After successfully completing two track days in one day with the car staying in one piece i was able to move on to the next phase of my plan. I'd confirmed that all of the cooling mods worked so I felt good starting to addressing some other things that were on my list.
First things was to pull apart the dash and remove a few of the warning lights that were blaring at me for no reason. They were for things that were no longer relevant, such as airbag, SRS and Foglights warnings.
To remove these I needed to pull out the dash cluster and take it apart in order to turn off the tiny led bulbs.
You can see the warning silhouettes here.
And the bulbs here. I opted for covering the bulb cones with dense foam and electrical taping the cut out on the bottom side.
While the cluster was out I jumped the tach signal from the back of the master plug and spliced it into a new incremental shift light. Power and ground for the shift light came from an empty plug that used to power the now removed knee air bag.
I cut some carbon fiber and bonded it to the sides of the shift light box to act as a sun-shade so I would be able to see the LED's in the daytime. You'll find most track session you'll do are in the early morning until about 11:30am- sun shading warning lights become something you would never think about unless you've been on track a million times wondering if your warning light is triggered or its just catching side light.
I used some split loom and cleanly ran the wires back under the steering column plastics.
Since the cluster was out I also drilled through the dash and bolted in a magnetic holder that could hold a phone or an Aim solo2 laptimer up in my field of vision.
After all this I drove the car out to Streets of Willow to help Amir shakedown his k20 turbo NSX. I drove out in the ISF and brought my helmet just in case. Sure enough around the lunch time Amir was done for the day and since I was there I got a pass to jump on track for a session. I ran a 1:24.2 on my second lap out which is VERY close to the 23 barrier that 99.9% of cars wont ever break. I think it could have been in the 23's had it not been for someone spinning and dumping gravel on the track at the bottom of the hairpin turn 3. On the third lap I hit a very inconsiderate s2000 driver and eased off on the straights to a 1:25. Even on tight twisty track like SOW this car has potential.
Video here:
After the track day I was pumped to start to working on getting the car to the next level. By now I had the aero plan in place and first order of business was attaching the splitter tunnels to the splitter. I trimmed material out of the carbon splitter blade to fit the tunnels.
Since I was using a combination of structural epoxy and peel type rivets I had to scuff both surfaces to promote adhesion.
After applying the epoxy I riveted the diffusers in place to secure the parts while they dried.
Being a quality parts the transitions into the diffusers are thin and wont cause much turbulence. These should promote some pretty substantial downforce on the front end.
I also attached some titanium skid pucks to the splitter since I plan on running the car very low. Titanium skid pucks make sparks and sparks make for cool pictures.
To balance out the front aero I had decided on adding a rear wing to the car. I wanted it to be different than anything I'd done before so taking inspiration (aka stealing) from the RCF GT3 car i decided that I would want to do a swan neck style mounting set-up.
This is honestly the best looking gt3 car at the moment.
To this end, we laser cut and test fit a few different upright shapes and measurements. There were a few rules that I was trying to stay within as far as roof height and such but mostly I just wanted it to look good and preform the best on the track. I am pairing the uprights with an RSFuture rear wing element, 72 inch span and a 14 inch cord non 3d shape. Its going to be epic.
At this time I pressed in some new ARP wheel studs and swapped to a WedsSport steel lugnuts. A big heavy car with lots of power these become more and more important; i think i've started in the past but it bears repeating- Use the SAME metal on the lugs as you are on the studs. You don't want an aluminum/titanium lugnut heating and cooling at a different rate than the steel studs.. This causes them to become loose. Weight savings is one thing, this is not the place to save it.
Around this time, a box that I'd been patiently waiting for finally showed up at my door. After my first track day epiphany, when i'd decided that i wanted to make the ISF a track car I started shopping for some better shocks. After much research I had a custom set of Penske double adjustable custom made. These had taken some time to get assembled but were now with me and ready to go in the car. To be fair, the KW V3's were actually pretty good on track in this form- and I had run the times to prove it. But moving forward with the wing and splitter aero loads and the speeds i'd be going I would require a finer adjust ability in the shocks. Penskes are known world-wide to be second to none in this department. I decided to wait and put them on the car only after it was back from fabrication. It wouldn't make any sense to put them on now just to have to do it all again after I removed more weight and added aero and different tires.
I also picked up a RR racing strut tower bar for the front. These are seriously beefy pieces. Debatable if the frame legs out front require more support but its relatively light weight and definitely wont hurt anything. I sanded it rough and wrinkle finished it black.
Looks good in its place in the car.
I was browsing around and found a set of almost impossible-to-find C-west carbon side skirts.
They were in great shape except for a minor crack where the previous owner had let his car down onto a jack. Since these were going on a racecar I really don't car about stuff like that. A major reason I ended up getting these was the larger fender opening gave me the option to further vent the wheel wells.
I pulled the OEM side skirts off and angle ground substantially more of the fender material off.
After that i attached the skirts. Fitment on these is great. Car looks very muscular with the additional bulged extractors.
