I am wanting to save a few dollars and gain a little more know how on working on my car. I am jumping in at the deep end as money is tight. I would like to have this done before possibly having the ECU unlocked and retuned.
I want to find out how I can advance the cam timing with my ajustable cam gears. Do i need special tools? difficult job? car off road? is dynoing while setting just to see the gain/loss, or can i do it and just get a full retune?will it ping etc
Any advice or instructions appreciated

Could be complely wrong here and pls correct me if i am.... don't u need a piggy back ecm before u can adjust the timing of the cam. The stock ecm is tuned and lock from factory and more than likly adjusting the cam timing will lose u power than gain it..

Could be complely wrong here and pls correct me if i am.... don't u need a piggy back ecm before u can adjust the timing of the cam. The stock ecm is tuned and lock from factory and more than likly adjusting the cam timing will lose u power than gain it..

Not correct on the magna mate. Adjusting the cam timing is a physical movement of the cams via adjustable cam gears.

yep correct as on all engines the cam has a direct mechanical link to the crank but my point being that adjusting that mechanic link will alter the cam timing and thus loose u power with a factory tune as the altermate settings for the cam profile are already set. even by a couple of degrees will more than likly loose u power with a factory tune. not to mention possible error codes.

yep correct as on all engines the cam has a direct mechanical link to the crank but my point being that adjusting that mechanic link will alter the cam timing and thus loose u power with a factory tune as the altermate settings for the cam profile are already set. even by a couple of degrees will more than likly loose u power with a factory tune. not to mention possible error codes.

Mate ive built and changed the cam timing on lots of magnas over the years and never once have i got a error/check engine light come on and none have lost power either. If ya read the thread starters first post, he wants to move his cam timing as he is getting steve knight to remap his ECU.

The variences from factory can see tha cam timing out by up to 5degrees anyway.

*Edit* but what would i know :doubt:

Mate ive built and changed the cam timing on lots of magnas over the years and never once have i got a error/check engine light come on and none have lost power either. If ya read the thread starters first post, he wants to move his cam timing as he is getting steve knight to remap his ECU.

The variences from factory can see tha cam timing out by up to 5degrees anyway.

*Edit* but what would i know :doubt:

:gtfo:
























:D

yep correct as on all engines the cam has a direct mechanical link to the crank but my point being that adjusting that mechanic link will alter the cam timing and thus loose u power with a factory tune as the altermate settings for the cam profile are already set. even by a couple of degrees will more than likly loose u power with a factory tune. not to mention possible error codes.

mate when it comes to cams and magnas jason is the person to see
from reading what hes done to the info he gives i known for a fact that this guys knows what hes on about
so i and im sure a few others dont really argue with what he has to say
i like what he says as its really helpful and you learn from it :)

yeah cool im still a newb just giving my opinion and i was wrong and glad to be proven wrong its how we learn didn't mean to offend or stand on any toes...

yeah cool im still a newb just giving my opinion and i was wrong and glad to be proven wrong its how we learn didn't mean to offend or stand on any toes...

Na its all cool mate no offence taken :P

anyone able to help with an how to?

The reason you may want to change the cam position is to change the engine power characteristics, throttle response and fuel economy.

Most manufacturers set their engines up with a lot of retard; typically 6-8 deg. Engines with variable cam timing generally start, idle and cruise with that much or more retard. Then at full throttle and low to about 80% maximum revs they go advanced, generally at least 9-11 deg (from the retard position, so 2-3 deg actual adv) but can be as much as 20 deg (actual 6-8 deg adv). At max revs they go retard (a true 2-6 deg) to get more cylinder filling and help HP from closing the inlet valve later.

Manufacturers retard for several reasons, but mainly for smooth idle and reduced emissions. Retarded the cam acts like exhaust gas recirculation so nitrogen oxides go down. The ex gases are hotter so the CAT converter burns better(at higher revs/load this is a problem so they pump extra fuel into the system to cool the CAT, hence stupid 11:1 A/F ratios at full throttle). However cam retard cuts low speed power and make for a dead unresponsive engine. You lose economy too because you have to use more throttle to get good power for hills and accelerations, not to mention whats wasted cooling the CAT!

