Enabling Nagle's algorithm should do this: Nagle's attempts to limit the number of small segments on a network by buffering data until it receives the previous ACK.
That being said, I have also seen Nagle's add noticeable latency to an application precisely because it is delaying sending data. According to the Wikipedia article on Nagle's (
Click here) it sometimes interacts badly with Delayed ACKs. I have not tried disabling those with Nagle's enabled though.
Also, I would create a new profile and leave the built-in tcp one at the default settings.
Denny