ABF is 100% definitely 10.5:1 - got the original seat brochure in front of me 150hp at 6000rpm, 133ftlb at 4600rpm according to this link, ADL is 10.5:1 also, 129PS (127hp) at 6000rpm, 162nm (119ftlb) torque at 4000rpm http://carinfo.autold.com/car-seat_ibiza-gti-18i-16v.html adl is 1781cc, abf is 1984cc. Relative size = 0.897. abf torque x 0.897 = 119 ftlb, spot on what the adl is quoted at suggesting a very similar tune level
Gurds, I don't mind CC'ing some heads for you if you want Also I've got access to a dyno, which we can use to chuck some engines together and do some testing..... I'm running a KR(block) ABF (combo) didn't really notice a difference in performance really but i've never dynoed my car?? I know changes were made to the exhaust valve or valve seat on the ABF (vw singh - hotgolf) can you clarify? cool thread by the way
It would be very interesting to to see how the torque curve would be altered if an ABF inlet cam was installed in one of these engines.
2L 16V ABF cam specs: Intake - 219deg @ 1mm, 10.8mm max Exhaust - 220 deg @ 1mm, 10.8mm max 1.8L 16V KR cam specs: Intake - 218deg @ 1mm, 9.6mm max Exhaust - 226 deg @1mm, 10.2mm max I am suprised the abf doesnot make more power than it does, the cams are pretty good really - seem to recall at some time hearing a story that VW deliberately kept the power down from the 170hp or so that was possible as it was getting too close to what VR6's were making
There is a story that has been circulating like that for a few years, but its source is unknown. The KR engine was also quoted 133lbft @ 4600 rpm like the ABF. However at 6100 rpm it only produced 111lbft of effort. The ABF engine on the other hand was still delivering 131lbft at 6000 rpm. This suggests to me that the exhaust and intake system and fully mappable engine control allowed VW to replicate flat torque delivery. Catalyisers and other marketing considerations aside it may have been easy for VW to make this engine have the ability to produce near 137lbft to 6500. Not that it would have been a VR6 with 181lbft@3500.
I could well believe that. Rumour is that when Vauxhall were developing the C16XE engine they were getting close to 150bhp from the std 1.6 which was 2.0XE territory, so they reworked the intake and emission controls to mute it a bit. Gotta love those marketing guys Good thread btw
In theory, but given that Kjet cars can have issues with pinking on standard compression, you'd need to modify fuelling, and probably change cams. Without getting too technical, the ABF head and cam setup is the best standard one, whether on Kjet, Digi or custom management. As a basic porting job, I'd still say ABF, but if you get into re-inserting the exhaust side of the KR/9A head, then that's probably favourite, as you then have 28mm exhausts VS the ABF's 27.
very interesting reading. i currently have a stock ABF which im putting on management and ITB's and wondering what route to go down for the best/cost effective mods i.e higher CR, or cam change etc etc and if so what to.
It depends a lot on what car it's in, because of emissions regs by age of vehicle. It depends even more on how much money you want to spend - one man's 'cost effective' is another man's outrageously expensive.
mike, going in a mk1 as a reliable track toy. i come from years of cosworth owndership, so everything seems cost effective lol
hi gurds , done some hands on road testing testing on this topic, i will let you know my thoughts on all the comniations i hav tryed out over the next few days ,. paul
Thread revival. Interesting reading I've been doing some searching around about trying to raise the compression ratio on a 16v on a budget. Did anyone find any definite ways to do this? I read in brooksters 16v build thread that a KR head on a ABF block increases the compression - can anyone confirm this? If this is the case and what hotgolf said about head skimming, is it possible to get 11.5:1 with a abf block and skimmed KR head (skimmed as much as possible) Has anyone found what is possible and needed to get the highest compression with factory components? Even if it requires machining of block pistons etc.
11.5 The KR head requires the left & right edges trimming on each cylinder so that the ABF pistons don't catch.
Brilliant thanks. Is it obvious what needs trimming? when offering the components together? Is 1mm the maximum head skim? Is there a thinner gasket?
The ABF pistons in std form won't catch the KR head as they are flat, although overisze Wossners will due to the design they use. JE's are fine. Wossners with taper starting from the outside edge: JE with taper starting further in which avoids head contact: As for head skimming, it's not that simple! What cams are you using, not just to work out compression but lift also. You don't want to be tw4tting your valves on your piston crowns!
Standard pistons catch see the piston on the left you can see then edges that were touching the head - ABF Piston Standard JE Pistons standard 10.5 : 1 compression
Hmmm, there's really no reason that std. pistons would catch the head, seeing as the head is sitting about 50-60thou above deck height on the gasket. Unless that is the block has been decked without prior knowledge. Plus, if it was hitting the head, which happened to Godspeeds BMW rally car, there was issues with headlift and compression, and this was literally a couple of thou. With the ABF piston being flat, suely it would have hit the front of the head infront of the inlet valves? Seeing as it also level with the isde of the chamber. I'm not out trying prove you wrong, but it doesn't make sense when you think about it logically. I'd go as far to say it's more of a headgasket issue.
