DastardlyDan
Active Member
A few people have now asked me to write up a little bit about the mods I've done/working on for the L series. Might as well make it into a small guide as well eh?
INJECTORS
First up, the Freelander injectors have been swapped out for Rover SDi injectors - these have slightly larger nozzles, that give an instant bump in power throughout the rev-range.
Expect to pay £50-£100 for a set, you'll also need new copper washers for the leakoff banjo joins, new leakoff pipe, and new sealing washers for the injectors themselves. Buying a large pack of copper washers is FAR more cost effective than buying the specific washers from Land Rover/ebay. And the injector washers can be had dirt-cheap from DMGRS:
L Series Injector Sealing Washers - ERR4621. (200/400/600/25/45/ZR/ZS) | Discount MG Rover Spares
PUMP
There's a fair few things I'm playing with for the pump, ranging from "simple", all the way to "wtf are you even doing??"
Easiest mod - the EVRY mod. The fuel pump used on our L series, is a Bosch VP37. This basically is a mechanical fuel pump, modified with a servo slapped on top, to move the fuel control collar (the mechanical ones simply move this with a lever, and an array of springs/weights). But as with any servo, there's a position feedback system. In this case, it's just a variable resistor. So we can force it to inject a bit more fuel, by simply making the ECU think the servo hasn't moved far enough.
How do we do this? Shove another variable resistor across the feedback wires!
To do this, you first need a 2K ohm variable resistor, and some wire. Solder the resistor to the wires, and then crimp/solder these two wires to pins 6 and 7 on the fuel pump wiring, yellow/black and red, respectively
With it set to maximum resistance - it won't affect the engine at all (or as I call it, the "MOT setting" ) But with it around 3/4 of the way round (approx 500 Ohms) it'll start to make quite a noticeable difference in power. If you go too far, it'll simply stall - so it lets you know rather easily. Mine is nearly the entire way round before this happens.
The next real mod, is fitting a larger pump head. Ours currently has a 10mm head, with a large camplate (3.2mm lift IIRC) whilst the Rover SDi pump has an 11mm head, but only 2.5mm lift on the camplate. It's a straight swap to replace the head+piston into the freelander pump. The freelander pump also has the stronger casing, larger advance piston cover, and the servo has more throw on it too. Only thing that is made awkward, is by increasing the piston diameter, the pump timing needs to be adjusted to suit. Once I've measured what the stock camplate lift @TDC is, it'll be easy enough to rework it to the new configuration. No guesswork needed.
Now, the "wtf are you even doing??" mod, is simply taking the EVRY mod to the next level. Instead of bodging a sensor reading, to move it a little bit futher... why not simply feed the servo a full-fat 12v signal, instead of a PWM 12v signal (PWM = Pulse Width Modulated, basically switching a signal on an off reeeally fast, to make it act like a lower voltage, with the same current. The more time it's "on", the higher the effective voltage, with 100% just making it the full source voltage).
I've tried this - but the ECU was NOT happy that it suddenly had zero control over the pump. It started to rev up, but the ECU soon cut all power, killing the engine. A future rework on this idea, is to bypass the ECU entirely with a pair of relays, activated by a switch at WOT. Should give an amazing smokescreen :lol:
TURBO
First things first - the turbo fitted to the L series, in every configuration, is a GT1549. Meaning the overall turbine can be considered a size "15" (you can't get any actual definitive measurements from this designation, it's simply used for size generalisations of the turbine housing - the bigger the number, the bigger the turbine housing) and the compressor wheel has a diameter of 49mm.
But not all wheels are created equal.. The SDi turbo is the middle brother of 3 types fitted - with the GT1549 fitted to Rover 25/45 MGZR/MGZS L series, being a far more efficient varient. The turbo fitted to ours is only capable of supporting up to around 130Bhp (at 19psi - going higher can lose power). But the late-spec turbo, can happily support up to around 155Bhp.
To fit the late-spec turbo, you need to swap the turbine housings over - this entails removing the four 8mm bolts holding the two steel plates on, that hold the turbing housing, to the core. Once you've removed these you need to remove the housing from the core... I recommend a LARGE copper hammer, and lots of penetrating fluid. Once you've removed both turbo housings, simply swap them over - the turbine wheels are identical across all the variants used on L series. Congrats - you can now support up to 155Bhp of airflow!