With fixed cam timing like on our Magnas and 380s we want the cam advanced for best economy, power and throttle response. Most road engines like the inlet valve full open at about 104-106 deg after TDC but if the compression ratio is too high for the fuel you may have to run less cam advance/less spark adv.

I don't know how much Mitsubishi have retarded the cams but a friend has just bought a 380 engine, a 3.5 engine and a set of Ralliart cams. He will let me know and I'll pass that on on the forum.

To time the cams takes a few tools and lots of patience when the engine is in the car. Out of the car it is a lot easier because you can see everything more clearly. I won't describe how to do it because you can link to lots of places to get the basic details(eg. http://www.compcams.com/Technical/Instructions/Files/145.pdf and go to page 8).

The most important thing is to first accurately find TDC, then find where the inlet valve is full open on both banks with your cam sprockets set to 0 deg. If its full open say 114 deg rear bank and 117 deg front bank then advance the rear cam 8 deg and the front 11 deg. Then double check your work and verify that the inlets are actually full open at both banks at 106 deg ATDC. Only on a dyno will you really find how much adv is best but 106 deg ATDC is a good starting point.

Actually just slotting the stock sprockets allows the same thing, its just a bit more of a fiddle. Some worry about a slotted sprocket moving. Thats not a problem if the bolt is properly tensioned. Its friction between the cam and sprocket that keeps everything in place, not the cam sprocket locating pin.

Cheers, Alan

The reason you may want to change the cam position is to change the engine power characteristics, throttle response and fuel economy.

Most manufacturers set their engines up with a lot of retard; typically 6-8 deg. Engines with variable cam timing generally start, idle and cruise with that much or more retard. Then at full throttle and low to about 80% maximum revs they go advanced, generally at least 9-11 deg (from the retard position, so 2-3 deg actual adv) but can be as much as 20 deg (actual 6-8 deg adv). At max revs they go retard (a true 2-6 deg) to get more cylinder filling and help HP from closing the inlet valve later.

Manufacturers retard for several reasons, but mainly for smooth idle and reduced emissions. Retarded the cam acts like exhaust gas recirculation so nitrogen oxides go down. The ex gases are hotter so the CAT converter burns better(at higher revs/load this is a problem so they pump extra fuel into the system to cool the CAT, hence stupid 11:1 A/F ratios at full throttle). However cam retard cuts low speed power and make for a dead unresponsive engine. You lose economy too because you have to use more throttle to get good power for hills and accelerations, not to mention whats wasted cooling the CAT!


With fixed cam timing like on our Magnas and 380s we want the cam advanced for best economy, power and throttle response. Most road engines like the inlet valve full open at about 104-106 deg after TDC but if the compression ratio is too high for the fuel you may have to run less cam advance/less spark adv.

I don't know how much Mitsubishi have retarded the cams but a friend has just bought a 380 engine, a 3.5 engine and a set of Ralliart cams. He will let me know and I'll pass that on on the forum.

To time the cams takes a few tools and lots of patience when the engine is in the car. Out of the car it is a lot easier because you can see everything more clearly. I won't describe how to do it because you can link to lots of places to get the basic details(eg. http://www.compcams.com/Technical/Instructions/Files/145.pdf and go to page 8).

The most important thing is to first accurately find TDC, then find where the inlet valve is full open on both banks with your cam sprockets set to 0 deg. If its full open say 114 deg rear bank and 117 deg front bank then advance the rear cam 8 deg and the front 11 deg. Then double check your work and verify that the inlets are actually full open at both banks at 106 deg ATDC. Only on a dyno will you really find how much adv is best but 106 deg ATDC is a good starting point.

Actually just slotting the stock sprockets allows the same thing, its just a bit more of a fiddle. Some worry about a slotted sprocket moving. Thats not a problem if the bolt is properly tensioned. Its friction between the cam and sprocket that keeps everything in place, not the cam sprocket locating pin.

Cheers, Alan

thanks. after reading that i will just probably just pay someone, as i do not have SST required for the job

The reason you may want to change the cam position is to change the engine power characteristics, throttle response and fuel economy.

