109 replies to this topic

[firstgencrx]

Update: 3/16/08 Prototype Plate

Holy Spark Plug Batman!

This thing was a lot harder to figure out than I originally thought. In spite of that, I got it! I am not finished yet with the whole thing, but the hard part is done.

One really cool thing I discovered by dumb luck, the OBD0 and OBD1 distributors have the exact same mounting! Really, really dumb luck. The two models, OBD0 (TD-18U) and the OBD1 (TD-14U) will be rotated on the engine slightly different. So that means the only real difference between the kits will be in how I make the little keyed drive end.

NOTE: I need to warn everybody, the forum software does something funny with my pictures when it shrinks them down. Makes the edges real jagged for some reason. Click on the top banner of the image to enlarge them. That will give you a better look at them.

Remember, I am not finished yet, but here are some shots of the adapter plate I built today. This first photo is of the distributor side of the adapter. I still need to countersink the mounting holes:


And the engine side of the adapter:


I will be making a flange that fits into the large bore you see above that will be long enough to sink into the adapter plate, and reach into the cylinder head. This is the flange that holds the o-ring on the engine side. Here is what that flange looks like on the old mechanical fuel pump standoff:


Here is a side view with the OBD0 dizy Ben sent me:


And a end view of the OBD0:


Here is a side view of the OBD1 I scored on ebay for 25 smackers:


And end view of the OBD1:


And a shot of the old standoff that will be replaced with the new adapter. Out with the old and in with the new!:


I made a design decision early on to make the adapter plate in two parts. I did this for cost reasons. The main part of the adapter plate is 3/4" thick and the flange needed that fits into the cylinder head is an additional 0.400" inches. That means if I were to make it out of one single piece of aluminum, I would need a minimum of 1.25" inch thick plate to start with. Well... 1.25" aluminum plate is three times more expensive than 3/4" plate. Plus, I would machine so much material away making the adapter from only one single piece, that it would take at least twice the time to machine, at least on my little modest CNC.

So the decision was made to make it out of two pieces. When I make the flange and drive keys, I will make another post. Once those parts are done, and I am convinced the adapter is good to go, I will make a couple more sets and ship them out to my secret testers.

Take care all!

David

[strudel]

[quote]NOTE: I need to warn everybody, the forum software does something funny with my pictures when it shrinks them down. Makes the edges real jagged for some reason. Click on the top banner of the image to enlarge them. That will give you a better look at them./quote]

Just a point of interest FWIW. On my old PC running XP with a 14" screen the comments are valid. On my shiny new Mac with a 22" monitor I see the images in the expanded view to start with so no fuzzy images for me. I was wondering why I could not enlarge them as they already are when I see them. Technology, who's to know what you can learn? I'm still figuring out how to do stuff on the Mac as it's a bit different for us old PC types.

Looks like pretty spiffy stuff though, congrats. JS

[firstgencrx]

Just a point of interest FWIW. On my old PC running XP with a 14" screen the comments are valid. On my shiny new Mac with a 22" monitor I see the images in the expanded view to start with so no fuzzy images for me. I was wondering why I could not enlarge them as they already are when I see them. Technology, who's to know what you can learn? I'm still figuring out how to do stuff on the Mac as it's a bit different for us old PC types.

Looks like pretty spiffy stuff though, congrats. JS

You'll have to make one of those funny Mac/PC adds you see on TV. You could do a skit where the Mac is an "Air Traffic Controller."

And the PC keeps making excuses as to why it's not ready to be one yet!

David

[strudel]

Righty, making fun of my retirement status! Burned out Air Traffic controller (Mac) chastising the PC for not being ready to take off when he says he is while the little iBooks just swish away when cleared to go.

Reminds me of an Air Canada joke: AC pilot is about number 5 in line and has been waiting for some time to depart and questions the controller as to why he is getting a big delay.

Controller. OK, have it your way. Cleared for take off! That is if you can climb over the 4 ahead of you or use the grass to taxi around them to the runway.

Chatter from all the others in line. Yeah, just take off, EH!!!

Jerry AKA disgruntled controller who used to be a nice guy. Now I'm retired and I don't give a sh*t, anymore.

[firstgencrx]

Righty, making fun of my retirement status! Burned out Air Traffic controller (Mac) chastising the PC for not being ready to take off when he says he is while the little iBooks just swish away when cleared to go.

