Project S2000 – Part 16 – Testing Track Upgrades


To perform my duct testing, I only installed the duct on the passenger side.  To install it, I jacked up one side of the car and turned the wheel to give myself more arm clearance to tighten the nut on the bolt.


I duct taped a piece of aluminum to my duct mounting bracket so that I could really wrench down on it.  The plastic could possibly break without the extra aluminum behind it.  The aluminum did space down the duct a little bit which helped with clearance to the sway bar, but it reduced the clearance to the wheel.  I did rub a little bit later in the day on the wheel, oops.


This was my first track day on the big track at Willow Springs and also my first time running with K.R.O.P.S.  Everyone knows about the dangers of turns 8 and 9 and it was awfully cold, so I took it pretty easy the first session out.  Of course, I did a little prep work by researching Billy’s info on the track.  This track day was my first to test out the new clutch, flywheel, and engine mount too.  So how did it all go?


Here is a datalog from the Hondata KPro set to a 5hz sample rate showing three laps.  Of note, the 235/40 NT01s are a little shorter than stock sized 245/40 tires, so the speeds will read a little higher than actual (roughly 1.5%).  Coming down the front straight, I hit a peak speed of 127mph before braking to72mph for turn 1.  Yeah, this is too slow for turn 1, but it was my first time at the track and I’d rather be safe than sorry.  Plus (read: excuse for going slow), slowing down more was testing the brakes harder.  Heading into turn 2, I hit just over 100mph and slowed down to about 90mph through the corner before accelerating to 104mph into turn 3.  Getting hard on the brakes again slowed the car down to 54mph.  I hit 85mph before slowing down again for turn 5.  From there, it was foot to the floor where I hit 120mph heading into turn 8.  At this point, my self-preservation instincts kicked in and I eased off to 110mph going through turn 8 before reaccelerating to about 115mph for turn 9.  For reference, Clint in Project 370Z was entering turn 8 at about 130mph and only backing off to 125mph or so.  Turn 8 has some undulations in the middle of it and with this being my first time to this track, in a convertible, I wussed out.  After cruising through turn 9 around 90mph, it was back to WOT on the front straight.  My average lap time was around 1:43.  Clint clicked off a 1:33 in Project 370Z; he’s got some new and very wide rubber on the car, so keep a look-out for his update!  The color codes for the bottom graph: blue = speed, red = rpm, green = TPS.  In the top graph, the blue line is coolant temp which stayed a rock steady 188F (87C).  The black line is the intake manifold temperature which varied between 90F-105F.  Keep in mind the ambient air temperature MAYBE hit 45F that day.  The IAT got cooler when at WOT and warmed up at closed or part-throttle.


The goal of the upgraded clutch was to eliminate clutch slippage on gear shifts.  The Centerforce Dual Friction clutch performed great with no slippage at all even with the stock delay valve still in place.  Whereas the stock clutch slipped on the 4-5 shift unless I babied it, there were no such issues with the Centerforce.  The first goal was achieved.


I zoomed into the 4-5 shift going down the front straight.  The shift took about 0.6 seconds from the time I was off the throttle to back at WOT with the engine speed increasing.  As you can see in the RPM trace relative to the throttle, there’s no slippage as I make the shift and go back to WOT.  Slippage would have shown up as the RPM trace spiking up a bit and coming back down as the clutch finally grabbed.


The primary goal for the Hasport engine mounts was to reduce engine movement thereby improving shifting precision.  The Hasport mounts actually made the car easier to drive on track in two ways: more precise shifts due to reduced engine movement and increased noise.  With the reduced engine movement, upshifting and downshifting in all situations was improved as it was very easy to find the gates even when shifting quickly and under G loads.  As for the engine noise volume, compare the following video to any of the previous videos of Project S2000 on track and you can hear the difference in engine noise volume.  Before the car was a bit too quiet for track work and I’d have to look down to see where the revs were.  Now, I can hear the engine better and shift by engine noise instead of having to depend on reading the tach. As a side note, after the initial install of the engine mounts, I increased the idle speed of the engine using the Hondata KPro from 850rpm to 950rpm to eliminate vibrations while at idle speed.


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