Honda DPFI vs MPFI...

[james92se]

Originally Posted by bobski

The Si transmission is hurting your highway milage... It's likely costing you 8-10 MPG compared to the DX gearing, but that doesn't mean there's no room for improvement. Which intake manifold and ECU did you use?

I'm not really sure what the intake manifold is, I got it off some kid on Honda-Tech. IIRC it's from a 91 Si but I'm not certain. Why do you ask though? Is there a difference? The ECU is a PM6

Originally Posted by aalb1

I saw your garage on how you said "Virtually a brand new car!" It's great that your saving a EF since they are getting way more scarce these days. If you invested so much in restoring this car and you are doing 90% highway driving, my suggestion is swap the SI 5th gear to an hf 5th gear. You'll keep your first through fourth for acceleration purposes but have lower rpm's for cruising... best of both worlds!

Hmm I never thought of that. How much work is that, exactly? I don't remember what my old DX transmission was revving at on the highway, but the Si transmission seems to be perpetually 3000+RPM on highway driving and I'm not sure the d15b2 likes that too much FE wise.

[GasSavers_bobski]

Originally Posted by james92se

IIRC it's from a 91 Si but I'm not certain. Why do you ask though? Is there a difference?

Yes, there is some variation in runner and plenum size, but I'm not sure how much it affects FE.

[guest001]

Originally Posted by bobski

To add to the stuff you mentioned, 4 years of advancements in computing hardware and electronic engine management.
The ECUs used in '88-91 Civics and CRXs were designed in the mid eighties... The amount of computing power you could fit in that metal box (with a reasonable price tag) was fairly limited. The additional years of development would allow for faster, more complex computing hardware, running superior software, yielding more precise and efficient results.

I read somewhere on Automotive Repair Reference Center, which is a repair database w/ service literature like ALL DATA that states that both the 88-91 and 92-95 computers are both equipped with an 8 bit microprocessor.

[GasSavers_bobski]

Originally Posted by guest001

[...] both the 88-91 and 92-95 computers are both equipped with an 8 bit microprocessor.

Desktop computers made the same transitions that processors in automotive applications have... 8 to 16 to 32 to 64 bit. Are you suggesting that, within one of those groups, the processors introduced at the beginning of development would be just as powerful as those released later on? Developments in architecture and/or maximum clock speeds can make big differences in processing power, without messing with the bus size.
It wouldn't surprise me if both ECUs had 8-bit processors... A more powerful processor probably would have been excessively expensive and just plain overkill. I doubt even the ECUs sold in new cars use anything beyond a 16 bit processor.

[theholycow]

Originally Posted by guest001

I read somewhere on Automotive Repair Reference Center, which is a repair database w/ service literature like ALL DATA

For those not familiar with it, ARRC is free of charge for use at many public libraries or by library members for use at home. Check your library's website, look for something about online databases or online reference, and look for either ARRC or EBSCO (EBSCO is the company that provides ARRC).

[guest001]

Originally Posted by bobski

Desktop computers made the same transitions that processors in automotive applications have... 8 to 16 to 32 to 64 bit. Are you suggesting that, within one of those groups, the processors introduced at the beginning of development would be just as powerful as those released later on? Developments in architecture and/or maximum clock speeds can make big differences in processing power, without messing with the bus size.
It wouldn't surprise me if both ECUs had 8-bit processors... A more powerful processor probably would have been excessively expensive and just plain overkill. I doubt even the ECUs sold in new cars use anything beyond a 16 bit processor.

The 88-95 systems are referenced in there fuel and ignition systems in the same section. They do mention the only thing that has change was some evolutionary changes and ecu is now called a pcm. whatever that means. I'll have to find all the relevant data and post it. I'm not really saying anything. I can't read a manufactures mind. I'm just stating some facts.

Originally Posted by theholycow

For those not familiar with it, ARRC is free of charge for use at many public libraries or by library members for use at home. Check your library's website, look for something about online databases or online reference, and look for either ARRC or EBSCO (EBSCO is the company that provides ARRC).

If you didn't know, your *** better call somebody. It's AWESOME!!!!!!!!

[thisisntjared]

Originally Posted by guest001

I'm not really saying anything.

.... then why are you posting anyway, car computers dont need more instructions sets.

[aalb1]

Originally Posted by theholycow

For those not familiar with it, ARRC is free of charge for use at many public libraries or by library members for use at home. Check your library's website, look for something about online databases or online reference, and look for either ARRC or EBSCO (EBSCO is the company that provides ARRC).

hmm my library didn't come up with anything on a websearch. I'll check next time I am actually in there.

So how detailed is this?
All City Data/ Helms detailed?
Or Haynes/Chilton detailed

[theholycow]

Haynes/Chilton. I'm pretty sure it's actually made of Chilton's content...I think I remember seeing Chilton copyright marks.

I'd be surprised if your library didn't offer some access (maybe only in the physical library) to the EBSCO databases, less surprised if they offered some EBSCO access but not the ARRC.

[aalb1]

Found it! And it's available online! I don't need to go to the library! Sure it's not a Helms but better than nothing.