near coventry area tuner needed please

Hi,
I have a 1.6 GTI 8v with an after market bolt on Turbo Technics kit and following a rebuild I am now having tuning and running problems, following a couple of attempts of get it rolling road and static tuning I am no further on, I need a and old boy tuner or a garage that can help, I have already tried the mighty stealth racing with no success seems Vince has set his mind on newer plug and play tuning not our mechanical k jet systems
The car will miss/bog on low revs but when it gets into boost 3500rpm or over will fly along with no problem the plugs are black with soot witch indicates to me to rich mixture although I have been told the Co has been set at idle.
Help please needed as I am in despair beyond belief its been at this stage for around 2 months thanks in advance to anyone who can help I am in the Coventry area.