But... that's not all you can do
On the left is a stock SD GT1549 (the one that's lower than the SDi turbo) and the one on the right, is the Mk3 hybrid - using a different (secret) turbine housing, machined to suit a GT1752 from a Saab. This happily made the first 180Bhp L series
Since then, it seems almost any 52mm wheel, running at around 23psi, will get an L series to around 180Bhp. I've currently got a GT1752 off a Movano van, that I'm making adaptor plates up for, to bolt on with no fuss. Much simpler than importing housings, and getting them machined!
MAP SENSOR
This was the most current experiment - to see how "crude" our ECU actually was. Turns out it's not as dim as I thought it would be :lol:
Someone handily made this little chart a while ago, that maps boost pressure to output voltage:
Now, when you start to play with the EVRY mod, and more fuel... what you'll find is once you start to go above 21psi (which will happen if you suddenly dump a LOT of fuel in) is that the engine will refuse to fuel any further, meaning the engine simply won't rev any higher. Incredibly irritating, and damned scary.
I was going to simply cap the voltage to 4.3v with a zener diode, but then thought, why not simply replace the MAP sensor entirely, and just feed in a constant 4.3v? Was worth a try....
What happened? Well the low-end response was amazing - as the ECU thought it had a full 19psi, even at idle. But once you tried to rev it, it brought on the engine warning lamp. As I had no idea how it would further try to compensate, I just removed it.
REMAP
Not a mod I've made myself - but it does need to be said....
If any remappers tell you "it can't be done", then they're talking out of their arse, or they simply only think you can remap through an OBD port. This ECU requires the two memory chips to be desoldered, and sockets fitted to allow the chips to be swapped out, with reprogrammed items. All the wiring things I've mentioned, are at best - bodges. Once you start going with bigger turbos and bigger pumps, you NEED a remap to get the best out of your engine, and can get you far more power, with less smoke (these mods have zero refinement don't forget).
Once I've got one of the two turbos fitted, I'll be taking mine to a close friend up in Wakefield - trading under "Dieselpowered", easy to find on FB:
https://www.facebook.com/dieselpowered?fref=ts
He mapped the first 180Bhp L series, has made a ridiculous amount of advancements in mapping the later L series lumps, and owned+mapped the first L series that broke 200Bhp (212Bhp, to be exact)
So... those are all the engine mods I've made so far. With far more waiting to be tried
INJECTORS
First up, the Freelander injectors have been swapped out for Rover SDi injectors - these have slightly larger nozzles, that give an instant bump in power throughout the rev-range.
Expect to pay £50-£100 for a set, you'll also need new copper washers for the leakoff banjo joins, new leakoff pipe, and new sealing washers for the injectors themselves. Buying a large pack of copper washers is FAR more cost effective than buying the specific washers from Land Rover/ebay. And the injector washers can be had dirt-cheap from DMGRS:
L Series Injector Sealing Washers - ERR4621. (200/400/600/25/45/ZR/ZS) | Discount MG Rover Spares
PUMP
There's a fair few things I'm playing with for the pump, ranging from "simple", all the way to "wtf are you even doing??"
Easiest mod - the EVRY mod. The fuel pump used on our L series, is a Bosch VP37. This basically is a mechanical fuel pump, modified with a servo slapped on top, to move the fuel control collar (the mechanical ones simply move this with a lever, and an array of springs/weights). But as with any servo, there's a position feedback system. In this case, it's just a variable resistor. So we can force it to inject a bit more fuel, by simply making the ECU think the servo hasn't moved far enough.
How do we do this? Shove another variable resistor across the feedback wires!
To do this, you first need a 2K ohm variable resistor, and some wire. Solder the resistor to the wires, and then crimp/solder these two wires to pins 6 and 7 on the fuel pump wiring, yellow/black and red, respectively
With it set to maximum resistance - it won't affect the engine at all (or as I call it, the "MOT setting" ) But with it around 3/4 of the way round (approx 500 Ohms) it'll start to make quite a noticeable difference in power. If you go too far, it'll simply stall - so it lets you know rather easily. Mine is nearly the entire way round before this happens.
The next real mod, is fitting a larger pump head. Ours currently has a 10mm head, with a large camplate (3.2mm lift IIRC) whilst the Rover SDi pump has an 11mm head, but only 2.5mm lift on the camplate. It's a straight swap to replace the head+piston into the freelander pump. The freelander pump also has the stronger casing, larger advance piston cover, and the servo has more throw on it too. Only thing that is made awkward, is by increasing the piston diameter, the pump timing needs to be adjusted to suit. Once I've measured what the stock camplate lift @TDC is, it'll be easy enough to rework it to the new configuration. No guesswork needed.
