wur mod

[mk2bal]

will i benefit from the wur trick or is it only to be done when it needs it (ie fuel pressure 2 low) or can any1 get a gain from it? my k-jetted abf is making 159.5 and i need more, if digi abfs make 170-180 can i get that aswell? its been rolling road tuned, the wur wasnt touched, but if it can be upped then re-tuned to make the 170+ im all for that..

[rubjonny]

good guide here:
http://www.clubgti.com/forum/showthread.php?t=81658
make sure the system and warm up pressures are ok before going for the wur mod. once all that is fine, you tweak the wur. all this will do is give you more fuel over the whole rev range, its a bit crude but it can help. k-star+fuel is a better solution because with that you can play with both the ign curve and the fueling across the range, but you gotta find one and also someone who knows how to tune it.

i doubt wur mod on its own will give you +10 bhp though. you have to remember also that not all rolling roads are created equal!  for example my mk2 had a completely std mk2 digifant engine, just had a 2.0 bottom ebnd swap. I got 142bhp on storms rollers, which was nice to see but I dont think it was very accurate   then totally completely std 1.8 MK2 digi went on straight after me and got 127bhp, to give you an idea.

[mk2bal]

i know what your saying, theres definitely a discrepancy between everyones rollers. the rollers ive used are def out a smidge, my old engine (a 65bhp 1272) made 66bhp, and this standard abf, 159.5. my old 9a which died cos of the crank keyway made 158 there also. ive compared the two plots and the 9a is much stronger on 1st,2nd and 3rd gear, and on the road thats the way it felt. it was very torquey/ urgent off the mark, where the abf needs revving to feel strong. although the abf peaks 1.5bhp higher it feels like a 1.8 kr compared to the old 9a. what can i do to get the edge a bit? ive got a spare kr head 051 103 373,a spare 9a head 051 103 373d (looks though it may have been diy ported slightly, maybe thats y it felt faster) and the abf 051 103 373d. as the abf and 9a have the same heads im guessing the same valves in length etc, can i swap the two over? i have 9a kr and abf cams to use so whatever, i know its uneconomical to go BUY another head/cams for an abf etc but ive got all the gear i just want the best setup from it!

[rubjonny]

the abf heads have the best casting 'out the box' but if you're getting one ported they will all end up pretty much the same. if porting work looks good on the 9a head then it may be worth swapping over, also worth a check to see what cams it has in there maybe they were better?
there is some discussion over if kr or abf cams are better, good thread over on clubgti where someone swapped abf cams into his kr to give you an idea.  the abf should definitly pull strong though, might be an idea to have a close look at the inter-cam timing and check over the dizzy, they like a wee bit more advance than standard. might be that the k-jet system needs a tweak as you say, toyotec has some really good posts on this dotted around cgti.  my mk2 with abf on kjet was great, but unfortunatly i didnt get it rollered. it had the wur mod and all the pressures were checked by me as i have the proper VAG k-jet pressure tool. i put new mercedes brass injectors on it as well, worth doing for sure

I've since put the proper abf stuff on there and there isnt really much in it, the abf stuff feels a lot more refined but its still quick. since the k-jet felt a bit more 'raw' you know you're going fast, with the abf stuff being more refined it takes you by surprise sometimes

[emery1990]

I dint think the digi abfs make 180bhp mate, i was saying the ABF's with megasquirt would get that, think stealth do the WUR mod for about £100. The posts of cgti about what cams to have in the head concluded that the abfs where better, but was not noticeable better,. as in theres no point swapping for abf cams if you have not got them.

Have you fitted that abf now then ?

edit, got you muddled up with someone else!

[mk2bal]

sweet well if the heads are identical in fitment (ie valves wont hit pistons etc) ill take the old one off, get it skimmed and new gasket n give it a try. The porting does look a bit diy dremel job,the guy told me he rebuilt the head with new valve stem seals,you can see that its been off the engine and cleaned separately etc.the 9a its coming off has the kr cams in it, i swapped em in when i did the 1st conversion, to 9a. ill put the abf ones in it this time though-thats what i was worried about, if the abf/kr cams had more lift or duration than the other i wouldnt wanna kill the new abf by being a bell n not checking. whats the inter cam timing? i thought the chain was the only the only thing governing them, or is that not inter cam timing? my chain does make a noise though-or tappets? not 2 sure its done it since i had it n rolling road man says it might quieten up with a couple of oil changes?

[spacerat]

159.5. bhp and u still struggle away from my old 8v which has never been set up on a rolling road  your right bal u do need more power.

   

[mk2bal]

struggle! behave kev!

[rubjonny]

yeah the chain does the inter-cam timing, with that power level its prob ok but doesn't hurt to check. if its rattly it might be a bit worn, a loose chain may rob you of a bit of power also

[mk2bal]

are the kr/abf chains the same? if so ill use my chain from the kr cams in the other head im fitting... doing a bit of airbox work, took the front cold inlet pipe out to open up the front of the box,its alot noisier but im not sure its any better. gonna stick it back in the box with a cold pipe feeding it, but should i cut the length of tube thats inside the box, so its just the round inlet hole with no length to it. or does the length aid the flow/speed at all.basically whoes messed with their 16v box and what happened?