NA to Turbo Swap with AC, B230FT

[Wheel_Wizard]

Hello Guys,

I’m planning to do a NA to Turbo engine swap. I’ve just bought a fully functional Volvo 740 Turbo with rear-end fire damage. The engine runs fine and was overhauled before the fire (less than 12,500 miles).

Now, I have a question about the electronics: What exactly do I need to swap the engine into any naturally aspirated (NA) car? I read somewhere that the wiring harness is the same for both Turbo and NA models, and you only need to change the control units. Is that true? It doesn’t sound right to me.

The car also has AC, which I’d like to reuse. Do I need parts of the wiring harness or the entire thing? Or can i just remove the hole thing and bolt it right back when i swap the engine.

Another question: Will I need to modify the chassis, since the air filter is located in a different spot, or are the mounting points already there in NA models?
Is there also a difference in the suspension or brakes between the Turbo and NA models? Because to get TÜV in Germany, everything has to be the same or original, including the brakes, suspension, exhaust, and gearbox.
So if I want to drive the swapped Turbo legally, I need all the important parts that the Turbo versions had back then, including the brakes, etc.

Feel free to ask if you have any questions. I hope this is understandable, as my English isn't perfect since I’m from Germany.

Volvo 740 Turbo 2,3 Liter
165HP from 1990

Has the ECU already been tuned because of the BSR?

 

[2manyturbos]

You need to start out by telling us what year your NA 740 is. The brakes are the same, Turbo vs. NA.

 

[Wheel_Wizard]

I haven't thought about that yet. I thought it wouldn't make much of a difference since I was planning to buy the Volvo 740 NA next year. What would be the best option if I am looking for one?

The one I have to strip right now is a 1990 740 Turbo 2.3 8V. 165hp

 

[2manyturbos]

It just depends on how strict your laws are. Any NA 740 older than 1989 here in the US runs LH 2.2 fuel injection. Anything newer than a 1990 Turbo 740 here in the US is quite different from the 1990 model. The drive train is almost identical from 1985 on. The brakes changed in 1990 to different calipers and rotors for the front end.

 

[Wheel_Wizard]

Sadly, it's Germany—laws are laws, no room for negotiation. I think I have an LH 2.4. Is it worth pulling the whole wiring harness from my car in terms of time and nerves, or should I just buy an LH 2.4 conversion harness from this site: https://www.prancingmoose.com/harnessconversions.html#LH2.4plusEZK-740?
If I buy a car with an LH 2.2.
And does it have any effects if I switch/convert the harness from a 2.2 to a 2.4 on other components like AC, electric windows, etc.?

Is there a big difference in the drivetrain? What are the differences, if you know?

Because I would like to use my overdrive gearbox and, if possible, my lockable diff. Are they plug-and-play between all the older and newer models? Or is a normal diff (weldet or else) better for a fun street/drift car ?

I probably have to use the bigger brakes for the front end. Can I just strip them from my Volvo and later bolt them right onto the new car, or is there a difference/incompatibility with the new or older models?

Thanks so far for the help!

 

[dl242gt]

The easiest path for this I see is to use an 89 or newer n/a 740. That is a model that usually runs LH2.4 injection the same as a 1990 turbo model. Then you can reuse your preferred gearbox and driveshaft setup. Don't buy a Regina injected car. That would only be adding a lot of work.

 

[Wheel_Wizard]

Sounds like a good plan. In that case, I can just put in my I think Stage 1 ECU, and I can ignore all the other electrical stuff. My brake calipers are just bolt-off from the old car and onto the new one, right?

The turbo airbox mount to the frame through a hole and a screw? Do the NA models have this too, or do I need to drill it?

The AC will still require a lot of parts to reinstall. Are the cables and connectors at least already there to connect everything?

 

[dl242gt]

Sounds like a good plan. In that case, I can just put in my I think Stage 1 ECU, and I can ignore all the other electrical stuff. My brake calipers are just bolt-off from the old car and onto the new one, right?

The turbo airbox mount to the frame through a hole and a screw? Do the NA models have this too, or do I need to drill it?

