解决DISCUZ X1.5帖子标题80字符限制

<span style="widows: 2; text-transform: none; text-indent: 0px; border-collapse: separate; font: medium 'Times New Roman'; white-space: normal; orphans: 2; letter-spacing: normal; color: rgb(0,0); word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px" class="Apple-style-span"><span style="line-height: 16px; font-family: 'Trebuchet MS',Arial,sans-serif; color: rgb(64,64,64); font-size: 13px" class="Apple-style-span">
<p style="padding-bottom: 0px; margin: 0px; padding-left: 0px; padding-right: 0px; padding-top: 16px">DISCUZ X1.5帖子标题有个80字符限制，个人感觉字数少了些，何况UTF-8下一个汉字占了3个字节，DISCUZ X1.5主题标题80字符也就是限制最多只能用26个汉字。怎么修改这个呢？比如我要修改为120字

<div style="overflow-x: auto; overflow-y: auto; background-color: rgb(231,229,220); margin: 18px 0px; width: 594px; font-family: Consolas,'Courier New',Courier,mono; font-size: 12px; padding-top: 1px" class="dp-highlighter">
<div style="padding-left: 45px" class="bar">
<div style="border-left: rgb(108,226,108) 3px solid; padding-bottom: 10px; background-color: rgb(248,248,248); padding-left: 10px; padding-right: 8px; font: 9px Verdana,Geneva,Helvetica,sans-serif; color: silver; padding-top: 3px" class="tools">
<a style="outline-style: none; color: rgb(160,160,160); font-size: 9px; margin-right: 10px; text-decoration: none" onclick="dp.sh.Toolbar.Command('ViewSource',this);return false;" href="#">view plain<a style="outline-style: none; color: rgb(160,160); font-size: 9px; margin-right: 10px; text-decoration: none" onclick="dp.sh.Toolbar.Command('CopyToClipboard',this);return false;" href="#">copy to clipboard<a style="outline-style: none; color: rgb(160,160); font-size: 9px; margin-right: 10px; text-decoration: none" onclick="dp.sh.Toolbar.Command('PrintSource',this);return false;" href="#">print<a style="outline-style: none; color: rgb(160,160); font-size: 9px; margin-right: 10px; text-decoration: none" onclick="dp.sh.Toolbar.Command('About',this);return false;" href="#">?