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3.2 to 3.0 conversion

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Hey guys, just got a nice low mileage 95 or 96 (escapes me right now) 3.2 motor. My question is swapping it into my 91. I am almost positive it is a straight swap. I plan on getting headers(so i know i need the 3.2 ones) but all else seems to be same. Anyone know? I got the motor cheap, and it is complete, although i will be tearing it down and building it this summer. Think i can get 310~320rwhp N/A. Really should not be too hard.

Thanks in advance.

Eric Dorn
EDR PERFORMANCE www.edrperformance.com
 
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Provided you have all of the other functioning equipment as well.

IE: ECU and Drive by Wire stuff you should be ok.

The majority of the engine stuff is the same, its the electronics, fuel management, and throttle control that will be a PITA to convert into a 91'.

If you are looking purely for getting the performance out of a 3.2, it has been recommended by more than one person to me to just change the core engine components themselves.

ie: block, pistons etc etc. And leave everything else as it is. Keep yer existing ECU (but change the fuel map to handle the bigger engine), and keep your existing throttle system.

Just my 2 cents, in what ive found while researching the same idea.

-B
 
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wow...I beat nsxtasy to this one(maybe he's typing a response right now:p)

The 3.2 came out in '97, so if you have a '95-'96 motor then you don't have a 3.2 block, sorry to say.

However, if it is from a '97+ NSX then you've got the 3.2 motor. How much did you get it for if I may ask? I'm curious to know how much motors go for these days. Thanks


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Richard
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Lud

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Throttle-by-wire is obvious, but it is not the only issue. The intake and injector connections are different. You will get into a real mess of ECU and wire harness differences if you try to use the 3.2 manifold in a car that came with a 3.0 motor, esp. a pre-ODBII one.

Simple solution: Use a 3.0L manifold (the one from you '91 will be fine) and forget about throttle-by-wire and keep the wire harness and ECU that are currently in your car.

[This message has been edited by Lud (edited 16 April 2002).]
 
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Originally posted by Lud:
...keep the wire harness and ECU that are currently in your car.

Just curious, won't a 3.0L ECU cause a 3.2L engine to run lean?


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Russ
'91 black/black
 
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Originally posted by EDRNSX1:
Think i can get 310~320rwhp N/A. Really should not be too hard.[/URL]

If you are trying to build an aggressive NA motor, you might want to just jump to a programmable engine management system when you do the swap. AEM makes one that plugs into the stock harness in place of the early (3.0L) ECUs.
Just use the 3L intake and harness, then plug in the AEM box.
 

Lud

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Originally posted by Russ:
Just curious, won't a 3.0L ECU cause a 3.2L engine to run lean?

No... David's suggestion to go w/ third party management makes it a moot point though. The 3rd party mgmt is a good idea if you are indeed trying to build a really aggressive NA motor. I didn't really address that part of the post, I was just trying to answer about swapping a 3.2 into a 3.0 car.

I don't think I would characterize getting 320 NA RWHP as "not hard" (or at least "not involved and expensive") if doing it the RIGHT way.. meaning not tuning it specifically to hit that peak HP mark at the sacrifice of the rest of the power curve or the driveability or reliability of the car.

[This message has been edited by Lud (edited 16 April 2002).]
 
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Originally posted by Lud:
No... David's suggestion to go w/ third party management makes it a moot point though.

Assuming for the sake of the question that no 3rd party ECU exists and an OEM 3.0L ECU is used... how would it not run lean? Aren't the MAP tables based on 3.0L displacement, and if so, wouldn't the ECU provide only sufficient fuel for that size engine?


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Russ
'91 black/black
 
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Originally posted by Russ:
Assuming for the sake of the question that no 3rd party ECU exists and an OEM 3.0L ECU is used... how would it not run lean? Aren't the MAP tables based on 3.0L displacement, and if so, wouldn't the ECU provide only sufficient fuel for that size engine?



You would have to raise the factory fuel pressure...... This would provide enough fuel for the motor.
 
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Hey guys thanks. Couple of things i should have mentioned. 1. The motor was WAYYYYY cheap(no, i wont say) 2. I plan on using all my existing elect, throttles, injectors, and ECU. 3. I plan on having the ECU redone. I will wait until i get on our dyno and dial it it with that. I do not believe in "off the shelf" chips or ECU's. I know all the elecs would not swap. I was just curious about "core" of motor, ie short block set up. The only thing i did not consider was the intake manifold. Thanks. Seeing i drive it very little and seeing it sits all winter long, i thought it would be a fun project. I build race engines for a living. Yeah, Roadrace motorcycles, but still very similar. I have a full machine shop and not too mention a good friend of mine owns a machine shop that builds ALOT of fast Honda and Acura's. Also have a good friend from High school(ouch, now i feel old) that works for one of the top NSX shops(starts with a C) So resource wise, i should be ok. As for hp gains? Simple, I have a set of High Compression pistons, I plan on using an aftermarket crankshaft, blueprinting all clearences, porting cylinder heads(bike heads are SOOO much nicer production wise) comp. valve job, having a set of custom cams made(keeping the asymetrical "low rpm" lobes the same, just changing the Vtec lobe), custom adjustable cam gears, rework the intake manifold, full headers, cat bypass pipes, exhaust, intake and custom ECU. I already have the bypass, exhaust, and japenese gearbox setup. Should be fun. Hell if i can take an R6 yamaha that makes 120hp(crank,, 95rwhp) at only .6 litre and then build it to make over 150hp (crank, 119rwhp) adding 15% to my NSX3.0(3.2)litre should not be hard. Hell, we have a BONE stock kawi ZX12 (1.2litre) in the shop right now. It is all stock except for a full exhaust and alot of ECU tuning and we are getting 181rwhp! (@210crank hp) Heck both are without race fuel. I don't mind if i have to run race fuel in my NSX, i never go farther than a full tank anyways.

Or maybe jsut a huge waste of my time. But hey, i love to "f--k" with engines and for what i got this motor for,
wink.gif
I can't not at least try.

Thanks again for your input.

Eric
 
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