Reminds me of an Air Canada joke: AC pilot is about number 5 in line and has been waiting for some time to depart and questions the controller as to why he is getting a big delay.

Controller. OK, have it your way. Cleared for take off! That is if you can climb over the 4 ahead of you or use the grass to taxi around them to the runway.

Chatter from all the others in line. Yeah, just take off, EH!!!

Jerry AKA disgruntled controller who used to be a nice guy. Now I'm retired and I don't give a sh*t, anymore.

I figured you'd get a kick out of that!

[Elias]

please give me some links to understand what these adapters are made for and what ECU must be used in D15A3?
lots of thanks!!!

[zakats]

p05 pr4 p75 p06... the list goes on pretty much any OBD 1 honda ecu without vtec- preferably one that is chipped for tuning to accept the changes

[firstgencrx]

please give me some links to understand what these adapters are made for and what ECU must be used in D15A3?
lots of thanks!!!

You should also spend some time at:

http://forum.pgmfi.org/

A fantastic site with more info on hacking Honda ECU's than you will ever want to know about!

[jsgprod]

Once those parts are done, and I am convinced the adapter is good to go, I will make a couple more sets and ship them out to my secret testers.

Very neat David, so, I'm sitting here looking at those two countersunk holes near the center and wondering WTH?
Those things don't need to be there?

Then I see the 3rd pic and read your explanation! Now I know what they're for .

Once those parts are done, and I am convinced the adapter is good to go, I will make a couple more sets and ship them out to my secret testers.

HHHHM..Really?

Jay

[strudel]

p05 pr4 p75 p06... the list goes on pretty much any OBD 1 honda ecu without vtec- preferably one that is chipped for tuning to accept the changes

How dramatic are the wiring changes? I suspect as in the blacktop swap into a CRX there are major changes required. Is it the same for these ECU's? One would need the appropriate wiring diagrams to get it right. JS

[firstgencrx]

Very neat David, so, I'm sitting here looking at those two countersunk holes near the center and wondering WTH?
Those things don't need to be there?

Then I see the 3rd pic and read your explanation! Now I know what they're for .

Ya, the flange will press fit into the adapter plate, but I thought a couple of screws are cheap insurance. Once I put it together, you would never have a reason to take it apart.

Are you one of my secret testers?

David

[firstgencrx]

How dramatic are the wiring changes? I suspect as in the blacktop swap into a CRX there are major changes required. Is it the same for these ECU's? One would need the appropriate wiring diagrams to get it right. JS

I am going to look at that with help from others as well. It would be cool to have some kind of tips and tricks guide later on that outlined some of the possible options one would pursue doing a swap like this. There are many ECU's to choose from as well as the two OBD0/OBD1 style choices. We could put something cool together and post it all in the Wiki.

I am starting to wonder if the OBD0 is even worth the bother when the OBD1 has more options? I know some of the really cool free tuning software like "Crome" is only OBD1 friendly.

Good questions!

David

[zakats]

right obd1 > obd0 tuning x99999
the wiring would, like previously sated, be mostly like the black top teg swap plus a few different I believe..not too much really

edit: both obd 0 and 1 use about 45 ecu pins so it should mainly be a matter of repining and adding the electronic distributor advance wires

[DEIVIONCRX]

I did all the wiring for my OBD1 Bswap already. Except the ECU changes.

To add electronic advance, you will need to add the ICM(B15, B17) and CKP(B10, B12) sensor wiring, CKP needs to be shielded. You will also need VSS wiring(B16), along with a power wire pin swap at the ECU(A17 ->B1). As well as lengthen the Coil power and tach signal wires from the firewall to the distrubitor.

Since theres no real way to run a EIACV on the EW's youll need some managment system to delete it or live with the code, Crome or TurboEdit will do it. The stock one should work fine and control the idle, just not computer controled.

All of that will get you OBD0, to go OBD1 youll just need a OBD0->OBD1 conversion harness, distrubitor and ECU. There shouldnt be any Wiring changes needed, just use the supplied pigtail with the conversion harness, to run a 4wire O2 Sensor(or delete and wideband tune), and the switch for the Diagnostic Mode.

[3GCVC]

that is nice work definately put me down for one of these when they are finished.