Transmission options.

[sarguy01]

Originally Posted by Mista Bone

Straight transmission swap, no tuning involved. I was just learning how to rebuild these trannys and made a few mistakes as well as trying different ratios. One year (2000 or 2001) I was swapping transmissions about every three weeks. The tune that Blundar (David Blundell - Tuner) used was a best guess first shot, there was more there but 10-12 much was unknown about the limits of the tuning.



soD: either low rpm like most prefer on here or a higher more normal rpm like I prefer both require the same amount of fuel when cruising at same speed in same car on the highway. The advantage of the higher rpm is if you have to pass someone, like a 18 wheelers doing 55 mph and cars are allowed 65 mph. To make that pass I had to use less throttle input. With longer gears you will have to use more fuel to safely overtake, same thing if on a hill or a stiff headwind.

Sounds like a good candidate for drafting...why pass??

[sarguy01]

Originally Posted by Mista Bone

Old Mech: pgfpro = rrussel on another forum we are on. I'm transzex on that forum...

I did some FE testing 64.8mpg - D-series.org



Performance AND Economy, aka have your. cake and eat it too.

I recall that rrussel was on here? Or at least his thread was linked on here before. He was running a turbo and using premium fuel.

How did he come up with 64.8 mpg?? I didn't go through the thread, but I would love to know how he came up with that number. (I am not trying to be rude, just curious. Was 64 mpg consistent from fill to fill??)

Plus, how much did he spend on that car, just on parts? Turbo, tune, exhaust, engine, all of the nuts and bolts...$3,000? $4,000? The payback is a really long time, like 250,000 miles for $3,000. Yes, you get a turbo car and the fun that goes with it, but most people aren't going to spend $3,000 for 64 mpg, when that car was probably getting 45-50 mpg stock.

[user removed]

I read through about 7 pages of the thread. His mileage figures were based on a minimum 200 miles trip with no stop and go, at lower than 60 MPH (did not say how much lower) with one cold start.

Most of his gains were from running lean mixtures with IAT temps at around 120 degrees. I did not read far enough to see if he swapped out the tranny, think he was using stock DX tranny and ratios.

I doubt that he would have seen higher mileage with a VX tranny and I did not read through the whole thread to see if he ever swapped one in his car.

I owned a VX that I purchased totalled in 2008 and rebuilt. The car was a time capsule, stored in an insurance training center andused to train adjuster in writing estimates. Built in August 1993 it was a 94 Federal model. It had 27,492 miles on the odometer when I got it. Still had the original tires, even the original wiper blades.

My best tank (not really a full tank) was driving from Willaimsburg to Chantilly Va and back. Temps in the 80s.

300 miles on 4.627 gallons of fuel (from memory almost 6years ago), 68 MPG and I averaged right at 64 MPH. About 30 milesof that was stop and go and the return trip was at night.

I can see how his results are probably true and possibly accurate. His testing parameters are nothing near real world. Under the same conditions my Fiesta would average 55 MPG in stock condition.

Mista Bone, you made a statement that fuel economy is not dependent on engine speed.
I disagree with that statement. Every engine has it's sweet spot asfar as efficiency. This has been proven in dyno testing going back decades. Take a 2.5 liter GM 4 cylinder engine load it with 20 hp on a dyno, use the fuel consumption as your basis at 1. Now increase the load to 50 hp. While your power generation increased by 150% your fuel consumption only in creased by 50%. Theadditional 30 horsepower generated only cost half again as much fuel as the first 20 hp. This is the basis of higher efficiency.

regards
Mech

[user removed]

I split this post into two parts so I would not loose it altogether. I used to lean out Z cars with the first fuel injection 75-78. My 1976 had no cat or egr and it was emissions legal.

At the time Federal law imposed a $10,000 fine for emissions tampering and $2500 for owner emissions tampering. A law seldom enforced but something every dealer or shop knew could shut them down in a heart beat and have their customers cars confiscated as evidence.

The reason lean burn died was NOX emissions. California VXs had no lean burn and their mileage drop was considerable compared to Federal lean burn versions.

I can understand your position on lower final drive ratios after reading the linked thread or at least part of it. If i need to pass another vehicle I just downshift, get the job done and get back into top gear.

You should read up on Transonic Combustion. They have a patented injector design that uses supercritical (450 degrees f) heated fuel at 3000 PSI pressure that once the engine is warm ignites upon injection without any spark. It is multi fuel capable and I believe it is the current eveolution of old Smokeys work decades ago. It just took that long for technology to catch up with his theorey in a way that is practical and safe.

It's soo good that engine out exhaust gasses require no emissions controls whatsoever.
Truly a homogenous mixture that does not even reach peak combustion temperatures where NOX formation begins and it only needs a spark plug to warm up.

http://www.tscombustion.com/

regards
Mech

[user removed]

On the 280 Z you could adjust the spring loaded flap on the air flow meter. Increase the spring tension and the car ran lean. Then add a rheostat in the water temp circuit that fooled the ecu into thinking the water temp was lower than it actually was. Mount the rehestat in the dash and you had dash adjustable mixture control by simply turning the knob.

This was in the late 1980s. At the time fuel economy was not much of a consideration.
Under the same (or close to it) conditions one car mag tested the 84 Crx 1.3 and got 73 MPG at 55 MPH. That CRX was bone stock. I bought a 1.5 CRX brand new The serial number was 1015, built in July 83, first months production. I was 32 when I bought that car. I averaged 44 MPG in that CRX for 50,000 miles, even commuting to work in Washington DC area traffic.

Based on the difference in cost of fuel (premium versus regular) in my area drivng my Fiesta under the same testing scenario as pgfpro my cost per mile would be very close to the same he achieved factoring in the cost difference between premium and regular fuel.

