Trying to get grid classes back from susy depending on the type of grid

Markup

<!-- Set up the container to have 8 columns -->
<section class="row-8">
    <div class="columns-6">
       <!-- Needs to inherit the width of the 6 col container -->
       <div class="columns-4">
           ...Content
       </div>
       <div class="columns-2">
           ...Content
       </div>
    </div>
    <div class="columns-2">
       ...Content
    </div>
</section>

susy grid classes

.row
	+container
	position: relative
	@extend %clearFix
	//+susy-grid-background()

// Loop through each grid number and pull settings
@each $n in 3 $grid3-column-width $grid3-gutter-width $grid3-grid-padding, 4 $grid4-column-width $grid4-gutter-width $grid4-grid-padding, 5 $grid5-column-width $grid5-gutter-width $grid5-grid-padding, 8 $grid8-column-width $grid8-gutter-width $grid8-grid-padding
	// set variable of grid total number just used for clarity of code.
	$gt: nth($n, 1)

	//extend susy settings with each loop setting
	+with-grid-settings($gt, nth($n, 2), nth($n, 3), nth($n, 4))
		//creates the row-#{number} classes
		.row-#{$gt}

			// set default column styles
			.column, [class*="column-"]
				+nth-omega(#{$gt}n)
				min-height: 1px 
				position: relative

				// lets you center a column
				&.centered 
					float: none
					margin: 0 auto !important

			// apply single columns width
			.column
				+span-columns(1, $gt)

			// loop through numbers 2 through total column 
			// number to generate column-#{number} classes

			@for $i from 2 through $gt
				.column-#{$i}
					+span-columns($i, $gt)

				.column-#{$i}-omega
					+span-columns($i omega, $gt)