GTM roll cage modifications and race car build log

[kabacj]

Nice fender work. You might consider an aluminum splitter. Shane widened the front of my car for 315's then made a wider splitter and wrapped it in carbon fiber print vynl material. Looks great. Your wheels look great. Are you worried about the wide front tires not getting enough heat for track days?

Hi Roger.

Yeah actually aluminum would be the easiest way to solve for the splitter if I was only driving on the street or occasional track days., but since I have ripped off and destroyed 2 splitters so far, I need to make the splitter that is both strong and a sacrificial part.

I reused the composite splitters until I either lost or ground off big enough chunks to make repair and reuse too difficult.

I was thinking using a combination of balsa and carbon fiber if I go with a moldless solution or maybe carbon fiber and foam if I make a mold. Then an aluminum sheet under tray as that part hopefully will not take as much abuse.

I really like the idea of aluminum , but a composite part that harmlessly rips off and lets me keep going is better than something that will bend and stay attached I think.

Regarding the wider front tires.

I found that I needed to adjust my driving style trail brake later and carry more speed into the mid corner section of the turn and scrub speed with the tires as the tire size got bigger in order to get heat into them.

That’s exactly what you were not doing with the 245s or smaller width tires. Like all production cars the GTM was setup to drive safely on the street as the front will push before the rear lets go. Its much easier to control a car that’s pushing understeer then a car that suddenly breaks rear traction.

To make the bigger front tires work I needed to add front spring to support the added loads and tune the roll bars so the car was neutral mid corner. The next goal is adding more aero grip up front this way I can tune the car for the fast sweepers where I can pickup time and just deal with a little more push in the slower corners.

Tire choice also determines how big you can go up front and still get heat into them.
Hoosier A7s heat up in 1 lap. If I did not flat spot one tire a weekend they would be my go to front tire. Even the hoosier S80s heat up pretty quickly and are much more durable. I like to use them with the s100s or the R7 rears.

I guess I could get a $10,000 dollar racing ABS setup, but eh I think ill just burn up tires for now.