IndyCar has revealed minor alterations to the 2.6-mile, 11-turn temporary street circuit in Sao Paulo, Brazil, that will play host to the IZOD IndyCar Series this weekend.

Circuit designer Tony Cotman said the painted Turn 1 runoff – which became extremely slick in the heavy rains that hit the track on race day last year – has been addressed along with a “pretty significant” bump in the transition from the concrete surface of the Anhembi Sambadrome to the asphalt leading into Turn 1.

“The layout of the track has not changed and the curbs have not changed,” Cotman told IndyCar.com. “Reducing some of the bumps was among the goals that have been addressed. Also, drainage in five or six locations has been addressed. Now that it's all done, we hope we don't need it.”

Early forecasts, however, suggest that drainage might be critical again, predicting light rain Friday and Saturday and thunderstorms in the Sao Paulo area on Sunday, with temperatures around 70 degrees...

Cotman added that the tweaks for this year are a minor refinement in comparison with the significant challenges the track faced in its first two years, which included a comprehensive grinding of the track during race weekend in 2010, and a full resurfacing for 2011.

“You look back to year 1 and it was do whatever you could to get the race on," he admitted. "Year 2 was a significant repave of the entire circuit with higher-grade asphalt and reducing bumps. The lap times were quicker, but we weren't able to utilize it on race day because of the weather. Year 3 is about fine-tuning some of these areas.

“For us, it's more of an overseeing role, like it should be, rather than a hands-on role and that's been the biggest difference.”

The Itaipava Sao Paulo Indy 300 presented by Nestle airs live Sunday on NBC Sports Network beginning at 11 a.m. ET.