740/940 Regina +T

[500dollar744ti]

So first off, what is a Regina 740/940? A Regina 740/940 is a non-turbo B230F powered car that got the Siemens/Bendix engine management, produced for the American market from 1989-1994. Not all cars from those years have the Regina fuel system, depending on your locality. It is my personal belief that Volvo got a bin of cheap, out-dated EMS parts from Siemens/Bendix in bulk and decided they could cut production costs by throwing these systems on American market cars because we wouldn’t know the difference.

Regina cars differ from Bosch LH2.4 cars in a few ways. The Regina fuel system relies on a MAP (manifold absolute pressure) sensor to calculate engine load instead of a Mass Air Flow sensor, there is only 1 primary fuel pump in the tank, and the coil has a built-in ignition module. There are many other differences but the fact of the matter is that it is a non-turbo car with a non-turbo fuel system that cannot be modified for turbo use like a Bosch system can be.

The easiest way to identify a Regina car is to look at the ignition coil, if it looks like this, it’s a Regina…


Many threads have been started about turbocharging a Regina car but to my knowledge, nobody actually has done it. This made me curious, to the point that I had to try it.

I am not going to go too far into depth explaining how I ran the oil line and return for the turbo, there are a plethora of threads on this site explaining how to do that, do a search and you will find multiple ways to run a oil feed line to the turbo and a return line from the turbo. I removed the oil gallery plug at the front of the block and used that as my feed for the turbo.



The return is simply a stock return line, cut and extended with some silicon hose to a pipe fitting that I put in the oil pan. The pipe fitting is just something I had laying around, I put a nut on the back of it and two copper crush washers in between, it doesn’t leak.


I chose to use a 1st gen Mitsubishi TD04H-13c turbo for its fast spool, adjustable wastegate actuator and built-in bypass valve. You can use whatever you want but a big turbo isn’t necessary for this. Obviously, you first need to remove the n/a manifold and downpipe. Bolt up a 90+ manifold and your turbo to the block, run your oil feed and return before going further. The transmission cooler lines will probably get in your way, don't worry, just carefully bend them out of the way of the turbo.


Use a stock 740t downpipe to plumb your freshly mounted turbo into the stock n/a exhaust system. If you go to a local auto parts store you can find any hardware needed to do this if you can’t figure it out.

Using stock 740t coolant lines, the lower radiator hose and coolant reservoir feed hose I mean, hook up the coolant feed lines to the turbo. Since we aren't installing any sort of oil cooler it would be in your best interest to use a watercooled turbo as I have.

After mounting the turbo, remove the stock airbox and intake, pull the IAT sensor out of its housing and just let it hang in the fender hole to get adequate airflow.

Install a stock intercooler and piping. You need the upper and lower i/c mounts to do this. From the turbo to the throttle body you should have no problems. If your car has a clutch fan, you’ll need to trim about an inch off the round part of the shroud so it doesn’t come in contact with the engine. Also, you will have to cut an inch or so off of the upper radiator hose since you'll be pushing the radiator closer to the engine.


Cut the IAC hose short so that you can put it on the hotside intercooler pipe where it would go on a turbo car. You will need to take the PCV hose that was disconnected from the stock intake and extend it with a coupler and some more hose over to the inlet side of the turbo. Use the elbow that was originally at the throttle body on the n/a setup as an elbow at the turbo inlet. Route the PCV hose over to the intake elbow and install it pre-turbo. Use the rubber intake hose from the Regina setup to extend the turbo intake from the inlet elbow you installed to up and over the battery. Install any sort of cone filter on the end of that. Don’t forget to run a vacuum line over to the CBV!


Now that all the hardware is installed, it’s time to start tricking Regina into working with a turbo. I was able to slacken the wastegate actuator arm down some so that it only boosts at 4-5psi, it’s up to you if you want to do that or stick with the stock boost. If you lower it you’ll be able to run 87 octane gas which is nice.

Get a 4.0 Bar fuel pressure regulator and install it in place of the Regina FPR. These can be found on turbo Dodge cars and the like. This will bring the injectors up to about 20lb/hr from 18. I used an adjustable FPR that I had laying around but I tried it with a 4-bar to make sure that would work too.

The key to really getting that seat of the pants oomph you want when you punch the gas is to hook up the cold start injector so that it runs at WOT. You need a standard Bosch 4-pole relay to do this, and believe me it’s really simple to hook up.

