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Mazdaspeed Archive => Suspension => Topic started by: joeereid on September 10, 2015, 04:44:43 AM



Title: APR GTC-200
Post by: joeereid on September 10, 2015, 04:44:43 AM
Got my APR GTC-200 wing a while back and finally got around to sorting it out  for installation on my spare lid. First impression, Nice piece. Second impression, that can't be right!. The location point they give you to start with doesn't match what the pictures in the instructions show. There's also not enough adjustment to get the mounting plates (which don't match the lid contour at all) to line up with the edges of the lid and brackets on the wing. Hopefully they have sent me the wrong parts or they have some other solution I overlooked during the 2 hours messing with it.
Miata Specific?...apparently not this one. Gonna wait until they have a chance to explain themselves before I break out the grinder and fix it myself.
Any body else here install one of these? Curious as to how it 's fit for others.


Title: Re: APR GTC-200
Post by: millsj on September 10, 2015, 12:44:05 PM
I don't know any specifics with the APR wing, but I have the COT wing and the mounts from FM.  The NA and NB mounts are different.  I'm not exactly sure the differences, but I know they are different.  Maybe they sent you the wrong mount?


Title: Re: APR GTC-200
Post by: joeereid on September 10, 2015, 01:48:15 PM
That's what I'm hoping is the case because they clearly don't fit right. I was thinking the only difference between the NA/NB trunk lids was the high mount brake light hump on the NB, but maybe the lid width dimensions are different.. unfortunately no NA handy to measure. Where's an older miata when you need one!


Title: Re: APR GTC-200
Post by: millsj on September 10, 2015, 02:28:01 PM
The FM COT mount attaches in the drain rails, so there must be some other differences. 


Title: Re: APR GTC-200
Post by: '95MSM on September 10, 2015, 03:55:21 PM
... Where's an older miata when you need one!

In my garage. The LO MSM trunk lid is out behind the shop, since it picked up a ding during the move.

The widths are nearly identical. I measured at more or less the same point (just ahead of where the MSM spoiler mounts and just ahead of the R package spoiler on the '95) and the difference was about 1/16".  So little of the under the skin stuff changed between NA and NB models that this didn't surprise me at all.


Title: Re: APR GTC-200
Post by: millsj on September 10, 2015, 04:07:52 PM
Are the two trunk lids the same if you look at their cross section?  As if you were looking at the side of the trunk from the rear quarter panel.  My memory is fuzzy, but I had it in the back of my mind that this is where one of the differences are.


Title: Re: APR GTC-200
Post by: '95MSM on September 11, 2015, 12:21:03 AM
I'm sure the contours are different, but the relative size is very similar.


Title: Re: APR GTC-200
Post by: mr_hyde on September 11, 2015, 02:54:42 AM
If you attach the supports to the mounting points on the wing, do they come down on the trunk lid or just outboard of the trunk lid?  I'm on a COT wing but two local guys have APRs.  Bob Bundy has a 'generic' one that lands outboard on the fenders.  He built mounts out of aluminum angle to give it a firm mounting that still allows the trunk lid to open most of the way (he has double risers).

John Mann has the miata version that mounts to the trunk lid.  He used this successfully for year or two until he decided to install the optional Gurney flap.  At the same angle of attack, the extra force at ~140mph folded the trunk lid into the gutters on the first session out.   :shockeyes: :shockeyes: :shockeyes:  He bent the lid back into position and fabricated blocks to transfer the load onto the gutter which will hold anything that is thrown at it.  Moral of that story - get the Gurney flap.  It will significantly increase downforce with little/no increase in drag.

If yours land outboard, it is a better design but would require drilling into the part of the car you would rather not.  If it lands inboard, it should be correct.  Got pictures?



