Turbo systems for X1/9's

Aftermarket ECU question, for use with a turbo install.

Recently it seems there are several new options on the market for programmable ECU's. And they seem to be offering a lot more features for a lot less money than ever before. One thing I've been wondering has to do with the sensors most of these ECU's utilize. In addition to a crank position sensor for timing (fuel and spark), they also prefer a cam position sensor. The cam sensor is merely to tell the ECU which cycle the crank is on (as I understand). So it needs a signal every four rotations (hence the use of the cam) and is not as critical as the crank sensor as far as absolute accuracy (again, as I understand). I guess one question might be if all of this "as I understand" info is correct?

But my primary question has to do with utilizing such a ECU (requiring a cam sensor) on the X's SOHC. As far as I know there isn't a cam sensor for the SOHC that can easily be added. I did learn about one used on the Fiat Punto(???) that is essentially a replacement for the distributor. It is basically the lower half of a standard distributor with a wheel and sensor for the top half, no cap and high-tension wires, etc. By giving one signal per distributor rotation it is the input for the stock ECU on that engine. For use on the X's engine, replacing the distributor is not an issue as the aftermarket programmable ECU now controls all ignition functions with external coils. So this would work, unfortunately they are very difficult to get (in good working order) and very expensive if found.

But it has given me an idea. As an alternative could the standard X distributor be used as a cam position sensor by removing three of the four posts on the reluctor wheel? The distributor would now give one signal every four crank rotations (one distributor rotation), as needed. At least some (if not all) of the aftermarket ECU's are compatible with reluctor signals so I don't think that aspect would be an issue. The standard rotor would be left off and a replacement for the cap fabricated (basically a dust cover).

Any reason why this would not work?

On the Bosch systems I've worked with, the cam sensor is set to TDC on #1 as baseline. Any deviation created serious starting and/or drivability issues, as I discovered (after MUCH headache) when I addded aftermarket cams that had defective end cap slots. I'd get a cup & sensor from an existing (easy to locate) system & adapt them for your setup. Not hard to gut the dist & attach the cup & sensor cap. I'd lean toward modifiying a Cam end cap to house the sensor though, and have the cam drilled & tapped to retain the cup. Less work, IMO.

tdc-in-2.jpg
 
Alternatively using a cam based distributor for this use would get rid of a whole series of lash and variation from the equation.

Hussein and I were posting at the same time.
 
Thanks guys.

Karl, the crank sensor isn't as difficult to add due to it having an externally exposed pulley. It is the cam sensor I was more concerned about. But you have me intrigued about the twin-cam pulley you mentioned. What engine are you referring to?

Huss, when you speak of a "cup" are you referring to a wheel type trigger? And how would it be any different to adapt the distributor with a "cup and sensor from an existing system" than using the trigger system already in the X's distributor? I'm not questioning the suggestion, but wondering what advantage it offers.

I agree with both of you that driving a sensor directly off the cam might be a little more accurate. My thoughts were that, A) it is much more involved to develop a cam driven sensor vs a distributor based one for this engine, and B) the cam sensor does not have to be quite as precise as the crank sensor (but not certain if that is true) so a distributor based one would be fine.

As to the question of getting the sensor adjusted to TDC, that is an advantage with the distributor based design...easy to adjust.

Appreciate any further thoughts and details offered, thanks.
 
In another thread, "Mxgrds" said:
"My setup takes cooler air from outside the car, but also limits the intake air capacity. I didn’t realise who much air the turbo needs. Lately I was looking for the reason my turbo pressure dropped. This was the reason. I removed the hose and take the extra heat from the engine. Back to the drawing board."

What is limiting the air capacity? The location of the intake, the size of the tube, the size of the filter, or ??
Sorry, need to correct myself. It turns out the timing was to late. It was spot on 0 degrees, but that was not good enough. I moved the sensor about 4 degrees earlier (i am on vacation, so just on gut feeling). The car runs much better now. So i replaced the closed air filter and that als works fine now. Although hot (30 degrees in France Vosges) and long steep climbs, the radiator fan still hasn’t turned on. And all the power of the ut is utilized. I’m happy.
 
That's encouraging to hear. Keep us posted of any new developments.
And you are brave; not only did you take the X on a trip, but then you dared to start tweaking on it while away from home...things could get very interesting before the vacation is over.
Oh, and I'm totally jealous, I want to be there.
 
Sorry I meant the crank position sensor from the 138 based twin cam, it didn’t use a cam sensor that I am aware of though one never knows.

If you are using an adjustable cam wheel you could add a toothed wheel to that and mount the sensor to the cam cover. Alternatively one could add one to the back end of the cam where a cam driven distributor would have lived, either end is as accurate as the other. You would need to check but as the cam sensor is for timing your injection moment you may only need the one tooth or you may need more, it would depend on what the computer is expecting. The crank position sensor is for the ignition timing though some systems will interpolate the injection timing from that too.
 
Thanks Karl. I knew you were referring to the crank pulley/sensor. I was asking what specific engine that is from? Off hand I don't recognize what the "138 based twin cam" engine is.

I do have an adjustable cam pulley so there may be some options there. Good idea, I'll look closer. Unfortunately the other end of the cam won't work for this project. The intercooler is right there so no room for a cam mounted dizzy or any trigger wheels, etc.

I still need to get more details from the manufacturers. But with the newer aftermarket ECU's I'm looking at I have the impression (and it is only an impression so far) that the computer calculates both fuel and spark mainly from the crank sensor. The cam sensor only helps to say if the crank is on the 'fire' stroke each time around. In fact they have the option to just batch fire the fuel and a wasted spark and not use any cam sensor (crank only). But I'd like to run them sequentially since they offer the capability. I think this is one of those differences with these newer designs vs the entry level MegaSquirt units, actually more technology for the same money. But I'm still learning so things may change.

Anyone happen to know more about the type of signals given from the X's dizzy ("VR") vs the typical crank/cam triggers/sensors? I'm referring to the later electronic ignition dizzy for the X, and how the signals differ. Thanks again.
 
just look up "hall sensor" signal, versus "variable reluctance" signal ......

make sure whatever ecu you use - has the ability to measure that type of signal (basically the VR type inc in amplitude with rpm, and hence there is a "movement" of where is crosses the 0-volt line" due to the slope increasing with rpm.......hall doesn't have this type of issue.......

chk the "update rate" of said sensor type versus process speed of any ecu ....

rgds

sdo
 
The other day I did a little porting on some of the turbo project components. I'm not trying to change the design or make a big gain in output. But really just cleaning up the transitions from connecting components, hoping to decrease back pressure and therefore heat build up.

The intercooler/pressure pipes I'm using are larger diameter than the stock UT ones. Basically mine are the same diameter (ID) as the OD of the intake manifold's inlet (at the throttle body). So I wanted to taper off the transition going from/to any necks that the pipes clamp onto. Here is the inlet for the intake manifold:

011.JPG 012.JPG

And the inlet to the turbo compressor (from the much larger air filter):

013.JPG 014.JPG

Also the same treatment to the turbo's exhaust inlet, to better transition from the exhaust manifold (also ported but no photo):

017.JPG

And the internal wastegate port was opened up to allow more accurate boost control by the aftermarket ECU. This was also transitioned internally, along with the turbo inlet (above):

016.JPG

Combined with the large intercooler and the much larger downpipe and exhaust, these should help with reduced flow resistance (I hope).
 
Last edited:
Sorry its the twin cam version of the SOHC engine, it goes by the 159 engine moniker. I neglected to look it up earlier.
 
Thank you Andy. I was aware of its existence and what it does, but that's the first time I've seen exactly what is inside of it. In fact it might have been you that brought it to my attention initially?

At that time I was considering using all of the stock UT management (ECU, AFM, Ignition, Triggers, etc). But there were problems with doing that on the X's engine (SOHC 1500). The flywheel needs to be swapped with the UT one (for the rear sensor), but that requires a lot of clearancing of the bellhousing. You need to find a method of adding a cam sensor, which is why I looked at these cam phasers. The UT AFM is required to replace the X's, but these are very difficult to find, especially in working order (much like the cam phaser). Etc, etc. Although I had a few of the parts needed, I was missing the difficult ones. I did find a cam phaser available from Europe. The description said it 'should be' in good working order but they had not tested it to confirm (not a lot of confidence there). And the selling price plus shipping expense was rather excessive (in my opinion). Then there were other questions about the limitations of the stock UT's ECU program, and its use on a 1500. So ultimately I've decided to go with an aftermarket ECU. But I still need a cam position sensor. Having previously learned of the Punto "cam phase sensor" I got to wondering....

I'm thinking perhaps the stock X1/9 electronic (VR) distributor could do the same thing. By modifying the trigger (reluctor) wheel to only have 1 post (i.e. one trigger per dizzy rotation), it would provide the same basic function as your "cam phase sensor" does...giving one pulse for every four rotations of the crank. And it mounts/drives the same way; at the dizzy hole and off the aux shaft. So its level of accuracy, reliability, etc would be no different. I just need to find out from the aftermarket ECU makers if the type of signal it provides is correct. The specs for most of them say they work with hall sensor and reluctor type signals, but I need to confirm everything with them (unfortunately not a lot of detail on their websites).
 
If you prefer Hall to Reluctor you can get the bosch internals from a volvo or VW, I converted mine to hall using the internals from a 244 volvo disy they bolted straight in and have been working perfectly for six years
 
Dr Jeff,
I'm just slowly getting together the main parts for a 1.9 turbo and was thinking of using an ECU from OMEX as they are based in my home town.
I then came across this Uno Turbo build
http://www.guy-croft.com/viewtopic.php?t=3363
I'm not looking for this level of power but I noticed he was using a Punto Gt ECU that he had custom mapped by these guys
http://www.fcperformance.co.uk/fiat-punto-gt.php
They are not too far from me also. The power levels stated are for a 1.4 engine not a 1.9.

