Quote:
Originally Posted by Weather Spotter
Update: test run
Today I needed a tube of caulk and some 1x2s to make a floor in the tail. My brother was heading off and so I had him follow me for a mile and watch the light snow flow off the tail. Then we swapped cars I and watched. I also took a video clip (not sure how to embed so here is the link) :
Nothing fell off on my trip into town. I taped the gaps and the tape held just fine.
I also took some pics:
snow build up, so I think this area could use some help:
Ideas? |
Weather,I'm late to the party so first off let me say 'wow',I'm really impressed with your project!
I watched the videos and have been burning the still photo images into my brain.
*The transition down the roofline of the Matrix and onto the tail looks good.
* The sides appear as though they are not 'bulged-out' as much as the Matrix body but I understand how complicated it is to do a perfect integration from one to the other.
* Without photos from above,looking down,it's difficult to figure the 'curvature' of the sides as they project rearward from the Matrix.A straight sided cone is going to offer drag reduction but with a bit of penalty compared to the extremely complex compound curves of an organic boat-tail.
*Also,as I'm sure you are well aware,the sharp intersection between upper sides and roofline are apt to produce some vorticity.And of course,to construct a radiused intersection there requires drastically more time to fabricate!
* So there may be a little drag penalty with all that,but as you may have considered going into the project,could easily be justified against the additional trouble to construct.
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* As to the bottom,without a complete bellypan,some mid-section turbulence is probably being maintained from the end ofthe forward pan,all the way back,cutting into the performance of the aft pan/diffuser.
* The belly of the tail is steep,with separated flow,and without a movable diffuser which raises and lowers,the steepness is something we have to live with to survive driveway ramps and the like.
* The back-soiling of snow is normal,as the sharp cut off of the tail forces separation and the turbulence transports the snow into that area.The recommendation to install short panels all around the periphery of the taillight area I would second.
* I also second the recommendation for tufts when you can do it.The snow,while quite light,has much more inertia than the air,and will not give as fair an evaluation of flow as smoke,inkblots,or tufts will.
* Living in a 4-Season environment may require that mods be done which can 'grow' with three of the seasons,then 'retreat' for winter.
If you can find it in you to complete the pan it will be like an insurance policy for all the aft mods.Hucho and others tell us that the onset flow to the rear of a vehicle must be absolutely perfect for rear mods to perform.Cleaning up any upstream turbulence will pay big dividends!
I think your numbers are well in range.Next spring I think you'll be all smiles at the gas pump.Great work,thanks for doing all that!
