diff --git a/offline/packages/trackbase/ActsSurfaceMaps.cc b/offline/packages/trackbase/ActsSurfaceMaps.cc
index d92e387ca0..69cd94ece6 100644
--- a/offline/packages/trackbase/ActsSurfaceMaps.cc
+++ b/offline/packages/trackbase/ActsSurfaceMaps.cc
@@ -34,6 +34,11 @@ bool ActsSurfaceMaps::isTpcSurface(const Acts::Surface* surface) const
   return m_tpcVolumeIds.find(surface->geometryId().volume()) != m_tpcVolumeIds.end();
 }
 
+bool ActsSurfaceMaps::isSiSurface(const Acts::Surface* surface) const
+{
+  return m_siVolumeIds.find(surface->geometryId().volume()) != m_siVolumeIds.end();
+}
+
 bool ActsSurfaceMaps::isMicromegasSurface(const Acts::Surface* surface) const
 {
   return m_micromegasVolumeIds.find(surface->geometryId().volume()) != m_micromegasVolumeIds.end();
diff --git a/offline/packages/trackbase/ActsSurfaceMaps.h b/offline/packages/trackbase/ActsSurfaceMaps.h
index 94c327be79..e90263c49a 100644
--- a/offline/packages/trackbase/ActsSurfaceMaps.h
+++ b/offline/packages/trackbase/ActsSurfaceMaps.h
@@ -37,6 +37,9 @@ struct ActsSurfaceMaps
   //! true if given surface corresponds to TPC
   bool isTpcSurface(const Acts::Surface* surface) const;
 
+  //! true if given surface corresponds to the silicon
+  bool isSiSurface(const Acts::Surface* surface) const;
+
   //! true if given surface corresponds to Micromegas
   bool isMicromegasSurface(const Acts::Surface* surface) const;
 
@@ -65,6 +68,10 @@ struct ActsSurfaceMaps
   /** it is used to quickly tell if a given Acts Surface belongs to the TPC */
   std::set<int> m_tpcVolumeIds;
 
+  //! stores all acts volume ids relevant to the Silicon
+  /** it is used to quickly tell if a given Acts Surface belongs to the Silicon */
+  std::set<int> m_siVolumeIds;
+
   //! stores all acts volume ids relevant to the micromegas
   /** it is used to quickly tell if a given Acts Surface belongs to micromegas */
   std::set<int> m_micromegasVolumeIds;
diff --git a/offline/packages/trackreco/MakeActsGeometry.cc b/offline/packages/trackreco/MakeActsGeometry.cc
index 07f3dbe71c..366510574c 100644
--- a/offline/packages/trackreco/MakeActsGeometry.cc
+++ b/offline/packages/trackreco/MakeActsGeometry.cc
@@ -283,6 +283,12 @@ int MakeActsGeometry::InitRun(PHCompositeNode *topNode)
     }
   }
 
+  // fill Si volume ids
+  for (const auto &[hitsetid, surface] : m_clusterSurfaceMapSilicon)
+  {
+    surfMaps.m_siVolumeIds.insert(surface->geometryId().volume());
+  }
+
   // fill Micromegas volume ids
   for (const auto &[hitsetid, surface] : m_clusterSurfaceMapMmEdit)
   {
diff --git a/offline/packages/trackreco/PHActsTrkFitter.cc b/offline/packages/trackreco/PHActsTrkFitter.cc
index d0006ac25c..72647a2295 100644
--- a/offline/packages/trackreco/PHActsTrkFitter.cc
+++ b/offline/packages/trackreco/PHActsTrkFitter.cc
@@ -526,11 +526,11 @@ void PHActsTrkFitter::loopTracks(Acts::Logging::Level logLevel)
 
