fitting an omex

[monka]

i have looked around, and found that the renix needs taking off and the coil taking out.

but which terminal is positive and negative?

[volvodspec]

it's printed on the coil, you see it when you take it of the renix unit

[monka]

ok cheers mate

anyone on here fitted one with success?

and from what i understand, one wire to the positive on the coil, one wire on the negative, and one to ground?

i like knowing how things work, and i cant work out how the omex's work.

as the positive on the coil pulses doesnt it? so it wont have a constant live? how does it detect rpm? or cut spark, as the only wire it needs to go to is the negative.

[volvodspec]

i've fitted a omex unit with launch control; works perfect and i'm very happy with it!

it detects rpm by the frequency of the coil pulsation, that's why you need to set it for a 4, 6 or 8cyl type. at the same time it cuts spark by grounding the positive coil if max rpm is reached

[monka]

ok cheers mate, thanks for the help

on a side note, been looking at putting a different renix unit in. and with a 415 fitted to mine currently, and looking at the table near the bottom of this http://www.volvo300mania.com/forum-uk/v ... =39&t=9046

just about any other renix unit will be better will it not?

[volvodspec]

that's the late b172 type if i'm correct?

that ignition curve is made to have a huge advance at half load to make it more fuel economic than the b14.
swapping any other renix will probably be a performance decrease and increase risc that it starts detonating at certain rpm

if you want to do something about the ignition curve, install a custom unit (123 ignition for example) and get it mapped.

[monka]

ok, just i swear i read somewhere on here there was a renix that would be a good swap.

anyone know of it?

also, anyone know the voltage of the coil? and if a more powerful aftermarket one would be any better? was clearing out the workshop at work and found an aftermarket one, dont know the voltage yet, and i know i'd have to run some wires, but i have read on the net, that if you get one with more voltage, you can increase the spark plug gap, which improves performance? that how it works or just a load of rubbish?

[Chris_C]

Best option really would be an early 1.7 renix, so you have an extra 2deg at top end. Most likely need super though.

Other option is b18kp cam, renix and carb jets

[monka]

what car does the b18kp come in?? i'm going to the scrappy on thursday so will have a look. lol

[Chris_C]

It's a 400 engine, but rare as hell. There is one in Soton to check things like renix numbers though... you just have to bribe the poor misguided 300 driver that owns it that he wants to have a mini meet

Looking through the green books, the cam is the same as a B18F which is a common as 400 engine so it's just working out the renix really. I was going to do it to Fake before Adam waved the F7R under my nose