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Duratec 2.5 Revisited
- Thread starter Bill Blue
- Start date
DanR
Diamond Level Sponsor
Mr Bill, I'm proud of you....Power is, as the Rolls Royce people used to say, "Adequate". You say On your second gear run up the hill in front of your house, it got to 60 sooner than the car ever has and that was with my left foot firmly mashing on the brake, well that is very nice. When I had a short drive in your car Apr 2013 I thought it was exceptionally "swift".... Boy I'm waiting for a re-run (if you are still so kind?).
Barb is marvelous to allow you to drive her car
DanR
Barb is marvelous to allow you to drive her car
DanR
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Mr Bill, I'm proud of you....Power is, as the Rolls Royce people used to say, "Adequate". On your a second gear run up the hill in front of your house, it got to 60 sooner than the car ever has and that was with my left foot firmly mashing on the brake, well that is very nice. When I had a short drive in your car Apr 2013 I thought it was exceptionally "swift".... Boy I waiting for a re-run (if you are still so kind?).
Barb is marvelous to allow you to drive her car
DanR
Dan, as I drive the car more, I'm not so sure it quicker than it ever was. Some days, the old engine was incredibly powerful. But so far, the new setup is more consistently powerful. The strange thing, the power was always a Will of the Wisp thing. On a good day, maybe 30% of the time the power would be there. On a bad day, it was never present. Very frustrating. One thing I've noticed, you soon get used to the power and forget what the old performance was like.
Barb is a very sharing and gracious person. I'm sure a re-run would be no problem. Does this mean another Carolina Invasion is in the works?
Bill
Update.
Tuning has progressed very slowly, the process is hindered by my ability to assimilate the Megasquirt tuning process. The main thrust has been toward low rpm power and smoothness, mostly smoothness. Some highlights:
I've always been plagued by a "cough" at about 1500 rpm. Most visible while driving round town. You know the drill - slow down to turn the corner, downshift to 3rd, accelerate at a moderate rate back up to 30 or so. Only it would be "downshift to 3rd, accelerate (cough) to 30". Very annoying. At long last I discovered it was caused by a spark deficiency. Had to chase the dwell all the way to 3.5 ms in order for it to go away entirely. But its gone!
The spark advance is pretty flat until 1500 rpm. Just seems to be smoother and more predictable. Low rpm power is very good. So good that it got me to thinking about a Top Gear episode in which a car (can't remember which one) was accelerated from 0 to 130(or there about) in one gear. So I gave it a try. It so happens that on level ground, a 4th gear start is no real trick, can do it without exceeding 1000 rpm, and the engine will accelerate smoothly from there. With the current gearing and redline, that means 0 to 120 in one (4th) gear. Not too shabby! It also means that low gear (3.73) is far from optimum, but it will just have to do. If the tranny is ever rebuilt, it will be with the 4.0 trans ratios, which give a 3.40 low. Not perfect, but better.
Midrange power is very good. At the current tune, using my usual shifting technique, the rear wheels give a good chirp shifting into 3rd. The 2.3 engine was not really able to do that after I switched to the 185 - 15 tires.
While Tuner Studio will tune the engine throughout the RPM range to my specification, it has to run under the appropriate load to do so. Rather than repeatedly revving to 80 in 3rd, I tried applying the brake while in 2nd, which allows full rpms at slightly less than 60. Good idea, but less than perfect. In cool (low 80's) weather the rear tires start spinning at about 3500. This is in large part, caused by the front/rear brake bias, but still some impressive power at work. Waiting for some warmer weather to try again, this time on a stouter hill.
All this is without VVT. I had read how the engine would be a gutless turd in midrange without the VVT. ABSOLUTELY NOT TRUE. I'm thinking the VVT is used to control emissions and improve gas mileage. But I will eventually turn it on and see what it does do.
Bill
Tuning has progressed very slowly, the process is hindered by my ability to assimilate the Megasquirt tuning process. The main thrust has been toward low rpm power and smoothness, mostly smoothness. Some highlights:
I've always been plagued by a "cough" at about 1500 rpm. Most visible while driving round town. You know the drill - slow down to turn the corner, downshift to 3rd, accelerate at a moderate rate back up to 30 or so. Only it would be "downshift to 3rd, accelerate (cough) to 30". Very annoying. At long last I discovered it was caused by a spark deficiency. Had to chase the dwell all the way to 3.5 ms in order for it to go away entirely. But its gone!
