if you go onto any silvia forum this is one of the most common mods done to the ca18, they all swear by it that it should be removed and the the holes welded up

In the link I've posted below (that useful link on butterflys) one - there was a guy who dynoed the car with them full open and full closed.

He found that the torque was greater when fully closed till 4800rpm I think, and after then there was more torque with them open....so you will have more torque with them working below 4500rpm.

The method I'll use to control them will probably open the butterflys around 3000rpm unfortunately - but it will do until I look into this vovlo cruise thingo.

I also dynoed them. And tuned the opening revs on a dyno. Worth considering keeping them on a street car. The guys that say removing them is a good idea, have spent 2 or 3 days removing them, and spent maybe a couple of hundred dollars. I see a lot of people quoting my research, but there is more than a simple vaccium hose involved in hooking them up. The rate at which they open is important too. You want them to snap shut and open slowly.

Yeah I agree the way I'm going to do it is far from the most elegant and design intent solution.

I thought the best compromise from mucking around with tanks and vaccy lines, and not having the butterflys at all.

What did you find to be the optimum opening revs on your modified CA?

either plumb up some vaccuum or don't either way i doubt you'll notice a difference and if you change your mind, either pull off the line or put it on. to start your car you just need to hook up four wires and give it some fuel, that way you can come join us on the track like you keep saying... hurrrrry uuuuuup! i have a friend exactly like you, i call what he does piddly mods

Your a harsh task master Leigh....got a couple more 'piddly' issues to sort, but at least there are no more major issues.....

By the way - this is me hurrying Leigh! hehe

Haha, i'm just teasing. but seriously, you've got all the bits - get cracking!

Just when I think I'm near the end with this car 5 more jobs pop up....get cracking....hopefully I don't completely crack under the pressure of dying to drive this thing!

If D sells his 1K we all may not have to worry about all this trivial stuff. All that old school stuff I have collected will all be melted by the sun!!

On a more positive note... Get Cracking!
After a few coffee's if you can still concentrate, get into it.