Most manufacturers set their engines up with a lot of retard; typically 6-8 deg. Engines with variable cam timing generally start, idle and cruise with that much or more retard. Then at full throttle and low to about 80% maximum revs they go advanced, generally at least 9-11 deg (from the retard position, so 2-3 deg actual adv) but can be as much as 20 deg (actual 6-8 deg adv). At max revs they go retard (a true 2-6 deg) to get more cylinder filling and help HP from closing the inlet valve later.

Manufacturers retard for several reasons, but mainly for smooth idle and reduced emissions. Retarded the cam acts like exhaust gas recirculation so nitrogen oxides go down. The ex gases are hotter so the CAT converter burns better(at higher revs/load this is a problem so they pump extra fuel into the system to cool the CAT, hence stupid 11:1 A/F ratios at full throttle). However cam retard cuts low speed power and make for a dead unresponsive engine. You lose economy too because you have to use more throttle to get good power for hills and accelerations, not to mention whats wasted cooling the CAT!

With fixed cam timing like on our Magnas and 380s we want the cam advanced for best economy, power and throttle response. Most road engines like the inlet valve full open at about 104-106 deg after TDC but if the compression ratio is too high for the fuel you may have to run less cam advance/less spark adv.

I don't know how much Mitsubishi have retarded the cams but a friend has just bought a 380 engine, a 3.5 engine and a set of Ralliart cams. He will let me know and I'll pass that on on the forum.

To time the cams takes a few tools and lots of patience when the engine is in the car. Out of the car it is a lot easier because you can see everything more clearly. I won't describe how to do it because you can link to lots of places to get the basic details(eg. http://www.compcams.com/Technical/Instructions/Files/145.pdf and go to page 8).

The most important thing is to first accurately find TDC, then find where the inlet valve is full open on both banks with your cam sprockets set to 0 deg. If its full open say 114 deg rear bank and 117 deg front bank then advance the rear cam 8 deg and the front 11 deg. Then double check your work and verify that the inlets are actually full open at both banks at 106 deg ATDC. Only on a dyno will you really find how much adv is best but 106 deg ATDC is a good starting point.

Actually just slotting the stock sprockets allows the same thing, its just a bit more of a fiddle. Some worry about a slotted sprocket moving. Thats not a problem if the bolt is properly tensioned. Its friction between the cam and sprocket that keeps everything in place, not the cam sprocket locating pin.

Cheers, Alan


fyi the 3.8 runs ralliart magna profile cams.

Standard 3.5's run 2 degrees retard. Ralliart and 380 are 6 degrees retard. The retard is used to boost top end power. Valve overlap is what helps EGR. Thats why 380's don't have an EGR valve the extra overlap even only very slight helped with emissions that it could be deleted.
Fit adjustable sprockets and you can tailor the torque curve to your requirements.

Cheers Dave.

Overlap can help with EGR too but manufacturers like to minimise overlap to smooth the idle, get HC emissions down and possibly help economy. Cam retard gives more EGR at light throttle and lower rpm, usually (but not always depending on where NOx is high) the EGR system comes in under engine load with more throttle so each arrangement is used to counter emissions at different engine operating conditions.

Did the Ralliart Magna use EGR valve? I doubt if the bigger cam in the 380 was the reason for them being able to get rid of the EGR system as some stock engines have quite "sporty" cams yet need EGR to pass emissions testing while others barely have a cam and don't need EGR. Combustion chamber and piston crown shape, bore size, rod length and stroke, mixture homogenisation, temperature and swirl, ECU mapping of fuel and spark all affect the burn and cylinder pressure, and what NOx levels will be.

Manufacturers also like cam retard as it helps kill low speed torque and traction problems. The traction control doesn't have to be working so often, less torque steer, wheel spin, etc.

Cam retard can sometimes help a little bit with top end HP but because of the losses elsewhere you never do that to a performance or race engine. These always are best with the cam straight up or advanced. Usually advanced unless you have traction issues and want to kill torque, or the compression ratio is too high and retarding the cam is hurting the power less than retarding a lot of spark.

Has anyone actually checked a 380 cam to see if its the Ralliart profile?

Also at what point are the 3.5 cams 2 deg retarded, and the Ralliart and 380 retarded 6 deg? Was that at the inlet full open compared to the exhaust full open?

