Electronics Suite - Preliminary Decisions

Every guy I know love their gadgets. The GTM electronics suite is a vast opportunity to devise, scheme, plan and plot a digital cornucopia. With the order date for the kit a mere three and half months away, it is time to start making decisions. As with everything, decisions begin to narrow your options - this is a good and bad thing.

The CarPuter or Car PC is a powerful option. Mobile Computing Solutions is a great site to research the available options. Centerfuse Auto provides software framework to load apps (similar to iPhone and Droid) to a XP, Vista or Windows 7 environment. 

The CarPuter idea is seductive and extraordinarily powerful. Unfortunately, there are some red flags. Many of the apps rely on an external board connected to the CarPuter via a USB 2.0/3.0 cable (in some cases up to 10 possible inputs). I live in this world professionally, and my experience has been that trying to push a Windows OS with 6 USB inputs is iffy at best. This is going into a car. I need it to be reliable. The other warning flag was that people are relying on hacks to make things work (e.g. hand soldering boards). Again the reliability/kludge factor causes me to pause -  especially in a car capable of 200 (or better) mph.

I went with an independent TPMS system offered by Orange Electronics.  Most systems are rated to 7 years on the Lithium Ion batteries. This is a direct monitoring system. The pressure monitor is mounted on the inside of the wheel rim. I plan to mount the screen on the lower left hand side of the dash. This becomes critical in the build, as I want to get the car up on wheels no later than July. Therefore, I need a TPMS solution ready to go by then. This also means I have to decide on tires and tire sizes.

The electronic suite consists of the following:

• Parking Assist Sensors
• TPMS (My buddy Vern hates these things)
• AM/FM/DVD/BT/MP3/GPS/XM
• HomeLink
• Automatic Headlight Sensor (under $30)
• Auto Dim Mirror
• Compass
• Temperature
• Trip Computer
• Forward and Rear Cameras (Night vision is a plus)
• OBD II Diagnostics
• Cruise Control
• inTouchMax
• Seat heaters (this is a Minnesota car - needed for late and early season driving)

Directed Electronics 545T Nite-Lite System uses a photo electric sensor to measure light and automatically turns on/off the headlights, tail lights and parking lights as necessary.

The goal of the electronics suite is functionality. This means I need to pack a lot of functionality into a small number of versatile interfaces. One of the major driving factors is space. The GTM is not a Chevy Suburban that has boat loads of room. It is basically a cockpit strapped to a rocket motor inside an exotic body shape. The center console has room for a double din unit and the ISIS inTouchMax screen (after I move the shifter towards the rear). The ISIS system already has 1 Master Cell, 3 Power Cells and a inMotion Cell. These all need to be deployed out of sight, and they require flat mounting surfaces. ISIS localizes 95% of the controls to the inTouchMax screen. Add to this speakers and an amplifier (I'm thinking of hiding this under the passenger seat) for the sound system and there aren't many places to stick a CarPuter.

This is a Bluetooth enabled scan tool that is compatible with Droid, Android and Torque. Torque is an Android app that directly monitors the vehicle's ECU. I plan to use this with an Android (Samsung Galaxie II) tablet on an as need basis. I will test it on the Corvette and see if Torque lives up to its billing.

Since space is at a premium, you start asking questions:

1. Does the GPS and/or cameras get deployed to the rear view mirror or the sound system controls?
2. Does the sound system use a fixed screen double din solution, or a single din with a motorized screen solution?
3. Does HomeLink get deployed to the rear view mirror, or is it an independent 3 button solution? If so, is there room on the headliner?
4. Does the parking assist system use 4, 6 or 8 sensors? And how does it interface to the screens?
5. Do the OBD II diagnostics get pumped to a really ugly instrument panel (looks like a cheap 1980's Nintendo system)? 
6. Is a 7 inch touch screen large enough to adequately display the information?
7. Where do the compass, temperature, trip computer and map lights get deployed?
8. Is there even room to go with a paddle shift controller behind the dash or inside the tunnel?
9. Does the GPS software have a built in trip computer? If so, how good is it?
10. Is there a reliable vendor and method to update the GPS map and software?

For the parking assist system, I am going with  a 2 speaker, no display, 8 sensor system. One sensor on each corner, and two sensors on each bumper. I plan to deploy the speakers so I can differentiate the front from the rear. The rear sensors activate when the back up lights engage. The front sensors activate when the brakes are applied. The stated range is five feet. Each has an independent controller.

