hi all, based for a golf mk2 GTI running carbs.. right, ive looked throught the search for some threads on vernier pulleys but dont find alot! how do you manage to understand what sort of advance / retard you need on your vernier when your sitting on your drive.. can it be done or would i need to take my car to a rolling road place? what sort of gains can you get from one? when fitting a new cam do you nessisarily need a vernier pulley? or can you just cam it and still get good performance? if just camming the car (hydraulic lifters) would it be a good idea to use double valve springs to stop valve bounce?.. but obviously you would need to remove the head to do this! Or is it not worth the major hassle? FINALLY: when camming a car, you need to adjust the timing... using a timing gun and the timing marks on the gearbox.. but how else would i do it? do i keep that dizzie vacuum on whilst i do it? and at what RPM should i hold it at to advance the timing? thanks boys! .. thats all.. for now
Gti's run double valve springs anyway . Lots of people fit cams without Verniers , and get good performance , having the adjustment will only get a few more bhp . It's handy if you have a skimmed head/block and the relationship between the cam and crank pulleys have changed . However , I personally will be putting one on mine , just so I know its as good as can be . You won't know by just adjusting it on the drive how much is needed , it needs a very trained driver and a good spin , or better , a rolling road session . What you can check is to see how much advance/retard you can adjust by before you start hitting valves off pistons , by having it on TDC and adjusting the vernier back and forwards .
ok but how do i normally advane the ignition timing when ive changed the cam?.. or dont i change that... do i simply plug and play?
Oh you do , but ign. timing is totally separate to the cam , you just change it by twisting the dizzy . Speaking broadly , more advance equals more power , but also increases the danger of detonation .
yeah i know to time the ignition for your cam you twist the dizzy, now ive read my previous post it doesnt say what i was meaning! i ment, how would i advance the timing.....(not literally twist the dizzy, i mean vacuum advance wise) i would use the timing marks on the flywheel, use a timing gun.. but when setting the advance, do i have the vacuum advance on or off? because some engines you take the vacuum advance off, then set the timing at at certain amount of revs, then put the vac advance back on and it would give you an advance... how is it done on the golfs?
and quickly... which way will advance the timing?? - twisting the dizzie clockwise, or anticlockwise? its just a quick question to save me afew minutes really
Anti-clockwise to advance an 8v. If you're adding a cam it'll need setting up properly, as it'll need a bit more fuel. I wouldn't go advancing the dizzy beyond standard without getting the fuelling right at the same time, or you'll likely end up with detonation problems.
advance method depends on the dizzy you have fitted and the mark on the fly. std settings are listed in the elsa win emmissions faq I posted up, but may not apply depending on what setup you have on your car! Which dizzy did you put on it?
standard GTI K-jet 8v dizzie so it has the vacuum advance diaphragm on it this is why i need to know how to advance the timing ... whether i keep the vac advance on whilst i use the timing gun, or do i take the advance off then advance the dizzie, then put the vac advance on..
I did mine by ear tbh , with the vaccuum connected , mostly because I hadn't got the "book" setting .
I have one of those vacuum things i think (saucer shaped) on the side of my dizzy though it's never been connected to anything, might have something to do with the 5th injector & k-star fitted?
ok set it up with the book figures for a K-Jet GTI, which can be found in the ElsaWin Emmissions FAQ mike ideally it should be hooked up but tbh at full throttle theres hardly any vacuum so the advance weights take over. Although does the k-star plug into the dizzy? if so the k-star unit may have taken over all the advance calculations...
mike, the "saucer" thingy should be hooked up with a small vacuum pipe which goes onto the servo / inlet pipe vacuum.. correct john? and ive got a figure of... 21-65.. 65-21 and this is the timing apparently.. but i dont understand the 21-65... could you explain? cheers
did you look at the elsawin emmissions faq post? theres a pdf for the k-jet MK2 GTI. within it: Test figures for emission check Engine oil temperature - min. 80 C Without idling speed boost - 950 . . . 1000 rpm With idling speed boost - 800 . . . 1000 rpm Vacuum hose - off When using RON 98 - 4 . . . 8 before TDC When using RON 95 - 02 CO content at idle without catalyst - 0.5 . . . 1.5 Vol. % edit: 'vacuum hose' being the one to the dizzy, block the engine side to prevent a vacuum leak. the 4-8 setting is done by lining up the large diamond on the flywheel with the arrow on the gearbox at idle, with a timing light. Like this:
I'm sure the k-star advances & retards the engine itself so must be why it is that way. Made over 160bhp for 124k before a rebuilt without it connected so must be normal.
yeah I'd have thought so too thats the idea of the unit on a 16v is it allows you to fiddle with the ignition map, do do this on an 8v it would need to have the ability to change the ign map itself, since the TCI only fires when it sees what the dizzy advance vac and weights are doing
yes you do change the map itself through the software on my 8v. just hope it still works after being off for more than 2 yrs..... Going back to the thread yes you advance/retard by slowly rotating the dizzy either way, had do do it on occasions in v hot weather when the car was running a bit close to the mark.
Hmm, im still not 100% on how to do it personally.. and i have nobody to help me do it i may just fit the cam, then mess around with the timing untill i get it sounding ok-ish.. then ill take it to a rolling road and do it properly! only big problem now is, i need to change the block as my piston ring has gone! but i want to change it to a 1.9 or 2.0 tall block.. so therefore the fuelling will be out..(it is already) so this will make it even harder for me to get it timed by listening to it, because the mixture will be crap! i have a 32/34 carb on mine at the moment.. anybody know how many screws out it needs to be to run roughly the right mixture on a 1800? then ill unscrew it from there!.. unless anyone knows how many screws out it would need to be for a 2.0! cheers
