MODIFICATION , EFI Electronic Secondary Stage Controller

[A20A1]

I wonder about ignition Vacuum Advance
Both carb and EFI have two ports. One for Cold and one for warm.

The cold one I think doesn't advance as much as the regular one.

I figure you could hold onto the advance for as long as you want using;
Vacuum Holding Cannister
Vacuum Check Valve
Vacuum Solenoid
RPM Switch

Hook it up to either the cold or regular advance port.
You'll probably have to bypass any stock ECU/Thermovalve interventions into the Vacuum Advance or at the least make the new system independent while sharing the same port.

You'll want to dump the advance before 3,600 RPM

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[Strugglebucket]

the stock system on the efi engine has a vacuum holding canister and a check valve (hose #13) already.

one thing to note with the summit rev switch is that it is specified for 8 cylinder engines only, so if you use it with a 4 cylinder engine whatever rpms you set it at are actually half of what it will "see"(8 sparks=1 rotation to the circuit, 4 spark per rotation engine means 2 rotations=1 rotation registered to the circuit). for example, if you set it to 2,000 rpm (the lowest setting), it will switch when our engine reaches 4,000 rpm.

[A20A1]

the stock system on the efi engine has a vacuum holding canister and a check valve (hose #13) already.

I was refering to duplicating the secondary system for ignition advance... that is why I listed an extra holding cannister, check valve, and solenoid. I assume #15 is the cold advance. Odd how #5 & #15 are hooked up within the black box... I'd think they'd use seperate solenoids.

[Rendon LX-i]

So this is only for 88-89 for the fact beening that 86-87 only have the single.....No Secordenderys LOL like 88-89s right? looks intresting thou

[Vanilla Sky]

honestly the 86/87 manifold is a better piece.

[lostforawhile]

the stock system on the efi engine has a vacuum holding canister and a check valve (hose #13) already.

one thing to note with the summit rev switch is that it is specified for 8 cylinder engines only, so if you use it with a 4 cylinder engine whatever rpms you set it at are actually half of what it will "see"(8 sparks=1 rotation to the circuit, 4 spark per rotation engine means 2 rotations=1 rotation registered to the circuit). for example, if you set it to 2,000 rpm (the lowest setting), it will switch when our engine reaches 4,000 rpm.

they make rpm switches that work on 4 cylns. thats a reference. you just set the dip switches depending on what engine you have. just like a tach

[lostforawhile]

here are some examples msd. 8950 rpm activated switch,uses msd modules,59.88$ if you want you can plug in the msd 8670, 47.69$ it lets you choose 12 rpm limits with a knob. that one is 3000 to 5200 rpm.

[lostforawhile]

you don't have to use the switch i thought it might be nice to set the point where secondaries come on. why not just hook it up with a t fitting at the secondary then you could have the secondary operate normal or have it come on sooner if you want.

[lostforawhile]

honestly the 86/87 manifold is a better piece.

yea,why does everyone think the manifold is so terrible? i think it a well designed manifold, the bottleneck is whats on the top of it. this manifold can flow a lot more then the stock carb can. this really is a performance manifold it's the carb that sucks. no pun intended. from studying automotive design for years as a hobby i think it's a great manifold.

[Strugglebucket]

they make rpm switches that work on 4 cylns. thats a reference. you just set the dip switches depending on what engine you have. just like a tach

hey man, don't gimme that smiley summit only makes one rev switch and it's a good deal but there are no dip switches for #of cylinder selection. so the lowest you can set it with a 4 cylinder is 4k, that's all i was sayin'.

[lostforawhile]

hey man, don't gimme that smiley summit only makes one rev switch and it's a good deal but there are no dip switches for #of cylinder selection. so the lowest you can set it with a 4 cylinder is 4k, that's all i was sayin'.

just cutting up with you,i know they make rpm switches for 4 cyls a lot of ricers use them for NOS switches. oh heres a picture of the manifold without all the crap on it,it really is automotive art. the japanese like to make beautiful parts,it the culture.

[A20A1]

there was no room in the box for the switch?

[Oldblueaccord]

Is it just me or do our cars sound way different with them fully open?

It does to me. Very differant sound when they open up.


wp

[A20A1]

The Carb Model secondary is throttle + slightly shorter runner length

Your EFI throttle is independent of the Secondary air passage.

It's simply too dangerous to have throttle not based on the throttle linkage / cable / return spring. You may end up with run-away engine speeds if the system fails.

It could fail if there is a vacuum leak
It could fail if there is an electrical issue
It could have a mechanical failure

With the carb secondary how it is now all you have to worry about is a mechanical failure... much safer. The vacuum diaphragm system is backwards so a vacuum failure would actually be to your benifit in a bad situation cause the throttle would close.

I mean it's certainly possible, but it's not somthing I would do.


The safest way would be to use the stock diaphragm and hook it to venturi vacuum, making sure the diaphragm can open the plate all the way... it's on a fairy tight return spring. Anyways, if that works then the EFI solenoid would act as a controller for venturi vacuum supply.

Problem with a venturi vacuum supply is venturi vacuum inscreases with throttle / RPM. This will limit how early the secondary would open since there is only a weak venturi vacuum signal at low rpm/throttle.

You could hook both venturi and manifold vacuum up, with a check valve where needed, and maybe add some lower rpm operation speeds to the secodnary, but then you again run the chance of the solenoid failing and then secondary getting vacuum when it shouldn't.

If you trust the solenoid enough then it may be a very worth while mod, and fun.

[A20A1]

Nope, vacuum pulls the diaphragm to open the secondary, much like the distributor advance...

If they had it the other way a vacuum leak would cause it to open which would be bad since that would increase the throttle and up the rpms.

Also you'll have to disable the mechanical secondary part of the throttle linkage... since it keeps the diaphragm from opening.


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[logic]

The 86 and 87 came with 110 and the 88 and 89 had 122 the butterflys help a lot but are not the whoole reason for power there was a large compression increase and anew exhaust manifold used along with some removed vacume lines.

1988starter, what all is different? I just dropped a new engine when mine died and they gave me an 87 instead of an 88. I swapped both manifolds, but what did I miss?

[logic]

1988starter, what all is different? I just dropped a new engine when mine died and they gave me an 87 instead of an 88. I swapped both manifolds, but what did I miss?

O.K., Anyone help me out here.... Is there a difference in the head or the crank, or just the cam? Hello....(long echo, then nothing....)

[logic]

O.K., Anyone help me out here.... Is there a difference in the head or the crank, or just the cam? Hello....(long echo, then nothing....)

Hello? Does no-one care to answer my question because no-one cares, or did I offend everyone already?

[A20A1]

I dunno what did you miss?

The engine compression can be changed with pistons, head gasket thickness, or the cylinder head clearance.

A compression ratio increase can increase power.

A different cam profile can give more power, but I dunno if there was a difference in 86-87 and 88-89 cams.

The intake manifold it the only real visable difference between the two, You already have the 88-89 ECU and vacuum controls since you had the 88 engine in your car before you swapped to the 87 motor.

[Swap_File]

I think having the ability to vary the disengagement point would only be helpful if you boost. Go ahead and set the point at when the turbo spools and full boost comes into play.

And if you are boosting, why use the stock manifold? An aftermarket unit would be much, much better. Heh.

For turbo applications, a B16 or B18 stock intake manifold would still probably be better than a A20 stock manifold with the secondary control modification, right?

[Strugglebucket]

(as originally posted by justanothermike):

u can always try removing the iabs and making the 88 up manifold into a single runner manifold. Having a two piece manifold makes it really easy to get a die grinder in it to port it out. It would probably out flow a B16 manifold but maybe over kill for internally stock A20s. With a B16 manifold u can use the newer larger throttlebodies aswell, but we have adapted the top part of an H22 iab manifold onto the A20 manifold but 1 bolt did not matchup and there may have been a slight vacuum leak. This is what the IAB manifold look like with the single runners. The top one is the manifold on our H22 accord and the bottom one is a GSR thats going on my 1.9l LSVTEC