Seen afew people do this, and im wondering what gains there are from doing this? I know putting a KR inlet cam in a 9A adds more horses, but what does putting ABF cams in a KR do?
Have a scan though this - it's a sticky thread in this section that compares various 16V cams: http://www.clubgti.com/forum/showthread.php?t=156126
Tried it on mine - swings & roundabouts to be fair. ABF have more lift KR have more duration. I have no before/after graphs to quantify how my KR felt after fitting the ABF cams but it was similar enough to the KR's to advise you not to bother doing the swap. I wouldn't do it again to be honest
As per Chris. Not worth it if you already have the KR 027 inlet paired with a 027 exhaust camshaft. That is providing the engine is not a later 9A w/051103373D head fitted, in such a case you will need an ABF "051 101" inlet cam to replace the original "051 101m" intake cam. On well optimised engines the KR and ABF cam sets shift power/torque some +500 rpm right in the engine speed over CIS-E controlled engines. This gives a very sporty feel.
Here's a graph of actual measurements (not claimed figures) and a dyno (same car, same day) @ the wheels and interesting to see that the KR cams had the quickest acceleration of the rollers as they had the largest "area under the curve" for torque. Having said that... in real life accelerating on rollers (inertia mode) from 2K - 6.9K in 11.74 or 11.89 secs... does it really matter? For the record, std pulleys and sprockets were used; none of them adjustable; and on K-Jet... .
On 2 litre 16v engines the curves for ABF and KR cam sets will be similar to what you displayed for a 1.8 engine with the same head ( early 051). On later 051***D there is even a further benefit to torque. In real life it would be difficult to distinguish between the two on the road in gear hence the comments .
For the sake of comparison- I have a replacement 051 (ABF) head I am going to fit to my car to get mobile again to replace the OEM ACE head. To keep it cheap & usable I am going to use KR cams (free from a friend) instead of the ABF cams (rare to find & more expensive). Seems sensible whilst the head is stock. I expect performance will still be fairly strong & very similar to my previous setup
Considering theres no real gains to be had from ABF cams im going to stick with porting the KR head i have and get hold of a 2L block for power/torque gains. Seems cheaper and alot easier!
Seems to be just as easy finding a complete 2L block as it is to find a dragon's first dump of the day.
Great thread! Thanks a lot to Nellis!!! These results stand partially in contrast to what gets often recommended in car-forums, where some people talk about great gains in midrange-torque with the ABF-cams or double-exhaust-cams. The results harm my "world-view" in terms of cams a bit too (I know that facing the truth can hurt a lot [:^(]). Therefore I have to point out my old convictions first: 1.) The volkswagen engineer generally made the best choice in terms of overall performance. 2.) So "sharper" the cams are, so higher moves the torque-curve. What what you gain in top-power you will loose proportionally at lower revs. 3.) Changes in the cams profile are only reasonable if they meet special purposes (race) or personal preferences in driving-style. 4.) Known and (in my eyes) widely uncontrasted performance-gains are the following: - KR-inlet into PL with 98 Oct and proper adjustment of the KE-Jet and VEZ = +10 bhp (139 BHP - PL turns into KR) so maybe 6 bhp due to the cam only. - KR-Inlet into 9A and proper adjustment of the KE-Motoronic = + 14 bhp (150 BHP) (About the changes in torque I never did read anything of substance.) 5.) The group of the 260-cams: Here we have - the old and the new cams of Dr. Schrick, - the ABF-Cams and - the combination of two exhaust-cams (one modded). The old Schrick-260-cams were reported to give among 6-9 bhp on a KR. These cams were at there times expensive too. The newer ones have more lift and should deliver a bit more performance. http://www.ebay.de/itm/Schrick-Nock...604704272?pt=DE_Autoteile&hash=item43a963e210 I refer to the old Schricks, because the manufacturer is known as a serious one we have - thanks to Nellis - precise and comparable measurements: http://www.clubgti.com/forum/showthread.php?t=156126 Cams Duration at 0.07 mm lift max. Lift Duration at 1mm lift Schrick old in 259,7 10,2792 225,3 Schrick old out 259,6 10,2792 225,3 ABF in 255.9 10,799 219,6 ABF out 253,9 10,799 219,7 double-outlet-mod 9A-out 262,3 10,195 220,8 KR-out 255,9 10,1215 219,7 KR-in 252.8 9,5640 212 Nellis wrote: "Keep in mind that these are actual measurements, hence the slight difference to the "advertised" or "published" specs." The 9A and the KR outlet-cams should be identical. Therefore there comparison should give an idea of the error-margin or of production (can't imagine this) or of Nellis-measurements (how is this possible?) These values can anyway only be the "cornerstones of the curves" that describes the cams profile best. Looking at the curves for KR/ABF/Schricks http://www.clubgti.com/forum/showthread.php?t=156126&page=2 we see that the surface under the curves is approximately identical between ABF and Schrick cams and in both cases superior to the KRs; what the Schricks offer more in duration is compensated by the ABFs in peek-lift. Although the double-EX-cam-combo would play in the same league. Said this, we should expect similar peak-power-values for all three 260-Cam-Combinations with presumably Schrick ("for respect for the Name") in the lead. When 6-9 bhp are achievable with Schrick, I feel justified to expect at least 4-6 bhp from the ABF and not only 1.6 bhp (1.2 kw) as measured by Nellis. So where is the mistake? Are the supposed values for the Schricks 260s put to high? Nellis measured 7,8 kw (10,61 bhp) for the 268 (witch brand/peak-lift by the way?), therefore I see no reason to doubt the reported values for the old Schricks. How big is the error-margin in the whole procedure (changing cams, setting up K-Jet, running the test on the rollers)? 3-5%-statistical error-margin on the total values would explain much (and destroy every credibility of the test on rollers). Which intake-manifold was mounted? The smallest works best with the KR-cams while sports-cams may suffer with the small one and flourish with the 50mm-inlet (?). In which state of maintenance was the car, were maybe the injectors worn out? 6.) I could never believe the ABFs or double-exhausts to give more torque. Supposably this impression came from the readjustment of the K-Jet after the cam-switch. I think, the topic still deserves some more discussion Cheers