       // position comes from the silicon seed, unless there is no silicon seed
       Acts::Vector3 position(0, 0, 0);
-      if (siseed)
+      if (siseed && !m_ignoreSilicon)
       {
         position = TrackSeedHelper::get_xyz(siseed) * Acts::UnitConstants::cm;
       }
-      if (!siseed || !is_valid(position) || m_ignoreSilicon)
+      if (!siseed || !is_valid(position) || m_forceTpcOnlyFit)
       {
         position = TrackSeedHelper::get_xyz(tpcseed) * Acts::UnitConstants::cm;
       }
@@ -574,6 +574,13 @@ void PHActsTrkFitter::loopTracks(Acts::Logging::Level logLevel)
               continue;
             }
           }
+          //else if (m_forceTpcOnlyFit)
+          //{
+          //  if (surface_apr->geometryId().volume() < 14)
+          //  {
+          //    continue;
+          //  }
+          //}
           bool pop_flag = false;
           if (surface_apr->geometryId().approach() == 1)
           {
@@ -643,7 +650,7 @@ void PHActsTrkFitter::loopTracks(Acts::Logging::Level logLevel)
       float seedphi = 0;
       float seedtheta = 0;
       float seedeta = 0;
-      if (siseed)
+      if (siseed && !m_forceTpcOnlyFit)
       {
         seedphi = siseed->get_phi();
         seedtheta = siseed->get_theta();
@@ -984,6 +991,9 @@ SourceLinkVec PHActsTrkFitter::filterSourceLinks(const SourceLinkVec& sourceLink
     if (m_forceSiOnlyFit && (m_tGeometry->maps().isMicromegasSurface(surf) || m_tGeometry->maps().isTpcSurface(surf)) )
     { continue; }
 
+    if (m_forceTpcOnlyFit && (m_tGeometry->maps().isMicromegasSurface(surf) || m_tGeometry->maps().isSiSurface(surf)) )
+    { continue; }
+
     // update vectors
     filtered.push_back(sl);
   }
@@ -1070,7 +1080,7 @@ void PHActsTrkFitter::updateSvtxTrack(
     track->identify();
   }
 
-  if (!m_fitSiliconMMs && !m_forceSiOnlyFit)
+  if (!m_fitSiliconMMs && !m_forceSiOnlyFit && !m_forceTpcOnlyFit)
   {
     track->clear_states();
   }
@@ -1097,9 +1107,20 @@ void PHActsTrkFitter::updateSvtxTrack(
   track->set_y(params.position(m_transient_geocontext)(1) / Acts::UnitConstants::cm);
   track->set_z(params.position(m_transient_geocontext)(2) / Acts::UnitConstants::cm);
 
-  track->set_px(params.momentum()(0));
-  track->set_py(params.momentum()(1));
-  track->set_pz(params.momentum()(2));
+  auto* seed = track->get_tpc_seed();
+  
+  if(!m_forceSiOnlyFit)
+  {
+    track->set_px(params.momentum()(0));
+    track->set_py(params.momentum()(1));
+    track->set_pz(params.momentum()(2));
+  }
+  else
+  {
+    track->set_px(seed->get_px());
+    track->set_py(seed->get_py());
+    track->set_pz(seed->get_pz());
+  }
 
   track->set_charge(params.charge());
   track->set_chisq(trajState.chi2Sum);
@@ -1134,7 +1155,7 @@ void PHActsTrkFitter::updateSvtxTrack(
 
   // in using silicon mm fit also extrapolate track parameters to all TPC surfaces with clusters
   // get all tpc clusters
-  auto* seed = track->get_tpc_seed();
+  
   if (m_fitSiliconMMs && seed)
   {
     // acts propagator
diff --git a/offline/packages/trackreco/PHActsTrkFitter.h b/offline/packages/trackreco/PHActsTrkFitter.h
index 056c3e88b3..8d0cf352a8 100644
--- a/offline/packages/trackreco/PHActsTrkFitter.h
+++ b/offline/packages/trackreco/PHActsTrkFitter.h
@@ -84,6 +84,11 @@ class PHActsTrkFitter : public SubsysReco
     m_forceSiOnlyFit = forceSiOnlyFit;
   }
 
+  void forceTpcOnlyFit(bool forceTpcOnlyFit)
+  {
+    m_forceTpcOnlyFit = forceTpcOnlyFit;
+  }
+
   /// require micromegas in SiliconMM fits
   void setUseMicromegas(bool value)
   {
@@ -217,6 +222,7 @@ class PHActsTrkFitter : public SubsysReco
   bool m_fitSiliconMMs = false;
 
   bool m_forceSiOnlyFit = false;
+  bool m_forceTpcOnlyFit = false;
 
   /// requires micromegas present when fitting silicon-MM surfaces
   bool m_useMicromegas = true;