Cheers, Alan

Hi All, I spent 7hours on Monday replacing the cam belt and water pump and have the cuts to prove it. I also fitted adjustable cam gears, Steve Knight and his mate Dave, recomended 4deg retard from stock position, I must say there is a small BUT noticable difference through the whole rev range. It has a more distinct throb at idle too. Next is inlet manifold and 80mm T/B and then a SKR retune:cool:

Hi All, I spent 7hours on Monday replacing the cam belt and water pump and have the cuts to prove it. I also fitted adjustable cam gears, Steve Knight and his mate Dave, recomended 4deg retard from stock position, I must say there is a small BUT noticable difference through the whole rev range. It has a more distinct throb at idle too. Next is inlet manifold and 80mm T/B and then a SKR retune:cool:

Hey John why bother with the larger TB?

My current "donkey" engine is running a stock plenum and a flowed stock TB and had no problems flowing enough air to make the output that it did on SKR's dyno.

Hi All, I spent 7hours on Monday replacing the cam belt and water pump and have the cuts to prove it. I also fitted adjustable cam gears, Steve Knight and his mate Dave, recomended 4deg retard from stock position, I must say there is a small BUT noticable difference through the whole rev range. It has a more distinct throb at idle too. Next is inlet manifold and 80mm T/B and then a SKR retune:cool:

Maybe the placebo effect. I have dyno charts and 60 foot times to prove my car has less torque than with advanced gears, and slower times compared to stock. Unless your talking about a change in less bottom, more top, cos you cant have both. Was that 4 more than the said 6 factory degrees on a ralliart?

Yes Alan the 380 cam profile is the same as a Ralliart. And yes before that cam the Ralliart cam the 380 neede EGR. The Ralliart had EGR because MMAL made provision for it because there was several profiles of cam before one was chosen and yes idle quality was an issue.

Cheers Dave

OK thanks Dave for that info.

For anything except emissions and idle quality cam retard is generally not a good thing for everyday driving.

There are exceptions as I've already outlined - it helps with traction problems and if the compression ratio is too high a mix of cam retard/ign retard can hurt the torque curve less than just ign retard. One other area it helps that I forgot was in manual tranny cars retard can help driveline jerkiness, and in bikes chain snap and shudder.

Compared to a cam 4-6 deg advanced, with very short duration/low lift baby cams sometimes up to 2-3 deg retard will let the engine rev a bit higher past max HP rpm and maybe make 1-2% more torque at cutout revs, but more than 3 deg retard you lose out everywhere in my experience. Even at only 2-3 deg retard the torque curve takes a beating from idle revs right up to max HP revs and on all the dyno pulls I've done. At small throttle openings of 15-35% open that we use in everyday driving the engine can be losing 20% torque in the 1200 to 3500 rpm range(at full throttle its generally about a 5-7% drop so isn't as noticeable).

Manufacturers know this and that is why many state the head or block shouldn't be milled more than say 0.005 - 0.010" combined (some even state there is to be no head or block milling done) as this retards the cam/s.

Cheers, Alan

alan i enjoy your input its informative and well written, cheers!!

OK thanks Dave for that info.

For anything except emissions and idle quality cam retard is generally not a good thing for everyday driving.

There are exceptions as I've already outlined - it helps with traction problems and if the compression ratio is too high a mix of cam retard/ign retard can hurt the torque curve less than just ign retard. One other area it helps that I forgot was in manual tranny cars retard can help driveline jerkiness, and in bikes chain snap and shudder.

Compared to a cam 4-6 deg advanced, with very short duration/low lift baby cams sometimes up to 2-3 deg retard will let the engine rev a bit higher past max HP rpm and maybe make 1-2% more torque at cutout revs, but more than 3 deg retard you lose out everywhere in my experience. Even at only 2-3 deg retard the torque curve takes a beating from idle revs right up to max HP revs and on all the dyno pulls I've done. At small throttle openings of 15-35% open that we use in everyday driving the engine can be losing 20% torque in the 1200 to 3500 rpm range(at full throttle its generally about a 5-7% drop so isn't as noticeable).

Manufacturers know this and that is why many state the head or block shouldn't be milled more than say 0.005 - 0.010" combined (some even state there is to be no head or block milling done) as this retards the cam/s.

