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1989 Sport Roof White Pkg 7M-GTE + mods
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Discussion Starter · #61 ·
As you said tuning tools are getting easier and smarter as the years go on also.
The hard part is going to be tuning for drivability in all the areas or scenarios you can imagine.
The harder part is when you encounter drivability problems or scenarios you never imagined.
To have a comfortable and reliable daily driver you need all these bases covered.
This shouldn't be that hard. The stock tuning should cover the parts I didn't optimize. The part I need to optimize is pretty straight forward. My house is about 65 feet above sea level. My office is 13 feet above sea level. My drive is 55 miles one way. The only "hills" of which there are three are highway overpasses. 35 of the miles are on a highway with no stoplights or signs. The rest of it has five stop lights. (I drive in rural-ish country. I see cows and fields of crops every day on my drive.)
 

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I don't want an MK4!
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I could not even read the rest of this (after the 1st 20).. Have got to the part where he says I don't need the vaccine because "reasons"
 

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In 1986 that was true. We have knowledge and technology today we didn't have back then. Injectors are a great example. Also, Toyota didn't plan on someone daily driving an A70 like a Camry. I need to optimize my car from idle to ~2400 rpm. I spend so little time above that it only has to be in the ball park.
Unfortunately for you, that area below 2400rpm is the hardest to tune if you want to strike the perfect balance :p Getting it to pull nice and safe from there on WOT/on boost, takes only a handful of pulls.

If you're on 264 cams I wouldn't expect massive economy to be honest. You're throwing low RPM volumetric efficiency in the dumpster in exchange for an increase higher up.

That doesn't mean you can't improve it notably, 18mpg is pretty dismal. What's your complete setup list?
 

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1989 Sport Roof White Pkg 7M-GTE + mods
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Discussion Starter · #64 ·
All the details from the original listing are in my profile. If there is something left out ask and I will learn what it is.
 

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Taller gears are important here as well. Not sure what rear end you have but for your driving use case you ever to keep that highway speed rpm as low as possible. Something wrist to look at.
 

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1989 Sport Roof White Pkg 7M-GTE + mods
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Discussion Starter · #66 ·
I have a lot to change. I am sure my 245 front and 275 rears are not helping. Going back to OEM 225’s is my next car modification. That should reduce the mass of rim+tire the engine has to rotate.
 

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This shouldn't be that hard.
it is one of the hardest actually.

Care to take a guess at the time and resources the OEM sink into doing just that?

It is numerous TEAMs.

the list;
Data Aquisition
Testers/Validators
Hardware Engineers (incase they need to revist what they created due to latencies)
Software engineers (programmers that work along side the hardware engineers)
Engineers that designed the many parts of the car; Suspension, engine, chassis, comfort etc.
Drivers
Controlled environments (such as the subzero cold chambers to test negative starting).
I will not even include Supply chain teams which are many, and other none tech related folks.

When time spent between each team member and all the teams are added together, it quickly turns into years of equivalent man hours just to get the car to behave the way it does (and I am talking of back then, now it is even worse due to all the security, and interconnection that happens between subsystems. Almost exactly like in the aviation world).

Then of course the part that really counts,$ .I actually did an exercise on this on another post with some generous, albeit impossible numbers to reach.

Just using a 2 person per team and a single year. The tally came out to 5 million dollars just in R&D.

The probability of a single person doing that same work in the same time frame is none existent.
 
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Figgie gets it.

I use laboratory chambers / dyno's here in my line of work.
The line item cost / purchase orders are so high I can't comment.

I also used to run a 2nd shift vehicle dynometer (cash crop tractors). Power testing / climate controlled chamber, hot vs. cold vs. humidity ect... Endless combinations.
Just the amount of fuel used alone was astronomical.
Excluding the time, engineers and overhead.
 

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Discussion Starter · #69 ·
So I just learned that ECUs are expensive. Having never bought one I was guessing several hundred, not a couple thousand. I can get a used UZ1 from an SC400 for under $1,000, which is my future plan. I would be better off to save the $2K+ it will cost to buy the ECU plus all the time it will take to install and tune it for my eventual swap to a V8. It looks like my mods will have to stop short of a new injection map.
 

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90T
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I think many of you miss the point that its not the ECU hardware that is driving efficiency, it is the accuracy of the engine characterization and specifically the ability to model the engine behavior and translate that to optimum fuel and ignition events. Today, like 30 years ago, there are only two relevant output variables from an ECU which are fuel injector duration/timing and ignition dwell/timing. That part has not changed. Any ECU can calculate those two parameters with precision far beyond what a carb and distributor could do years ago.

Now you could argue that valve timing is also part of the mix since any modern engine has that now and it certainly plays an important role in efficiency, but the 7M doesn't have it, just another reason why a 30 year old design will never reach the same levels of efficiency as a modern engine, so its not relevant here.

Replacing the TCCS with a standalone will almost certainly be a step back in efficiency. First, the TCCS has millions of dollars of dyno time baked into it. The code was written in assembler so that while the hardware may not be as capable, the software is extremely light and makes up for the 20 MHz clock rate to give you ignition and fuel updates for every power stroke. The TCCS code is full of tables of corrections for temperature, load, altitude, knock, voltage, and so on. Those tables were based on meticulous measurements over all the expected operating parameters of the car, not just room temperature at your local tuning shop. The ignition and fuel enrichment maps are full of bumps and dips that took thousands of measurement to determine. All of this translates into extracting as much performance as they could out of the engine. Good luck improving that with your $1000 "tune".
 