The differenceis his car is technically (based on my understanding of the legal situation) illegal, while mine is stock, passes current emissions and it is also an automatic, which my wife can drive if she had to.

This is not meant as an argumentive post. In my opinion it is a rational comparison of two cars, one totally stock with higher pressure tires, sidewall max at 44 PSI not 55-60 which I consider dangerous (his pressure). I run the cheapest regular gas I can find regardless of the source. Last tank with credit card discount was $3.049 a gallon.

regards
Mech

[sarguy01]

Originally Posted by Old Mechanic

I read through about 7 pages of the thread. His mileage figures were based on a minimum 200 miles trip with no stop and go, at lower than 60 MPH (did not say how much lower) with one cold start.

Most of his gains were from running lean mixtures with IAT temps at around 120 degrees. I did not read far enough to see if he swapped out the tranny, think he was using stock DX tranny and ratios.

I doubt that he would have seen higher mileage with a VX tranny and I did not read through the whole thread to see if he ever swapped one in his car.

I owned a VX that I purchased totalled in 2008 and rebuilt. The car was a time capsule, stored in an insurance training center andused to train adjuster in writing estimates. Built in August 1993 it was a 94 Federal model. It had 27,492 miles on the odometer when I got it. Still had the original tires, even the original wiper blades.

My best tank (not really a full tank) was driving from Willaimsburg to Chantilly Va and back. Temps in the 80s.

300 miles on 4.627 gallons of fuel (from memory almost 6years ago), 68 MPG and I averaged right at 64 MPH. About 30 milesof that was stop and go and the return trip was at night.

I can see how his results are probably true and possibly accurate. His testing parameters are nothing near real world. Under the same conditions my Fiesta would average 55 MPG in stock condition.

Mista Bone, you made a statement that fuel economy is not dependent on engine speed.
I disagree with that statement. Every engine has it's sweet spot asfar as efficiency. This has been proven in dyno testing going back decades. Take a 2.5 liter GM 4 cylinder engine load it with 20 hp on a dyno, use the fuel consumption as your basis at 1. Now increase the load to 50 hp. While your power generation increased by 150% your fuel consumption only in creased by 50%. Theadditional 30 horsepower generated only cost half again as much fuel as the first 20 hp. This is the basis of higher efficiency.

regards
Mech

In reality, he made the car a lot faster, but the mileage stayed about the same.

[California98Civic]

Originally Posted by Mista Bone

The big thing is, I'm allowed to easily play with the engine tuning parameters, 96 and up it is not so easy. Now if you could, you could see some gains.

So you have the Russel car? He sold it after building it. You have that car? Now I get your point. You made a faster car that gets about the same fuel econ under freeway conditions as a lean burn v-tec-e engine might. I have looked into chipping, but as you know, OBD2 does not have the options in the aftermarket world that the OBD1 has. Still, though I lose timing if I want "power" to pass something, I can get the power I had in fourth on my old DX transmission simply by dropping to third in my current VX/CX tranny. Fortunately, I have no interest in passing. I like the draft. In warm weather, I easily cruise at steady state 60mph with 60+ mpg averages over scores of miles. Drafting (not too close) I'll top seventy mpg at 60 or even 65mph, easily. But it is true I do not have the power/mpg flexibility options you describe. My car is all about high high fuel economy of the cheap and within the range of my modest skills.

[Mista Bone]

I do NOT have his del Slow, although my Civic HB was the same color as his Sol

In my driving I was averaging 67-70 mph (70-73 mph) indicated, mostly on I-75 between Detroit and Cincy.

Above a certain ambient temp the ECU starts to use less timing as an overkill measure to protect the engine. This kills performance and MPG, well it did in my testing with THAT tune. Normally my drives were at night to avoid the mid day heat.

Knowing what I have done with my old car, reading what pgfpro has done, as well as what I'm learning on here, if all that info was combine into one car....yeah.

But drop the hammer and the car isn't boring anymore. I drag race and autocross for fun.

With OBD-2 you can convert back to OBD-1 to be alble to tune....unless you are in Cali with the smog Nazi's. Thing is I'm putting out less pollution per mile even if NOx numbers are slightly higher (ppm) they end up lower (ppM) per Mile driven.

[Ecky]

Very interesting thread.

Not exactly in direct response, but a bit about my experiences with RPM and the like:

I have a Del Sol with a B18A1 (92-93 cams, peak torque at 5200RPM, same as B1) mated to a 92-95 B16A3 (Y21) transmission. At ~35MPH, shifting from 4th to 5th (2800RPM -> 2100RPM) results in going from about 33MPG to 47MPG. Similarly, at 75MPH, shifting from 4th to 5th (5200RPM, point of peak torque -> 4000RPM) results in a change from around 23MPG to 33MPG. I don't have a vacuum gauge, and perhaps my gearing is past the supposed point of returns for shorter gearing, but without ECU modifications, I would without a doubt be better served with taller gearing.

As an aside, I get pretty much constant fuel economy starting at around 48MPH up to nearly 65MPH.

Are you implying that playing with my timing and AFR would have equal impact to taller gearing? Also, at what point is shorter gearing too short?

[Mista Bone]

You should be using the GSR 5th but with ECU tuning you can get by with the higher rpms. LS motor with bigger bore is happier at a lower cruising RPM, but that is getting into some engine dynamics that isn't understood here.

Imagine doing 70 mph in 4th gear and getting 47+ mpg.

Vacuum gauge and driver mod is the first and best gains, then ECU tuning.

Myself I tend to use very light throttle, enough to pulled to 3500 rpm, then shift to next gear while not lifting off the gas pedal.

I hope to set up a video camera in the car to show how I drive the CRX and my old HB, then maybe others will understand.