need help on performance

hi guyz,
i new at this forum,Thanx 4 havin me on it.Now, i've gotta e39 525 uk spec year2001.You see recently i got my rims changed 2 a 9½ in[rear]with265/35/18 & 8½[front]with 235/40/18 now after fitting it my 0-100 pickup got slower.i've check around and got some options:>1.superchip,is one. 2.spring booaster,something new 2me.How it works:shakehead ITS FITTED at the back of the accelerator paddle & what it does is-it send a quick respond 2 the ESU.hence instant respond:nono: so how?what u guyz think?or any other options?
also,my drive is a bit bumpy,even after changing my steering rack,is there anything i can do 2 feel the same as when it was all 7½in 235/40/18?

sanjaynv

hi there im new too ! and my speling suks . how ever you can chek on e bey there is a member who sels litle elektronic tinks to bust the power up .
I think your weel roking is be kause the tyers are wiyd , friend of mine had the same think .:thumbsup:

thanx mitko,
i got 'sprintbooster' fixed 2 my car,so far i'm feelin the power.well, u can recommend it to ur friend.read about it at sprintbooster.com.
and by the way ur english,is fine:)
sanjay