Neil's Aventador build (Page 35/74) Neils88 MAR 11, 04:23 PM quote Originally posted by GlennGdman: Good idea to not post them... I heard about what you did on vacation!!! Sssshhhh!!!! They'll all want to know.... Neils88 MAR 12, 04:13 PM I am embarking on a secret project... I spent about 5 hours at the Pick n Pull today picking up what I need. Why is it secret you ask? That way when I crash and burn with the project I can make up all kind of lies and not admit to what I was trying to do... Hopefully I'll have a good idea tomorrow if this will work or not. Now off to look for a wiring diagram.... RCR MAR 12, 08:57 PM Bob Neils88 MAR 26, 08:18 PM Ok...time to let you all in on the secret project I've been working on... (I've held you all in suspense long enough...) Despite people here telling me not to attempt this, I decided to go ahead and upgrade the HVAC system to a non-Fiero system. My Fiero did not have AC and being a summer driven car, it is definitely a required feature. One option was to simply swap out the Fiero heater unit to a Fiero AC unit, but there were several factors that made this a bad choice. First of all, because of all the metal removed from the dash area, I have a structural beam that lays over top of the existing HVAC system output. Trying to get air out of it nicely just really wasn't an option. Secondly, I plan on integrating the HVAC system with an OEM Aventador HVAC control system, and while I could automate the cable system of a Fiero, it would be expensive and not a simple option. Lastly, since the windshield on my build has been moved about 2 feet forward, it is very difficult to get the defrost output anywhere near where it needs be. So....against eveyone's advice...I decided to install the full HVAC system from a 2004 Grand Prix. Be aware...this is not a project for the faint of heart! (...but I'm not the first to install something like this) Less text...more pics.... So this is the stock heater unit in place. Note the new windshield line several feet forward. Here you can see how the top of the existing unit is blocked by the structural beam. So...off to the local Pick 'n Pull....this is what a 2004 Grand Prix looks like once you tear out...everything.... (I purchased the full heater/AC box, ducting, controller and cabling for $50 Cdn. ) Once the Fiero system is removed, this is the nice opening that you are left with... Unfortunately I forgot to take some good pics of the 2004 Grand Prix HVAC system before "preparing it"...but this is what it looked like before I made a critical cut... So, of course a Fiero and a Grand Prix are far from compatible. I couldn't use the whole system without major alterations. The major change is that I need to separate the main unit from the blower motor. Now that I have some space and a smaller unit to deal with, I test fit it in place... You can see that the floor vents actually sit in the perfect location... Lots of room around the unit, so I know I'm on the right track with this... I also decided to remove a little extra metal from the dash. The flat section between the firewall and the new structural beam have now been removed to make room for the new duct work that will eventually find its way there. No structural concerns, since the whole dash between the bottom of the windshield and the firewall will be connected with an 18 gauge sheet metal plate. The structure will actually be quite beefy. You can see in the pic that I've also started to box in the HVAC unit. Essentially the HVAC unit sits inside the car...the housing is completely sealed externally and only opens through the firewall. The unit will sit in a box that can be opened from the front. The cover plate can be removed (after removing the forward trunk box) and the whole HVAC system pulled out very quickly. This makes life simple if I ever need to replace the evaporator, the heater core, actuators, etc.... Here's the box with the unit removed.... Lastly...here's a pic showing the air distribution ducting starting to be built up... The front part of the air distribution ducting splits in 3 parts, driver's side and passenger's side vents, plus the central vents. The forward opening is the defrost system, and will have the main windshield defrost vents (basically right above) and two side ducts that will run through hoses to the side window defrost vents. Of course the floor vents are already in place. I was planning on using the oem Grand Prix duct work (cut and glued as required) but will likely just use some HVAC flex hose (from Summit Racing) since it is easier to work with. The blower motor (to be installed shortly) fits just behind the glove box with a duct connecting the blower output and the main unit that runs down the side of the main unit housing. The fresh air intake is located at the firewall and will be protected with a small "tortuous path" system to remove any water and a grating to protect from debris. The oem Grand Prix controller uses a single wire DLC data communication system from the BCM. I have no intention of trying to decipher the data between the BCM and the HVAC controller since I have no intention of using it anyway. Instead, I have set up an Arduino controller (with full DAQ capability), using an Adafruit 4 channel motor controller connected to the individual vent actuators and the blower motor controller. From testing, I have full control of all features of the HVAC system, but do still need to finish writing the software to set the vent positions at the various switch positions. Since everything worked perfectly during testing, I'll hold off on finalizing this until I'm working on the cars electrical system. Hopefully in the next couple of days, I will have the air distribution box finished and the dash closed up from the firewall to the bottom of the windshield. The last two key parts will be to install the blower and the ducts. GlennGdman MAR 27, 07:58 AM About time you did some work in the garage Hey wait...not everyone recommended you stay with the fiero set up....hmmmmmm ok seriously, this is looking good.... the next project is moving that master cylinder forward... really going to suck if you ever need to add fluid or even replace it.... RCR MAR 27, 09:42 AM Great stuff, Neil. Any reason you chose the GP HVAC over something else? Even a vintage Air setup (other than cost)? Bob Neils88 MAR 27, 10:47 AM quote Originally posted by GlennGdman: the next project is moving that master cylinder forward... really going to suck if you ever need to add fluid or even replace it.... I actually looked at that very closely. First, I checked that I can reach every bolt from the front with the trunk removed. Filling the reservoir won't be easy, but I plan on building a funnel specifically designed to make it manageable. Moving the clutch master cylinder is just not an option. I'm comfortable that I'll be able to deal with this. I even have a small boroscope so I can see everything easily...bought specifically to make life easier for working in that area. Neils88 MAR 27, 11:11 AM quote Originally posted by RCR: Great stuff, Neil. Any reason you chose the GP HVAC over something else? Even a vintage Air setup (other than cost)? Bob I looked at the shape / size of pretty well every system available. I ended up going with the Grand Prix unit for several reasons. First, I wanted to stick with something that would be readily available from the Pick n Pull that I use. Parts for the Grand Prix are relatively cheap should I want to buy parts new, but easy to find at the yard if necessary. The unit is actually one of the more compact units, and with the blower separated, it fit the space that I had available really well. The configuration of actuators and the blower controller were also very simple for me to connect and control using my own Arduino controller. I looked at the Vintage Air system (and several other similar systems). They had a few advantages...but the cost was definitely too high. Admittedly, the Vintage Air system might have been a little simpler to install, but there would be fabrication work either way. Weighing all the options, once the housing is complete, I think the Grand Prix unit is far superior. (...and labor is free ) Neils88 MAR 27, 06:06 PM I managed to finish putting together the air distribution manifold. Just needs a cover plate on top and then a rear plate to attach the duct flex hoses (which I still have to order). Neils88 MAR 28, 05:04 PM Slow day today. I didn't get as much done as I had originally planned. I did manage to get the the cover plates put onto the air distribution manifold. That includes an opening for the windshield defrost that will be hooked up once the actual dash gets put in place. Side window defrosts are now routed to the rear edge of the manifold, along with the driver's and passenger's middle and side vents. I still need to make the panel that closes the rear opening of the distribution manifold and allows the duct hosing to be hooked up. I ordered the necessary ducting from Summit Racing (2 sizes...2.5" for the vents and 1.5" for the side window defrost), and will make the final panel once it shows up.