I just got it back Saturday and they did not think the dump pipe was responcible for the heat. It seems the builder had the fan wired for MANUAL ONLY! They rewired it back to stock so it should come on with the thermostat.
However, the dump pipe DID change the mapping. They did some mods, but it will require dyno tuning to get it perfect. The shop I took it to builds a lot of turbo busa sandrails. These things are AWESOME! Anyway, they do not use the micron exhaust that comes with the kit, so I bought the entire micron exhaust from them for $300 and it has never been used. Not sure if I will ever use it, but that price seemed to too good to pass up. Check out Scott's shop, he is AWESOME! He also built VegasDude's turbo Busa.
http://headsup.dragbikecentral.com/