Duratec Performance

[RootesRacer]

I think it might be good to have your manifold hose go to your filter, and the have the filtered side go to both the ECU and the FPR.

Both the ECU and the regulator will see the same signal and any phase shift in the filter will be common to both items.

Its worth a try to see if this helps with the filter mix and eliminating the bimodal AFR behavior.

 

[Bill Blue]

Don't really understand your comment. The squarish thing located beside the TB and between the two large hoses is my vacuum source. It is open to the plenum and cannot be plumbed to the manifold hose (the upper large hose? It sees manifold pressure). How about if I install a Tee into the manifold hose, install an orifice, etc. and use that as the vacuum source?

Bill

 

[RootesRacer]

Not sure what all your hoses go to (nor is it very important).

What I am saying is that the ECU and the FPR should be seeing the same filtered manifold vacuum signal.
If you filter the tube to the ECU and connect the FPR manifold reference line direct to an unfiltered manifold vacuum connection, the ECU will have a different phased signal than the FPR will, which is probably not helpful to you.

The OEMs usually have the FPR and MAP line off the same vacuum port, or off have similar size and length lines between the manifold and the ECU or FPR.
This way they see essentially the same signal even if they arent directly connected to one another.

 

[Bill Blue]

What I am saying is that the ECU and the FPR should be seeing the same filtered manifold vacuum signal.
They are. There is one plenum port which has two outlets. Each outlet has a .030" orifice. The lines are dissimilar in size and length. I will take some of the ECU line and use it for the FPR.

Bill

 

[Bill Blue]

The combination of smaller injectors and no reservoir is working well. Drivability is the best its ever been. kPa's vary by 3 (97.3-100.3) while accelerating from 1200 to 6500 @ WOT. Variation across any 1000 rpm range is much better, more on the order of 1 kPa. kPa's at the top end are almost 2 less than at the bottom. I will install the smaller FPR line and maybe play around with even smaller orifices. I'm done with reservoirs. Maybe with an entirely different setup.

I did some Googling of dendrites and whisker formation. Could find nothing on passivation of solder. As near as I can tell, formations are associated with electronics and pure tin. In fact, one of the solutions is the addition of lead, which my solder has.

Bill

 

[RootesRacer]

The combination of smaller injectors and no reservoir is working well. Drivability is the best its ever been. kPa's vary by 3 (97.3-100.3) while accelerating from 1200 to 6500 @ WOT. Variation across any 1000 rpm range is much better, more on the order of 1 kPa. kPa's at the top end are almost 2 less than at the bottom. I will install the smaller FPR line and maybe play around with even smaller orifices. I'm done with reservoirs. Maybe with an entirely different setup.

I did some Googling of dendrites and whisker formation. Could find nothing on passivation of solder. As near as I can tell, formations are associated with electronics and pure tin. In fact, one of the solutions is the addition of lead, which my solder has.

Bill

If you are down to 1kpa at any given MAP point you are done, whatever you ended up with is good enough.

The dendrites are as you read from the tin. With enough lead, the lead will rather oxidize than the tin. I dont think you can passivate lead alone, passivisation usually involves reacting an undesireable metal to a state where it wont harm whatever you are concerned with.

In any case, my point was dont use solder for small ID restrictors, it will bite you in the butt. Use plastic or epoxy or pretty much anything but solder.

Back in the day when I used to jet a lot of carbs, I would solder up an oversized jet and drill it out to a smaller orifice to find what jet should be used. This was only a temporary jet and once the correct jet was ordered it replaced the temp jet. Just leaving one of those jets in fuel for a week or so would usually show bloom on the solder and was already shifting the calibration to the lean side (for fuel jets).

 

[Bill Blue]

I actually went to the trouble to note the variation in each tuning cell from 1500 up. 15-2000 was the worst, 1.8 kPa variation. So I have some more to go. With the .030" orifice and 1.6" reservoir, the variation was more like .2 or .3 kPa. Really tight. Too bad it drove like a pig.

Drilling out the solder and packing with JB Weld. I can do that. Very good idea. In addition, it drills a lot easier than solder! I think that I will pack the hose adaptor its entire length, so the "orifice" will be about an inch long. Should have some impact.

Bill

 

[Bill Blue]

Well now, this is interesting. The tubing adaptors were packed with JB Weld an drilled out to .032" the entire length of the adaptor, so the restriction was about an inch long. The kPa variation was worse in each tuning cell, some by a factor greater than three!

The increased restriction really did a number on the tune. Idle was rich, WOT up to about 5,000 was leaned out but still rich. Above 5500 it went very rich. Drives without a hiccup.

