Goodwin Racing NC going to Superlap Battle USA COTA 2020
#41
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Worked through the RX8 Rear Hub/Bearing/Spindle conversion today. Our donor parts came from a 2005 Automatic RX8.
RX8 Spindle (Left) and NC spindle (Right).
RX8 Bearing (Left) and NC bearing (Right). Both are 80mm OD, but the RX8 bearing is 5mm longer, with larger ID for the larger axles (45mm vs 42mm):
RX8 axle stub, 31 splines (Left) and NC axle stub, 28 splines (Right):
RX8 hub (Top) and NC hub (Bottom). Tried to take this picture a couple different ways, it's kind of hard to tell in the photo but the radius between the hub flange and the shaft is much thicker on the RX8 unit i.e. stronger:
RX8 spindles with fresh bearings pressed in and our ARP extended studs swapped over from the previous NC hubs, ready to go in the car:
The NC axles won't work with the RX8 hubs. The trick is to remove the outer CV joints of the RX8 axles and swap them on to the NC axles. Straightforward process; remove the CV boot and then hammer the outer end off the axle shaft with a brass hammer. It will go all at once when it pops past the C clip. The RX8 end goes on the NC axle shaft the same way, just hammer it on. The boots on the NC axles work on the RX8 ends.
Removing the end:
RX8 outer CV end (top) NC outer CV end (bottom):
Finished NC/RX8 hybrid axles:
And finally, we used the RX8 ABS sensors (left) instead of NC sensors (right):
Weights:
NC:
Hub + Bearing 5.25 lbs
Spindle 8.55 lbs
Axle CV end 3.65 lbs
Total 17.45 lbs
RX8:
Hub + Bearing 5.90 lbs
Spindle 9.40 lbs
Axle CV end 4.25 lbs
Total 19.55 lbs
Net weight gain just 2 lbs per side.
RX8 Spindle (Left) and NC spindle (Right).
RX8 Bearing (Left) and NC bearing (Right). Both are 80mm OD, but the RX8 bearing is 5mm longer, with larger ID for the larger axles (45mm vs 42mm):
RX8 axle stub, 31 splines (Left) and NC axle stub, 28 splines (Right):
RX8 hub (Top) and NC hub (Bottom). Tried to take this picture a couple different ways, it's kind of hard to tell in the photo but the radius between the hub flange and the shaft is much thicker on the RX8 unit i.e. stronger:
RX8 spindles with fresh bearings pressed in and our ARP extended studs swapped over from the previous NC hubs, ready to go in the car:
The NC axles won't work with the RX8 hubs. The trick is to remove the outer CV joints of the RX8 axles and swap them on to the NC axles. Straightforward process; remove the CV boot and then hammer the outer end off the axle shaft with a brass hammer. It will go all at once when it pops past the C clip. The RX8 end goes on the NC axle shaft the same way, just hammer it on. The boots on the NC axles work on the RX8 ends.
Removing the end:
RX8 outer CV end (top) NC outer CV end (bottom):
Finished NC/RX8 hybrid axles:
And finally, we used the RX8 ABS sensors (left) instead of NC sensors (right):
Weights:
NC:
Hub + Bearing 5.25 lbs
Spindle 8.55 lbs
Axle CV end 3.65 lbs
Total 17.45 lbs
RX8:
Hub + Bearing 5.90 lbs
Spindle 9.40 lbs
Axle CV end 4.25 lbs
Total 19.55 lbs
Net weight gain just 2 lbs per side.
#42
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Also installed our fresh differential today. 3.63 final drive to stretch the 6 speed's ratios out a bit, OSGiken LSD, assembled by the fine folks at Walter Motorsports with their upgraded race bearings, and topped off with SuperPro diff bushings:
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Making progress! Here's where we left it last night. Things are coming together.
An update on turbo choice; for our power targets we know we want more than a 2860 can provide, so we discussed changing to a 30R, but during Fab9's test fit of the kit prior to sending to us they found that wouldn't fit so what we have here is a GT2871R. Garret rates this turbo for 280-475 HP on engines from 1.8L to 3.0L. With a 2.5L upwards of 300 whp, we should be right in the sweet spot with this turbo in terms of both spool and efficiency.
An update on turbo choice; for our power targets we know we want more than a 2860 can provide, so we discussed changing to a 30R, but during Fab9's test fit of the kit prior to sending to us they found that wouldn't fit so what we have here is a GT2871R. Garret rates this turbo for 280-475 HP on engines from 1.8L to 3.0L. With a 2.5L upwards of 300 whp, we should be right in the sweet spot with this turbo in terms of both spool and efficiency.
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Why not the newer technology G25-550 or G25-660? They have made huge strides on the turbine side of these new turbos.
https://www.garrettmotion.com/racing...eries-g25-660/
https://www.garrettmotion.com/racing...eries-g25-660/
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We are up and running! Had to work through a few details to get everything happy and working together - as is the case with any major changes (MAP sensor was giving us issues and had to backtrack to a returnless fuel setup for now). Tuning with Mike at Xero Limit the last few days. Car is now up and running well on wastegate @ ~8psi with a conservative tune on pump gas. Already feels pretty quick. We swapped the hood over from our silver 2007 supercharged car for the hood venting goodness, and the Blackbird Fabworx NC RZ roll bar is now fully installed and providing some nice pop! Getting loaded up and hitting Willow Springs Raceway tomorrow
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Exciting times at Willow Springs! I only got some baseline laps in but the car was already ripping. WSIR is a fast track. Just on low boost and conservative pump gas tune at this point and already keeping up with a Porsche Cayman down the long front straight. Had a bunch of fun in those five laps catching some fancy hardware including a Corvette and several Porsches.
The fun was ended early by smoke and fire, but I was able to react fast to it. Everybody reading this has a fire extinguisher in their car, RIGHT? With quick reaction the damage was contained pretty well. The turbo had melted the plastic valve cover. It should be noted that our GT2871R turbo is larger than the 2860 intended for the kit, so it sits closer to the valve cover, and we had already done hours of street driving/tuning with no hints of this issue. I feel confident saying a street car wouldn't encounter this. Just goes to show what we already know - that there's nothing else like the abuse of track use. Everyone on this forum knows this well, but many don't. Melting stuff never looks pretty, but the good news is a turbo blanket will solve this issue easily. We've already spoken with the folks at PTP and got a blanket here. Going to replace the valve cover and a few of the hoses that got a bit crispy, get this blanket on, and get back out there for further testing.
It was a cool day but temperatures were rock solid, so it looks like we're on the right track with the oil cooler development. We've been trying a few different cooler cores and configurations, honing in on what we'll offer in the kit. More to come on that front after more testing.
The fun was ended early by smoke and fire, but I was able to react fast to it. Everybody reading this has a fire extinguisher in their car, RIGHT? With quick reaction the damage was contained pretty well. The turbo had melted the plastic valve cover. It should be noted that our GT2871R turbo is larger than the 2860 intended for the kit, so it sits closer to the valve cover, and we had already done hours of street driving/tuning with no hints of this issue. I feel confident saying a street car wouldn't encounter this. Just goes to show what we already know - that there's nothing else like the abuse of track use. Everyone on this forum knows this well, but many don't. Melting stuff never looks pretty, but the good news is a turbo blanket will solve this issue easily. We've already spoken with the folks at PTP and got a blanket here. Going to replace the valve cover and a few of the hoses that got a bit crispy, get this blanket on, and get back out there for further testing.
It was a cool day but temperatures were rock solid, so it looks like we're on the right track with the oil cooler development. We've been trying a few different cooler cores and configurations, honing in on what we'll offer in the kit. More to come on that front after more testing.
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So we stole the Supercharged NC's vented hood for WSIR, but that was a limited time deal, supercharged 2007 wants that hood back! So the turbo car got it's own set of hood louvers today, just in time for our Cars & Coffee event tomorrow.