Cheers, Alan

I have aa dynoo print showing only 5 hp gain retearding cams 2 degrees over advanced 4 degrees. It also shows the torque lost at low revs, whish is what i want back

Hey John why bother with the larger TB?

My current "donkey" engine is running a stock plenum and a flowed stock TB and had no problems flowing enough air to make the output that it did on SKR's dyno.

Both Steve and Dave said the inlet manifold is too long and the stock T/B is to small, but Mitsubishi wouldnt let them change it in the develoment of the engine. So the idea is to try a 100mm plenum with 80mm T/B and inlet manifold 1inch shorter in the runners. The runner length is a bit of an educated guess and a start point that both Steve and Dave seperately recommended. Dave worked in the dyno shop at Mitsu, from what I can gather, and said 4deg retard will give about 8kwatw.
Will keep ya posted:D

Both Steve and Dave said the inlet manifold is too long and the stock T/B is to small, but Mitsubishi wouldnt let them change it in the develoment of the engine. So the idea is to try a 100mm plenum with 80mm T/B and inlet manifold 1inch shorter in the runners. The runner length is a bit of an educated guess and a start point that both Steve and Dave seperately recommended. Dave worked in the dyno shop at Mitsu, from what I can gather, and said 4deg retard will give about 8kwatw.
Will keep ya posted:D

It would be 8kw at the very outside perhaps, but you must bear in mind that 8kw is in the top end, where the car is rarely driven constantly. It is great to have a high figure but essentially it is the takeoff and general ability for spirited driving occassionally that you will enjoy most, and this is where the autos suck, especially as i noticed after my mods. i do agree however a bigger throttle body can be of good advantage.

Both Steve and Dave said the inlet manifold is too long and the stock T/B is to small, but Mitsubishi wouldnt let them change it in the develoment of the engine. So the idea is to try a 100mm plenum with 80mm T/B and inlet manifold 1inch shorter in the runners. The runner length is a bit of an educated guess and a start point that both Steve and Dave seperately recommended. Dave worked in the dyno shop at Mitsu, from what I can gather, and said 4deg retard will give about 8kwatw.
Will keep ya posted:D

John to give you a guide that the TB isnt a major restriction on a mildly worked 3.5L (especially your ralliart), Chris aka Levi has a 75mm TB on his fairly worked 3.5L NA magna and made about 4kw's less than my car with stock TB, also steve said to me that there was no need for a larger TB on my "donkey" engine when we dynod it a couple of weeks ago and all that was limiting my engine making more power was the lack of fueling from 4700rpm upwards.

Really unless your going to up the comp (to at least 10:1 and add some larger cams (272deg duration upwards), i think the larger TB is a waste of time for now, my current donkey engine is proof of that.

I have aa dynoo print showing only 5 hp gain retearding cams 2 degrees over advanced 4 degrees. It also shows the torque lost at low revs, whish is what i want back

Yes I would trade 5 hp up high to get back 5 hp at mid range any day. Also remember those figures of yours are at full throttle. At 15-35% throttle where we spend most of our time the low rpm torque losses are even worse with cam retard.

5 hp is the sort of gain I normally see with short duration low lift stock cams on a 200-250 HP engine with 2 deg retard, but that will only be at around 6300-7000 rpm. Unfortunately the loss right through the rev range , say from 1200 rpm to 5200 rpm, is much greater so the top end gain doesn't come close to compensating for what is lost at anything just below cutout revs.

I have a lot of confidential propriety info filed that I can't really display on the forum but I'll have a look through to see if I can find some dyno figures that I can post in part to give a better idea of at what rpm the power losses and gains are located in a typical stock engine like our Magnas/380s. These are engine dyno figures without smoothing so give a pretty reliable picture of what happens with cam swings. Wheel dyno software has so much manipulation of the power graph small gains/losses are not easy to see.

