on the bottom end. Here's the 55mm MAF vs. the mostly-optimized 80mm MAF. You can see a 7-8HP gain.
At this point the MAF curve is pretty close. I actually put in another 3% (~0.4pt difference), then made a run with the secondaries opening at 3800 RPM vs. 4150 RPM, and pulled a little bit of spark out on the bottom end as I was getting a little bit of pinging (not really evident in the dyno charts). I also changed the commanded A/F ratio to lean out the mixture on the top end a little bit (not much).
The 3800 RPM opening is obviously too early. Where I had it before was pretty close to correct. I then tried a program with a 13.2:1 or so A/F from 4000 RPM and up. The secondary runners went back to 4150 RPM.
Not much difference there. I decided I'd try adding 4 degrees of spark advance to see if there was anything to be gained. This was 4 degrees on anything over 3650 RPM. In retrospect I probably should have tried this on the richer mixture. It may have showed some gain there though probably not. I zoomed in on the torque curve for this one since that's where you'd see anything (if there were anything to see).
I think I'm about done with computer tweaking. I pulled the spark back out (back to dynorun10's settings), and dropped in a K&N panel -- had a Purolater filter on up to this point (I was trying to break 250):
1.5hp gain, which is within the dyno accuracy (the A/F curve varies a bit between runs, perhaps due to the computer adding fuel for coolant or air temp changes). FWIW, the paper one is going back in since I'm tired of cleaning the MAF. Note that the dyno software at the shop reported this as 249.7 whp, so I hadn't hit 250 yet (not sure why the runviewer7 software shows it slightly different with the same SAE correction algorithm)
The last and maybe most interesting change was the cam timing. Dynorun #13 is with the cams advanced 2 degrees, dynorun #14 is ******** by ~3.5 degrees. Baseline (#12) is ******** by 2 degrees.
The shop showed 251.2 for the last run, woohoo!
Interesting that the torque differences are mostly confined to the 4000+ RPM range. There may be some difference at ~2200 RPM but there isn't enough data there (I was trying to get 1700RPM and up but the guy was a little late hitting the go button on some of the runs).
You can see the somewhat soft torque curve on the stage IIs. I'm not sure what it would look like without the sprocket overlap change (advanced exhaust cam by 3 degrees relative to intake).
Anyway, I had a great time and had a lot of fun running the car out. There's probably more power in there that people more experienced could get, but it's probably not a lot. I'm a lot happier now that I know I have a MAF curve that is closer to what it should be (though the low-end, part-throttle area is a bit hard to tune on a dyno this way).
-Lance
<small>[ March 21, 2004, 08:13 PM: Message edited by: Lance Cheney ]</small>
I just attended a Dyno day with the Baysho group yesterday and had a chance to sit down for about 75 minutes to do some tuning on my car. The rest of the group was doing 3 pulls for $50 (with A/F monitoring). I learned some very cool stuff about my car and the software and the tuning time allowed me to get a good level of additional performance as well as get the curve for my 80mm MAF to something a lot more correct than I got on the original mail-order chip.
First, mods on the engine so people have an idea of what I'm doing.
I have a 3.2L block; internals from an ATX inside of a bored-out 3.0L engine with 3.0L heads that had new seals, guides, and valve springs put on them when it was rebuilt (~20k ago). No performance porting or anything. I also machined out the fuel rails and dropped in a set of Ford Motorsports 30lb injectors (only come in sets of 8, doh!).
I like top-end power so I dropped stage II cams into the motor and installed ShoNut's adjustable cam sprockets. They're setup up with 3 degrees of overlap reduction (exhaust advanced vs. 0 timing) and the baseline runs had 2 degrees of overall timing retard (I believe his markings are in cam degrees but I may be wrong). The intake manifold has been extrude honed and port-matched to the heads and to the surge tanks (I had a writeup about this earlier -- I was surprised how much material needed to be removed from the surge tanks to mate to the long runners). I have Sho Shop BBs installed as well.
The exhaust is a Sho-Shop Y pipe (old style), modified for a 3" catback, which consists of one 4" Dynomax bullet muffler and one 5x11x22" SS Magnaflow in the tail.
The intake has stock airbox with the outer removed and a 3 or 4" PVC pipe to the fender well and a 80mm MAF (in some runs) and a K&N (in some runs).
