Mounting door outer panel to door frame. Had the fiberglass shop that did my hood and rear spoiler throw together some fiberglass "angle iron". Bonded to door skin, rivets to the door frame.
Boxing in the side coolant pipes. Made 2 temples. Started with a flush top which looked really nice. Then I figured I would incorporate the door seal into the piece.
I love your attention to detail, as well as the patience that you have building this car. I haven't even had mine a year, and I struggle at times with how long I foresee it taking to complete my car.
Sal Mennella
Unfinished GTM #30 FFR - in progress!
Roadster 5132 - sold
Wow.....what an incredible amount of work you've put into that! Looks like it's coming along pretty nicely!
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
I love your attention to detail, as well as the patience that you have building this car. I haven't even had mine a year, and I struggle at times with how long I foresee it taking to complete my car.
Luckily I have other projects that I can bounce around on when I need a break. My GTM is by far 10x the work compared to the other car projects I have... But I think it will be my favorite when it's done.
Passenger side was the prototype, made great progress on the driver's side last night and today. Symmetry is the ultimate challenge here, especially starting with the asymmetric GTM body.20241213_123221.jpg20241213_123242.jpg20241214_143411.jpg
Driver's door bodywork nearly done.
Was considering options for license plate mounting with the center exit exhaust, including below one of the taillights. Will mount it above the diffuser. Ordered diffuser strut mounts to finalize diffuser location. As it sits, diffuser angle is 18 degrees which is on the high end but I think it will be functional with the spoiler assisting it.
Wow....you're going to have a ton of storage space there!
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Hey beeman. Looking at the rear picture you have there...don't mean to be negative or anything...but in my experience with these cars, you are going to need a lot more ability to evacuate hot air out the back of the car than what you have there. I understand that this is just work in progress shots and maybe you have a plan. Just trying to give you a heads up before you are too far down a particular path.
Mike- I'm hoping that my setup won't have significant heat issues. I'm going to use Shane's aluminum vented aluminum hatch insert instead of the supplied glass. I will have venting above the resonators on my rear trunk panel as well to help the exhaust heat to escape. I'm also dropping the diffuser which will open the rear quite a bit. I'm a NA 525hp so I'm not pushing the limits with forced induction, etc. What do you think?
Originally Posted by Power Surge
Really cool engineering as always. Do you have a rendering of what you expect the car to look like when done?
I did one back in 2017 (holy cow), but quite a few changes since. jwxrtbi7.jpg
Working on finishing the bodywork, found my way around to the engine air intake. Started analog with paper and Styrofoam, then realized that I will be making a mirror image on the passenger side (fresh air into the engine bay vs oil cooler) because it's going to look lopsided if I only put a snorkel on one side. So off to CAD, a bit rusty, can't remember the last time I used it. I'm using the existing Lamborghini Evo style intake that I drew up previously, now I need to duct that intake to the GTM body at the rear 1/4 window which feeds my airbox. The body has compound curves in this area, so I'm not going to be able to print something that will be perfectly formed to the body ( I don't have a 3D scanner). So I drew up a duct, will print it, and will blend it to the body and make a fiberglass part. Printing will help keep the driver and passenger sides symmetric.
[QUOTE=beeman;571383now I need to duct that intake to the GTM body at the rear 1/4 window which feeds my airbox. The body has compound curves in this area, so I'm not going to be able to print something that will be perfectly formed to the body ( I don't have a 3D scanner). So I drew up a duct, will print it, and will blend it to the body and make a fiberglass part. Printing will help keep the driver and passenger sides symmetric.
[/QUOTE]
About a year ago I started on the same task for my 818, scoops for the 1/4 windows to feed air box. I got 2 revs printed and test fit before I had to shelve the 818 for a few years. Hopefully you finish before I resume and I can improve my design based on your work
Sorry the quote function is not working, but back to post 862...I ran a 525 LS3 for quite some time and it needed all the air evac I could get. I too have gone over to Shane's aluminum rear window and it works very well. Lots of air can move through that insert. HOWEVER, we did a string test to see how air is actually moving out of that louvered rear insert and you might be surprised that air is actually moving INTO the engine compartment and very little is moving out with that insert. Of course we have the entire rear of the car open for air flow so it might be different than what you have there. You can always cut it open later. That's what we did as we developed the race car. It started with everything intact and then went to more air flow as needed. Closing up the floor behind the driver and under the engine area really boosted the requirements for more air evac from the engine area. I also have wrapped the exhaust in four layers of Lava Wrap. We closed in the 1/4 panel vents after the fire where the driver got his suite singed by the flames that came forward out those vents. Probably not as big an issue if you are using those vents with a sealed connection to the engine intake. My suggestion is to leave the rear how you have it and just be prepared to open it up when/if it is needed. Maybe keep this in mind when building body supports and such.
