Toyota Engine

I read somewhere that the point of change to the racing cam can be modified at the ECU/software? Is this true?

If so, would lowering it to say 5k rpm reduce the reliability/lifespan?

regards
Rob

don’t know this for sure… but i reckon the 2nd cam could probably be sorted to come on at 5k revs as you mention… don’t know what the down sides would be except that the pins that move to cause the 2nd cam to kick in were subject to recall in the earlier version of VVTi so i guess if they come in at 5k revs then they will be in more often and so will wear faster… IYSWIM…

Have you seen a dyno plot of the toyota engine? Its quite obvious from it that the higher cam and the lower cam power cross at the change over point - Seems that the high cam would make less than the lower cam at 6000 rpm.

It may be ECU related to letting rip with the higher cam but if it made more power at 4-5K then that where Lotus would of set it to swap there. Talk on the elisetalk board in the US of changing the lower cam to make more power than stock and moving the switch over up! so say 160 bhp → 7000 then 190-> 8500

Do you have a link to a dyno plot at all?

I read somewhere recently that the new supercharged Exige R has the second cam coming in at 5000rpm so it must be possible, but no idea whether this would work with the NA engine.

[image]http://www.111r.org/Rullata.JPG[/image]

RichB

its true that moving the cam-change point might not benefit the driving experience but even tho’ there is an overlap dusnae mean it can’t be done…, remember that the lower cam’s primary job is to give you economy the 2nd cam will be wilder and still might make more power at 5k revs that the lower cam.

Its almost certain that the change point can be controlled by ECU… doesn’t matter that its NA.

I don’t mean to suggest it would be worth doing but then that’s not what the original query was about…

I think it’d help the S2. You’d be able to drive it less like a nutter, trying to keep it in the higher cam.

Ian

Thats half of the fun, keeping it on the higher cam.

The new 240r changes cam at 4000 rpm (according to the lotus press release)

Jeez… and people think a turbo makes a car too unlinear… look at that cliff face

thats a different power curve to the lotus one

lotus S2 Exige v’s 240r

Impressive torque on the 240R, how much does the car weigh (including s/c gubbins) ?

The Lotus X axis is squashed compared to the previous graph though …

900 kg’s I think it said.

its says somewhere 22% increase in power, 23% increase in torque and only a 1.5% increase in weight.

And a std 190 S1 can still keep up with it?! Go figure?

I guess it must be the weight. It’s about 1.5 people heavier than an S1, which has a significant impact on track.

Ian