A little more research and I found that there is program called TunerPro that can be used to change the Map on these Motronic 2.7 ECUs
The 2.7 ecu is used on the Ferrari 355(among others) and they used Tunerpro to remap their ECUs. It's not quite as easy as plugging in and remapping but it is possible.

My thinking is that if I can use as many OEM parts as possible then should I breakdown then the recovery guys may have a chance to get us up and running at the road side. Also a lot of the setup for things like warmup, temperature , altitude and knock corrections have already been worked out.

The cost so far for a used ECU and wiring loom with most of the sensors is about 1/4 of just the ECU from OMEX.
The Punto GT uses a hot wire MAF meter so does not have the restrictive flap type used on the Uno. The crank speed is measured from the front pulley ( std 60/2 tooth arrangement) so any flywheel can be used.
I would not get too hung up about sequential injection on a road car. Using an electronic ignition distributor would be the easiest way to get cam position though.

Food for thought.
Andy
 
If you prefer Hall to Reluctor you can get the bosch internals from a volvo or VW
That would be very handy if whatever ECU I choose prefers a hall signal (it is the more common type).
Funny because I've worked with numerous Bosch distributors, the majority being hall effect, and I've never had a need to convert one to another format. So I did not even consider that idea. I am a bit surprised you were able to bolt things directly over, as Bosch seemed to make different main shafts for almost every application. But that is great to hear, thanks.
 
I noticed he was using a Punto Gt ECU that he had custom mapped by these guys
Thanks Andy.
Unfortunately we never got the Punto in any form here, and certainly not the GT. So finding components for them puts me back in the same predicament as with the UT stuff. By the time I located things in Europe, shipped it here, and had it custom tuned, I would have the same money tied up on used parts as if I bought a new custom ECU. But for your situation it sounds like a great idea. Hopefully the maps can be altered enough to work with your turbo 1.9; that's a big jump from the stock Punto GT.

I'm curious, how does the MAF meter's flow capacity compare to having no MAF or AFM (as with a aftermarket ECU)?
 
Dr Jeff,
I'm just slowly getting together the main parts for a 1.9 turbo and was thinking of using an ECU from OMEX as they are based in my home town.
I then came across this Uno Turbo build
http://www.guy-croft.com/viewtopic.php?t=3363
I'm not looking for this level of power but I noticed he was using a Punto Gt ECU that he had custom mapped by these guys
http://www.fcperformance.co.uk/fiat-punto-gt.php
They are not too far from me also. The power levels stated are for a 1.4 engine not a 1.9.

A little more research and I found that there is program called TunerPro that can be used to change the Map on these Motronic 2.7 ECUs
The 2.7 ecu is used on the Ferrari 355(among others) and they used Tunerpro to remap their ECUs. It's not quite as easy as plugging in and remapping but it is possible.

My thinking is that if I can use as many OEM parts as possible then should I breakdown then the recovery guys may have a chance to get us up and running at the road side. Also a lot of the setup for things like warmup, temperature , altitude and knock corrections have already been worked out.

The cost so far for a used ECU and wiring loom with most of the sensors is about 1/4 of just the ECU from OMEX.
The Punto GT uses a hot wire MAF meter so does not have the restrictive flap type used on the Uno. The crank speed is measured from the front pulley ( std 60/2 tooth arrangement) so any flywheel can be used.
I would not get too hung up about sequential injection on a road car. Using an electronic ignition distributor would be the easiest way to get cam position though.

Food for thought.
Andy


If it's of interest to any would be turbo builders I have a 1.4 ecu, re conditioned afm, dastek uni chip and other ignition parts that I no longer need as I have gone for a mappable ecu. There is no wiring loom but it would be a good start. It was running at 185hp (lots of other go faster bits needed to achieve that) but I would say a safer option would be nearer 150-160hp as the standard engine management system struggles to control the fueling much above this
 
If it's of interest to any would be turbo builders I have a 1.4 ecu, re conditioned afm, dastek uni chip and other ignition parts that I no longer need as I have gone for a mappable ecu. There is no wiring loom but it would be a good start. It was running at 185hp (lots of other go faster bits needed to achieve that) but I would say a safer option would be nearer 150-160hp as the standard engine management system struggles to control the fueling much above this
PM sent
 
I have a 1.4 ecu
Is that the UT Mk2, with the ECU as part of the AFM? From what I understand it is capable of some map upgrades (I believe what you called a "dastek uni chip"), which the Mk1 UT (1300) is not. Definitely a benefit. Given the Mk2 uses a different turbo, how compatible is this set up with the Mk1's turbo? Also, is that chip programmable (as in the maps can be customized)? Thanks for the info.
 
It is a Mk2 ecu and afm. The ecu is separate to the afm but is capable of upgrades with such as a Dastek Unichip. It is wired in between the afm and ecu and intercepts certain signals to and from the afm and then modifies the fuel and ignition outputs according to your need. You need the right software to programme it , consider it a halfway house to a fully mappable system as standard ecus are designed to a price and for a limited set of parameters.
The systems on the mk1 and Mk2 are very similar and so I would see no reason why you couldn't use one on a mk1
 
Back
Top