Nodejs Sending multiple files - node.js

Question

I'm trying to send multiple files to a used and have them displayed, for now I'm testing with simple txt files.
Since piping more than 10 files at a time causes warnings/errors I have tried to only pipe 10 at a time. The function gets called the right amount of times but, for some reason, only sends part of the data ( always seems to stop at 2.3mb ). Any reason why?
app.get('/file', function(req, res) {
console.time('leggo');
var lowerbound = req.param('lowerbound'); // 3 vars used for the file.
var upperbound = req.param('upperbound');
var filename = req.param('filename');
res.writeHead(200, {
'Content-type' : 'text/plain',
'Content-disposition' : 'inline'
});
var readst = fs.createReadStream(base+ lowerbound + last); //first file.
var count = 0; // number of files that are being sent atm.
var add = function(i) { // add i'th file to the pipe
console.log('whatevs');
++i;
readst.push(base + i + last);
};
var started = 0;
function sendem() { //send files.
++count;
++started;
var mycallback = function () { //callback when doit finished
console.log(count + ' ' + started + '\n');
count -= 1;
if (started == upperbound)
return;
if (count < 10) sendem();
};
function doit(mycallback) { //send a file then call callback
add(started);
mycallback();
};
doit(mycallback); //start sending.
}
sendem(); // start the "main" sending function.
readst.pipe(res); // pipe everything, also tried using this earlier, same effect.
readst.on('end', function(err,data) { // "everything" was sent.
console.log('done');
console.timeEnd('leggo');
});
});