Cam timing update
Discussion
As it was explained to me, the cam timing was retarded by one tooth on the 3 litre M12 cars so provide a larger performance gap between the M12, and the similar, but much more expensive M400.
It also had the benefit of reducing the torque slightly, reducing the load on the gearbox, and reducing the possibility of warrenty claims in the early years, as M12's were expect to sell more cars, and therefore had a greater risk or warrenty work, than the smaller production run M400 cars.
May be right, may be wrong, but at least you sort of know what you are talking about now
Matt
It also had the benefit of reducing the torque slightly, reducing the load on the gearbox, and reducing the possibility of warrenty claims in the early years, as M12's were expect to sell more cars, and therefore had a greater risk or warrenty work, than the smaller production run M400 cars.
May be right, may be wrong, but at least you sort of know what you are talking about now
Matt
StreetDragster said:
As it was explained to me, the cam timing was retarded by one tooth on the 3 litre M12 cars so provide a larger performance gap between the M12, and the similar, but much more expensive M400.
It also had the benefit of reducing the torque slightly, reducing the load on the gearbox, and reducing the possibility of warrenty claims in the early years, as M12's were expect to sell more cars, and therefore had a greater risk or warrenty work, than the smaller production run M400 cars.
May be right, may be wrong, but at least you sort of know what you are talking about now
Matt
Isn't that the other way around? Advancing timing gives you power lower down and more torque but will induce more lag. Fine for little T25s on the 3/3R but with the T28s on the M400 it would have made the car too laggy so I'd imagine the timing to be retarded on the 400 to reduce lag, reel in some torque and generally push the power higher up the revs which the bigger turbos are capable of still blowing into at those revs. It also had the benefit of reducing the torque slightly, reducing the load on the gearbox, and reducing the possibility of warrenty claims in the early years, as M12's were expect to sell more cars, and therefore had a greater risk or warrenty work, than the smaller production run M400 cars.
May be right, may be wrong, but at least you sort of know what you are talking about now
Matt
I didn't want to change mine on the 3R because I actually like the surge of torque the standard setup provides and although there's more bhp/lbft to gain from doing the mod (along with many other component changes of course) I didn't feel the smoothness of pickup was suited/necessary.
I'm sure on track it makes sense as it becomes more N/A-like but on the road I feel you lose the fun factor.
Blu3R said:
Isn't that the other way around? Advancing timing gives you power lower down and more torque but will induce more lag. Fine for little T25s on the 3/3R but with the T28s on the M400 it would have made the car too laggy so I'd imagine the timing to be retarded on the 400 to reduce lag, reel in some torque and generally push the power higher up the revs which the bigger turbos are capable of still blowing into at those revs.
I didn't want to change mine on the 3R because I actually like the surge of torque the standard setup provides and although there's more bhp/lbft to gain from doing the mod (along with many other component changes of course) I didn't feel the smoothness of pickup was suited/necessary.
I'm sure on track it makes sense as it becomes more N/A-like but on the road I feel you lose the fun factor.
Not sure dude, thats just how it was explained to me. I'm having the mod performed, simply as its what the engine builder recommends.I didn't want to change mine on the 3R because I actually like the surge of torque the standard setup provides and although there's more bhp/lbft to gain from doing the mod (along with many other component changes of course) I didn't feel the smoothness of pickup was suited/necessary.
I'm sure on track it makes sense as it becomes more N/A-like but on the road I feel you lose the fun factor.
Matt
If you're aiming for 450+ bhp (don't quote that figure, may be more may be less) then you're into the realms of changing the timing to the M400 spec anyway and your associated parts to make the whole package will hopefully work well with it. My point is more for those who want a 'stage 1' sort of increase rather than a huge step change.
Of course if you're going 500+ then you'll almost certainly be looking at GT turbos which spool much quicker anyway so you build torque earlier and can map out some boost to protect the box.
What I don't understand is whether there's a benefit to altering each cam's timing relative to the other I.e. Inlets to exhausts, can anyone enlighten me???
Of course if you're going 500+ then you'll almost certainly be looking at GT turbos which spool much quicker anyway so you build torque earlier and can map out some boost to protect the box.
What I don't understand is whether there's a benefit to altering each cam's timing relative to the other I.e. Inlets to exhausts, can anyone enlighten me???
the stock GT03 has the exhaust cam timing retarded 1 tooth over standard ford timing, inlet is same as standard ford... it was done before the M400 came out and for some reason I have it in my mind that it was done because the standard valve springs were found to 'bounce' when the boost was turned up at higher revs, so the timing was changed on the exhaust to drop the power down the rev range 500rpm and thus away from the valve bounce territory.
In order to get more power for the M400 they has to solve the valve bounce so replaced the springs, Im not 100% sure as I haven't stripped an M400 but I believe they don't use the standard ford timing and you need to do machine work to match it! certainly the timing on my engine can't be replicated without machine work.
You won't 'loose' power with the cam timing change you discuss (i.e. back to standard ford on exhaust) IF you do the valve springs at the same time... it just moves the torque up the rev range and thus you will get a more drivable car IMO... you still get the same punch in the back, its just 500rpm higher up the rev range, and the engine revs better!!!
I originally did the cam timing without valve springs (iteration 1 of the mods to my car), it had one hell of a punch in the back but valve bounce meant it couldn't be rev'd with any real boost so I couldn't take advantage of the extra revs... hence I say do both together.
In order to get more power for the M400 they has to solve the valve bounce so replaced the springs, Im not 100% sure as I haven't stripped an M400 but I believe they don't use the standard ford timing and you need to do machine work to match it! certainly the timing on my engine can't be replicated without machine work.
You won't 'loose' power with the cam timing change you discuss (i.e. back to standard ford on exhaust) IF you do the valve springs at the same time... it just moves the torque up the rev range and thus you will get a more drivable car IMO... you still get the same punch in the back, its just 500rpm higher up the rev range, and the engine revs better!!!
I originally did the cam timing without valve springs (iteration 1 of the mods to my car), it had one hell of a punch in the back but valve bounce meant it couldn't be rev'd with any real boost so I couldn't take advantage of the extra revs... hence I say do both together.
ALL valve springs need upgrading if you up the power, All engines need the timing changed to make the big power, there's no change on the 400 on cam timing, as my engine received the same treatment from Jetstream when I upped the power over 500.
Edited by Hollowpockets on Wednesday 30th April 16:23
Hollowpockets said:
ALL valve springs need upgrading if you up the power, All engines need the timing changed to make the big power, there's no change between 3R and 400 on cam timing, as my engine received the same treatment from Jetstream when I upped the power over 500.
I thought the 3r and the m400 did have a different cam timing ?I think there is some confusion concerning the timing, the difference in timing between a 3/3R & M400 is based on a alteration on the cams which because they are not adjustable is by altering the position within the chains by a tooth. This will be what the engine tuner / builder will be suggesting & as Andy states inconjuction with the uprated valve springs will allow it to rev higher & produce more power etc etc.
The timing mod Graham refers to is a completly different thing & is only required/done on the very high powered cars, this also requires different cams etc etc etc.
The timing mod Graham refers to is a completly different thing & is only required/done on the very high powered cars, this also requires different cams etc etc etc.
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