On the cold start injector there are two wires, one is blue/green the other is gray/black. Tap a lead into the gray/black wire and run it to the ’87’ pole of the relay. Ground the wire from the ‘30’ pole of the relay to somewhere on the body, I used the firewall ground for mine. Tap into the 4th fuel injector power wire which is green and run that lead to the ‘85’ pole of the relay. Lastly you need to tap into the TPS pin #3 wire which is red/white, and run that lead to the ’86’ pole of the relay.

If you did it right, with the ignition on and engine off, you should hear your relay click when you stomp the pedal to the kick-down position. Furthermore after doing that a few times you should be able to notice excess fuel being delivered because when you start the car it will take longer to fire and run a bit rough for a second.

This is exactly how I did it on a 1990 740GL with Regina fuel system and the car runs awesome, it’s so much faster than n/a and really feels like a stock turbo car. I hope you can get your car to run just as well.


Videos added for motivation!

[stylngle2003]

wow, nice work dude.

[Jeh]

Nice work Matt. Its good to see someone try "the impossible" and make it happen.

[Ryan_R]

Really excellent stuff!

Cheers!
-Ryan

[Janspeed]

nice job! The stock NA compression and LPT boosting will make for a very pleasant DD. Probably good mileage as well.
what did you use in this +T car?
- stock cam or T-cam?
- stock injectors or greentops?
just for clarification purpose.

[Ryan_R]

Just for giggles, did Regina throw and OBD codes?

Any hint of rich running when open-loop on start up? Regina is supposedly pretty smart.

I'm really diggn' it. If I can scrape the parts together, this may be the spring project with the '91 745.

Thanks!
-Ryan

[500dollar744ti]

Originally Posted by Janspeed

nice job! The stock NA compression and LPT boosting will make for a very pleasant DD. Probably good mileage as well.
what did you use in this +T car?
- stock cam or T-cam?
- stock injectors or greentops?
just for clarification purpose.

i installed a T-cam, injectors are stock 18lb/hr.

Originally Posted by Ryan_R

Just for giggles, did Regina throw and OBD codes?

Any hint of rich running when open-loop on start up? Regina is supposedly pretty smart.

I'm really diggn' it. If I can scrape the parts together, this may be the spring project with the '91 745.

Thanks!
-Ryan

no OBD codes, Regina is dumb as a rock, it doesn't know that we are slaving the cold start injector for WOT purposes, nor does it know the fuel pressure has been raised. everything runs perfect, it's so fast compared to stock. i'd do it again in a heartbeat, it was easy, fun, and took two lazy afternoons to put together.

[gear whine]

this is awesome matt, good job. seriously.

[Ryan_R]

Originally Posted by 500dollar744ti

Regina is dumb as a rock,

That's kinda what I meant. Smart in a dumb way.... or dumb in a smart way.

Thanks for the info and effort! Brilliant!

-Ryan

[Manbeard]

Originally Posted by 500dollar744ti

i installed a T-cam, injectors are stock 18lb/hr.



no OBD codes, Regina is dumb as a rock, it doesn't know that we are slaving the cold start injector for WOT purposes, nor does it know the fuel pressure has been raised. everything runs perfect, it's so fast compared to stock. i'd do it again in a heartbeat, it was easy, fun, and took two lazy afternoons to put together.

hmmm may have to scrounge parts together and have you spend a lazy afternoon or two and help me do this. some day.. good work though man. you do some cool **** with your cars

[MrSam]

I've never owned a regina car, but if I ever end up with one this will be extremely helpful. I've driven a few regina cars, and they are pretty lacking. Even compared to the other N/A's.

Ok, so what are the chances of this system failing in the future? I don't know exactly why it would, but it seems like there's a reason nobody's done this.

I mean, if it were so difficult and intimidating for anyone else, could it really be that easy?

[WindowsBreakerG4]

Originally Posted by 500dollar744ti

no OBD codes, Regina is dumb as a rock

Bet that's why it was never CA legal

[Harlard]

Matt, I'm thinking of +Ting my 940. Do you think orange tops would work as well? Also, what is the line pressure of the stock Regina FPR? I have 3.0 bar and orangetops, so I thought that might be easier for me, so...

Any idea of what AFRs are looking like at boost?

[740volvo]

Orange tops from a 850 turbo car?? Yes they would but what are you going to use to subtract gasoline?? Need some sort of airflowconveter, I run a apexi vafc.

[Harlard]

Originally Posted by 740volvo

Orange tops from a 850 turbo car?? Yes they would but what are you going to use to subtract gasoline?? Need some sort of airflowconveter, I run a apexi vafc.

I know nothing about Regina. Do tell me more.

I am thinking of running an SMT6 to control fuel a bit.

