AE86 with racing engine help!! pls! pls!

i have the ae86 with racing engine and i read the thread about the shift points.... i think its 8k 9k 10.5k... i was wondering why my car turns crappy at some points through AKINA. especially in 3rd gear, i got stuck around 109 and with my foot on the accelerator then if i shift to the next gear i lose my speed. why is that? :banghead: