ECU from a EX to LX?

[thewoahna]

I was wondering if the ECU in an EX is the same as an LX. I have a 90 LX 5-spd and was wondering if I would gain anything from an EX ECU.

Thanks

[Kabuki]

Re: ECU from a EX to LX?

Originally posted by thewoahna
I was wondering if the ECU in an EX is the same as an LX. I have a 90 LX 5-spd and was wondering if I would gain anything from an EX ECU.

Thanks

They aren't the same, but you can use the m interchangebly with little difference in performance.

[MRX]

the ignition and fuel map are a bit different and more aggresive in the ex ecu depending on what model engine you get it from. ECU of choice is the f22a6 ECU from 92-93 ex, se's (respectively). Since the f22a6's have about 15 hp more than our f22a1's and 10 more than the f22a4's the ecu is more capable of controlling parts swapped from the actual f22a6 engine. Especially control over the a6 intake manifold. If u just stick the a6 ecu on your car its not gonna show noticeable gains...if any....but your setting yourself up to show some pretty decent ones down the road. If you can get your hands on one for cheap then do it but you have to know the future of your car i.e. if you want an h-series motor or if your sticking to the f-series family. I think the a4 ecu is the same as the a1...i think. So far for all i know is that the exhaust system is slightly larger in diameter for those ex and se models which gives them an extra 5 hp over us. But don't worry, you can still catch them

[thewoahna]

If i get the a6 ECU, can I swap the a6 Intake manifold with my stock one on my 90 without much modification?

[MRX]

you can swap everything on the a6 engine including the dual runner intake manifold without any modification. And just between you and me...do the intake manifold definately...the sound that thing makes is just evil

[thewoahna]

Now, besides the new ECU and the Intake manifold from the a6, I do not need to do any other building on my current motor for it to safley handle the new intake manifold? I only got 80k on the motor now, I want it to live a nice long healthy life without straining anything a whole lot. Oh, one more thing, do I have to have a computer from a 5-speed, or will an auto ECU work?

[ChIoVnIdCa]

If I put an EX ECU in my LX would I lose my 115 speed limiter?

[MRX]

sorry i failed to mention that benefit i believe. Most if not all of the a6 ecu's don't have a speed limiter. Some of the a4 ecus have them and it seems like all of the a1's have them. So in most cases yes you'd be getting rid of the limiter. All of our engines are the same with a couple variations in bolt-ons that make for the power difference. Your is not going to strain at all with swapped parts because the internals like the valves, pistons, rods, and the stuff that actually matters is ALL the same. The power parts from the a6 engine are the intake manifold, exhaust manifold, ecu, bigger exhaust piping by about 3/4's of an inch i believe, and the camshaft has a slightly more aggresive lobe that moves the top end hp up about 200-400 rpm over the others. The main parts you'll want to get are the manifolds...those make up the bulk of the 15 hp. And if you collect them all you'll have 140 hp and with your 90 dx you'll be 100+ pounds lighter which means you'll be faster. Oh and you SHOULD get the ecu that corresponds to your tranny. There's little resistors and stuff in there that you want to correspond with your tranny

[ChIoVnIdCa]

All I want is to get rid of that limiter for now, I can get an ecu at the junkyard.

[thewoahna]

nice, nice.... I did some research and I found a place that will sell me the ECU and Intake Manifold shipped for $275 from a 93 5-Speed Accord EX. Is this worth the $$? I am not very mechanical (I know some stuff), would I be able to do the swap myself? Also, while the manifold is off, should I take it to a machine shop to have pollished? If I do all this you say, I can gain about 10 hp? (I already have a DC header and exhaust) I know this is a little off topic, but I was also going to order the NGK IX iridium plugs, do they woth getting?

Thanks for all your help, I really am considering this!

[MRX]

I did the swap myself and i'm no mechanic by any means. While your at it you might want to order a polyurethane rear engine mount insert ($15) and put those in also. Don't pay more than $125 for the intake mani and no more than like $80 for the ecu...but $275 shipped doesn't sound bad. Having the manifold port matched and polished would be great. Might even want to have them do the throttle body while they're at it. As for the plugs, don't buy into the spark plugs add horsepower b.s...cause they don't. Just get yourself some nice NGK v-powers or something will be just fine and their only like $2 or $3 a piece. Don't buy into the plug wire hype either. If you research both of those things you'll see what a waste of money they are. The OEM wires are great if your setup is mild and your not making like over 300hp or you engine bay isn't heating up way too much.

the woahnna i think the next mods you should do after the intake mani and ecu if you haven't already are intake, reground delta cam, fuel pressure regualtor and then get it tuned on the dyno...i think you'll be quite surprised with the power you'll put out then.

[Fearit22]

If I'm already going to get my intake manifold ported and polished is it still really worth it to switch over? You don't have to do anything else besides just swap out the ecu and bolt it on?

[MRX]

You really don't have to even swap out the ecu. The ecu just controls closes the butterfly valves anywhere below like 4400 rpm and then opens it above that. The valves themselves stay open if the ecu isn't present to operate it...i can chip my tires in first gear by going WOT at like 1200 rpm so i know i didn't lose alot of low-end torque by having it open. i think it'd be better to p&p the a6 intake mani because the whole point of swapping it is to get better flow on the low and top end of he powerband, right? Well polishing the a6 will flow far greater up top than the a1' and a4's because it already does stock. I wouldn't say it will add more than like 3hp tho if P&P'd. Porting then port matching the intake mani, head, and exhaust mani would benefit the greatest tho.

[MRX]

err...extrude honing is also an option to speed up the air flow