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Replacing the TCCS with a standalone will almost certainly be a step back in efficiency. First, the TCCS has millions of dollars of dyno time baked into it. The code was written in assembler so that while the hardware may not be as capable, the software is extremely light and makes up for the 20 MHz clock rate to give you ignition and fuel updates for every power stroke. The TCCS code is full of tables of corrections for temperature, load, altitude, knock, voltage, and so on. Those tables were based on meticulous measurements over all the expected operating parameters of the car, not just room temperature at your local tuning shop. The ignition and fuel enrichment maps are full of bumps and dips that took thousands of measurement to determine. All of this translates into extracting as much performance as they could out of the engine. Good luck improving that with your $1000 "tune".
That is very true, however, it only stays true as long as the powertrain is completely untouched.
 

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The fine print says premium gas. If you try to run regular or mid it will feel like you are dragging a ball and chain. I got a tank of bargain price gas that was supposed to be premium (Murphy Oil at Walmart) I could tell right away that it was not premium. I added a bottle of octane booster to get through it and never went back.
 

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Discussion Starter · #73 ·
The fine print says premium gas. If you try to run regular or mid it will feel like you are dragging a ball and chain. I got a tank of bargain price gas that was supposed to be premium (Murphy Oil at Walmart) I could tell right away that it was not premium. I added a bottle of octane booster to get through it and never went back.
I am doing an experiment right now with different octane levels of gas. I've been driving with 87. I am going to do five tanks each with 87, 89 and 93 of Shell capturing MPG and miles per dollar. I am on tank three of 87 but look forward to the higher grades.
 

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man I would love to data log your knock sensors on that test ....
so what if 87 is the lowest cost per mile if your knock sensor lights up 500 times on the drive VS 50 on 93 octane. a fair answer to that is so what, I don't beat on my car so it will last longer anyway (not meaning to be critical here at all just barfing out ideas / brainstorming...)

I bet one of those colorado/jeep tiny diesel engines would get fantastic mpg--and your in texas right so that makes even more sense right ?

swapping electronics to a faster better CPU / w more features (sequential / cop) coupled with a more modern engine with better combustion chamber design and lighter components ...thats the win. and why not use oem parts if performance goals are secondary to efficiency
 

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Discussion Starter · #75 ·
man I would love to data log your knock sensors on that test ....
If there was some way to log data I would love to do so. I am an engineering nerd at heart. I drive the Supra for the physical platform, not the performance, so there are all sorts of things I would try if I had the money. I can spend on mods & repairs but complete engine replacements is beyond that.
 

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90T
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That is very true, however, it only stays true as long as the powertrain is completely untouched.
Yes and no. Efficiency is defined almost entirely by the low load performance which is largely determined by combustion chamber design and low flow characteristics inherent to the head design. Those don't see much change even with aggressive mods to intake and exhaust components because the throttle valve is the limiting variable. Additionally, the long times between low rpm fuel pulses means there is little impact from changes in spray pattern. Changing injectors is not going to give you a 50% bump in fuel economy as someone proposed. You will need to go to direct injection to see any impact.
 

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Very interesting thread. I just don't understand why anyone would care about fuel economy on a Supra, other than to realize that if it drops significantly then you probably have other issues.

With that said, when I can get 40mpg out of my Accord (not hybrid), I am happy because I drive 25 to 30K a year for my business.

I used to get about 28 on the freeway (Supra) until I started doing stuff. Then it went lower but was consistent.

The higher octane is a no brainer. What if you forget you are cheaping out on fuel and actually drive the car and use the power that Toyota gave you.

I too, would like to see the KS info, I would assume it is some sort of 0-5 volt reading but do not know for sure. Everything else seems to be.

Not judging, just wondering.
 

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We have a 2000 LS400. It easily nets 30mpg highway. Bone stock, yet it cruises effortlessly, and has all the power I'd need, if / when I want it.

A friend of mine has a Tesla S, it gets around 100mpg-e. Bone stock, yet it also cruises effortlessly, and it actually has a very respectable amount of power.

The biggest difference between these cars? Both were bought used, the Tesla was about 10x the cost. Can buy an awful lot of premium fuel with that difference...

My point is, is the cost of an engine swap or all these other ideas worth it? I mean, at $4/gallon, I could see it eventually paying off, given the OP's driving habits, but I wonder if the value is in the experiment itself? If so, carry on, and post up results! If the end goal is simply to save money, there are easier ways to do it.

On the subject of rolling stock, stock wheels are HEAVY. Do they act somewhat like a flywheel? If so, there might be some benefit to keeping them stock. If not, I'd highly recommend a set of RPF1's, to drop about 9 lbs off each corner. I do that on my cars for suspension and ride quality reasons, but it also makes tire swaps and maintenance easier.

Also, just gonna leave this here...

 
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Knock monitoring is not a 0v-5v signal...

Is it sound converted into low level ac waveform.

To log knock requires either a seperate standalone knock box such as;

Plex knock monitor v2

Link Knock Block

TunerNerd knock monitor pro

Standalone teed off knock sensor/s while oem still control everything.

Might be others out there but this is a start.
 
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Knock monitoring is not a 0v-5v signal...

Is it sound converted into low level ac waveform.

To log knock requires either a seperate standalone knock box such as;

Plex knock monitor v2

Link Knock Block

TunerNerd knock monitor pro

Standalone teed off knock sensor/s while oem still control everything.

Might be others out there but this is a start.
Man, I have to say I always admired your knowledge and, how do I say, explaining shit to the rest if us and not acting like we (me) are complete idiots.

Now I just briefly looked and will look more but it indicates that the package includes a new KS.
And this will work on out cars?
Does this replace OEM or just give you another KS that can be logged. I have a ZT2 and I like logging stuff and poring over the data later.
Strange I guess.

Thanks

Dan
 
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