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Non-metric wheels for 512BBis

Discussion in 'Boxers/TR/M' started by speer, Mar 22, 2013.

  1. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
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    I may buy me a set of the Carobu wheels in gold for that BBLM look, and save my TRX wheels and tires for concours and resell.
     
  2. boxerman

    boxerman F1 World Champ
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    #77 boxerman, Apr 12, 2013
    Last edited: Apr 12, 2013
    Over5 years we have had a variation of this thread. It's always thesamedebate back and forth, even offers of group buys but people do nothing.

    Fact is modern tryres are different and one needs a wheel that works with them. If you want an original look for your BBI because you can't get crap trx's tryres then just get bb wheels.

    Otherwise 17 in rims are the way to go. A number of us have tested these waters and that truly is the way to go. It preserves the look of the car and enhances everything.

    Now someone is trying to make a visually correct wheel and is getting trown this way and that by people debating they no not what. Most ate not going to buy wheels anyway, they never do.

    Look at the carobu dimensions, they spent many years working out the optimal dimensions and offsets for a boxer, we don't need to reinvent the wheel(no pun intended) just copy carobu sizing and dimensions.

    I have had 16 in rims on my car from Boyd. They worked ok but the offsets were wrong and tyre choices limited. Ride and handling were infinitely better but steering heavy.

    I went from thoseto17's from carobu, plus I setup the suspension as per Mario. The car is a dream all around.

    If you want original, you can get trx's still or go to bb wheels. If someone is doing these new wheels pick up the advances of more modern rubber, just as they did in period when people went to a bbs wheel and p7's.

    Some say it waspoliticswith Michelin, others that Ferrari insisted a mid car was too much for the public. Whatever the reason trx's tryres on a boxer are not just bad, they are truly horrid in feel grip and ride. Their breakaway characteristics make the ca dangerous and their elastic sidewall rob the steering of feel and response. Changing wheels and tryres is the single biggest upgrade you can make to these cars, it enhances the driving p,erasure even if you don't go fast.

    Why make aftermarket wheels and them compromise them in terms of tryres because you are trying to size so e original look. Firstly is not possible short of truck tryres to go to trx's sidewall. Secondly 17's preserve the look in a slightly muted form.


    The problem with aftermarket wheels for boxers to date is you had to have a style that was different due to two piece designs. Now we can have that original look in keeping with the car. If you don't want modern rubber, just go for replacement tryres. Personally I think that the gr4 wheels will grow boxer values because an original look is always good and if some rag tries a boxer with new rubber they will start hailing it as the forgotten great.

    Meanwhile all these talking heads are driving gr4 to distraction, most won't buy anyway because they never do, and or the want the original dimensions so should just keep what they have.

    We are being offered a wheel that hews as closely as realistically possible to the original design, with dimensions that suit modern rubber. BBi have240 fron tryres already. 245 works great. As some here have done even 285 fits great in the rear although275 is IMO p,entry. Many today run tr spec trx's. 's which are 280.

    Please stop this mindles churning debate. If you want stock for show stick with stock. If you want to upgrade don't reinvent the wheel, 17 with 245 fronts and 275 or 285 rear works better than great and looks prefect, not ultra low profile but still preserving some sidewall look.
     
  3. ferraripete

    ferraripete F1 World Champ

    i agree with all you have said. i am getting the gr4 wheels when they are avail..

    i would like 8x17 and 11x17 but will settle for 10's in the rear if that is all that is avail.. i am also considering a dot race tire...avon or toyo.
     
  4. boxerman

    boxerman F1 World Champ
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    10 rears are going to be fine and suit most. As to tyre choices I run ps2's and its probably overkill already in terms of grip for a boxer. One thing I will say between a stiffer sidewall for the front and more tread in the rear you eliminate two boxer foibles. Thefrontgoing now has turn in and bite with close to lotus like directness and feedback. The rear is planted with none of that feeling of mass wanting to break away. It tolerates mistakes now.