Title: Re: APR GTC-200
Post by: joeereid on September 11, 2015, 05:55:21 AM
Well, after some back and forth with APR today, they have confirmed that I do indeed have the "miata specific" mounts and I have confirmed that the fitment leaves a lot to be desired. Apparently it's a torque+tweak type install. The bases don't match the contour of the lid very well at all and if you follow their instructions re; placement, they end up being @3/4" to far forward, which makes the fit even worse. No wonder most of the pics I found looked the the lid was tweaked. I thought it was from the downforce but that may, or may not, only be a contributing factor.
  They give you a dimension of 18 1/2" for the rear stud measured back from the front point of the lid, but their pics show it landing in the stamp-out for the msm wing attaching bolt, which is actually at 19 5/16".
  The bases themselves rock back and forth on their  opposing diagonal corners. The outer  front corner is @ 1/8" too tall, and the inside rear needs a kiss more radius to get them to lay flat. Installing them as-is out of the box would definitely distort the hood in that area.
Another problem is that the mounts on the wing itself are basically parallel to the centerline but the NB lid splays @ 2.5 deg, rear to front, per side from the centerline (5 deg total). So that means you need to tweak 2.5deg of splay out of each riser in the span of @ 6". If you try to mount the bases parallel to the centerline then the front stud interferes with the trunk gasket, i.e.;trunk won't close.
  So I spent an hour grinding the powder coated base bottoms to fit. Fit is near perfect now. Got a few other tricks up my sleeve that I'll save for later
APR did say that their instructions were for the "old" wing being installed on an NA lid. Curious as to wether the OEM wing stamp-out is in the same place on an NB lid.

Hyde! your'e alive!...missed you around here lately. I was at the Ridge that day Mann had his wing issue. If I recall, we put  sockets in the rain gutters under the bolts  and slammed the trunk. The load transfer issue is one of the tricks up my sleeve....

and here's tonites feature;

If you assemble the wing and set it on the lid this is how the bases want to fit. But If you want the trunk to close, you have to line the base up with the outer edge of the lid
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01284.jpg)


See all that daylight under the front inner corner?  I have masking tape to indicate where to stop grinding. The gap is actually worse than in this photo because the outer rear corner still need to come down some more. Nothing I can't handle, just thought "Miata Specific" meant I wouldn't have to.
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01279_001.jpg)


Title: Re: APR GTC-200
Post by: joeereid on September 11, 2015, 06:03:03 AM
... Where's an older miata when you need one!

In my garage. The LO MSM trunk lid is out behind the shop, since it picked up a ding during the move.

The widths are nearly identical. I measured at more or less the same point (just ahead of where the MSM spoiler mounts and just ahead of the R package spoiler on the '95) and the difference was about 1/16".  So little of the under the skin stuff changed between NA and NB models that this didn't surprise me at all.
How do the fore-aft measurements to the underside stamp-outs for the spoiler holes compare between the NA/NB?I thought the contours were the same at the rear where it starts going down, just the tail light and high mount brake were different?


Title: Re: APR GTC-200
Post by: mr_hyde on September 12, 2015, 06:35:18 AM
Hyde! your'e alive!...missed you around here lately. I was at the Ridge that day Mann had his wing issue. If I recall, we put  sockets in the rain gutters under the bolts  and slammed the trunk. The load transfer issue is one of the tricks up my sleeve....

Yeah, this has been a very strange year.  I won't threadjack commiserating on '90MSM growing pains but someday, I'll get around to updating my thread.  I've been lurking more and posting less but once I get through MRLS, I should have a better handle on my time.


Title: Re: APR GTC-200
Post by: joeereid on September 13, 2015, 05:18:50 AM
  I've started working on the  APR fitment issues. 3 belts sanders/3 grits in 3 different vises saved a fair amount of time but still tedious work when grinding too far is not an option.
Up first is the  location of the rear hole issue. The instructions say to mark it at 18 1/2" but their pictures show it at the stamp-out. Their instruction pics are from an NA install, so if someone can send me a pic showing the dimension to the stamp-out on an NA lid, that may clear up the confusion. I'll be sending  this info to a guy at APR so they can amend/alter/advise as needed for the NB installation, as they were unaware that the lids were different.           

Heres the stamp-out location on an NB lid. On the MSM, this is where the spoiler bolts are.
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01290.jpg)

Here's the bottom of the base plates after grinding/fairing them to lay flat on the lid. Also had to re-concave the middle section a little after taking off @1/8" on the  outer front corners.
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01287.jpg)

These are some lid-edge stiffeners I fabbed to try to keep the lid from getting tweaked, inspired by the John Mann incident Hyde spoke of.
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01286_001.jpg)


What I thought was a semi-rolled seam around the perimeter of the lid was actually some sort of OEM caulking. I shaved it flat so the aluminum stiffeners would lay flat. I still need to sand more of it off so the 3M 5200 will work. The forward base plate hole is going to land right in the middle of that stamped ridge so I wanted to shim the outer edge to match height-wise, so the nut/washer would bear on a flat surface. Of course I discovered it was caulking after the hours spent fabbing the 1/8" stiffeners....3/16 may have been a better choice thickness-wise, but harder to bend that radius at the rear
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01289.jpg)