Crash.....yeah, that makes sense if you have a really effective path somewhere for air to be drawn out of the engine bay....that it would be drawing air into that louvered window replacement panel. As you said, whether that panel draws air/heat out, or allowed fresh air in is going to depend on what other methods you're using to both get fresh air in and draw air out. If you install that panel on a car that has our diffuser louvers installed, I would fully expect for those louvers to have more "pull" than the hatch area.....so air would flow toward the diffuser. On cars without the diffuser louvers and a good path for air to be forced into the engine bay, I would expect that the heat/air would flow out of the hatch panel.
Shane Vacek
VRaptor SpeedWorks, LLC www.vraptorspeedworks.com
Turn-key GTM, SL-C & Ultima GTR Built to Your Specs!
Offering a full line of GTM Upgrades and Custom Parts
Some things aren't apparent until assembled and on the car. The first prototype had the contours of the snorkel continued towards the rear of the car, rather than perpendicular to the face of the intake. This has been corrected. (this isn't evident in the photos as spacers were added to correct this).
The first prototype also had the face of the intake parallel to the surface of the car bodywork, rather than parallel to the duct body. This also has been corrected. (this also isn't evident in the photos as spacers were added to correct this). I also brought in the outer margins of the base about 5mm to better fit the 1/4 window recess.
Prototype 2.0. Contours flow better. Extended away from the body more. Now I'm concerned about aerodynamics/drag and will make another version that hugs the body closer.
What are thoughts about airflow in this region? Can I get enough air into these if the intake shape is attached to the body? Or do I need to get them up into airflow away from the body?
Did FFR ever release the GTM air tunnel results?
This is probably nothing new knowing your background and studies in race car aerodynamics, but i'm bored at work so I'll type away
I know your GTM is vastly different than the stock GTM, but I bet crash has some string and tape tests in that region he may be able to share. The focus is laminar flow over the body in this region. If I'm a betting man, with the mirror and window upstream of the intake, there is a lot of turbulent flow in this region. The more turbulent the airflow across the body, the farther you would want the scoop from the surface. If there was perfect laminar flow across the body you could tuck it right next to it. This is obviously all theory and would need relevant testing to validate.
I went through a similar exercise on front canards for my build. I never liked the "flat" 45 degree body feature that FF put in the Gen 2 version, so we cut that out, smoothed it over, and gave a fresh surface to start with. I was able to grab a set of universal CF canards from the same guy that did my mirrors and chose the size and location based off solid theory on location and size. Would a wind tunnel with smoke be a lot better to try for placement and size, absolutely, but we gave it our best guess on the theory. Plus, I won't super competitively race mine. I'll track it on fun days, but mostly a fun kick butt show car for me.
I'm not sure FF shared any wind tunnel data, but if they did, I'd love to see it.
I agree, Sean, I don't think there is much attached flow in that region. Plus the air tends to crash down off the roof, so I may angle the intake up some, or recontour the intake to "catch" more air at the lower aspect.
Side mirrors are still in development. I played around with a side mirror with the side intake installed, and could actually see more behind me that I figured I would. But probably will go with a pair of cameras with an lcd screen for each side, I had planned something like that from early in the build.
I do plan to track the car some, but also would like to do some 1/2 mile airport runs where drag becomes a major factor.
How's your car coming? Is it still in Iowa?
"I know your GTM is vastly different than the stock GTM, but I bet crash has some string and tape tests in that region he may be able to share. The focus is laminar flow over the body in this region. If I'm a betting man, with the mirror and window upstream of the intake, there is a lot of turbulent flow in this region. The more turbulent the airflow across the body, the farther you would want the scoop from the surface. If there was perfect laminar flow across the body you could tuck it right next to it. This is obviously all theory and would need relevant testing to validate."
