PrInSu Design Studio Roof Racks BS Thread

With the exception of sectioning and fitting the weather-stripping (i effed that up with my bench press - bit grabbed the metal strip and tore the hell out of one, so sectioning is what is left) .. finit. My little 5-lug slug has attained maximum utility capabilities. Thanks Zach, for a mighty fine product.

 

It got to a point where there was so much variation in shells, and how the tracks were installed that making each rack a custom length was problematic. Instead I made it so the feet are adjustable as shown. Also made the side rails a bit shorter so there was more room to get your hands under to bolt down RTT's.

I can still make the old style if it is preferred. This one is just easier and more functional.

 

Most of them will fit flush straight out of the box. If they don't simply add in a few more washers between the bar and the mounting feet on the outside edge to shim it to match the angle of the tracks. Again, so much variety between dealers, manufacturers, etc that each case will be slightly different.

 

with the new style toprac I give the 2 hd bars and 4 regular if you order regular. That way you have the 2 hd for the mounting feet. Eventually my goal is to move away from the standard bars and only offer the HD. I am getting to a point with volume where I can potentially offer the HD bars at a little lower price.

 

I like that better so I can be sure it works.

 

Got plenty of RTV remaining, that it will take a Category-5 Hurricane to pull them off when i am done.

 

Awesome! Thanks for the direction!

 

Sub

 

Soooo... day 1, first drive on the highway .. holy wind-tunnel noise, Batman!

It starts at ~55 km/h .. and part of it is focused on the passenger side, which leads me to think that it might be the Prinsu laser-cut logo chiefly to blame on that side, but at this point, most of the wind-rush is focused on the center, where the overhead center-console is.

I may well experiment with blanking off the Prinsu logo from the rear using a pop-riveted aluminium plate on the back-side.

A dynamated ceiling is definitely in the cards, at this rate.

I had the shield centered in the middle position, using the two middle of the 4 possible screw locations.. except that it appears that it is only 3..

Zach, i am assuming here - a big assumption, that the four holes are meant for variable positioning of the front deflection shield from low to high?

If that is the case - the bottom screw holes are off, by a wide margin.

When i got home, i went to move the deflection shield down to the bottom position, from middle to see if that would reduce the turbulence boundary ... and discovered that the bottom screw appears to be out by about 1/4" or so .. too widely spaced. Please see photos below.

Comments?

 

@HackD maybe loosen up all your cross bars (and maybe the mounting bolts too) and see if you can line up the bottom two holes. Then re-tighten everything. Just a thought...

I have mine set in the bottom two holes. When I mounted mine, I was solo, so I mounted the side pieces first, but left them loose, then added some loose cross bars and wind spoiler, then tightened the roof bolts down and then added the rest of the x-bars and tightened everything up. Hope that helps

 

This actually was an issue for my buddy's cabrac as well. To move the deflector closest to the roof/window line, we had to elongate the last set of holes to make the cross bar fit. Measured a noticeable difference between the two holes vs a set higher up.

 

Yeah... no, that's not the issue. I did a bit of back-track research on this topic, and around page 122 on this thread, other people reported that the bottom wind-deflector mounting holes are definitely drilled out of spec, and have encountered the same issue. As you can see in my first photo .. the hole is drilled 1/4" (or so) too wide as compared to the other 3 holes in series, for the wind-deflector support beam. I've got it attached by one bolt on either side at present, and will see how this setting works on tomorrow's commute. I've also got a water-pipe insulation noodle coming along for the ride, to slide on the base of the wind-deflector, in order to compare relative noise levels.

If the lowest setting is indeed an improvement - I already know what the permanent fix will be for the out of spec hole spacing.. 2 L-brackets, and a couple of t-slot bolts on one leg of the L-bracket, tieing the other leg of the bracket into the next higher usable wind-deflector mounting hole. In essence, making a corner bracket as a McGyver-fix.

Edit: I would elongate the hole as RonRon23 did with his buddy's .. but i have the feeling that it would require removal of the rack in order to do it with the necessary precision required, on the workbench.. weather is turning too quickly towards winter, to be undoing what was done this weekend.

I used my rack as the drilling template to mark measurement points, during the install - using two cross-bars to keep it in rigid configuration - so everything was perfectly aligned during the drilling of the roof, and bolting down. Everything worked out to the millimeter.

 

I noticed the same thing when trying to line up the bottom 2 holes... It didn't bother me too much as I just went up to the middle 2 and they lined up fine. I also have the deflector set to the top 5 holes across just to bring it down a bit. I notice some more noice but it's not that much more than normal... Even my wife didn't notice until I pointed it out to her. I also have bigger tires and the TRD Exhaust which makes everything a bit louder. I have the logo on the driver's side and I don't think that makes difference..

 

When I first built and designed the accessrac, the fitment of the wind deflector relied so much on how the installer placed the rack on the roof that having extra holes to adjust the wind deflector wasn't needed. It was intended to simply be assembled and then placed on the roof to get the desired fit before drilling holes. The extra holes were there to mount the deflector using 2 1x1 crossbars vs the single 2x1 crossbar as an alternate means of mounting the wind deflector. The singe center bar works so well that I haven't sent out the deflector compatible with two bars in a long time.

That being said if you want to play with adjusting the deflector, you shouldn't have to enlarge those holes much for it to line up. If I remember right they are only about 1/8" off if that. A bigger hole or a dremel bit will make quick work. Also, I know that drilling holes is not preferable but if you need to drill other holes on the rack to try different options for anything you can do so with peace of mind that the aluminum won't corrode.

Not having an access cab myself and the placement of the rack being so dependent on the installer the wind noise will vary greatly. If you find a setting that works really well though post here and let me know so I can add it as a recommendation in the install instructions.

 

If you're not using the bars daily, I got a huge difference in wind noise by moving the most forward bar back of the second bar. Ill move it back forward when I've got my raft up there, but for the time being it made a absolute massive difference

 

That is very interesting. I have been testing the number of bars recently. I have it to the point where with 11 bars on the cabrac I have no noise whatsoever unless I am going into a headwind. If there is a strong headwind then I get noise. I will have to play with moving that front bar back and see what it does in a headwind.

 

Well, thanks for the comments Zach and Brent.. more variables to play with.

Last nights lowering of the wind deflector improved things to a minor degree for the commute to work this am, and the addition of the water-pipe insulation noodle to close off the gap between the roof and wind-deflector, moderately improved things further for the commute home. The focal point of the wind-rush is definitely now on the passenger side of the compartment .. so i'll also play with blanking off the laser-cut Prinsu logo.

Placement of the bars on the front portion of the rack will also be a variable to eyeball on my end, and i'll report on results as i experiment with them also.

I'm not expecting an entirely quiet drive, with a rack that obviously has turbulent effect on slip-stream at speed - that would be an entirely unrealistic goal, obviously. I do, however, desire to reduce the noise signature closer to being the quietest vehicle that i had owned in 30 years of driving, prior to the addition of the rack.. as of yesterday's post-commute posting, it was the noisiest :/

 

Any word on where that bar is?

 

Got the last bar today! Thanks for sorting it out!!

 

Threadlocker or no threadlocker on rack bolts? Thanks!