    I will warn most boxer owners though. If your suspension is worn you are going to notice it reall acutely with gropier rubber. All that play in the front end and rear will be magnified, and can make the car feel all over the road. Many of you are going to have to rebuild your front end if its never been done and rear suspension bushings may need redoing too.
     
  5. ferraripete

    ferraripete F1 World Champ

    i plan on rebuilding my front end this summer. i too am chosing to have my shocks done be y truesports (they are THE koni authorized rebuilder). i may go the ps2 route too. i do not think they are overkill. yoyo ra-1's or another 90 treadwear tire might be overkill:)
     
  6. Mario Pano

    Mario Pano Formula Junior

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    #81 Mario Pano, Apr 13, 2013
    Last edited: Apr 13, 2013
    Lets keep in mind PS2s will be going away and they will be replaced by Pilot super sport.

    More grip and hopefully as soft riding with no tram lining as PS2s
    Ps2s in 245/45 and 275/40 in 17 are still available.

    Still street tires and nothing like sport cups or racing dots.

    A super cheap tire for those that do not go to the track for play are the continentals extreme contact DWs and they perform great and very close to PS2s

    Mario
     
  7. SCantera

    SCantera Formula 3
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    The Group 4 website is now advertising the Boxer wheels. Sizes shown are 8x17 front and 10x17 rear.

    I met a friend at a car show this weekend that has a beautiful BBi. He was very happy to hear about the Group 4 wheels and is ready to order. Although I have a BB w/ a set of 7x15 and 9x15 originals plus the Carobu wheels too, I like these better than either. I'm going to order a set too.
     
  8. CambioManuale

    CambioManuale Formula Junior

    Jul 18, 2004
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    Nothing new. They have been advertising for a few months now.

    I will order a set as soon as available. Pls lets all make sure that Group4 paints them in the correct original BBi finish.
     
  9. ferraripete

    ferraripete F1 World Champ

    i plan on ordering too. i am happy with the sizes of 8" and 10". as it is currently my car is undriveable as i have a bad rear tire. i need the new wheels.

    pcb
     
  10. speer

    speer Rookie

    Jun 23, 2008
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    Group 4 is prepared to go ahead with production subject to having a sufficient number of orders for one set of wheel sizes. I know that there are some who wish to stick with the originally proposed wheel widths of 8" front and 10" rear. There are others who have argued for even wider wheels.
    The primary consideration leading to non-metric wheels is the unavailability of TRXs for our existing metric wheels -- and in general being at the mercy of a single tire manufacturer that makes a run of tires only sporadically at best. Research shows that we would be in the same position of unavailable matching tires for both ends of the car with 8" and 10" widths. The same would be true for even wider widths.
    Following is what research has shown with respect to wheel widths that would allow the continued use of tires that perfectly match the widths and diameters of the TRXs we are currently using:

    "The original stock wheels of a BBi are 180mm wide on the front and 210mm wide on the rear. Those numbers translate to 7”wide on the front and 8.26” wide on the rear.

    The stock TRX tires ( 240/55/415 ) which are the same front and rear have an outside diameter of 27.2” and a cross-section of 9.8”.
    When it comes to finding matching tires for front and rear, the use of 8” and 10” wide wheels front and rear produces virtually no sets of matching tires.

    There is one alternative that works: wheel dimensions of 7 ½ ” front and 8 ½ ” rear. That would allow for the use of tires sized 235/55/17 both front and rear. The measurements of the 235/55/17 tires are virtually identical to the stock TRXs we run now. 235/55/17s have a diameter of 27.2”, just like the TRXs, and a cross-section of 9.8”, just like the TRXs. Tires sized 235/55/17 would easily fit on wheels widths of 7 ½ “ and 8 ½." The greatest advantage of those wheel dimensions is that there is a huge number of available manufacturers who are currently making that size of tire. At Tire Rack alone, there are modern zx rated tires from Michelin Pilot Sport, Pirelli P Zero, Goodyear Eagle, Dunlop, Yokohama, Sumitomo, BF Goodrich, Continental, Bridgestones, Kumho and Hankook, perhaps among others, all with virtually identical diameters and widths as TRXs and at a fraction of the price."

