I max bored a stock TB leaving no inner ridges, and made a new heavy brass throttle plate for it. Took me 6 hours to complete, installed it, and it worked very well idle-wise. However, I noticed that it did not respond as crisp as the old one (I have 2 of them, 1 unmodified). I went this route to avoid buying a 70mm. The modded one did not make much of a difference in performance- in fact I think it made no difference. I think it reduced some lower and midrange torque (softened the response). I was expecting better top end performance WOT. Does a larger TB necessarily improve drivability and acceleration? I'm thinking that it helps during high air flow conditions (3rd gear above 90mph) although I didn't notice anything with my modded TB. What are your experiences with the 70mm TB- does the low end torque increase? Does the engine respond quicker? The stock one seems better maybe because of better air velocity at street speeds. I get more wheelspin with the stock TB. I have max ported my M90, ported just about everything else except heads, 73mm MAF, modded air box, 5% pulley, underdrive pulleys, raised top (even bored this out more), max adjusted the TPS. Why does the stock TB make the car feel faster? I ran with a new WS6 easily past 110mph with power reserved with the stock TB- it felt like I could overtake him. I'm getting globs of torque throughout the power band with a stock TB and very mildly modded exaust. I don't get it-
Randy
'92 SC w-AOD
Sorry about the long thread-
Randy
'92 SC w-AOD
Sorry about the long thread-
Last edited: