most aftermarket turboed cars dont do so hot in autocross competitively. Heck, most OE turboed cars arent usually as quick as their non-turbo counterparts (case in point: mr2 turbo v. mr2 na; saab 900t v. 900s, etc). You really never have a chance to hold down the gas for more than a second or 2, so yeah, lag is a killer. Its still plenty fun, you just wont be that competitive (btw, that would put you in SM, so youd have some pretty well prepared cars in your class)