Here's the stiffener in place. It will be bonded along its entire length to the lid with 3M 5200. The hash marks  on the base indicate the hole locations. The dotted line is the where the trunk gasket contacts the lid. The forward bolt may/may not interfere with the gasket so I may need to fiddle with that a little
I'm working on some load transfer blocks that will sit in the rain gutter but still allow the water to drain.
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01288.jpg)


Title: Re: APR GTC-200
Post by: joeereid on September 14, 2015, 03:38:06 AM
Here's what would happen to the trunk lid had I not re-fitted the bases. I'd seen this pic a while ago and assumed the damage was caused by the downforce/drag of the wing

(http://www.mazda-speed.com/albums/SplitterBuild/DSCN1221_zpsx2tijzmp.sized.jpg)


Title: Re: APR GTC-200
Post by: mr_hyde on September 14, 2015, 04:24:23 AM
Their instruction pics are from an NA install, so if someone can send me a pic showing the dimension to the stamp-out on an NA lid, that may clear up the confusion. I'll be sending  this info to a guy at APR so they can amend/alter/advise as needed for the NB installation, as they were unaware that the lids were different.           

I'm a bit whupped to get to this tonight but I have both trunks in the garage (the NB is even the correct color).  I can try to look at it after work Monday or if you are in the north end sometime this week, I can let you know when I'll be home.


Title: Re: APR GTC-200
Post by: joeereid on September 14, 2015, 05:41:20 AM
Good enough. I may be going to Whidbey for some more spares this week.


Title: Re: APR GTC-200
Post by: mr_hyde on September 15, 2015, 04:27:08 AM
I'm minutes off that route.  Give me a call.


Title: Re: APR GTC-200
Post by: joeereid on September 15, 2015, 02:31:09 PM
After scouring web images it appears that the NA lid may be wider at the rear than the NB. The NB is @ 41 3/4" at the front and only @40" at the rear, right before the cut for the tail light. That may explain why the bases don't want to sit flush with the edge of the NB lid, because it is not square. I think the NA lid may be more of a square.


Title: Re: APR GTC-200
Post by: joeereid on September 21, 2015, 05:49:41 AM
So the NA hood is pretty much the same shape on the top, but @7/8" shorter F~R, as is the trunk space. Thank you to mrHyde for allowing me and my measuring devices to invade his garage, so that mystery is solved. Now for the not so good news...
Drilled and mounted the "modified contour" bases on my donor lid to see if that helped with the fitment issues. Not gonna happen without every connection point above the bases being under severe angular and lateral loads. Driver side upper+lower turnbuckle slots are out by a good 1/2", passenger side out by 1/4" and the turnbuckles don't like it. Put the wing upside-down on my dead flat/dead level workbench to see whats what.  The end plates don't line up so it teeters on the table. Laid my digital angle block across the chord only to discover that the wing is actually warped to the tune of 2 degrees from one end to the other. Okay....thats probably not good.
Right about the time my buddy was just finishing the Solidworks design for the new pedestals to address the lid splay issue I realize that something is really amiss with the driver side bracket and after some ingenious measuring/squaring on my part I discover that although the non adjustable brackets are the same distance apart, they form a parallelogram not a rectangle, which initial measurements indicated. So the trunk lid forms a trapezoid and I'm supposed to attach a parallelogram to it....where's Escher when you need him..
So not really happy...but a little bit smarter
Pics and emails sent to the parties involved...hopefully this doesn't turn into another Xida-gate.


Title: Re: APR GTC-200
Post by: joeereid on September 27, 2015, 10:24:21 PM
So a lot of fiddling around with squares and inclinometers later, they are adjusting their foil mounting points  and assembling me a new wing with the updated "Truly Miata Specific" dimensions. We sent them a detailed drawing with some specific lateral and diagonal dimensions required for the mounts, pedestals and brackets to  orient themselves properly once everything is tightened down. For $800+ they should be able to do better than "assemble loosely and tighten and adjust as needed to fit", "adjust" being a simpler way of saying "Force,Twist,Yank,Pull etc. .....Now they just need to do something about getting the bases to fit the lid properly for the next guy.


