Please read my post carefully, I didnt say 'HP' i said 'improvement' because it has nothing more to gain unless you upgrade the engine or the ECU. Grounding kit improves the flow of current, especially if you have an old car, lumalabo connection habang tumatagal so grounding kits just improves the flow.
*renzo_d10
No problem bro,
You can DIY your ground kit, parts are readily available on radio shops or electrical stores.