Yes things are also slightly different on the FFR PDG GTM race car. For instance, we use rear view mirrors that are attached to the front fenders. This gives us far better sight lines than in the original door/A pillar position. Likely also does not disrupt the airflow on the B pillar as much either. We are not allowed to use door windows on the race car so this area really is what it is. Not a whole lot we can do there besides getting rid of things that cause disruptions in the air flow. I did try and skirt the window rule with break out-able windows ala NASCAR super speedway design...tech safety people did not like...and then half windows...again safety tech did not like, so we have not ignored this area completely, but, like I said, because of safety concerns, we are kind of left with open windows. What I can tell you is that racing the car in the rain for hours at a time the driver and driver's area did not get wet even with open windows. This suggests that the air flow between 80 and 150 MPH, which is what we ran for speeds in the rain, does not try and stay on the side of the car on the sides of the greenhouse. We removed the side scoops, as I said earlier, for safety reasons, so again, it is kind of not an issue for us at this point. Therefore the working design is to just keep it as clean as we can. I did make the 1/4 windows "openable" by using a hinge on the front edge and screwing in the rear edge so I can access things like the fuel and dry sump systems via those windows. Proven to be very helpful for us. You may want to try and work it into your design. Ended up putting the hinge below the level of the fiberglass because the hinge needs to be in a straight line while the body in that area, as you have noted, is not flat our straight. Might be difficult in some cases if the scoops are attached and sealed to the engine intake system.
"I went through a similar exercise on front canards for my build. I never liked the "flat" 45 degree body feature that FF put in the Gen 2 version, so we cut that out, smoothed it over, and gave a fresh surface to start with. I was able to grab a set of universal CF canards from the same guy that did my mirrors and chose the size and location based off solid theory on location and size. Would a wind tunnel with smoke be a lot better to try for placement and size, absolutely, but we gave it our best guess on the theory. Plus, I won't super competitively race mine. I'll track it on fun days, but mostly a fun kick butt show car for me."
We used to constantly fight the front end grip issues that are inherent to rear and mid engined cars...until we changed to Fox Shox. Fox made us some custom shocks that are three way adjustable and we are now able to dial up and down the grip in the front end to the point that we no longer need canards. We still have a large front splitter, but with the adjustability of the Fox Shox and how the shocks also allow us to dial in at speed ride height, this allows us to use the front splitter to full effect as far as aero dynamic down force, and thus we don't need the draggy front canards.
Those 1/2 mile events look like a ton of fun!!! I also liked the idea of side cameras versus mirrors, but shelfed the idea for maybe a future effort. I could totally see putting in additional screens similar to what I have seen on other race cars for side mirrors.
Yup, my GTM is still with Shane and he is working on it full time. When I first shipped it out, we knew that it was going to be used as fill in work as he was finishing up his last project. I can't say enough great things about the process Shane has set up for his clients. We have been in constant contact clarifying details from my "request sheet" and executing accordingly. I regularly receive videos and photos with fit up and alignment clarifications/questions (e.g. canard size and fit up) to make sure I'm getting exactly what I'm looking for and if I need to think about or research something, he is flexible enough to pause on that item and focus on another as I make a decision. For me health wise this was the perfect decision for me to have Shane finish my GTM for me. I'm still struggling with lower spine issues and going through the very slow process of strengthening my core to help minimize any future injuries. Thankfully I know I will be able to enjoy this car once complete, but may struggle down the road being able to do any large builds like this again.
Reply to Post 872:
That's a great bit of information to have in my back pocket if I see handling issues. I had contemplated 3 way adjustable shocks, but landed on the custom Bilsteins that Ted at QRP offered some time ago.
Ted offers(or offered?) good products. The Bilsteins you purchased should be the same as the originally developed ones for the FFR PDG GTM race car. Ted handled that for the team. They should be a good choice for both the street and track days. In reality the Fox Shox we have would be way too harsh for street duty even turned all the way down.
I didn't know these were originally developed for the FFR PDG GTM car, that's really cool and I'm glad I picked them up.
I say offered, as a handful of the items state out of stock on his website and I believe he needs a minimum order to get more of them, but I could be wrong on the minimum order for the shocks. I thought someone tried to get a couple items from Ted a while back and they were trying to pool up multiple owners to get a minimum order going. That very well may have been the front sway bar, so I may be confusing items.
Yeah that was what I meant by my question/statement in parenthesis'. Just that I understand that Ted does not necessarily offer these items any longer as I have heard a number of people say they could not get orders filled from him. He, along with many of the rest of us, have moved on from offering GTM parts since the kits are no longer being sold by FFR. I am really not building any more parts for GTMs and once the items on the shelf are gone...they are gone.
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Originally Posted by crash
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