GT350 Carbon Fiber vs. Aluminum Wheel Weight Difference

[steveespo]

Neema
Which 18's do you think will clear those brakes?

 

[ArizonaBOSS]

FWIW Brembo recommends 3mm clearance on all faces.

 

[VoodooBoss]

I'm becoming less and less concerned about tracking the carbon wheels the more I learn about them.

After seeing the wheels in person and talking to the Ford engineers I too am becoming less and less concerned about running the CF wheels on track. Not that I'm going to have to worry about that now with my track pack car on order. : I wouldn't be surprised to see Ford Performance sell the wheels at a more reasonable price than the $15K a set the OEM replacement wheels retail for. That won't happen until Carbon Rev gets caught up on production and has capacity to make extra wheels.

BTW rumor has it on Friday afternoon of Track Tour Laguna Seca a BMO member dropped a wheel off track which got scratched and Ford quickly had it replaced.

 

[neema]

Neema
Which 18's do you think will clear those brakes?

18" wheels would be nice but I want at least 5mm of clearance. Which ones are going to fit? I'll be looking for 11" wide wheels for either NT01's or Trefeo R's.

Doh, sorry guys. Just saw this.

Finspeed assured me that 18s would fit over my 380mm brakes because they fit over 400mm rotors. Obviously the face of wheel comes into play, but the barrel clearance is there with some wheels.

Snippet from an email:
"We have 18's on cars that are running 400mm rotors, and have good clearance. The minimum we like to see is 5mm."

Only downside is that they're 3000+ for wheels. Kind of negates the 18" tire savings depending on how fast you go through sets. They'd look good though

 

[ArizonaBOSS]

The FRPP BBS 18x10 and 18x10.5 wheels will clear the Brembo Race calipers and 380mm rotors per Rehagen.

 

[KBBOSS1086]

I read in an article (sorry I can't remember which one) that Ford needed to retune the magna ride shocks for the R vs the track pack 350's to compensate for the reduced weight of the CF wheels. I wonder if an 8-10lb increase in weight by going with a good aluminum wheel is significant enough to cause a noticeable effect on handling.

Probably more noticble by a pro test driver, but it must have been enough if they spent the time and money to retune them. Add slicks vs the (admitidly pretty sticky) OEM tire and there's another variable that may cause less than ideal performance.

 

[VoodooBoss]

I read in an article (sorry I can't remember which one) that Ford needed to retune the magna ride shocks for the R vs the track pack 350's to compensate for the reduced weight of the CF wheels. I wonder if an 8-10lb increase in weight by going with a good aluminum wheel is significant enough to cause a noticeable effect on handling.

Probably more noticble by a pro test driver, but it must have been enough if they spent the time and money to retune them. Add slicks vs the (admitidly pretty sticky) OEM tire and there's another variable that may cause less than ideal performance.

This is a big question many of us have. I asked an engineer about this and he said the R and track pack cars have the MR dampers optimized with the stock wheel and tire packages. While he wouldn't tell me how much variance is built into the calibration there has to be some. I don't plan on making many mods to this car but here's my take on this:

1. If the cars are able to adjust to so many different street and track conditions they should be able to adjust to changes in grip and wheel weight. Ford knows that many of us are going to use different track wheels and tires. Will it be optimal? Probably not. This should be similar to dampers on the Boss, that were optimized for that specific package, and how they reacted to lighter wheels and more grip. The Boss dampers weren't optimized for lighter wheels and sticky tires but they still worked with no ill effects. The MR dampers are going to be a significant upgrade to the stock Boss dampers.
2. They did test slicks on the cars.
3. I asked the engineer if I installed the PSC2 tires on the track pack car how close will the two cars be on lap times? He said "close".
4. Lighter wheels are always a good thing, heavier wheels are always a bad thing. This should be no different with these cars.
5. This isn't the first car to have MR dampers. All MR dampers have been calibrated to their specific application. There could be, but I haven't read, other cars having issues changing wheels and tires. I've been reading over on Camaro5 about ZL1 owners taking their cars to the track and changing tires and wheels with no issues and only improvements. Same goes for changing springs.
6. Until proven otherwise I'm planning on adding lighter wheels, they should be 23 lbs each or 10 lbs lighter per wheel, and the PSC2 tires to my TP car.
7. I'm also considering installing the shorter and stiffer R front springs and shorter RSB end links. I asked the engineer about doing this and he suggested I drive the car as is. But he did add it wouldn't be "a train wreck".
8. I'm also considering installing the R front splitter and rear wing if I feel more downforce is needed. The wing is the big question as I'm not paying real stupid money for one. Again I'll drive the car and if it pushes with the PSC2 tires I can add the front splitter to add more downforce on the front. All vehicle dynamics apply to this car just like any other.

I want to stress that the engineers I talked to, and one specifically, all stated we should drive the cars as they come off the showroom and they will be fine. That includes the brake pads. Literally the cars can be taken to the track straight off the showroom floor and hammered. The cars do come with DOT 4 brake fluid stock. I plan on running mine stock at my first track day and then make decisions from there. I might have the lighter wheels and tires on the car for the first track day but that's TBD.

Anyone else have thoughts on this?