[jerryc]

I seem to recall that Regina fpr is 2.5 bar.
The Regina system interests me because of the high mpg claims, that too many people who I think are reliable, report. I'd really like to know what the car in the OP does for mileage.

[740volvo]

The SMT6 will help a bit, I would say get an airflowconverter witch tricks the ecu and makes it think it's not reading pressure and you can control the % of the gasoline.
I run 440cc INJECTORS with Regina and the VAFC on 14psi w/out a problem I also have a walbro 310 in tank (11.8 AFR).
I get about 25-29 mpg on the HW and about 21-23 in the city (aka stop and go).

[500dollar744ti]

Originally Posted by harribert

Matt, I'm thinking of +Ting my 940. Do you think orange tops would work as well? Also, what is the line pressure of the stock Regina FPR? I have 3.0 bar and orangetops, so I thought that might be easier for me, so...

Any idea of what AFRs are looking like at boost?

it will run pig rich without a way to subtract fuel when out of boost. what i did was just a bare bones +t for those who want about 150hp out of regina.

if you want to start changing injectors and stuff like that, talk to 740volvo as he knows what aftermarket tuning components are needed to add to regina or trick it into working with much bigger injectors.

the +t i did here was a 2 hour job, what he did probably took longer than 2 hours.

my purpose was to prove that regina could handle a +t without adding any extra fuel/ignition controllers. if you want to start running bigger injectors, more boost and stuff like that you will need these things.

[740volvo]

That's still good though Matt you did a great job, I just went out of my way to be different and make it work with bigger injectors, I guess that's why I went from slammed Hondas to slammed Volvos

[Harlard]

Originally Posted by 500dollar744ti

it will run pig rich without a way to subtract fuel when out of boost. what i did was just a bare bones +t for those who want about 150hp out of regina.

if you want to start changing injectors and stuff like that, talk to 740volvo as he knows what aftermarket tuning components are needed to add to regina or trick it into working with much bigger injectors.

the +t i did here was a 2 hour job, what he did probably took longer than 2 hours.

my purpose was to prove that regina could handle a +t without adding any extra fuel/ignition controllers. if you want to start running bigger injectors, more boost and stuff like that you will need these things.

Got it, for a second I thought it was as simple as making K-Jet run pig rich on boost only. I'm probably going to run SMT6 as some of my buddies here have a lot of experience with it.

Originally Posted by 740volvo

The SMT6 will help a bit, I would say get an airflowconverter witch tricks the ecu and makes it think it's not reading pressure and you can control the % of the gasoline.
I run 440cc INJECTORS with Regina and the VAFC on 14psi w/out a problem I also have a walbro 310 in tank (11.8 AFR).
I get about 25-29 mpg on the HW and about 21-23 in the city (aka stop and go).

The VAFC sounds bitchin' though. I did some reading on it and the thing has a great interface. Sadly it might be a bit out of my price range.

About the airflow converter, you are talking about getting a converter on top of the piggyback? What would be the point?

I figured that if I can't make it work properly on Regina I can just install 2.4 with a 240 harness instead and call it good (changing the pressure plate would be a pain, but whatever.)

Originally Posted by 740volvo

That's still good though Matt you did a great job, I just went out of my way to be different and make it work with bigger injectors, I guess that's why I went from slammed Hondas to slammed Volvos

[Ryan_R]

Originally Posted by WindowsBreakerG4

Bet that's why it was never CA legal

I suspect the primitive MAP couldn't handle EGR.

-Ryan

[Ryan_R]

Originally Posted by 500dollar744ti

my purpose was to prove that regina could handle a +t without adding any extra fuel/ignition controllers. if you want to start running bigger injectors, more boost and stuff like that you will need these things.

I think we all greatly appreciate what you did! Thanks! Opened my eyes!

-Ryan

[740volvo]

Originally Posted by harribert

Got it, for a second I thought it was as simple as making K-Jet run pig rich on boost only. I'm probably going to run SMT6 as some of my buddies here have a lot of experience with it.





The VAFC sounds bitchin' though. I did some reading on it and the thing has a great interface. Sadly it might be a bit out of my price range.

About the airflow converter, you are talking about getting a converter on top of the piggyback? What would be the point?

I figured that if I can't make it work properly on Regina I can just install 2.4 with a 240 harness instead and call it good (changing the pressure plate would be a pain, but whatever.)

the VAFC is an airflowconverter, I wouldnt buy a new one that's for sure.
I found mine for $80 bucks from a local guy selling it on craigslist, I would check that may find some thing worth a try...

[Mad Adder]

I have a 92 Regina 940 and this is awesome to know. Thank you for doing the homework!!