  Stripped-envelope supernovae (SE SNe) of Type Ib and Type Ic are thought to
result from explosions of massive stars having lost their outer envelopes. The
favoured explosion mechanism is by core-collapse, with the shock later revived
by neutrino heating. However, there is an upper limit to the amount of
radioactive Nickel-56 that such models can accomplish. Recent literature point
to a tension between the maximum luminosity from such simulations and
observations. We use a well characterized sample of SE SNe from the Zwicky
Transient Facility (ZTF) Bright Transient Survey (BTS) to collect a sample of
spectroscopically classified normal Type Ibc SNe for which we use the ZTF light
curves to determine the maximum luminosity. We cull the sample further based on
data quality, light-curve shape, distance and colors. The methodology of the
sample construction from this BTS sample can be used for many other future
investigations. In total we use 129 Type Ib or Type Ic BTS SNe with an initial
rough luminosity distribution peaked at Mr = -17.61 +- 0.72, and where 36% are
apparently brighter than the theoretically predicted maximum brightness of Mr =
-17.8. When we further cull this sample to ensure that the SNe are normal Type
Ibc with good LC data within the Hubble flow, the sample of 94 objects has Mr =
-17.64 +- 0.54. A main uncertainty in absolute magnitude determinations for SNe
is the host galaxy extinction correction, but the reddened objects only get
more luminous after corrections. If we simply exclude objects with red, unusual
or uncertain colors, we are left with 14 objects at M = -17.90 +- 0.73, whereof
a handful are most certainly brighter than the suggested theoretical limit. The
main result of this study is thus that normal SNe Ibc do indeed reach
luminosities above $10^{42.6}$ erg/s, apparently in conflict with existing
explosion models.