I also mocked up a shift-beeper that i used to run in my NSX. I put the beeper behind one of the switch blanks and but a piece of removable foam to dampen its volume while im not on track.
I took the car out to Chuckwalla Raceway for a Nitto Tire appreciation day. The track was about 2 seconds off pace for everyone from the windstorm the night before but It was SO fun sliding the car around.
Video here:
Meanwhile, I was working out more of my aero mounting plans with Chris. I had a few ideas i was working out and all of them involved cutting into the OEM trunk or getting a new one. Since I knew i would need something eventually, I jumped on a carbon fiber trunk. When i say 'carbon fiber' in this context i typically mean a carbon fiber sheet laid over a fiberglass shell. Still lighter than aluminum or steel but not as light as it would be if it were 100% carbon fiber.
Since the trunk i'd be using would no longer need to hinge i was able to get rid of the under structure and shed a couple additional pounds.
I also picked up a 997 Porsche cup-car seat. This one is ACTUAL carbon fiber not the fiberglass stuff. When brand-new this was about a 6 thousand dollar seat, I got it for a great deal from Amir. Super tuff and super rigid. It'll look awesome inside the ISF when i was done with it.
Another big item that i had to wait on was the OSGiken Limited Slip Differential. The one i ordered is the special TCD model featuring OSG's fancy new plate engagement and anti slip/chater technology. It needed to be built in japan then sat on a slow boat before I could get my hands on it.
After another long wait and I received my carbon-kevlar roof. This is one of the MAIN things I wanted to do after getting the ISF on track the first time. Having such a great chassis, suspension layout and engine meant that the car really only needed to be made lighter. All but only a very few ISF's came with sun roofs. Sun roof racks, glass and motors would typically not be described as 'light'.
Removing ANY weight is a good thing, it has a knock on effect to the brakes, cornering and acceleration equally.. Removing weight from the very tippity- top of the car the absolute best place. There was quite a bit of speculation on the internet of the actual weights of the roof and sunroof assemblies actually are but I knew that they would not be light.
This on the other hand...
The bottom side of the roof is carbon-kevlar with absolutely perfect weave.
The top is more of the same but with only a carbon fiber layer showing. As with all CF; at a distance it looks grey but as you get closer you see the weave. On a black base car this is going to look absolutely awesome- hood, trunk, roof, splitter, wing, skirts and other stuff in carbon.
Another carbon thing I got was a one piece driveshaft. This will indeed save a little weight but is more about dampening 'shock loading' that you normally see though a steel or aluminum driveshaft. Since the carbon fiber is 'springy' it wont shock the rear end if you modulate the throttle out of a corner. The lighter weight will also help the rotational mass be able to spin up quicker and with less energy getting that much more power to the ground.
These are VERY cool pieces. Things like this were unheard of at the consumer level 8-10 years ago.
Total weight is 24lbs. Not sure what the oem steel on weighs but ill make sure to weigh it as i replace the two.
By now I had taken the car over to Chris at Wisecraft. He had some drawings I'd made for him as a guide on how I wanted to lay things out. This wasn't going to be a full out-and-out 'racecar' type build, rather a very quick car that was capable of driving itself to the track and home again after setting some VERY quick laptimes. To this end, I am trying to balance my a weight goal of the car without sacrificing things that make 3 hour drives bearable. I was keeping the AC and heater as well as the radio, bluetooth and cruse control.
Chris wasted no time in drilling out the spot welds and pulling the roof off of the car.
Test fitting the new carbon roof.. perfect.
We weighed the OEM roof skin..36lbs for just the skin not including the sunroof glass and rack..
And 35lbs for the sun roof glass and slider rack. The entire carbon roof that will replace it came out to 7lbs.. When factoring in the roof airbags, headliner and other misc stuff that has been stripped off the roof; that's around an 80-85lb weight savings off of the roof alone. Now some of it would get put back in in the form of a rollbar, but not as high up and not as much weight.
The first version of the roll bar. Main hoop fitment is on point. I decided against this 'X' and just kept the drivers side brace.
Now the car was stripped and work was really begenning..
Here's the plinth tac welded in place. The bottom side of this box has an X reinforcement to increase it foot print on the underside.
I also picked up some 2 piece rotors to replace the boat anchors that come on the car. These rotors are SIX POUNDS lighter PER WHEEL(!!) and reduce the amount of heat that transfers from the brakes though the top had and into the hub of the car. They also have specially designed cooling channels on the interior to cool the rotor ring faster and the OEM version. The weight reduction at the wheel should pay HUGE gains in the transient behavior on compression/rebound directional changes. Lighter unsprung components mean the main shock spring and internal valving has to work less hard to change directions, this means finer adjustments can be felt.
I also picked up some rear traction rods and a solid transmission mount to keep all of the transmission and rear end aligned under G loads.
So far I had run street tires and a very mild R-compounds on the car. (RE71r and Nt01) I was extremely impressed with the re71r's speed but I tended to go through a set within a couple track days, especially the rears. The Nt01 had been on the car for a couple track days and were showing very good wear rates so far. Overall grip was good on both tires but I really wanted to get a bigger wheel that would allow me to step up the tire size.
