  Current Type Ia supernova (SN Ia) models can reproduce most visible+IR+UV
observations. In the X-ray band, the determination of elemental abundance
ratios in supernova remnants (SNRs) through their spectra has reached enough
precision to constrain SN Ia models. Mart\'inez-Rodr\'iguez et al have shown
that the Ca/S mass ratio in SNRs cannot be reproduced with the standard nuclear
reaction rates for a wide variety of SN Ia models, and suggested that the
12C+16O reaction rate could be overestimated by a factor as high as ten. We
show that the same Ca/S ratio can be obtained by simultaneously varying the
rates of the reactions 12C+16O, 12C+12C, 16O+16O, and 16O({\gamma},{\alpha})12C
within the reported uncertainties. We also show that the yields of the main
products of SN Ia nucleosynthesis do not depend on the details of which rates
are modified, but can be parametrized by an observational quantity such as
Ca/S. Using this SNR-calibrated approach, we then proceed to compute a new set
of SN Ia models and nucleosynthesis for both Chandrasekhar and
sub-Chandrasekhar mass progenitors with a one-dimensional hydrodynamics and
nucleosynthesis code. We discuss the nucleosynthesis of the models as a
function of progenitor metallicity, mass, and deflagration-to-detonation
transition density. The yields of each model are almost independent on the
reaction rates modified for a common Ca/S ratio.
