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I likewise apologize to you, Josh. I am only trying to accomplish what I have stated in the postings. Good luck with your car and I hope you find peace.
Has anyone considered what the larger tire will do to acceleration?
RAudi Driver, the Michelin Cup 2 specs from Tire Rack show the diameter of the 325 rear is 26.7", and the 305 is 26.3" diameter, so it would make the gearing effectively taller (approx. 1.8% increase as measured by circumference). The weight is 4 pounds heavier for the larger tire as well (28lbs vs 32lbs). As to the gearing, I have had the gearbox ratios and final drive (3.41 vs 3.89 for a 12.4% reduction) changed to match 997.2 specs, so the acceleration via gearing isn't a major concern (net final drive - including tires - change still is approx 11% lower than it was). The weight is a far bigger concern, but since I have modified the suspension greatly (Tractive/DSC, RSS full Tarmac kit, GT2 sway bars, etc) I am hoping the weight has been accounted for as best as it can be. May need to look into lighter wheels or stiffer springs - I will check with Tom Chan regarding this. Having said that, I never want an increase in unsprung weight if it can be avoided. I can only figure Porsche engineers felt the additional rubber contact patch was worth the extra weight (or they made the centerlocks on the 997.2 lighter to compensate?). More research required. As with so many things in life, it is usually a series of compromises. Good question, and thanks for your input.
Wow. I had no idea the amount of research you've done and dedication you have to this project. Another day and I feel compelled to apologize again. I'm sorry Jim. JBO
Thanks Jim. That's kind of you given what a jerk I've been. I had a 1990 F40 with 5500 miles, no abuse (owned by a couple dentists that drove it to their local cars and coffee events) Classiche Certified so bone stock and sadly some pinched head gaskets so a drip situation on a low mile major that hadn't timed out. I only had it for 1.5 years. I couldn't get the mechanic I wanted and I really couldn't afford it so I sold it to focus on my CGT because it was unique and imo less likely to break / easier to maintain. Then everything went to ****. Looooong story. I had four GT2s so lots to talk about on that front. I prefer 996 GT2s. Problem being I think most people on this board are already sick of my stories I've been on the board for 20 years plus. Before the RL / 6spd split. What's the story about your F40? My big plan was to trade the CGT/F40 for an MC12. It didn't happen and I took a long car hiatus. Then I decided to mess around with my 997 because I missed my RS and my wife liked that it kept me out of the house. That's the short version. JBO
It clearly won't be very relevant but just for the record, I do wonder what the 5mm OEM spacers weigh?
I know TOM is running Forgeline wheels.
from post #846 just from searching his name and forgeline:
"I was running Hoosier R7 235/35-19 and 315/30-19 on Forgeline GS1R 19x9 and 19x12.
This mod I am doing is for fitting R7 265/35-19 and 325/30-19 so I can keep up with the 991 GT3's into the corners.
Agreed on the taller sidewalls. The actual thread width of the R7 265 is only 0.2" wider than the 235, but its 0.6" taller."
Thanks Jim. That's kind of you given what a jerk I've been. I had a 1990 F40 with 5500 miles, no abuse (owned by a couple dentists that drove it to their local cars and coffee events) Classiche Certified so bone stock and sadly some pinched head gaskets so a drip situation on a low mile major that hadn't timed out. I only had it for 1.5 years. I couldn't get the mechanic I wanted and I really couldn't afford it so I sold it to focus on my CGT because it was unique and imo less likely to break / easier to maintain. Then everything went to ****. Looooong story. I had four GT2s so lots to talk about on that front. I prefer 996 GT2s. Problem being I think most people on this board are already sick of my stories I've been on the board for 20 years plus. Before the RL / 6spd split. What's the story about your F40? My big plan was to trade the CGT/F40 for an MC12. It didn't happen and I took a long car hiatus. Then I decided to mess around with my 997 because I missed my RS and my wife liked that it kept me out of the house. That's the short version. JBO
Josh, wow, what a collection!! I sold my F40 years back, but it has always held a special place in my heart. My favorites besides the F40 that I have had recently were a 1965 289 Cobra (CSX2554), and a 1965 Ferrari 275GTB4. I can only imagine what Ferrari would charge you to replace head gaskets!! The CGT is an amazing vehicle, and I cannot believe it is inherently unsafe (as was heard after the well-published crash of Paul Walker) unless someone drives like a mad man on city streets (ala PW). Regarding the GT2s you have owned, was there a reason you changed vehicles, or did they just wear out from usage? MC12 sure would have been an unusual sighting for anyone who saw it. Neat to hear you ended up back with the RS...was it also a GT2 or a GT3? I think my wife feels likewise about keeping me busy with my RS. - haha. I haven't yet heard your stories, so as far as I am concerned, continue on!!
Jim, ok you appear to be set to run the larger tires. I'm just a lowly stock .1 so I'm sticking with the stock sizes as I don't want to lose any pickup aka acceleration, or increase unsprung weight. I need all the help I can get. I also like throwing the car around fast and the smaller tires are more conducive to my style of driving.
Now just need my other thread to finalize an answer.
My CGT. I will never in this life come close to your stuff. You have impeccable taste. I switched GT2s because I'd be lured to something else, Challenge Stradale, and then I'd decide I Need another GT2. I did that a lot. JBO
Thanks Jim. It's one of one. Sadly I destroyed it. Since then it's been rebuilt by Porsche twice and no longer resides in the US. There are only 3 White CGTs remaining and they are all east of the Mississippi. Mine was the only Grand Prix White. I loved it. Truly loved it. CGTs and F50s are misunderstood and also happen to be my favorite cars. The MC12 is a car I really dig and wanted real bad but nothing drives like a CGT or F50. JBO
BTW one way to benefit from the bigger tires is to reduce unsprung weight elsewhere. James says the forged BBS five lugs are the best wheels for our cars. And they are the best by a mile. Mooty has tons of sets. Sadly they can't be easily ordered any more. But if you can find them they are awesome. James please sell me a set JBO
05-23-2019, 01:21 AM
I've been on the board for 20 years plus. Before the RL / 6spd split. What's the story about your F40? My big plan was to trade the CGT/F40 for an MC12. It didn't happen and I took a long car hiatus. Then I decided to mess around with my 997 because I missed my RS and my wife liked that it kept me out of the house. That's the short version. JBO