Bill

 

[Bill Blue]

Late last night I realized I had changed two things, I shortened the spaghetti tubing about 30" to use it for the fuel pressure regulator. So it seems likely the change in tune is not due to the change in the length of the orifice. I decided to employ two restrictions, one at the manifold and one at the ECU. So I plugged the hose coupler and drilled a .030" hole through it. So there is now 3 or 4 feet of hose with equally sized orifices on either end.

I'm going to drive it that way for a few days to evaluate drivibility. Initial impressions were not good, but it seemed to improve the last quarter mile of the second outing. I'm wondering if the orifice was partially plugged with a chip. I thought I was careful to get a good clear orifice and could see no obstructions before installation, but throttle response seemed to change suddenly.

Bill

 

[Bill Blue]

The .030" orifice at the ECU did not measure up. Throttle response was iffy and the engine was strangely gutless. So I drilled the orifice to .034". Made a huge difference. Throttle response was very good the engine was, in general, a bad ass. kPa variation was okay, but not as good as with the long spaghetti tubing. I'm going to re-try the long spaghetti tubing and only one orifice to compare it to the current set up.

Something I'm noticing. Set ups that produce low kPa variation also give higher kPa's. No idea why or if that is a good thing.

I'm zeroing in, like a moth at a candle.

Bill

 

[Bill Blue]

The long spaghetti tubing, when used with the .034" orifice was not good. Throttle response was iffy and there was a slight surge when cruising at 2000 rpm. The AFR at cruise was 15.5, but the engine can run smoothly at higher AFR's. The surge was slight and I thought it might be a combination of the road and my imagination. Idle speed varied over 100 rpm. I diddled with the tune around the idle speed so that as the tune went from cell to cell there would be no change in fuel or timing. Made zero difference.

So I drilled the orifice to .036". Once again, big difference. Idle leaned out, but speed was more consistent. Richened it (from 15.5 to 14.9) and idle speed became very steady. The throttle response was good and the surge at cruise was gone. It does need to be retuned.

So I think this is it, the maximum restriction that will allow good driving characteristics. Not that it is perfect or optimum, but is the best I can do with what I have to work with and the knowledge I have of the system.

Now to get it tuned.

Bill

 

[Bill Blue]

After a couple of days and two or three hundred miles, it became obvious there was a slight off idle hesitation. Enough that it messed up shifting, especially the 1-2 shift. A person would think that would be most noticeable on initial drive, but not with me. I think that is because when making trial runs I'm more attuned to engine speed and do not engage the clutch until engine speed is up.

This caused me to review the highlights of this little exercise. The overall trend is that volume is bad, restriction is good. So nothing left to do but reduce volume to the minimum and maximize restriction. That translates into the shortest possible length of spaghetti tubing with .030" restriction on either end. That has just been accomplished. Idle tuning was required. Without fail, every change, no matter how minor, has required retuning of idle. An adjustment of the idle offset and a minor bit of tuning in the 1,000-1,500 rpm range gave improved (I think) throttle response. Will drive it a few days and see how long that impression lasts.

Bill

 

[Bill Blue]

The change was good and is going to be permanent. Took a little spin out to Kearney, MO (1100 miles) and I'm very satisified. There's nothing like driving around town after 3 or 4 hours at 70 mph to tell just how driveable your car is. I've decided that in previous configurations, including those of last year, driveability was not all that good, it was simply a case of me acclimating.

The 3.80 rear end is working great. 70 mph in 5th puts you right at 3,000 rpm. Right at the begining of the power. The sprint from 70 to 85 is fantastic and the engine literally purrs at 85.

Mileage was so-so. About 27 mpg at 70-75 with the air on. Got me to thinking about timing. I vaguely remember didling with vacuum advance early in the summer. Just exactly why, I do not recall. Anyway, I decided that I had not looked at timing of any nature since I had shortend the intake runners. So Barb and I headed to the acceleration test track this afternoon. The idea was to do a 1,500 - 6,500 rpm run, recorded by the ECM. Then to conduct follow-up runs, with one degree ignition advance between runs. Initial run was 14.9 seconds. This equates to accelerating from18 mph to 80 mph. Last run was 12.9 seconds. A gain of two seconds in time!

The old timing curve was really pretty funky. 27 degrees from about 3,000 on up. I had verified this on two different occasions with the long runners. Both times I started at 34 degrees and backed off until performance began to suffer. This time I worked it the other way, but regardless, the result is a performance curve. If anyone asks why I am using it, I can say it works best. The new curve is much more traditional, hits a max of 34 at 3,000 and continues to 7,000.

Most of the gain was top end. The 6000 - 6500 time decreased from 2.7 seconds to 1.9. 5000 - 6000 dropped from 3.5 seconds to 3.0. 3000 to 4000 decreased by 3 tenths. 1500 - 2000 did not change, 2000 - 3000 .2.