The engine runs pretty well but has suffered the same fate my other engines have though I'm not sure if it's for the same reason. I'm burning about a quart of oil every 500 miles, no matter what my driving style. I haven't checked the compression, so I can't assume it's a little on the low side, though it probably is.
I have my own tuning software that I developed from some documents I found online vs. the original code in the chip. I have a LPM with a removable 32-pin DIP byte-wide EPROM/flash/EEPROM, which makes do-it-yourself tuning possible (vs. the black Autologic plastic modules which one of the other SHO attendees had)
The first thing to do was to make sure that my fuel injector setting was right. I installed the 55mm factory MAF and made a LPM program with the larger injector value (300cc/min) and the stock MAF curve. This would give me a baseline A/F curve to compare against what the computer was programmed to give.
First two runs were this way (first run on a lot people's dynos seems to be a little low -- not sure why):
The A/F ratio was basically about what the factory computer was programmed for (11.4 @ 6800 RPM). I was pretty sure that the 300cc injector sizing was about right. Next order of business was to attach the 80mm MAF and optimize the curve in the LPM.
When I first got the chip the car didn't really run that well and seemed to learn some pretty wierd habits. A simple voltmeter-on-O2-sensor-lead test showed it was pretty lean at WOT, so I added MAF in the LPM until I got something that felt better. My last dyno (Nov 2002) was all based off of this type of tuning, and yielded 233whp (no EH intake at the time, and a 2.5" exhaust -- cam timing was the same).
This chart has the first two passes with the bigger meter. The first pass was pretty lean so I upped the MAF curve for the second pass and it's now fairly close to correct, at least for relatively high flows.
It's hard to tell exactly how close it is to the right curve on the bottom end. Here's the 55mm MAF vs. the mostly-optimized 80mm MAF. You can see a 7-8HP gain.
At this point the MAF curve is pretty close. I actually put in another 3% (~0.4pt difference), then made a run with the secondaries opening at 3800 RPM vs. 4150 RPM, and pulled a little bit of spark out on the bottom end as I was getting a little bit of pinging (not really evident in the dyno charts). I also changed the commanded A/F ratio to lean out the mixture on the top end a little bit (not much).
The 3800 RPM opening is obviously too early. Where I had it before was pretty close to correct. I then tried a program with a 13.2:1 or so A/F from 4000 RPM and up. The secondary runners went back to 4150 RPM.
Not much difference there. I decided I'd try adding 4 degrees of spark advance to see if there was anything to be gained. This was 4 degrees on anything over 3650 RPM. In retrospect I probably should have tried this on the richer mixture. It may have showed some gain there though probably not. I zoomed in on the torque curve for this one since that's where you'd see anything (if there were anything to see).
I think I'm about done with computer tweaking. I pulled the spark back out (back to dynorun10's settings), and dropped in a K&N panel -- had a Purolater filter on up to this point (I was trying to break 250):
1.5hp gain, which is within the dyno accuracy (the A/F curve varies a bit between runs, perhaps due to the computer adding fuel for coolant or air temp changes). FWIW, the paper one is going back in since I'm tired of cleaning the MAF. Note that the dyno software at the shop reported this as 249.7 whp, so I hadn't hit 250 yet (not sure why the runviewer7 software shows it slightly different with the same SAE correction algorithm)
The last and maybe most interesting change was the cam timing. Dynorun #13 is with the cams advanced 2 degrees, dynorun #14 is ******** by ~3.5 degrees. Baseline (#12) is ******** by 2 degrees.
The shop showed 251.2 for the last run, woohoo!
Interesting that the torque differences are mostly confined to the 4000+ RPM range. There may be some difference at ~2200 RPM but there isn't enough data there (I was trying to get 1700RPM and up but the guy was a little late hitting the go button on some of the runs).
You can see the somewhat soft torque curve on the stage IIs. I'm not sure what it would look like without the sprocket overlap change (advanced exhaust cam by 3 degrees relative to intake).
Anyway, I had a great time and had a lot of fun running the car out. There's probably more power in there that people more experienced could get, but it's probably not a lot. I'm a lot happier now that I know I have a MAF curve that is closer to what it should be (though the low-end, part-throttle area is a bit hard to tune on a dyno this way).
-Lance
<small>[ March 21, 2004, 08:13 PM: Message edited by: Lance Cheney ]</small>