    512BBis are not undertired with TRXs. The legitimate knock on TRXs is the fact that we can't buy new ones and the ones we have are hard as rocks. Tires of those same dimensions but using modern technology and modern rubber would produce significantly better performance without having to change the appearance of the car while using tire dimensions that we know for sure will work. With wheel dimensions of 17 x 7 1/2" front and 17 X 8 1/2" rear there are a truly significant number of tire manufacturers offering ZX rated tires. Subject only to acceptable quality in terms of construction specifications and color from Group 4, I would commit to purchasing wheels of those dimensions. In order to pin down whether there is enough interest in wheels of those particular dimensions to persuade production by Group 4, how many BBi owners out there would similarly commit to 17 x 7 1/2" and 17 X 8 1/2" wheels if Group 4 produced them?
     
  11. boxerman

    boxerman F1 World Champ
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    If you think there is nothing wron with trx's then we come from very different driving enviro,nets and experiences. There is a reason why even in period people put bbs wheels and p7s on boxers, and why the countavh went to p7s

    I for one would not be interested in narrow wheels and 55 series tryres.

    The boxer was always compromised by tryres, you have no idea how great the chassis is with proper alignment and tryres. To me Its about the driving.
    My suggestion is if you want original then do original just get trx's tryres or get 15 in bb wheels for better tyre choice.

    We need wheels that are an upgrade for both BBI and bb, maybe narrow whhels have some appeal for a few bbi owners, but why would bb owners get a new wheel that is narrow and unable to take proper modern car rubber, when they already have that in 15 inches.

    What you propose is something like reengineer end points, when there is electronic ignition available which keeps the character but is so much better.

    Get proper wheels for driving and stock for show if that's your thing.

    Trx's are crap now, and they were crap then, maybe appropriate fot a late 70 s 7 series BMW.

    In short stick with 8 front and 10 rear or I am out.
     
  12. ferraripete

    ferraripete F1 World Champ

    Anything short of 8 and10 and I am out as well.
     
  13. Mario Pano

    Mario Pano Formula Junior

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    #88 Mario Pano, Apr 18, 2013
    Last edited: Apr 18, 2013
    With all respect to your personal reasons to do this you need to consider that TRXs were all weather tires not high performance summer and being mounted on different width rims was done for a reason of giving grip at the rear end and taking it away at the front.

    At the same time Ferrari gave the later BBs more fender space for larger rear tires than stock as they knew what the car needs and wanted the ones that would not alter or care for performance to not get in trouble.

    The original TRX set up gives new meaning to an understeering car...the front end used to plow and squeel the front tires long before the car was even close to its limits.

    With modern rubber you are choosing you will find the car will perform way different than the trxs because the modern tread designs and compounds will give you way more grip than the TRXs and not the balance Ferrari wanted you to have with the original set up.

    In addition 235 /55s are way taller than stock which was 26.6 inches so you are looking at much taller tires.

    I have seen 245 /45 and 285/40 around since the mid nineties when I changed my car over.

    I even have a set unused (with ten miles or so) of the Tr Trxs with 240 front and 280 rear.
    They mount on the original rims of the BBi and they did not perform any better than the original 240/55s

    If you think the look will be original with what you figure you will find out it will not look the same and neither would it perform the same.

    If you want something that will feel close to the original balance on the car you can try 235 at front and 255 at rear on the 8 and 10 size rims and go with a less sticky tire with emphasis to low noise and all season tread.

    When Ferrari want you to have handling they would give you a rim as wide as your sectional width as possible,since that is what eliminates flex side to side and you get better performance using your tread fully at the proper air pressure for the set up.