On the way home we adjusted the vacuum advance to the point the advance is in the high 30's while running at 50-60 mph. The engine seems to do well with that amount, will have to wait and see about mileage.

Bill

 

[MGBSS]

Sounds like you are getting it dialed in

 

[socorob]

yeah, did the 3.80s help keep it in the power curve better?

 

[Bill Blue]

yeah, did the 3.80s help keep it in the power curve better?

Depends on what your after. The 3.80 is nice on the interstate, cruise is right at the start of the big mid range power band. If your after 0-60 (7169 in second), your now going to have to touch third. On the 20-80 run, the engine becomes winded before hitting 80. I found some of the missing top end power by retuning the spark advance. Will look at that some more in the near future. The 3.80 also makes driving the country roads (some pretty hilly) at low speed in 5th very possible. All in all, a good choice for this engine/transmission/car weight/tire combination and the way I drive. Some might perfer the 4.10, but I think it would be too much for me.

Bill

 

[Bill Blue]

Robbie, I think it is important to examine my gearing from top to bottom. As I've noted 5th gear is really good.

4th is fine. A little revvy for driving at 60, but really - unless your climbing the Matterhorn, you should be in 5th anyway.

3rd is matter of preference. The 2.3 version carries a 1.50:1. I do not think there is any need for more gearing and can make a case for the 4.0 V6 ratio of 1.31. 3rd gear starts are not out of the question, just need a little clutch finese. I have accidently made them and instead of going to first, make on the fly adjustment.

Ditto for 2nd. 2nd gear starts will work unless your starting uphill.

Low, at 3.72, I'm convinced is just too damn low.

Overall, I think the 4.0 gears would be better. Here is how the 2.3 and 4.0 gears compare.

Gear - 2.30 - 4.0
First - 3.72 - 3.40
2nd - 2.20 - 2.05
Third- 1.50 - 1.31
Fourth 1.00 - 1.00
Fifth - 0.79 - 0.79

I don't recall your trans gearing, but if given the choice, go for gearing that looks more like the 4.0 ratios, especially if you use the 2.5. Even better would be to multiply the trans ratios by your final and compare the overall ratios.

For anyone thinking of using the M5R1 box, the 4.0 gears will drop into the Duratec case. But you will have to swap out everything. I think I would do that if I could find a cheap 4.0 box. Fat chance though.

Bill

 

[Bill Blue]

I simply could not rest, knowing that I had not gone beyond 34 degrees advance. Yes, that is normally considered to be the optimum, but there are so many things a person cannot investigate it makes no sense to not investigate where possible. So I returned to the "test track" and made runs up to 38 degrees (from 3000 rpms up) advance. No difference, plus or minus. I upped the 6000-7000 cell to 35 degrees, simply because of the big jump in performance from 33 to 34 and 38 did not harm performance. Maybe the wrong thing to do, don't know.

Bill

 

[RootesRacer]

Many newer engines will take timing even into the 40s, but at light load.

I myself sat down and got an Audi to cruise at nearly 45 degrees timing, while listening for det with amplified headphones.

That same engine though only needed 33 degrees at wide open throttle and atmospheric MAP pressure.

The correct procedure to set timing is to advance a single load point little by little while observing torque increase (acceleration in your case). When increasing half a degree doesnt change the torque output, you are at what is called the max brake torque point for that load.
OEMs usually find this point and back several degrees out just for safety to provide for bad gas and engine mechanical variation.
You can be safe with the timing at MBT only if you drive (reliably) with the same octane rating or better than what you tuned with.

If you feel you finally have a handle on tuning with my ECU, I would recommend taking me up on the firmware update offer so you can begin to tune ignition timing with more degrees of freedom than you presently have.

 

[Bill Blue]

I'm afraid further tuning by me would be performing brain surgery with an ax. Maybe a chainsaw. It is diffcult for me to detect improvement moving a degree at a time. For example, I did not detect any improvement in the 6000-7000 cell until spark had been advanced 2 degrees. Here are the seconds required to accelerate from 6000-6500, with one degree advance between runs:
2.7
2.7
2.4
2.4
2.3
2.1
2.2
1.9

There are too many variables and the measurements are too crude. Job for a dyno and someone who knows what they are doing. But I'm happy with what I have and will pursue it no further. I have established a baseline of Do It Yourself possibilities for the Duratec, both in the installation and performance, which was the purpose of this thread. As is, it appears to set the performance standard for Alpine engine swaps, so I think this is a good place to halt.

All this has been done using 87 octane gas, I will use 89 octane as insurance.

Bill