After asking Duane at R-compound he recommended I try the AR1 from Nankang. It came in the exact size I was looking for and he had a set in stock. They are apparently faster than the Nt01 but the down side is the tires weight. Since its made for wheel to wheel its got a very beefy sidewall that adds a lb or two over the comparable Nt01. Since I had just cut weight on the brake rotors and the wheels I figured this trade off would be worth a try. The pic below is a 275 NT01 vs a 295 AR-1; you can see the AR-1 has a more squared shoulder where the Nt01 has a similar overall width but the contact patch rolls off at sooner.
Another big change i am excited for is a brand new set of Regamaster EVO gen 2. These are 18x10 +35 in Almighty grey. I have had a bunch of sets of these wheels over the years and think they are hands down come of the most timeless designs ever. These are forged so they are much stronger and lighter than the TC-4's that I currently have on the car. I am going to continue to use both sets of wheels for back to back tire testing in the upcoming season..
Good god these are good.
By now the fabrication work on the rear uprights was taking place. It is quite a job to make sure the uprights are both the exact same height and facing the same direction.
Heres the trunk in place, you can see the Aerocatch latches that will hold it down onto the chassis. ill likely need to add some toggle latches to the bottom rear corners too.
Under the deck lid I wanted to try an idea I had for the wing mounting. The main goal was to have all the aero forces go directly into the strut towers and act upon the shocks down through the suspension. I also wanted to maintain use of the storage space in the trunk for things like tents, sleeping bags and coolers when i drove this thing to the track. You can see how the cross tube holds the uprights that will hold the wing mounts. extra reinforcement of a 1" tube to the down tube connects the mounts.
Looking mean so far..
Moving onto the rollbar, I had the main hoop gusseted to the chassis as reinforcement and to further stiffen the chassis. Yes, the bars will function as roll over protection, but its main goal was to actually provide a platform for me to mount 6 point harnesses, a jack point and something special I am doing with the rear doors. The chassis stiffening just happened to be nice low hanging fruit i wanted to take advantage of since we were there.
Here's the plinths all burned into place. The heat coloring is from the additional structure that's been welded on the bottom side before the final install.
Once of the other main reasons I wanted to bring the car to fab was to get the pinch welds of the frame rails reinforced. The factory claims that the pinch welds are supposed to be used as jack stand points when you put the car up in the air for service. In my opinion this is a pretty negligent design by Toyota. You inevitably end up folding the pinch welds over onto themselves and the car no longer sit sturdily on the jack stands. This is BY FAR the worst part of owning a Toyota/Lexus. Especially one that goes up and down on stands frequently.
I had Chris knock the pinch welds flat and then use two pieces of 90* angle he would welded together to increase the foot print of the stand point. Now I wont second guess getting under the car up on jack stands.
Burned in place and filled down the center.
Painted and done..
Because the trunk would need to be slit to allow the wing stands to pass though I was worried about water ingress. I had Chris weld up a rain tray that I will run a drain tube from so that the car would be able to be parked outside in the rain if needed it to.
Here the uprights with the trunk set in place.
Chris was able to trim most of the interior so that it still fit with the chassis gussets. I also had him move the 3pt OEM seatbelt lug down so ill still be able to use it with the new race seat in place.
Main hoop reinforcement on the roof. this will also keep the CF roof from potentially buckling.
Roll bar painted. You can see the harness bar set back so im able to use it with my drivers seat back and as low as it can go.
Speaking of which, I had Chris redesign the seat mounts so I could sit the seat super-super low for tall guy head clearance and better CG.
You can see how low and far back he got the seat. This took quite a few fittings to get in position but its all is worked out very well.
New Recaro SPG for the passenger side..
I also had him weld up a brand new indestructible dead pedal that i won't be able to snap off of the floor like the old OEM one.
For the rear doors I was originally going to just trim out the guts and run them as is. After speaking with John at Alpheyga who had done such a great job on the roof I decided that i wanted him to make some rear carbon door skins for me. This would save another 80lbs or so off of the car. He came and got the doors to make the mold from.
Meanwhile the wing upright came back from powder coat.
Chris also added a removable tray strut.
Now that the car was mostly together as far as the rear roll bar and wing mounting, we were able to put it on the ground and move it outside the shop under its own power. Even without doors, side skirts, splitter or wing its starting too look very cool. Wheels are PERFECT for the car.
I put the splitter on the ground just to get an idea of how it'll come together.
Door prepped for molding, cleaned and treated with release agent.
Mold transferred. This was done for both the left and right sides.
Carbon laying in the molds.
And finally, finished product. Trimmed and lightly buffed.
They each weigh about 5lbs a piece.
So this is probably enough for now. There are a bunch of things going on in the next few weeks to get this stage of the car finished up. I'll make sure to take pictures as always and post back here when I have a chunk of progress to report.
