Fiesta ST180 build. Advice needed. Pedal Crunching.

[Yeti]

So, I recently underwent a build on my 2015 Fiesta ST. It's now pushing around 250bhp with all the necessary parts.

I've had some issues with the front right tyre being gouged by the wheel arch (since sorted). Strange it only happened on the drivers side though...

The real thing worrying me is that whenever I put my foot flat in first and second gear I get a grinding/crunching feel through the gas pedal. Originally I thought this was where the arch was rubbing but it hasn't gone away since raising the suspension. My garage assures me this is normal, and is just due to fact there's a lot more torque going through the wheels now. Has anyone else experienced this?

I'd rather check and be safe before doing some damage. Thanks, Nathan.