This is what planning is about. In the final analysis, the only place left for the CarPuter was under the driver's side seat. I'm not sure how much space there really is down there. I've started making decisions (without putting a lot of money at risk). None of them are cast in concrete - that's the beauty of building your own car. The thing I like about the decisions I've made is that they are simple, modular and easy to replace.

Wheels!

One of the things I set up was an Ebay alert for 2 phrases: Factory Five and GTM. I receive an email anytime something new is listed for sale on Ebay. Many of these are listings for some really great cars people have built. The car listings are great for build ideas. There are usually enough pics so you can see if you like or dislike how something looks. Occasionally, something else comes up.

Wheel caps included.

I have already purchased the Big Brake Kit. These huge six piston brakes come with larger rotors and it is clearly explained that you need 18 inch or larger wheels to accommodate this upgrade. Factory Five sells a larger set of wheels in a bright silver finish. These wheels are Forgestar F14 and they are available in 9 different finishes. These wheels cost a little bit more than the Factory Five listing, but they came with free shipping, so there was a net savings of $100.

This is the rear wheel 18 x 12 in high gloss black (Forgestar calls this a Piano Black). This is a very big rim that is surprising lightweight (only 22 lbs). I left the protective plastic wrapping on the wheel. These will not be mounted until sometime next summer.

I conducted an informal poll on Facebook, text messages and people at the karate studio I where I work out. I explained the car was going to be red (Corsa red - Ferrari Racing Red) and the calipers are red. So did they like silver wheels or high gloss black wheels. There was an interesting split here. All the guys said high gloss black. All the women said silver. Although, the love of my life said I should do what I wanted. Once it was explained that I was planning a bright red car and not a cranberry red, the other women said black would be okay.

This is our Yorkie-in-charge checking out the Forgestar wheel.

The rear wheels are truly astounding. One of the things I discovered about the GTM is that I can go with different rear tire sizes for the larger wheels:

• 335/30 - 18
• 295/35 - 18
• 275/40 - 18

This is attractive, because it opens up the tire selection. Except once I saw the rear wheel, I knew I could only go with 335/30 -18 size tires. If I had decided to go with the donor car brakes, rotors and wheels, then I would be looking at the standard Corvette C5 of 245/45 - 17 (front) and 275/40 -18 (rear) configuration. Factory Five recommends Toyo tires. I prefer something other than a street legal racing slick, so I am probably going to put Michelin Pilot Sport PS2 tires on the car.

After Market Parts

Anyone who has perused the Factory Five Forum, or who has run a number of Google searches will realize that the GTM has spurred a vibrant after market. One of those places is Vraptor SPeedworks. These guys build GTMs, Superlite Coupes, Race Car Replicas and Ultima GTRs. They know where the problems exist, and they are contributors to the relevant forums. They manufacture and sell solutions to the problems they have run into on various builds.

This is a mounting plate for an ISIS Power cell. The problem addressed here is the lack of flat spots where the Power cells can be mounted on the frame. I figured out in an earlier post that I require 3 Power Cells and maybe an InMotion cell too.

So how frustrating or satisfying is it to deal with an after market GTM vendor? I have budgeted into the initial build estimate the Kooks Custom Exhaust supplied by Vraptor Speedworks. I figured I would like to know if they were a reliable source, before I plunk down $2000. A $140 order was my test case.

Mounting bracket for the ISIS Master Cell.

I put together a small order of ISIS mount plates, AC plenum and Stereo closeout panel. These were all items that addressed specific issues raised by multiple builders. My philosophy is to learn from those who have built one of more GTMs and have fashioned solutions.

The AC plenum relocates the blower motor from under the hood to the passenger side footwell. This provides better circulation of cool air inside the car.

I put my order together and emailed Shane at Vraptor Speedworks. He came back with the costs and a PayPal account to use. I paid the total and emailed a confirmation. Ten days later, the parts showed up. I dare say the service here was a darn sight better than some places I have recently dealt with (Grrrr, the Eibach Performance Sway Bars for the Boxster was an exercise in pulling teeth - not Eibach's problem, an unnamed vendor who will receive no more orders).

Stereo close out panel mounts between the dash and the tunnel. This reduces noise and  alleviates temperature issues by providing a seal around the stereo components. I might need one for the inTouchMax screen as well.