2012 Speedtec Zilhouette - Loud, Crazy ''Z4'' w/ 4.0L Ford V6!

Zilhouette race cars are very common at TT-Circuit Assen. They're tube chassis' based on the BMW Z4, powered by mostly stock BMW inline-6 engines. When this particular car flew by me for the first time though, I knew this wasn't just a usual Zilhouette Z1. It was way faster and louder and the engine tone barely interrupted by incredibly rapid shifts, told me this must be some custom build car, no longer eligable for the Zilhouette Cup.
After a bit of searching I stumbled across an ad for the Speedtec, which had recently been sold in the Netherlands, and it suddenly made sense. The rather unusual air inlet to feed the bigger V6 crammed in there, gave it away instantly. The 4.0L Ford V6 is coupled to a Drenth 6-speed sequential gearbox with powershift which also immediately explained the rapid shifts I was hearing (the slower Z1 Cup cars are manuals). The car weighs under 1000kg (2200lbs) which - considering the engine puts out around 360 horsepower - makes for a very serious power-to-weight ratio.
Two of these were built for the Supercar Challenge in 2012 in which it raced very competitively, managing to get on the podium. Speedtec continued to race the Zilhouette for a few years. These days the car is said to be eligable for the Super Sport class of said Supercar Challenge, which in modern day would make its pace comparable to the likes of GT4 and TCR cars.
I'll provide a link to the ad for a better picture of the build:
racecarsdirect.com/Advert/Det...
#racing #z4 #ttcircuitassen #builtnotbought #racecar #v6

[@Roddy_Zeh]

So is this is an old Cologne V6 built for racing or a built and stroked Cyclone 3.7 (evolved from the Duratec family)?

[@AlwinSV]

I think the latter. The engine was developed by KMS Racing Engines and the only Ford V6 work of theirs I can find is on the 3.7L Mustang engine. The horsepower figure also matches that particular engine so my guess would be it's the Cyclone 3.7 stroked to 4.0

[@Roddy_Zeh]

@@AlwinSV If so, that's the first time I see the Cyclone/Duratec reaching 4.0L, I honestly didn't know they could reach such displacement. Depending on the new crankshaft, the rods could hit the block internally, forcing them to chop some edges and other areas to accomodate the larger stroke crankshaft and new rods without facing these risks. And normally larger bore pistons also can make the cylinder block's walls too thin as well, weakening them.
Or, but I guess that may not be the case because the costs would be much, much higher, they went with a billet block already designed to accomodate larger bores and strokes without any clearance issues.

[@AlwinSV]

@@Roddy_Zeh All very valid concerns. Based of the ad and snooping around the KMS website I figured the Cyclone 3.7 would be the one and when looking up that particular engine I found ''Notable Cyclone features include a capacity for displacements ranging up to 4.0 L'' which to me made it all make sense. There is of course the possibility it's not completely correct on the ad or it could be the older engine and KMS might not work on it anymore so it wouldn't show on their site. Unfortunately we will not know for sure but if I get to see this car again I will certainly ask :)

[@Roddy_Zeh]

@@AlwinSV Thank you! 😁👍🏻And thanks for the video too, of course!
😎🤜🤛😎

[@AlwinSV]

@@Roddy_Zeh My pleasure, thank you for watching!