    240x 55%=132mmx2=264+415=679 divided by 25.4=26.73inches...not 27.2.....

    Tall and skinny tires will make this car ride nice on a straight road but not so good on corners,even though the modern tires would surprise you how much more grip they can provide.

    Maybe a Bridgestone turanza serenity plus in 245/50/17 with the same exact diameter as the 240/55 trx can be mounted at the rear on a 10 inch rim if the manufacturer tells you you can since it got 10 inch sectional width ...the front 8 inch would not be a problem

    I wish they did two different rear rims one at 9 or 9.5 and another at 11 so my 285 at the back did even better than ten inch rim which can run the same tire.

    Mario
     
  14. SLOT RACER

    SLOT RACER Karting

    Oct 20, 2004
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    I also agree with Sean and Peter. It's about the driving experience at this point and we have the opportunity at this point to get it done
    correctly. We can use our stock rims / TRX's for the shows but I'm all for unlocking the capabilities of these cars with the modern rubber that's available to use now as Sean has stated. I'm definitely in for a set but not less than 8 front and 10 rear as well.
     
  15. speer

    speer Rookie

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    If the consensus is wheels that are 8" and 10" wide, then great. If there are enough orders for those widths, I assume Group 4 will produce them. I was not trying to stir up controversy, and I'm certainly willing to admit it if I'm wrong. I'd sure appreciate anyone's input on what tire manufacturers are currently making tires that would be exactly the same model for both ends of the car and would fit wheel sizes of 17 X 8" and 17 X 10." Thanks!
     
  16. CambioManuale

    CambioManuale Formula Junior

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    I buy whatever size G4 will make those wheels, because the alternative for me is not to use the car at all or to put on one of those, in my very modest opionion, awful looking bling-bling wheels which would put me off to take the car out for a spin every time I saw them.

    So, please go for any size you have more requests on, but please, G4, do make those wheels and do make them in the correct ORIGINAL colour code AND before the season is over.

    Ciao
     
  17. boxerman

    boxerman F1 World Champ
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    #92 boxerman, Apr 20, 2013
    Last edited by a moderator: Sep 7, 2017
  18. Mario Pano

    Mario Pano Formula Junior

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    Nice color on that BB and those rear wheels look a little different.

    What is the of set on them?

    Are they further out than stock?

    Mario
     
  19. boxerman

    boxerman F1 World Champ
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    They are carobu wheels. I just had them bead blasted when made so the finish is a natural aluminum matt. As two pieces wheels the hub is held to the rim with bolts, so I used tiatnium hex bolts once again to go for that non bling matt look. Plus it makes then lighter.

    I will take some better pictures later this week. They dont stick out more than stock, maybe the rear does slightly. I dont remember the widths. I think its 9 and 10 or maybe 11.

    The great thing about these wheels is that the offsetts are perfect. The front end in particular has great feel and feedback.

    Next winter I will redo the shocks and make adjustable ride height soIi can set if up really well.

    BTW does anybody know what speed 7k rpm in 4th is or 64-6500rpm in 5th is. Not that I would do such a naughty thing but I belive my car would still be pulling well at these revs in 5th on an significant uphill grade. Makes me wonder how close to 7k rpm it wpuld pull in 5th on one of those flat auto bahn or texas straights.
     
  20. Murph

    Murph Formula 3
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    Ok so if I get the 17 X 8" and 17 X 10 wheels for my BBi
    what is everyone recommending for tire size and manufacturer?

    And are we endanger of these speed rated tires for 17" wheels becoming obsolete soon like the TRXs?
    The reason I ask is that several years back I got the 16" and 17" Campy clones for my Pantera because it was impossible to find a speed rated tire for the original 15" wheels but now I'm back in the same boat as I'm having a hard time finding the proper speed rated tires for the 16" and 17" Campy clones!
     