 

[cloud9]

This is a big question many of us have. I asked an engineer about this and he said the R and track pack cars have the MR dampers optimized with the stock wheel and tire packages. While he wouldn't tell me how much variance is built into the calibration there has to be some. I don't plan on making many mods to this car but here's my take on this:

1. If the cars are able to adjust to so many different street and track conditions they should be able to adjust to changes in grip and wheel weight. Ford knows that many of us are going to use different track wheels and tires. Will it be optimal? Probably not. This should be similar to dampers on the Boss, that were optimized for that specific package, and how they reacted to lighter wheels and more grip. The Boss dampers weren't optimized for lighter wheels and sticky tires but they still worked with no ill effects. The MR dampers are going to be a significant upgrade to the stock Boss dampers.
2. They did test slicks on the cars.
3. I asked the engineer if I installed the PSC2 tires on the track pack car how close will the two cars be on lap times? He said "close".
4. Lighter wheels are always a good thing, heavier wheels are always a bad thing. This should be no different with these cars.
5. This isn't the first car to have MR dampers. All MR dampers have been calibrated to their specific application. There could be, but I haven't read, other cars having issues changing wheels and tires. I've been reading over on Camaro5 about ZL1 owners taking their cars to the track and changing tires and wheels with no issues and only improvements. Same goes for changing springs.
6. Until proven otherwise I'm planning on adding lighter wheels, they should be 23 lbs each or 10 lbs lighter per wheel, and the PSC2 tires to my TP car.
7. I'm also considering installing the shorter and stiffer R front springs and shorter RSB end links. I asked the engineer about doing this and he suggested I drive the car as is. But he did add it wouldn't be "a train wreck".
8. I'm also considering installing the R front splitter and rear wing if I feel more downforce is needed. The wing is the big question as I'm not paying real stupid money for one. Again I'll drive the car and if it pushes with the PSC2 tires I can add the front splitter to add more downforce on the front. All vehicle dynamics apply to this car just like any other.

I want to stress that the engineers I talked to, and one specifically, all stated we should drive the cars as they come off the showroom and they will be fine. That includes the brake pads. Literally the cars can be taken to the track straight off the showroom floor and hammered. The cars do come with DOT 4 brake fluid stock. I plan on running mine stock at my first track day and then make decisions from there. I might have the lighter wheels and tires on the car for the first track day but that's TBD.

Anyone else have thoughts on this?

Everything you said makes sense to me too Rick. I will change the wheels and tires because I don't want to waste a set of street tires on the track, especially with less grip than Hoosiers. I am planning to run the brakes stock at first. Reading through the supplement Ford pointed out that you may hear brake squeal at low speeds which is a great indication that it might truly be a track pad. It would be nice if we can find out which brand they are using as OEM as I'm curious about the actual compound.

 

[VoodooBoss]

Good point about trashing the street tires on my first track day.

I'm hopeful the stock brake pads work well for someone like me that runs street tires, drives their car to and from the track and does 6-8 track days a year. I think guys like you that run slicks and are more serious about their track time will find the limits of the pads. Plus pads are a personal choice due to initial bite and feel and I expect to see you running your favorite Hawk DTC 70/60 combo after your first track day.

 

[KBBOSS1086]

Good info...Thanks guys. Ive gotta commit to getting one first (started looking for dealers in my area that aren't charging an ADM), but I've been pondering the thought of getting a base model without the MR dampers and adding a really good set of Penske's or Ohlins. I do really like the idea of MR's and the ability to go from a comfortable street car to track beast with the push of a button. Knowing that they tested slicks with the MR's makes me feel a lot better about them.

 

[VoodooBoss]

Good info...Thanks guys. Ive gotta commit to getting one first (started looking for dealers in my area that aren't charging an ADM), but I've been pondering the thought of getting a base model without the MR dampers and adding a really good set of Penske's or Ohlins. I do really like the idea of MR's and the ability to go from a comfortable street car to track beast with the push of a button. Knowing that they tested slicks with the MR's makes me feel a lot better about them.

They didn't tell me what the results of the slicks were though.

I also thought about buying a base car but what stopped me from buying one was the three coolers. The trans in that car does not come with the oil pump built into the trans. Went for the TP instead.

 

[KBBOSS1086]

They didn't tell me what the results of the slicks were though.

I also thought about buying a base car but what stopped me from buying one was the three coolers. The trans in that car does not come with the oil pump built into the trans. Went for the TP instead.

Very good points, Rick. I think you made the right decision; probably what I will ultimately end up doing...unless I get really really really lucky and find an R without an ADM.

 

[TMSBOSS]

Very good points, Rick. I think you made the right decision; probably what I will ultimately end up doing...unless I get really really really lucky and find an R without an ADM.

Sean

A GT-350R without ADM? In 2016 not likely...unless firearms are used in the negotiations. LOL. : Call me if you need me.

In 2017? Possible. With the new GT500 on the horizon, the market for the GT-350 may soften a bit.

 

[DGRacing]

The FRPP BBS 18x10 and 18x10.5 wheels will clear the Brembo Race calipers and 380mm rotors per Rehagen.

And they clear the 15" grand am brembos too.

 

[KBBOSS1086]

Sean

A GT-350R without ADM? In 2016 not likely...unless firearms are used in the negotiations. LOL. : Call me if you need me.

In 2017? Possible. With the new GT500 on the horizon, the market for the GT-350 may soften a bit.

I should have added another "really" (or 5) to my comment above, Tracy. Thanks for the support...it's good to know I've got some backup if the negotiations don't go my way 8)