GTM upgrades/revisions/mod ideas

[Power Surge]

I just picked up unfinished GTM #30. I would love to hear what people did beyond the basic parts and build. Things like upgraded parts, design revisions, and other modifications. Aircups, ABS/traction systems, digital dash or other dash upgrades, brake upgrades....etc etc.

Thanks!

[Shoeless]

Welcome to the madness that is the FFR GTM.

After spending 6 years building my GTM to a fully functioning go cart and nearly 98% of what I wish it was (only changes would be based on lessons learned and would be major so I set them aside for my next build), I'll share some of my perspective.

This forum and the remaining handful of active participants are going to be you best resource as you navigate this build. There are no stupid questions, although you may get some direct answers if its been something mentioned and can be searched for. I will say I much prefer the search function of the other site versus this one, but this site is more active nowadays compared to the others.

You will quickly learn, if not already surmised, you can go as simple or as far out as you want on this build. When done, I'll be well over 6 figures, but I went all out on some items and I love it. I also learned some very expensive lessons along the way. For example, I went with an AEM Infinity Series 7 ECU and CD-7 Race Dash just to find out the ECU has issues, caused me major stress and headaches, and now AEM has sold out to Holley and no longer support the Series 7 ECU. They wont even repair them. I couldn't risk that so I pulled all the AEM stuff out and went with a MoTeC M170 ECU and MoTeC C127 Dash. If I knew years ago what I know now, I'd have gone full MoTeC to begin with, including a PDU for the Chassis side of things. That's the only change I'd do on my setup. The rest I'm 100% happy with.

By the way they still support CD-7 Race Dash and its actually a pretty cool unit being a fully open architecture that you can change the designs and everything. I've got mine for sale if you are interested heavily discounted over a new unit that's only been used for 500 miles to break my engine in.

You mention some items that many have included. You will want to buy nearly everything Shane offers for GTM Fixes and Heat Management. Stance Air Cups offers a cool setup and I added that well into my build. You'll want to get tie rods that allow to adjust for bump steer. If you get this, also get bushings that lower the mounting of the steering rack for more adjustment. I did all the alignment on my GTM by myself and as is, there is a lot of bump steer. I did not do ABS, only because I was so far into my build it would haver required a ton of rework to install, and I didn't want to do that. I mentioned the dash above. I also went with Wilwood brakes on mine and others have done other brake upgrades.

I'm sure I'll remember more along the way, but back to work for now for me.

[cob427sc]

I would highly recommend obtaining a cable shift (if you don't already have one) and would move the coolant lines from the center tunnel to the outside rockers. This is experience from an early GTM build.

[VRaptor SpeedWorks, LLC]

I would second the recommendations above.....moving the coolant reservoir to the engine bay and definitely go with a cable shifter over the FFR rod set-up. The only other thing I would check out for sure is your suspension cam bolts. On the Gen I cars, the chassis suspension mounting points are too "thin" and the cam bolt washers end up tightening down against the step in the cam bolts before they get tight to the chassis.....which can allow them to spin unexpectedly under load. I sell some cam bolt washers to take up the slack so that the bolts tighten properly against the chassis. Your car might already have these installed if the original owner took care of this?

I do have a ton of stuff available for these cars. Some are "nice to have" things, while other stuff is stuff I would categorize as "highly recommended". One other thing I would recommend is that you do everything possible to get as much fresh air into the engine bay and as much heat out of the engine bay. If you use the perforated alum mesh that comes with the kit for all of the "venting", the engine bay gets insanely hot.....which makes the center tunnel and rear firewall insanely hot....which makes the interior insanely hot. Get as much air flowing thru the engine bay/tunnel/hood as you can.

https://vraptorspeedworks.com/custom-gtm-parts/

I'm not a paid vendor on the other forum....so not really able to "advertise" that stuff there. Lots of helpful people here on this forum.....welcome!

[VRaptor SpeedWorks, LLC]

PS....I have installed the BMW ABS on one car and it seemed to work well. I've installed the Race Logic traction control on a few cars and that worked great also....but they are now out of business. I have no connection to this company, but AFAIK, this might be the only other "stand alone" option for traction control? racetcs.com

[Shoeless]

I've heard a couple good things about racetcs.com unit. Can't remember where I saw it though.

One reason I wanted to go with a standalone ECU on my setup was having adjustable traction control. I've got 2 dials on my steering wheel that I can choose preset launch RPM and traction control setting. They are wired to my C127 Dash that takes the signal and throws it on the CAN Bus for the ECU to pull off and take action on. Have I mentioned how much I love my MoTeC set up LOL

[cob427sc]

One more item to go along with Shane's recommendations about getting the heat out. My early build, following FFR directions, the tunnel would get so hot you could not rest your hand on it. I dropped the aluminum pan that covered the bottom of the tunnel and the temperature dropped 30 degrees. I just wish I had moved the cooling lines to the rockers as I'm sure that would have made for a more enjoyable interior temperature.

[VRaptor SpeedWorks, LLC]

Yes ^^^^. Contrary to what you might assume, the air in the tunnel moves from the engine bay forward thru the tunnel instead of from the front of the tunnel back to the engine bay. So if your engine bay is hot, your tunnel will be hot. We try to keep all of the coolant tubes, heater hoses and AC hoses all at the bottom of the tunnel. Then create a "blanket" of insulation that spans all the way from one side of the tunnel to the other and seal that blanket to the chassis at the chassis tubes along the bottom of the tunnel. That way, 100% of the heat from all of the coolant is all isolated from the tunnel by this insulation blanket...and then we install one of our louvered belly pans below the tunnel to vent all of that heat out the bottom of the car. At the smallest part of the tunnel (between the main dash and waterfall), all of your electrical and shift cables will be routed thru there, and then we stuff insulation around there to plug up that part of the tunnel to seal it off from the engine bay (only plugging off the area above the "blanket" while leaving the area below the blanket open to the engine bay so that air can flow from the engine bay out the bottom of the car thru the louvered belly pan). All of this....plus adding as much airflow thru the engine bay as possible so that the engine bay temps never get that hot......makes a very dramatic difference in cockpit temps.