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Cosworth
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Gravel Spray
On a honda, the v-tech is not really "variable", just a second set of longer lobes are engaged at a specific RPM. 2 cams in one kinda deal.
True variable valve timing is infinite, within 7-15' usually and needs electronic control to operate correctly. Higher end ECU's will have a output for this. Megashit likely not.
Variable valve timing is pretty much useless in race engines unless it's a highly restricted formula like Group N. It's the last thing I'd worry about.
The new hondas are i-VTEC, which have both VTEC and variable cam timing on the intake cam.
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Gravel Spray
Neil Brown Engineering in the UK did a lot of developement work on Honda Group-A rally engines in the late 90's and early 2000's. They tossed all the V-tech garbage in order to make room for large cams and very large valve springs. With a careful selection of CR, cam, port shape and combustion chamber design you can have an engine that is VERY yanky down low and still screams like a mofo up top.
The only time I have ever seen true variable valve timing worth while at all is the Subaru system used in a Group N car. The oversquare Subaru engine is poorly suited for a inlet restricted turbo application and the variable cam timing helps eek out a "touch" more bottom end. In any other application it's a waste of time.
Neil Brown is making engines for Matt Neal and the likes in BTCC, not rally. They have MANY restrictions and specific power requirement. One of the restrictions were cam timing and the vtec was considered part of it and banned, and along with rpms, compression, valve lift, and throtle size limitations. Also, taking off the vtec means less weight on the valvetrain. And with the powerband matched with the correct sequential box ratios for each individual track makes things not too hard to actually "develop".
Also the Evo 9's with their Mivec in Group N made them the car to have in PWRC vs the Subarus and the Evo's are undersquare.
Neil Brown's work is currently touring car and DTM engines, but 15 years ago they carried out engine developement work on Group A rally engines for Richard Asquith Autosport which had a small amount of support from Honda UK. The driver was usually Neil Wearden. In Group A the valve train was free at the time and as you said the v-tech apparatus was not only heavy but it's mass inside the cam cover made fitting larger cams/springs nearly impossible.
The Evo was always the top choice in Group N, for many reasons. The only reason Subaru started showing up in the top of PWRC results over the past 7+ years is that they had made a big investment to lift the brand in the results. They handed over a lot of free donor cars, support and incentives to the top preparation companies to ensure the best drivers were in STI's.
