hydro st170

Hi im thinking of getting this done 2 my 2003 focus st170 i hear its a good idea and that u get an extra 10bhp.I dont really understand the whole idea of it and if im getting my car remapped do i need 2 do the pully 1st or does it not matter.Thanks

Davemurphy007

The vernier pulley allows you to adjust the timing of the exhaust camshaft in relation to the rest of the engine. It's a mod that typically gives good results, a 10bhp increase is not unheard of, but it's quite an involved mod to really get the best out of it. You need to remove the standard cam pulley which means removing the timing belt (so you might as well put a new one on while you're doing the job) and then the car really needs an hour on a dyno with a competent operator who can tweak the timing of the cam to give you the best gains.

There are people who will tell you just to retardt he cam by 6 degrees and that will guarantee you 10bhp, but every engine is slightly different so the actual change in the timing and the results you will get will be different from engine to engine - hence the need to use a dyno to get the best out of it.

A worthwhile mod if you do the job properly, but nowhere as simple as just fitting the new pulley.

ETA - If you're definitely doing the vernier AND getting the car remapped then do the vernier first.

hydro st170

I dont think ill get the pully done it sounds a bit dodge 4 not much gain.Theres no 1 i would trust 2 get it done.Ill just get the imrc disconnted as it in the stuck open position and get it remapped.I dont c y ford put the imrc in the car in the 1st place but im new 2 cars so mybe im missing something.

arkeye

How much roughly is the vernier pulley mod?

LeeBee

£100 for the pulley, and whilst you've got the cambelt off, you may aswell replace the cambelt, tensioner, water pump and aux belt. If you shop around online for parts you can save a bit. iirc including the pulley and the timing tools, it all came to roughly £250

arkeye

Then fitting on top?

LeeBee

Yea that's without labour. I did mine myself and just set it to -6 degrees, obviously to fine tune you're best off getting it set up on a dyno.

arkeye

Where did u buy your parts from?

LeeBee

Vernier - http://www.retro-ford.co.uk/shop/node/201
Cambelt kit - http://www.ebay.co.uk/itm/151108918560
Water pump - http://www.ebay.co.uk/itm/171229762998
Aux belt - http://www.ebay.co.uk/itm/270752002841
Timing tool - http://www.ebay.co.uk/itm/141173174508

LeeBee

I have just noticed that conti do a timing belt kit that has the water pump included, but I don't know how good it is, so personally I would stick to the standard ford water pump

The Underdog

iv got one set at -6. i just wanted the simple fit it option so went for the reccomended -6. it may not be perfect optimum but its definately an improvement. it does bog down below 2k though.

Davemurphy007

No need to do the waterpump at the same time as the cambelt as that's driven off the auxiliary belt, but i would do the cambelt idler pulley while it's all apart.

LeeBee

I did the water pump as it's behind the cambelt, and as I was there I changed it and the aux belt, it's gotta come off so may aswel stick a new one on. The idler pulley came with the cam belt kit.

arkeye

Awesome thanks LeeBee!

LeeBee

No worries, glad to help. If you do it yourself then the Haynes manual for the focus mk1.5 will tell you how to do it, apart from the VVT on the inlet pulley, you have to undo the plug out of the pulley and let the small amount of oil drain out of it, then losen the pulley as the manual says. If you don't do this when you put the new belt on chances are it will be slightly out of time.