The AC will still require a lot of parts to reinstall. Are the cables and connectors at least already there to connect everything?

Both models should have a/c that have lots of the same parts. Maybe a hose is routed different but nothing to bad. The turbo airbox is on the other side of the car from an n/a model. The hole should be there but I think there is a plastic plug in it on the unused side.

 

[Wheel_Wizard]

Do all Reginas have the LH 2.2, and all Bosch systems the LH 2.4? That would make it easier to tell which system they have. Is that image accurate?

 

[fatcatbestcat]

Do all Reginas have the LH 2.2, and all Bosch systems the LH 2.4? That would make it easier to tell which system they have. Is that image accurate?
View attachment 29464

What?

Regina is a totally separate system from LH 2.2 and 2.4, which are the Bosch systems. The picture you posted is the different ignition coils each system uses, so you can identify them at a quick glance.

Regina is Regina, it has no association with Bosch, or LH anything.

 

[Wheel_Wizard]

Oh, good to know. Is there a quick way to check if it’s an LH 2.2 or 2.4 without asking the seller every time?

 

[fatcatbestcat]

Oh, good to know. Is there a quick way to check if it’s an LH 2.2 or 2.4 without asking the seller every time?

The AMM/MAFs are different between 2.2/2.4 so you can just get the seller to take a picture of the part number on the AMM/MAF. It's usually visible right on the top, and it's in an easy to find location next to the airbox, usually.

I don't know all the MAF part numbers off the top of my head, I know 016 is generally the most prevalent 2.4 sensor, 007 for 2.2? Someone who knows better will chime in.

 

[Wheel_Wizard]

Are there any parts or other components, besides the engine and accessories like the radiator, ignition, etc., that I should remove to keep, or that I might need later, such as the front guard or brackets I may not yet know about?

 

[leecatd8209]

1990 Turbo models had a one year only egg crate grill. See if you can get that. It won’t help with the swap, but it looks neat.

 

[Jack]

This is such a German thread
Bench swap for years in order to be ready when the real car shows up

 

[Wheel_Wizard]

I can't deny it. We have very strict laws for cars in Germany, and it's better to have a plan beforehand and let the project sit for half a year than to start and have to think about everything while swapping.

Sadly, the car didn't have a grill when I bought it.

 

[Fa182]

There's a lot to go through here, but in essence the differences chassis-wise between Turbo and NA cars were minimal.
Same brakes, same gearboxes, same drivetrain for the most part.
Exhaust has a bigger diameter on Turbo (~2.5" vs. 2.0")
Airbox is on the opposite side as you already mentioned.

The BSR sticker on the ECU seems suspicious. The 563 ECU needs a daughterboard to accept chips, so you have to open it up to verify if one was installed.

This is such a German thread

I agree.
I do feel OP's pain though, it's similar here in Austria except it's even somewhat stricter.
Very limited what you can do (no aftermarket exhaust for example) and if you can do something, it gets really expensive really quickly to register.
I couldn't be arsed to register anything I did and here I am still driving 7 years later getting through inspection every year

 

[Wheel_Wizard]

I am currently waiting for an answer from BSR. Maybe they can at least confirm that they had their hands on it. If not, I’m going to open it. It looks like it was opened before (bending and scratching marks).

 

[Wheel_Wizard]

I saw that the ABS block is on the other side compared to the Turbos. Can I just move the brake lines to the other side, and it’s good to go? Is it even that easy if it didn’t have ABS before?
Also, I would need the axles from my Turbo. Are they interchangeable?

 

[bobxyz]

The '563 ECU in my parts pile is original and has a factory socketed EPROM.


The EPROM has a plastic clip over it so that it won't vibrate out of the socket (clip removed in above picture). To remove the clip, put a small flatblade screwdriver ~1/8" into the top/bottom slots and gently move the screwdriver handle towards the center of the chip. This prys the edge of the clip outwards away from the socket and releases that side of the clip. To reinstall, push down firmly until it clicks.


In my 563, the part number on the silver EPROM label is: 2 287 355 944. If it's been reprogrammed, it probably has a different label.