How do I target another database with tracker-enabled-dbcontext

Question

I'm trying to implement the tracker-enabled-dbcontext package from the documentaion and tracker-enabled-dbcontext git repository But I'm unable to change save changes to target a different database. I've modified my SaveChanges

public class MyDBContext : DbContext, IUnitOfWork {}
public class MacsAuditDbContext : TrackerEnabledDbContext.TrackerContext {}

in MyDBContext

public override int SaveChanges()
        {
            DateTime nowAuditDate = DateTime.Now;
            IEnumerable<System.Data.Entity.Infrastructure.DbEntityEntry<DomainEntity>> changeSet = ChangeTracker.Entries<DomainEntity>();
            if (changeSet != null)
            {
                foreach (System.Data.Entity.Infrastructure.DbEntityEntry<DomainEntity> entry in changeSet)
                {
                    switch (entry.State)
                    {
                        case EntityState.Added:
                            entry.Entity.Created = nowAuditDate;
                            entry.Entity.Modified = nowAuditDate;
                            break;
                        case EntityState.Modified:
                            entry.Entity.Modified = nowAuditDate;
                            break;
                    }
                }
            }

            using (MacsAuditDbContext db = new MacsAuditDbContext())
            {
                db.SaveChanges();

            }

            return base.SaveChanges();
        }

in my startup class

public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            AuthConfig.Register(app);
            GlobalConfiguration.Configuration
    .UseSqlServerStorage("MacsAuditDbContext");
                }
    }

But I am still unable to save audit logs to the target(secondary) database. my Domain entires saving my primary DB but not audit logs. Do I want to pass MyDBContext to MacsAuditDbContext? Or Am I doing something wrong? please help me.