Boganspeed

Iceman, how much do you think the auto tranny costs you in acceleration or percentage of lap times compared to the manual trans in terms of both power sucked up to run a slush box and having taller ratios and less gears ?

It obviously isn't holding you back too much.

IcemanG17

Good question.....so it weighs 50lbs more and probably costs some HP...but I don't think its much...maybe 10hp tops...since 195whp is pretty stout for an 84 US automatic.... I do think the gear ratios are NOT ideal at all...2nd is fine, especially for Thunderhill that doesn't have any real slow corners...but third is FAR too tall...the gap between 85mph gear and 139mph gear is just too much....a gear in the middle would be ideal...I'd guess 110mph

The only real comparo I have is when MK ran his 1979 5 speed at Thunderhill with 200whp and similar weight (both are open diff)...MK had bigger tires, but the track is faster now after being repaved.....we are within .1 of a second apart....he ran a 2:10.9 and I ran a 2:11.07....I do think he is a faster driver than me too... However the "estate" has ran as fast as 2:09.5 around thunderhill with a different driver....and the weather conditions were not good that day...he thought the car could do 2:08 easy....he thought it was close to his Spec Miata which is near track record times (2:07.5 over the top)

So my best guess is 1 second, 2 tops...everything else being equal....of course if I do a 5 speed conversion I'll do an LSD at the same time....so its hard to tell..

Since i did the R comps I have ran three different track days, all at Thunderhill....the 1st was the best at 2:11.07 but the conditions were just about ideal......the 2nd was VERY windy and I only got low 2:13's (same day as 2:09.5) and the last time was consistent 2:11's and the conditions were "okay"...a bit too windy for ideal times