Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - View Single Post - 949 Racing project car

949 Racing · 02-20-2019, 01:42 PM

More updates on the way. We have planned our strategy for 86 Cup Mod class very carefully. Some of the updates would be different if we did not have rules constraints.

APR FRP front bumper
Goal is to provide a teeny bit more front downforce while reducing weight. We have already removing the steel front bumper beam. We chose the APR bumper because it has the cleanest, design which should have the lowest drag. Every other bumper we looked at had big cooling vents, ducts or styling curves and dips that would disrupt airflow. Low drag is key.

Custom Renderos Racing clear polycarbonate duck tail spoiler
While a wing would be more effective, the rules add to many points. The duckbill spoiler OTOH, is far less points and will keep us from bumping to Unlimited. Ours will be roughly 8" tall, the width of the trunk and adjustable through a wide range.

MFactory lower 6th gear
We did a lot of math, using the data we had already collected from Blub and ou Miatas, S2000 background. The goal for lowest lap times is to have gearing to almost run out of gear on the fastest part of the track. The other requirement is keeping the engine as close to peak power as possible everywhere on track. The OEM 6th is really like a 7th gear that skips past 6th, such is the RPM drop. On slow tracks we never hit 6th but at ACS and WSIR, we will need 6th and the thing would fall off the powerband. So a shorter 6th goes in.

Mfactory 4.67 ring & pinion
One easy way to make a stock wider ratio transmission behave like a close ratio trans is to lower the final drive ratio. Being a 2013, our stock 4.1 let the engine fall off the powerband on half the corners on most tracks. Not good for lap times. The tradeoff to the low 6th and lo final drive is it becomes even more sucky on the highway. Jacks Transmissions in CO is doing the transmission. Unitrax in Anaheim, CA is doing the R&P swap. We're sticking with the Torsen, again because of the points we would take for our beloved OS Giken. The FRS Torsen is actually a pretty high bias diff. Feels more like the OEM Torsen in our GT350 than the OEM Torsen in our older Miatas or S2000.

We're swapping the 20mm front sway bar to a 22mm. Still experimenting at this point. We'll see how the balance is once we get the prototype Xidas on.

02-20-2019, 01:42 PM	#62
949 Racing FT86Club Official Vendor Join Date: Jan 2012 Drives: Miata, GT350, FR-S Location: California, USA Posts: 422 Thanks: 28 Thanked 919 Times in 300 Posts Mentioned: 10 Post(s) Tagged: 1 Thread(s)	More updates on the way. We have planned our strategy for 86 Cup Mod class very carefully. Some of the updates would be different if we did not have rules constraints. APR FRP front bumper Goal is to provide a teeny bit more front downforce while reducing weight. We have already removing the steel front bumper beam. We chose the APR bumper because it has the cleanest, design which should have the lowest drag. Every other bumper we looked at had big cooling vents, ducts or styling curves and dips that would disrupt airflow. Low drag is key. Custom Renderos Racing clear polycarbonate duck tail spoiler While a wing would be more effective, the rules add to many points. The duckbill spoiler OTOH, is far less points and will keep us from bumping to Unlimited. Ours will be roughly 8" tall, the width of the trunk and adjustable through a wide range. MFactory lower 6th gear We did a lot of math, using the data we had already collected from Blub and ou Miatas, S2000 background. The goal for lowest lap times is to have gearing to almost run out of gear on the fastest part of the track. The other requirement is keeping the engine as close to peak power as possible everywhere on track. The OEM 6th is really like a 7th gear that skips past 6th, such is the RPM drop. On slow tracks we never hit 6th but at ACS and WSIR, we will need 6th and the thing would fall off the powerband. So a shorter 6th goes in. Mfactory 4.67 ring & pinion One easy way to make a stock wider ratio transmission behave like a close ratio trans is to lower the final drive ratio. Being a 2013, our stock 4.1 let the engine fall off the powerband on half the corners on most tracks. Not good for lap times. The tradeoff to the low 6th and lo final drive is it becomes even more sucky on the highway. Jacks Transmissions in CO is doing the transmission. Unitrax in Anaheim, CA is doing the R&P swap. We're sticking with the Torsen, again because of the points we would take for our beloved OS Giken. The FRS Torsen is actually a pretty high bias diff. Feels more like the OEM Torsen in our GT350 than the OEM Torsen in our older Miatas or S2000. We're swapping the 20mm front sway bar to a 22mm. Still experimenting at this point. We'll see how the balance is once we get the prototype Xidas on. __________________ 949Racing.com facebook.com/949racing instagram.com/949racing Feelings ≠ Data Last edited by 949 Racing; 05-05-2025 at 10:30 PM.