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Almost done my engine swap.. running into problems now.


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I can probably do a logfile of my timing advance if you'd like. Good point on the DOHC vs SOHC difference, that would explain how it feels. I have a steep hill by my house and with the EJ25 I used to have a hard time turning onto that road in 2nd gear and getting momentum built up while climbing the hill. It was to the point where I'd slow to a crawl during the turn and hit 1st gear just to get some oomph to climb the hill. Now I can stay in 2nd gear and have plenty of power to get going.

Also.. 

:)
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These 2.2s make gobs of low end torque. 2.2 torque curve peaks around 3,500 rpm. The DOHC 2.5 torque peaks around 5,000.

 

But torque curve has more to do with the cam profile than ignition timing. The ECU will scale timing up until it detects knock. If it does it will pull the timing back to correct the knock. If it doesn't knock, it just follows a preset curve that's dependent on load calculation and engine speed.

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About the different ECU's, and to answer Bushwick as well;

I have about 9,000 (hard) miles on my EJ22 swap with an EJ25D ECU on EJ22E... well, everything else. Runs fine, although fuel economy (which might have to do with the automatic and more so the driver) has had a noticeable drop. It hasn't yet fouled out the plugs or O2 sensors, but I cant say for cats since it would throw codes with the old engine. I have yet to get a P0420 with the EJ22 yet, surprisingly. It sets monitors fine, or at least well enough to pass emissions in New York, which is basically a California emissions test without the sniffer. It wouldn't mis-fire and even straight-piped for a while there wasn't excessive afterfire caused by timing advancing or retarding when it shouldn't. No pings or spark knock, running on 89 or 87 or whatever the cheap button is. The ECU handles it just fine, you'd have no idea its for a different motor. The MAF sensor and O2 sensors measure what the ECU needs to know and therefore adjust, and it runs it no problem at all.

I wish I could be more helpful and provide maps as proof, but all I got is firsthand real-world experience that you wont have an issue unless you're really, REALLY looking for one, and that would be fuel economy. Ive had no uneven idle, or "hunting." Redlines at 6500 thereabouts. MPG wise, it gets high teens or low to mid 20s if you really try. My EJ25 5 speed 98 Legacy OBW gets 25 everywhere even driven by me, an 18 year old male no less cussing at worn synchros. Let me know what kind of mileage you get, or if you change ECUs! Just keep in mind, a different ECU may send up a red flag come inspection time unless you amend the VIN (unless it works differently in not-New York).

Edited by pginter96
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I can definitely tell the 2.2 had more low end torque now after driving it 300+ miles. I can also chug along at lower rpm easier without the engine feeling like it's lugging. Sohc ftw!

 

I do think I had some pinging going on with 87 octane. There was an odd noise I thought was my heatshield but it was too regular and consistent. Put 91 in and it stopped. My torque app has a knock detector mode and it passed 100% with the 87 in there but since the sound went away with higher octane I think it was detonation.

 

I haven't redlined it, I never do. Also can't calculate mpg yet cause I have to fix a fuel vent line that leaks when the tank is full. But if anything I think I'm getting better mileage or at least very close to the same. No emissions testing up here in my county of Maine so no worries. Got a fresh inspection sticker after the swap without issue. Mechanic and I talked all about the swap and he was impressed with the condition of my 241k mile 1999.

 

Once I fix the fuel vent line I'll update here on my MPG.

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I can definitely tell the 2.2 had more low end torque now after driving it 300+ miles. I can also chug along at lower rpm easier without the engine feeling like it's lugging. Sohc ftw!

 

I do think I had some pinging going on with 87 octane. There was an odd noise I thought was my heatshield but it was too regular and consistent. Put 91 in and it stopped. My torque app has a knock detector mode and it passed 100% with the 87 in there but since the sound went away with higher octane I think it was detonation.

 

I haven't redlined it, I never do. Also can't calculate mpg yet cause I have to fix a fuel vent line that leaks when the tank is full. But if anything I think I'm getting better mileage or at least very close to the same. No emissions testing up here in my county of Maine so no worries. Got a fresh inspection sticker after the swap without issue. Mechanic and I talked all about the swap and he was impressed with the condition of my 241k mile 1999.

 

Once I fix the fuel vent line I'll update here on my MPG.

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  • 3 weeks later...

Update on mpg.

 

Most of the time I'm running 24 to 25 but on a good tank without a lot of city driving I'm hitting 28. Best yet was 28.6.

 

I've rub 87 and 91 octane and haven't noticed a difference. I'm going to pull and check the spark plugs this weekend.

 

I'm loving the swap still! It's great seeing the reactions at meetups when I say I just finished knocking my HP down 30 ponies and love it more after.

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I run 91-93 in mine. It's habit due to my turbo'd Saab needing it. Very tiny difference with the factory ej22 ecm, but it does seem to go further on it vs. 87, but the trade-off obviously is 87 is cheaper.

 

Yeah, SOHC typically don't have the crazy large runners most DOHC (speaking in general) have, so you still get decent low-end flow. If you want to increase a few ponies and possibly increase MPG further, install a freer flowing muffler and be SURE to run a quality synthetic oil in the engine, and possibly in the rear pumpkin too. Run a good quality fluid in the trans too. Tires can help improve MPG, as well as lowering the car. If you are still running original O2 sensors, those can hurt MPG. I've had good luck with Summit Racing Turbo Mufflers in the past. They are rather subdued but lower back pressure. Avoid the hard metal welded case versions as they are closer to a 50 series Flowmaster (too loud). The regular variants are under $35 and VERY light. Give a nice quiet tone and free up top end power.

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Thanks for the advice! I'm actually starting to think about other things I want to do to the car now and a nice throaty but not loud muffler is on the list. What you described sounds EXACTLY like what I want. I've currently got Michelin Defender XT tires which seem like they'd be excellent for MPG. I've got synthetic oil in the EJ22 now, and the gear oil in the rear diff and 5MT is on my list of things to do soon. Any recommendations on which fluid I should look out for? I'm not sure if I want to lower it or lift it haha. Stock height for now is the best of both worlds I guess :P A 1-2" drop would look good, just swap in some WRX suspension I think is an easy way to do that. 1-2" lift is about all I'd do and isn't nearly as noticeable as a bigger lift which is what I'd really want. Maybe I will actually lower it haha.

Pic of my wheels and tires: https://i.imgur.com/S8iItfC.jpg

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