Understeering on a 4X4 solid front axle tubular chassis

I have designed a tubular rock racer with a solid front axle from an old Suburban, and a multi-link suspension, I have a mid engine facing backwards, at the moment  I tried to make my first turn, even on a paved road, I noticed a terrible understeer,Can anybody tell me what I did wrong? Sorry for my english, it is not my language.
Pls help.  

I really have no idea how your suspension is set up, what your weight distribution is, or if you are running spools front and rear. However, all else being acceptable, increasing the rear roll stiffness reduces understeer. Meaning you can try adding a stiffer rear sway bar to reduce understeer. Or if you have no rear sway bar at all, add one.  
John Cappa
Editor, Four Wheeler

Thanks a lot, I dont have a rear sway bar, I am going to put one in and I would tell you how it works