The spark advance is pretty flat until 1500 rpm. Just seems to be smoother and more predictable. Low rpm power is very good. So good that it got me to thinking about a Top Gear episode in which a car (can't remember which one) was accelerated from 0 to 130(or there about) in one gear. So I gave it a try. It so happens that on level ground, a 4th gear start is no real trick, can do it without exceeding 1000 rpm, and the engine will accelerate smoothly from there. With the current gearing and redline, that means 0 to 120 in one (4th) gear. Not too shabby! It also means that low gear (3.73) is far from optimum, but it will just have to do. If the tranny is ever rebuilt, it will be with the 4.0 trans ratios, which give a 3.40 low. Not perfect, but better.
Midrange power is very good. At the current tune, using my usual shifting technique, the rear wheels give a good chirp shifting into 3rd. The 2.3 engine was not really able to do that after I switched to the 185 - 15 tires.
While Tuner Studio will tune the engine throughout the RPM range to my specification, it has to run under the appropriate load to do so. Rather than repeatedly revving to 80 in 3rd, I tried applying the brake while in 2nd, which allows full rpms at slightly less than 60. Good idea, but less than perfect. In cool (low 80's) weather the rear tires start spinning at about 3500. This is in large part, caused by the front/rear brake bias, but still some impressive power at work. Waiting for some warmer weather to try again, this time on a stouter hill.
All this is without VVT. I had read how the engine would be a gutless turd in midrange without the VVT. ABSOLUTELY NOT TRUE. I'm thinking the VVT is used to control emissions and improve gas mileage. But I will eventually turn it on and see what it does do.
Bill
DanR
Diamond Level Sponsor
Mr Bill,
You said: "I've always been plagued by a "cough" at about 1500 rpm. .... But its gone!"
Now that is an accomplishment we all could hope for!
My Sv 1725 dual Strombergs will cough (when the engine is cold) without the choke.
As soon as IT WARMS A BIT, EVERYTHING IS GREAT.
I might be having a memory lapse or otherwise faulty, But it seems I had a 2:20 1st gear in a T10 behind my '58 Impala with the 425HP I implanted back in '62. The rear was a 4:56 posi.... Also at times I would swap the T10 2:20 to a 2:54 and the rear end to a 3:55 for travling. What would be wrong with gears similar to that in an Alpine with the 3:89?
You said: "I've always been plagued by a "cough" at about 1500 rpm. .... But its gone!"
Now that is an accomplishment we all could hope for!
My Sv 1725 dual Strombergs will cough (when the engine is cold) without the choke.
As soon as IT WARMS A BIT, EVERYTHING IS GREAT.
I might be having a memory lapse or otherwise faulty, But it seems I had a 2:20 1st gear in a T10 behind my '58 Impala with the 425HP I implanted back in '62. The rear was a 4:56 posi.... Also at times I would swap the T10 2:20 to a 2:54 and the rear end to a 3:55 for travling. What would be wrong with gears similar to that in an Alpine with the 3:89?
Dan, my cough was present under all condition - hot, cold, in between. Tuned rich, tuned lean. Timing made no difference. The only thing that worked was spark intensity. The surprising thing to me is when the cough would appear: Moderate throttle at low rpm. Who would of thought that set of conditions would require maximum spark?
What would be wrong with a 2.20:1 low gear with a 3.55 rear? Lots. I am running a 3.80 and second gear is 2.20. The tires are 24", so the overall rear ratio is probably pretty much like a 3.55 running smaller tires. While second gear starts are no big deal, I never do it. The 3.73 low is just so much better suited for the job. More important, low is used for more than launching the car. Things like creeping along in traffic and parking. A 2.20 low gear just sucks when used for those things.
I really don't see how the 2.20 low does anything to help. You still are stuck with the 1:1 top gear, all you've gained is a difficult to live with low gear. But the 3.55 would be of considerable benefit. At times when running the 3.55 I would drive in 4th just for the experience. Not bad. A little revy, but with a larger tires, very livable.
Bill
What would be wrong with a 2.20:1 low gear with a 3.55 rear? Lots. I am running a 3.80 and second gear is 2.20. The tires are 24", so the overall rear ratio is probably pretty much like a 3.55 running smaller tires. While second gear starts are no big deal, I never do it. The 3.73 low is just so much better suited for the job. More important, low is used for more than launching the car. Things like creeping along in traffic and parking. A 2.20 low gear just sucks when used for those things.
I really don't see how the 2.20 low does anything to help. You still are stuck with the 1:1 top gear, all you've gained is a difficult to live with low gear. But the 3.55 would be of considerable benefit. At times when running the 3.55 I would drive in 4th just for the experience. Not bad. A little revy, but with a larger tires, very livable.
Bill
Mileage
Just got back from a 950 mile tour with an old car group. We averaged 33.67 mpg. This was was very mixed driving, but predominately 50-60 mph. Two adults, luggage, top up, spare tire, tool box etc. A number of jackrabbit starts (gotta have fun) and about 75 miles of 70+ freeway cruising. But all in all, about the best we can expect.
