repatched for custom dynmaic field definition : https://drupal.org/node/1846860#comment-7805861

includes/service.inc

@@ -26,28 +26,6 @@ class SearchApiSolrService extends SearchApiAbstractService {
    */
   protected $solr;
 
-  /**
-   * An array of all recognized types.
-   *
-   * Maps the type names to the prefixes used for identifying them in the Solr
-   * schema.
-   *
-   * @var array
-   */
-  protected static $type_prefixes = array(
-    'text' => 'tm',
-    'tokens' => 'tm',
-    'string' => 's',
-    'integer' => 'i',
-    'decimal' => 'f',
-    'date' => 'd',
-    'duration' => 'i',
-    'boolean' => 'b',
-    'uri' => 's',
-    'location' => 'loc',
-    'geohash' => 'geo',
-  );
-
   /**
    * Static cache for getFieldNames().
    *
@@ -290,7 +268,8 @@ class SearchApiSolrService extends SearchApiAbstractService {
    * Overrides SearchApiAbstractService::supportsFeature().
    */
   public function supportsFeature($feature) {
-    $supported = drupal_map_assoc(array(
+    // Search API features.
+    $supported = array(
       'search_api_autocomplete',
       'search_api_facets',
       'search_api_facets_operator_or',
@@ -300,7 +279,14 @@ class SearchApiSolrService extends SearchApiAbstractService {
       'search_api_spellcheck',
       'search_api_data_type_location',
       'search_api_data_type_geohash',
-    ));
+    );
+
+    // Custom data types.
+    foreach (search_api_solr_get_dynamic_field_info() as $type => $info) {
+      $supported[] = 'search_api_data_type_' . $type;
+    }
+
+    $supported = drupal_map_assoc($supported);
     return isset($supported[$feature]);
   }
 
@@ -495,8 +481,9 @@ class SearchApiSolrService extends SearchApiAbstractService {
         }
 
         $inner_type = search_api_extract_inner_type($type);
-        $pref = isset(self::$type_prefixes[$inner_type]) ? self::$type_prefixes[$inner_type] : '';
-        if ($pref != 'tm') {
+        $type_info = search_api_solr_get_dynamic_field_info($inner_type);
+        $pref = isset($type_info['prefix']) ? $type_info['prefix']: '';
+        if (empty($type_info['always multiValued'])) {
           $pref .= $type == $inner_type ? 's' : 'm';
         }
         if (!empty($this->options['clean_ids'])) {