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Integrator
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Discussion Starter #1 (Edited)
"107" cam was designed to run with 104 MOP green dot pulleys.
Then... the pollution policies have been imposed and 910 engine has been de-tuned by the use of a variety of retard pulleys.

1986-88 USA Emissions Bosch 910, and all...1989-96 SE, S4, S4s GMP4 910.
MOP: Intake 110° (red)retard / Exhaust 100° (blue)(actually 97°)retard / Jack-shaft 104° (green) or 102.5°(yellow)
The above combination led to -6.5° intake cam retardation (!), 45° overlap and SLA=103.5°

Now, many owners are replacing the "smog" pulleys with correct green dot pulleys, which give you 0° int cam retard, 44° overlap and SLA=104°.
What is interesting, on most of the cars the auxiliary shaft pulley is green or yellow dot!
So, if you swap your red intake pulley with the auxilliary shaft green pulley you'll need to buy only one additional green dot pulley and you're all set.

If you have any "left over" blue or yellow dot round tooth HTD pulley, I'd like to buy it from you.

One "blue dot" pulley needed.
Please PM me if you have one.
 

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Integrator
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2,863 Posts
Discussion Starter #2
increase LSA= lobe separation angle= good idle, high vacuum, increase power band span (wide rpm range), flatten the torque curve, delay peak torque, but can reduce peak power. A short LSA (more overlap) makes the torque peak and fall early (and rapidly) in the power band, rougher idle, less manifold vacuum, strong mid range power.
 

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Integrator
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Slightly off topic, but many new cars run continuously variable valve timing systems now. My S80 twin turbo V6 has this on intake & exhaust. But very de-tuned down to just under 300HP & similar torque. Fantastic low-end torque, decent mid, dies at high RPM, but probably good fuel economy and emissions with this setup. Nice they can now control all this by computer, a tuner would make this car explode (but I've no interest in mucking around with the family sedan).

But on the Lotus, there will always be some tradeoff. Having more low-end torque is probably the setup most folks would prefer as it makes it easy to drive without having to race the RPMs as much.
 

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I guess it's all about moving the power "range" (band) and do so to soothe a prefer driving style. True the lower range power band will always make a car more street able, but if you are planning to track your car (downshift, rev-redline) and use a much bigger turbo than the stock T3 then a higher power band will be better/desirable.

JG
 

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if you know all the specs - which it looks like you have some of them. Then you can use a camshaft wheel that goes on the crank and degree them without it?
 
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