Title: Re: APR GTC-200
Post by: joeereid on October 11, 2015, 02:59:42 AM
Well the new wing showed up Friday. Initial measurements were  fairly close to the specs we provided them. Diagonals were within 1/16" so that's good, solves the parallelogram issue. However the brackets that attach to the wing don't match the contour of the bottom of the wing. If you were to tighten them down the way they came, you would either pull the nutserts out, break the bracket, or punch holes into the wing.  2+ hours of careful grinding on the compound, twisting, ever-changing  radius later and I have them fitting the wing properly. Now when I install it on the pedestals mounted to the deck lid, it fits PERFECTLY! Now it's "Miata Specific"!
  Now I think I know why I found it impossible to find any detailed close-ups of this thing installed on a miata.


Title: Re: APR GTC-200
Post by: SilverMiataRacer on October 11, 2015, 01:33:01 PM
So in other words the APR product is far from being a quality product?


Title: Re: APR GTC-200
Post by: joeereid on October 11, 2015, 03:26:42 PM
Well yes and no. The components themselves seem to be of good quality, just a poor job of execution on the fitment end. Maybe I didn't search long enough and hard enough on the web, but I couldn't anything pertaining to the issues I've found. I guess nobody really took a look at it very hard and just slapped it on the car.


Title: Re: APR GTC-200
Post by: joeereid on November 12, 2015, 01:31:01 AM
Success at last! Details in Me and my Aero.
(http://www.mazda-speed.com/albums/SplitterBuild/DSC01363.sized.jpg)


Title: Re: APR GTC-200
Post by: millsj on November 12, 2015, 02:20:25 AM
Looks great!  The trunk lid doesn't look bad either.   :mrgreen:


Title: Re: APR GTC-200
Post by: joeereid on November 12, 2015, 02:54:37 AM
As Brian described his track  car paint job, it's a 50/100....looks great from 50 feet going 100mph. You won't notice a thing once I put the 16" meatball on there, but the paints gotta cure some more before I can put it on.


Title: Re: APR GTC-200
Post by: mr_hyde on November 12, 2015, 05:44:29 AM
'90MSM is a 50/100 paint job.  That is no worse than 5/10 - looks great!  When are you taking it out for a shakedown?  I need to see how the new computer works so I might join you!


Title: Re: APR GTC-200
Post by: joeereid on November 14, 2015, 02:09:04 AM
'90MSM is a 50/100 paint job.  That is no worse than 5/10 - looks great!  When are you taking it out for a shakedown?  I need to see how the new computer works so I might join you!
Not sure when I'm going to shake'er'down. May tackle some other mods and just wait 'til March, but who knows...need a sunny day at Pacific or Shelton and we might have to wait a while for that to happen again.


Title: Re: APR GTC-200
Post by: joeereid on November 14, 2015, 03:02:08 AM
It figures;
http://www.miataturbo.net/race-prep-75/singul%C3%A4r-motorsports-aero-wing-86624/ (http://www.miataturbo.net/race-prep-75/singul%C3%A4r-motorsports-aero-wing-86624/)


Title: Re: APR GTC-200
Post by: shlbygt on November 14, 2015, 04:11:53 AM
That was at the Laguna Seca event. Looked well thought out.


Title: Re: APR GTC-200
Post by: joeereid on January 20, 2016, 04:39:05 PM
A word to the wise, if you order a gurney flap for your APR GTC-200 wing make sure they are selling you the right one. There's a 59" version and a 60" version and they are not interchangeable...and none of the retail sites who sell them divulge that important bit of info,...gee, thanks. Who needs a 59" gurney flap cheap?... my return/refund window has closed.


Title: Re: APR GTC-200
Post by: millsj on January 20, 2016, 06:08:15 PM
Can you not just use small aluminum angle for the gurney flap?  That is what I used for the COT wing.  I bought some small angle from Lowes or HD.  I think it is a little thicker than what it is supposed to be, but I made it work.  I I cut the angle in half so friction wasn't fighting me in trying to push the flap all the way in from one side.  There is a seam in the middle of the wing, but no biggie. 


Title: Re: APR GTC-200
Post by: joeereid on January 20, 2016, 06:49:18 PM
I have the 3-D, organic shaped wing which is all curved everywhere, so unfortunately a $7 piece of aluminum with not solve my $200 problem.