This is as good as what we got with the 2.3. So the increased smoothness and power does not carry a down side.
Bill
Just got back from a 950 mile tour with an old car group. We averaged 33.67 mpg. This was was very mixed driving, but predominately 50-60 mph. Two adults, luggage, top up, spare tire, tool box etc. A number of jackrabbit starts (gotta have fun) and about 75 miles of 70+ freeway cruising. But all in all, about the best we can expect.
This is as good as what we got with the 2.3. So the increased smoothness and power does not carry a down side.
Bill
Bill, every time I read a new post about your Duratec exploits, I wish it were 80-85% easier to do. I'm still fascinated by the fact that you fabbed an intake manifold, not to mention all the other stuff. I'm always impressed.
33.67mpg and bags of fun? That's the dream.
33.67mpg and bags of fun? That's the dream.
Greg, if it were possible to install one of these things without modding the starter and the cross member, I would probably be thinking about a kit. But as they say, "It is what it is". A difficult, involved installation.
In the meantime, I'd like to see some one try a N/A Nissan 2.4. Looks to be a lot easier engine to work with and the same potential. Tom Hall had a turbo 2.4 at the SUNI. The turbo 2.4 looked easier than the N/A Duratec. But that may be due to Tom's talent.
Bill
In the meantime, I'd like to see some one try a N/A Nissan 2.4. Looks to be a lot easier engine to work with and the same potential. Tom Hall had a turbo 2.4 at the SUNI. The turbo 2.4 looked easier than the N/A Duratec. But that may be due to Tom's talent.
Bill
The Price of Perfection
We just got back from a funeral in Michigan. One of the guys there works in a shop that builds high dollar cars. He had a magazine with a cover photo of a pickup that he said he built. Cost of the build, about $220,000. We had driven the Alpine, so I asked him to look at it and give me some idea what the engine work would cost if done in a first class garage. He was very hesitant until I told him just the engine, not anything else and that I was not wanting an estimate, or having any work done. Just wanted some idea of how much the job would cost if done right by pros. So he agreed.
When I popped the hood, he expressed surprise at what he saw and immediately said that they usually do swaps for $10,00 - $15,000. Then as he gave the engine a harder look, the price started to go up. Noting the complexity and tightness of fit - the estimate went to $20,000, then $25,000 if I supplied the car and the "big" parts.
The interesting part was his description of how the car would have to be built. Essentially the same way I had. Make a mockup of a part, trial fit, redesign, retry, modify, refit. He said it is common for a part to be bolted to the engine 10-15 times before it is sent out for finish and powder coat.
The only difference between his description and my experience: A couple of weeks after applying the finish I discover the part is in the way of the next part and has to be thrown away and a new part designed.
But anyway, there it is. 25 Grand to install your Duratec into your Alpine. First class job.
Bill
We just got back from a funeral in Michigan. One of the guys there works in a shop that builds high dollar cars. He had a magazine with a cover photo of a pickup that he said he built. Cost of the build, about $220,000. We had driven the Alpine, so I asked him to look at it and give me some idea what the engine work would cost if done in a first class garage. He was very hesitant until I told him just the engine, not anything else and that I was not wanting an estimate, or having any work done. Just wanted some idea of how much the job would cost if done right by pros. So he agreed.
When I popped the hood, he expressed surprise at what he saw and immediately said that they usually do swaps for $10,00 - $15,000. Then as he gave the engine a harder look, the price started to go up. Noting the complexity and tightness of fit - the estimate went to $20,000, then $25,000 if I supplied the car and the "big" parts.
The interesting part was his description of how the car would have to be built. Essentially the same way I had. Make a mockup of a part, trial fit, redesign, retry, modify, refit. He said it is common for a part to be bolted to the engine 10-15 times before it is sent out for finish and powder coat.
The only difference between his description and my experience: A couple of weeks after applying the finish I discover the part is in the way of the next part and has to be thrown away and a new part designed.
But anyway, there it is. 25 Grand to install your Duratec into your Alpine. First class job.
Bill
Bill, I think you are missing some very important items. Where do I find someone willing to pay $25,000? More important, where do I find the talent to make a $25,000 installation? Or even a $10,000 installation? Or the ambition to build even another "Basement Special?"
It sort of like a friend use to say "If we had some ham we could have some ham and eggs if we had some eggs."
Bill
P.S. Bill, I posted this to give guys some insight into the complexity of one off installations and the cost of a "pro" quality job. In other words, the difference between my car and yours. YOU are the one that needs to open a shop.
Bill
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