2.3 NA regina to 2.3 Turbo LH2.4 motor swap

[comanche250]

Nice job. Now, you have what you wanted. A nice clean car with decent power.

Thanks. I'm really happy with how it turned out. I drove it around a bit yesterday and it feels okay, a little slower than when it was in the parts car but that might be from the flange on the turbo downpipe not being on all the way. Probably messing with the O2 sensor reading. I can really hear the turbo with that leak though haha I wish I didn't have to fix it.

 

[comanche250]

Fixed the exhaust leak. I'm noticing a bit of a stumble if I go from no throttle to half throttle really quickly. Especially if I'm cruising and I just jab the throttle a couple of times.also there seems to be a flat spot right at 3000 RPM then after that the power picks up again. No codes yet.

 

[#!rolls2]

'91 740 Regina wagon here. Bought new at Dyer and Dyer in Atlanta - airbag, but no ABS.

Now, back to your regularly scheduled programming.

 

[DET17]

'91 740 Regina wagon here. Bought new at Dyer and Dyer in Atlanta - airbag, but no ABS.

Now, back to your regularly scheduled programming.

My 90 745 might have been bought new at Dyer & Dyer..... original owner was in Duluth. Mine has no ABS, which is fine with me! Yes, it has an airbag like your 91.

 

[comanche250]

the itch for more boost has begun

 

[2manyturbos]

the itch for more boost has begun

That was predictable, if not inevitable.

 

[comanche250]

I can really just run 12 psi and not have to do anything?

 

[fatcatbestcat]

I can really just run 12 psi and not have to do anything?

If you want to obliterate your fuel economy when in boost, sure. If you have a chippable EZK, get a chip tune and you'll be amazed how much it improves.

FWIW when I got my car, the manual boost controller was set at 12 psi on the stock tune and it struggled to get better than 20-22 MPG. Stock LH seems to just panic and dump fuel when it sees boost. I have the redblockpowered stage 1 tune currently and my city/highway average is closer to 24-27, but of course I also have a 5-speed.

 

[2manyturbos]

If you want to obliterate your fuel economy when in boost, sure. If you have a chippable EZK, get a chip tune and you'll be amazed how much it improves.

FWIW when I got my car, the manual boost controller was set at 12 psi on the stock tune and it struggled to get better than 20-22 MPG. Stock LH seems to just panic and dump fuel when it sees boost. I have the redblockpowered stage 1 tune currently and my city/highway average is closer to 24-27, but of course I also have a 5-speed.

The two are completely separate issues. LH 2.4 has no way of knowing the engine is receiving boost or not. There is no pressure sensor. I've had several 7-9 series cars with the Turbo Plus kit installed on them and their fuel mileage is the same as the 7-9 series cars without that system, unless, they are being pushed hard all the time. Those kits are designed to allow 12 psi boost vs the stock 7 psi. There is a device that controls how much throttle and boost an engine receives. It most cases, that is the driver's right foot which is supposed to be controlled by the driver's brain. What is likely going on is you had so much more fun you could keep your foot out of it. More boost requires more fuel. It's simple. The system attempts to maintain an acceptable fuel/air ratio.

 

[comanche250]

Well I installed a MBC and set it to 10 psi. My 0-100 time is about 9 seconds though disappointingly. I was expecting more of an increase.

 

[2manyturbos]

Well I installed a MBC and set it to 10 psi. My 0-100 time is about 9 seconds though disappointingly. I was expecting more of an increase.

Why? You only increase the boost 3 psi. 0-60 in ~ 9 seconds is right in the range of what you should expect out of a 3450 lb car with 170 hp and a 4 speed automatic transmission.

 

[comanche250]

I guess I just fell for the hype. It's still a nice increase but people hype it up like you get double the power.

 

[2manyturbos]

I guess I just fell for the hype. It's still a nice increase but people hype it up like you get double the power.

Wouldn't that be nice. You can safely run your boost at 12 PSI. That is what Volvo did with the Turbo Plus kit.

 

[comanche250]

Wouldn't that be nice.

I've been hanging around V8 people too long lol

 

[sbabbs]

If you use NA 240 lh 2.4 harness for boosted car with older 5xx ecu when you floor it, it changes to another map and goes way rich, you gotta cut that WOT wire at the TPS switch could be a problem. Factory turbo lh2.4 cars harness do not have that wire even. I got a video on my youtube on which one to cut.. Doesn't seem to be a problem with 9xx ecu's.. I cut it anyways.

 

[comanche250]

If you use NA 240 lh 2.4 harness for boosted car with older 5xx ecu when you floor it, it changes to another map and goes way rich, you gotta cut that WOT wire at the TPS switch could be a problem. Factory turbo lh2.4 cars harness do not have that wire even. I got a video on my youtube on which one to cut.. Doesn't seem to be a problem with 9xx ecu's.. I cut it anyways.

I actually pulled the entire harness from the 940 parts car. Wanted to keep it clean.

 

[comanche250]

Is it overkill running premium fuel (94 octane) or can I get away with midgrade? Don't mind paying the extra but if it's not benefiting in anyway I may as well save a few cents.

 

[fatcatbestcat]

Is it overkill running premium fuel (94 octane) or can I get away with midgrade? Don't mind paying the extra but if it's not benefiting in anyway I may as well save a few cents.

I've just been running mine at 12 psi on 91. I've heard take that on low boost it's "safe" to run 87 but I haven't tried that and I don't necessarily trust that... especially since my 940 is my only functional car.

I did briefly put 93 in to see if it made any difference, and I couldn't really feel any improvement - I'm still on the stock (early) intercooler, stock cam, stock turbo and stock downpipe so it's not like it's a fire breather or anything anyway.

 

[comanche250]

I've just been running mine at 12 psi on 91. I've heard take that on low boost it's "safe" to run 87 but I haven't tried that and I don't necessarily trust that... especially since my 940 is my only functional car.

I did briefly put 93 in to see if it made any difference, and I couldn't really feel any improvement - I'm still on the stock (early) intercooler, stock cam, stock turbo and stock downpipe so it's not like it's a fire breather or anything anyway.

I'd rather play it safe too. Regular is $1.58 and premium is $1.83 so it's not a big difference.

 

[2manyturbos]

I use 89 octane fuel in my daily driver 940 Turbo all the time. The manual calls for AKI 87 or RON 91 as a minimum octane. I don't hot rod my daily driver. If I'm using the car to cross the Siskiyou mountain range or something like that I run it on 91 octane. When I used to Autocross my 780 Turbos I always ran 91 octane in them while racing them. 91 octane is the highest octane in general throughout Oregon. Some stations have pumps that sell 92 octane. If I want to spend $6+ a gallon I can fill up with 100 octane at a station in Eugene.