Cheers, Alan

Yeah Im going to have to agree with Jason On this one, altho im really happy with my custom TB... i dont think it gave me any noticeable power gains or advantages at the end of the day & I lost Cruise! A Standard Flowed TB will do the trick nicely. :D
John to give you a guide that the TB isnt a major restriction on a mildly worked 3.5L (especially your ralliart), Chris aka Levi has a 75mm TB on his fairly worked 3.5L NA magna and made about 4kw's less than my car with stock TB, also steve said to me that there was no need for a larger TB on my "donkey" engine when we dynod it a couple of weeks ago and all that was limiting my engine making more power was the lack of fueling from 4700rpm upwards.

Really unless your going to up the comp (to at least 10:1 and add some larger cams (272deg duration upwards), i think the larger TB is a waste of time for now, my current donkey engine is proof of that.

Yes I would trade 5 hp up high to get back 5 hp at mid range any day. Also remember those figures of yours are at full throttle. At 15-35% throttle where we spend most of our time the low rpm torque losses are even worse with cam retard.

5 hp is the sort of gain I normally see with short duration low lift stock cams on a 200-250 HP engine with 2 deg retard, but that will only be at around 6300-7000 rpm. Unfortunately the loss right through the rev range , say from 1200 rpm to 5200 rpm, is much greater so the top end gain doesn't come close to compensating for what is lost at anything just below cutout revs.

I have a lot of confidential propriety info filed that I can't really display on the forum but I'll have a look through to see if I can find some dyno figures that I can post in part to give a better idea of at what rpm the power losses and gains are located in a typical stock engine like our Magnas/380s. These are engine dyno figures without smoothing so give a pretty reliable picture of what happens with cam swings. Wheel dyno software has so much manipulation of the power graph small gains/losses are not easy to see.

Cheers, Alan

Thanks Alan, that would be terrific if you could. Now, are you passing this way soon:shifty:

I'll get those dyno numbers regarding cam advance/retard asap. I've had a look through my files but can't find an engine with similar spec or similar cam spec to our Magnas/380. However I have a couple of good contacts so hope to find something relevant in their files. Graham Bell was doing some cam variable valve timing work for a USA manufacturer recently so I'll give him a call first and see what info he is able to pass on to us.

On the T/B issue the restriction is minimal in the stock unit. Other than getting rid of the ridges I wouldn't worry about anything else for most states of road tune.

What confuses most is the "bum dyno". When you fit a bigger bore T/B with the pedal pushed down 20mm you are effectively letting more air into the engine compared to the stock bore with the pedal 20mm down. Same thing with the pedal pushed 30mm down - more air into the engine. So the engine feels more lively and jumpier, and it is, particularly if you have a manual tranny. Without traction control a big bore throttle is a real pain, particularly in the wet as its a lot harder to modulate the power. Plus its harder to drive smoothly in bumper to bumper traffic etc. Thats why manufacturers keep the size down and why they have gone to electronic throttle control.

The other thing with a bigger replacement T/B is it probably doesn't have any hot water connected, so the engine gets a little more cooler air in. So theres a HP advantage there.

You can get reasonable power with quite a small throttle. Take 2 ltr F3 engines. 200HP+ breathing through a 23mm restrictor. Then there is 6 ltr NASCAR restrictor engines. They make about 500 HP with a flat plate stuck under the carby with four holes about 23mm dia. The small holes are bad enough but imagine the air exiting a big bore carby (four bores around 48mm) and bumping into a flat plate with four tiny holes. Its just a 1.6mm flat plate, no tapers or anything to smooth the transition.

Cheers, Alan

Graham has just emailed some censored torque curves from the work he was doing. He noted that these figures should relate fairly well to the Magna and 380 engines. The cams were similar spec to the Ralliart but he noted the wider lobe separation(111.75 deg) would affect the result. Magnas have tighter separation so relative to this torque curve 4-5 deg advance would be about the same affect as 8 deg adv. For the 2 deg retard that would like about 3-4 deg retard on a Magna engine.

Cheers, Alan

Hi all- the knowledge base on this site is really amazing- my question is simple- living in SE QLD, who or where should I go to to see about what appears to be- for someone with this experience- a fairly simple modification for my TL AWD?- I imagine the local Mistsu dealer service section would not want to know anything about this type of dark magic. Alos an estimate of likely cost for it to be done would be good? The car is just coming due for 90k timing belt- so is it likely that the cam adjustment could be done at the same time and save a few $ along the way and still pick up a few extra ponies?