S2 exige fitted with stage II and hurriance induction kit…
…when coming onto the 2nd cam at 6100rpm I get a fantastic sonic boom (okay not quite as loud but you know what i mean)
…but… if i drop revs to say 6000rpm and then go back through 6100rpm to the upside, I get another boom
…but doesnt this imply I am going back onto the power cam - I was under the impression that the cam doesnt change back until 5400rpm on the way down (to make it easier to stay on the power cam)
…is it broken?
My '05 drops on AND off cam at 6300ish.
never heard of 2nd cam changing back until 5400rpm on the way down. as far as i know should be at 6200ish coming on and off. once the engine warms up it lets you rev up to 8500 (instead of the usual 8000) for a short period to help you stay on cam when changing gear.
Yep, should be the same going up or down. The point at which it changes can alter slightly depending on various temps & conditions.
You really have to go to 8500rpm to ensure you stay on cam on the upchange.
Tim.
i’m sure Clarkson said it when he raced against the Apache helicopter (that it changes back at 5400rpm on the way down)
its a struggle to keep it on cam between 2nd and 3rd unless you bounce off 8500rpm in 2nd
i’m sure Clarkson said it when he raced against the Apache helicopter (that it changes back at 5400rpm on the way down)
I wouldn’t rely on the accuracy of tech stuff on any of the “motoring” problems! Top Gear is bloody good entertainment, but…
I thought it was 5800rpm on the way down?
Gav
not sure where you heard that. he never mentions 5400rpm when i saw it. you can still see the exige Vs helicopter on the topgear website. www.bbc.com/topgear go to the downloads section.
(its a struggle to keep it on cam between 2nd and 3rd unless you bounce off 8500rpm in 2nd)
thats the idea. change up when you hit the max rev limit (8500 rpm). there should be a red light on your dash for optimum gear change.
I am sure that when I looked in the manual it was 5400 and if you have a stage 2 you can hear the poping as unburnt fuel is dumped in the zaust and the cam changes back. Supposed to make it more driveable. (that the cam change not the popping )
any idea where in the manual it mentions the cam change. cant seem to find any reference to it at any rpm!
Found this…
The very high revving engine is governed to a maximum engine speed of 8500 rpm on up changes (8000 rpm at steady state). The change from the low speed cam to the high speed cam is controlled by the Lotus engine management system to achieve a smooth transition, which will not upset the balance of the car. This change occurs at around 6200 rpm, but can vary by a few hundred rpm depending on engine operating conditions. The return switching from the high speed to low speed cam occurs at 5800 rpm to extend the operating range of the engine on the high speed cam. This helps the enthusiastic driver stay on the high output cam between gear changes.
Looks like its 5800RPM
I am sure that when I looked in the manual it was 5400 and if you have a stage 2 you can hear the poping as unburnt fuel is dumped in the zaust and the cam changes back. Supposed to make it more driveable. (that the cam change not the popping )
Childish I know, but I’ve always wondered if it spits flames when you hear the pops and bangs as you come off the gas and go down the cams?
so back to the original question - should i be concerned that mine is coming on and off cam at the same point?
No, 'cause the ecu will vary the on/off point by a few hundred revs depending on operating conditions. It’s fine.
Tim.
If you had a crap zaust yes you would but have not seen it yet on a stage 2. You could re-map to get that batman look but not so good for zaust or fuel economy
You could re-map to get that batman look but not so good for zaust or fuel economy
Don’t forget that Flames + fibreglass = fire
Tim.