WP Query loop - in multiples of 3 posts in containing div.

index.php

<?php 
		
	$currentID 	= get_the_ID();
	$featured	= new WP_Query(array(

	  'post_type' 		=> 'post',
	  'order' 		=> 'DESC',
	  'posts_per_page' 	=> 8,
	  'post__not_in' 	=> array($currentID)
	
)); ?>

<?php $i=1; if ($featured->have_posts()) : ?>

	<div id="slider-wrapper">
					
	<?php while ($featured->have_posts()) : $featured->the_post(); if ($i==1 || $i%3==1) echo '<div class="slide-group">'; ?>
		
		<div class="slide">
					
			<?php the_title(); ?>
			
		</div>
		
	<?php if($i%3==0) echo '</div>'; $i++; endwhile; ?>
	
	</div>
				
<?php unset($featured); endif; wp_reset_query(); ?>