Scratchy Orange Build Thread

[autoracer86]

So after 8 track days on 215/45/17 Pilot Spot 4 I am upgrading to a semi slick(200tw) tire. The new setup is Braid full race A 17x8 ET35 with a 225/45/17 Potenza Race tire. I am very excited for my track day on Thursday !

[DocWalt]

Man, that will be such a big improvement! Curious what you think!

[autoracer86]

June 20th Track day

Track Temp 65F/18.3C

Max Speed: 95MPH/ Up from 93.9MPH/152KMH

Max RPM: 7417 Up from 7366

Max Brake Pressure: 966PSI Up from 796PSI

Seemed to use a bit less brake pressure in the afternoon. Probably over braking in the morning. 815PSI/852PSI/871PSI

Max Oil Temp: 253F/122.7C

Max Coolant Temp: 205F/96.1C

Oil Pressure: 27.2PSI - 56PSI AVG 44.5 Seeing oil drops in turn 7(right hander)with semi slicks.

[autoracer86]

Bit of a long post but if you wanted a bit more detail here it is...

My best lap of 2:05.4 is 2.3 quicker than my previous best on the ps4 tires with coilovers. I left about .6 on the table so the new tires seem to be closer to 3 seconds quicker than the ps4.

Over the 8 corners I did improve each corner was anywhere from .2 to .5 faster. There were 2 places turn 2 no improvement and turn 3 where I was slower by .3 so assuming a gain of .3 for those corners there could be another second improvement over the ps4.

But as of now 2.3 is the improvement I found from the traction mod and new wheel/tire package.

What I find a bit strange about all of this is I haven’t seen much improvement from my suspension upgrades and alignment. 2:07.9 was my best lap with a completely stock car on ps4 tires. Best I could manage with my suspension upgrades before the traction mod was a theoretical of 2:07.7 traffic messed up my fast lap but man I though I setting a new personal best would of been a lot easier with the suspension upgrades.

Now who knows maybe the ps4 tires were already past their prime by the time I got the upgrade causing my lack of pace but now I am on new tires that should be around 3 seconds faster and that’s about what I found. I feel like I could have just tossed these tires onto a stock gt86 and ran the same time. They do say tires are the most important upgrade so...

Driver is definitely factoring in here there are spots on the new setup where I just simply broke too soon or too hard. I think the issue is coming from the increased speed into the braking zone it’s just making me a bit nervous so I am over slowing. My goal with this setup is going to be something in the 2:03s that would be an overall 4 second improvement over the car when it was stock.

Some other take aways from the new tires. The grip level is definitely increased you can feel it and see it in the data but no surprise there. Was much more stable in the sweeping right hander(turn 5) sticky tires and traction mod working together ha. They held up fine and I didn’t feel as if they got greasy. Tested with 32psi and 30psi hot never got close to the triangles so maybe I can go even lower.

First set of semi slicks(200tw) tires in like a decade so I can’t really compare them to anything else sorry.

I am not sure I am pushing hard enough to really comment on if its feels pushy or loose but I would say its does seem like a tight setup the back end just won’t move much but maybe that’s due to my driving. Also not sure making the car rotate more would be any faster for me at this point but I could see myself upgrading from stock sway bars.

I started to feel the power steering cut people talk about never had that with the PS4. Oh and the traction control light flashed a few times in turn 3 when using my normal 5 second hold. Again also new and didn’t flash anywhere else not that I noticed anyway. More grip More Speed More tire

Just a few data points
Braking Force is up from 0.77 to 0.87

Corner force is up from -1.26/1.14 to -1.34/1.66

Gsum is up from 1.31 to 2.02

[autoracer86]

Screenshot from race studio showing the oil pressure drop from the added grip. This is a right hand corner. Its the double right hander turn 7 if you care to find the spot on my videos

[autoracer86]

Just a photo dump of tires lol Tested 32PSI hot then 30PSI hot

[autoracer86]

Photos from the last track day

[autoracer86]

Quick update before I head off to Oulton Park and Donington Park on Monday.

So I got the car aligned again and corner balanced. This time I used Division88 instead of LOH motorsports. A bit more camber front and rear and changed the rake from neg to positive

New setup is
Front camber -4.0
Front Toe 0
Rear camber -2.5
Rear Toe IN 0.10 1/16" total in.

Ride Height Center of hub to fender.
Front 351mm
Rear 353mm
Total Weight with driver 1352kg/2980lbs. Cross Weight 52%.

Other changes I ordered up some parts from Japan for the interior. Single piece dash trim, GRMN86 starter button and GRMN GR Yaris shifter knob.

And last change is I am trying out a 0.5L overfill

[autoracer86]

Two more tracks and another road trip to the UK in the books. Oulton Park and Donington Park are both great tracks and a major steps up from my local track.

The car give me zero issues on or off the track and the 0.5L overfill seems to be working as I saw no oil pressure drops but I will reserve judgement til I test again at Mondello in September.

My goal was under 2:10 at Oulton and 1:30 at Donington. I reached both goals and felt comfortable pushing so I am happy for the most part with my driving. A bit of review does show I could have been better picking up the throttle and just a bit braver in general. My lines looked good though ha.

The potenza races seem to be wearing just fine and were fine in the wet when pushing and TC off

[autoracer86]

August 13th Track day

Track Temp 65F/18.3C

Max Speed: 100MPH/160KPH

Max RPM: 7307

Max Brake Pressure: 833PSI

Max Oil Temp: 255F/123C

Max Coolant Temp: 203F/95C

Oil Pressure: 43.2PSI - 55.9PSI AVG 50.7PSI

[autoracer86]

August 14th Track day(wet)

Track Temp 59F/15C

Max Speed: 104MPH/167KPH

Max RPM: 7085

Max Brake Pressure: 796PSI

Max Oil Temp: 244F/117C

Max Coolant Temp: 194F/90C

Oil Pressure: 42.6PSI - 59.7PSI AVG 51.6PSI

[autoracer86]

August 14th Track day(dry)

Track Temp 66F/18.8C

Max Speed: 106MPH/170KPH

Max RPM: 7353

Max Brake Pressure: 796PSI

Max Oil Temp: 251F/121C

Max Coolant Temp: 197F/91C

Oil Pressure: 45.6PSI - 57.1PSI AVG 52.1PSI

[warhawk03]

Are you running an oil cooler? Max oil temps seem quite reasonable.

[autoracer86]

Originally Posted by warhawk03

Are you running an oil cooler? Max oil temps seem quite reasonable.

I have the oem style oil cooler from the old turbo Forrester. Basically same thing as the second gen twins. It’s really just a heat exchanger and only provides a little extra head room.

The real trick is only doing a few laps before coming in. Or doing a cool down lap in between your push laps