Now, the "wtf are you even doing??" mod, is simply taking the EVRY mod to the next level. Instead of bodging a sensor reading, to move it a little bit futher... why not simply feed the servo a full-fat 12v signal, instead of a PWM 12v signal (PWM = Pulse Width Modulated, basically switching a signal on an off reeeally fast, to make it act like a lower voltage, with the same current. The more time it's "on", the higher the effective voltage, with 100% just making it the full source voltage).
I've tried this - but the ECU was NOT happy that it suddenly had zero control over the pump. It started to rev up, but the ECU soon cut all power, killing the engine. A future rework on this idea, is to bypass the ECU entirely with a pair of relays, activated by a switch at WOT. Should give an amazing smokescreen :lol:
TURBO
First things first - the turbo fitted to the L series, in every configuration, is a GT1549. Meaning the overall turbine can be considered a size "15" (you can't get any actual definitive measurements from this designation, it's simply used for size generalisations of the turbine housing - the bigger the number, the bigger the turbine housing) and the compressor wheel has a diameter of 49mm.
But not all wheels are created equal.. The SDi turbo is the middle brother of 3 types fitted - with the GT1549 fitted to Rover 25/45 MGZR/MGZS L series, being a far more efficient varient. The turbo fitted to ours is only capable of supporting up to around 130Bhp (at 19psi - going higher can lose power). But the late-spec turbo, can happily support up to around 155Bhp.
To fit the late-spec turbo, you need to swap the turbine housings over - this entails removing the four 8mm bolts holding the two steel plates on, that hold the turbing housing, to the core. Once you've removed these you need to remove the housing from the core... I recommend a LARGE copper hammer, and lots of penetrating fluid. Once you've removed both turbo housings, simply swap them over - the turbine wheels are identical across all the variants used on L series. Congrats - you can now support up to 155Bhp of airflow!
But... that's not all you can do
On the left is a stock SD GT1549 (the one that's lower than the SDi turbo) and the one on the right, is the Mk3 hybrid - using a different (secret) turbine housing, machined to suit a GT1752 from a Saab. This happily made the first 180Bhp L series
Since then, it seems almost any 52mm wheel, running at around 23psi, will get an L series to around 180Bhp. I've currently got a GT1752 off a Movano van, that I'm making adaptor plates up for, to bolt on with no fuss. Much simpler than importing housings, and getting them machined!
MAP SENSOR
This was the most current experiment - to see how "crude" our ECU actually was. Turns out it's not as dim as I thought it would be :lol:
Someone handily made this little chart a while ago, that maps boost pressure to output voltage:
Now, when you start to play with the EVRY mod, and more fuel... what you'll find is once you start to go above 21psi (which will happen if you suddenly dump a LOT of fuel in) is that the engine will refuse to fuel any further, meaning the engine simply won't rev any higher. Incredibly irritating, and damned scary.
I was going to simply cap the voltage to 4.3v with a zener diode, but then thought, why not simply replace the MAP sensor entirely, and just feed in a constant 4.3v? Was worth a try....
What happened? Well the low-end response was amazing - as the ECU thought it had a full 19psi, even at idle. But once you tried to rev it, it brought on the engine warning lamp. As I had no idea how it would further try to compensate, I just removed it.
REMAP
Not a mod I've made myself - but it does need to be said....
If any remappers tell you "it can't be done", then they're talking out of their arse, or they simply only think you can remap through an OBD port. This ECU requires the two memory chips to be desoldered, and sockets fitted to allow the chips to be swapped out, with reprogrammed items. All the wiring things I've mentioned, are at best - bodges. Once you start going with bigger turbos and bigger pumps, you NEED a remap to get the best out of your engine, and can get you far more power, with less smoke (these mods have zero refinement don't forget).
Once I've got one of the two turbos fitted, I'll be taking mine to a close friend up in Wakefield - trading under "Dieselpowered", easy to find on FB:
https://www.facebook.com/dieselpowered?fref=ts
He mapped the first 180Bhp L series, has made a ridiculous amount of advancements in mapping the later L series lumps, and owned+mapped the first L series that broke 200Bhp (212Bhp, to be exact)
So... those are all the engine mods I've made so far. With far more waiting to be tried
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