  21. turbo-joe

    turbo-joe F1 Veteran

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    I would try yokohama A008 if still available???
    this is a nearly semi slick tire for very high performance, only in rain it is not good. sizes I don´t know because of the 17 "
     
  22. Mario Pano

    Mario Pano Formula Junior

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    Thanks about the wheel info ,I would be curious to know the of sets(or ET) front and rear.

    I think this a subject we need to be bringing up here for the guys that make the rims for everyones benefit.

    I will dig up mine they work great too and post the exact measurements in regards to of sets.

    Another subject is the size of the centers.

    The old rims have small centers and some friends of mine in Europe agree the smaller center of the 15 inch wheels looks better even if the total rim is much larger.
    That poses certain issues with look only!

    You can figure 20mph on fourth and 26.6666 on fifth per thousand rpm.

    That means over 130 at 6500rpm on fourth and 176.666666.....lol be careful....

    I did it in the nineties .......after shifting out of fourth close to 140 you get to 165 fairly fast and then you need to stay wide open throttle and cruise....if you are not going uphill or anything it is slow but you will pick up another 10mph slowly.

    With your size tires it will probably be less as you are running 25.7 inch tires.

    Your speedo will be generous ......go 105 and see if your tach is on 4000 rpm

    Please make sure you do not have low psi on any tire and that you never got a flat in the past with the tires you are running since new.

    You do not have to redo your shocks for height.
    you can put sleeves on the original shocks...the ones...made in Holland...the US guys in Koni......true choice not so true.

    Mario
     
  23. boxerman

    boxerman F1 World Champ
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    #98 boxerman, Apr 22, 2013
    Last edited: Apr 22, 2013
    So based on tyre diameter differences and revs if I was going those revs in 4th and 5th I would have been doing about 135 in 4th and somewhere around 165 in 5th. I would say then the car will comfortably top 170 in a reasonable distance if not 175 but not much more, because I think you will need a long road for that climb from 67-6800 rpm to 7k in a BBI. but not as long as most people think. I agree though you get up to 165 real quick, and at that speed you are already using up a lot of road quickly. Great thing about the boxer is how stable it is at speed, and how well the suspension soaks up undulations while feeling buttoned down. As to the speedo, based on what it says my car should top 185 easily, so we can just discount any speedo reading.

    The tyres are 2 years old, and I check the pressure faily regularily..

    Its amazing how quickly a boxer piles on those higher speeds, most cars loose the plot around 130 ish.

    Herad a pretty ugly story once about some dude going for it in a 930 turbo that had had aflat fixed, it blew out somewhere north of 160 and there were lots of pieces od car and driver all over the place.
     
  24. Mario Pano

    Mario Pano Formula Junior

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    #99 Mario Pano, Apr 23, 2013
    Last edited: Apr 23, 2013
    As soon as you go over 6000 rpm the car is doing 165
    You will add around another 13mph when you get to 6600rpm.....again 26 per thousand on 5th and 20mph on 4th.
    Easy to check your speedo how true it is if you do any even number of rpms on fourth times 20 equals your speed.
    I have seen a few Ferraris that show higher speeds as their speedos show more as the speed goes up over actual speed.

    These info about speed on each gear is in the owners manual of the BBi posting the numbers at 6000rpm.

    Trxs blow all at the same time if you sustain high speeds over 150.

    There was a big law shoot when an idiot run a Tr in a Nevada race and he wrecked close to 180 because he was doing that with TRXs which do not do very well in sustain speeds over 150.
    His argument was why would a car maker build a car that can sustain those speeds with tires that are not able to do so
    Ferrari won the law shoot because he was racing and he did not know the difference.
    The passenger got killed and he survived.

    Another reason to have safe rims with tires like ps2s or similar even on the street on these cars or anything that can go close to the tires speed ratings.
    Always choose tires that can do more than the car can.


    Mario
     
  25. boxerman

    boxerman F1 World Champ
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    I was reducing speed per revs as the PS2's have 5% less diameter. so I reduced speed per revs by that amount. Not sure if the math is correct.

    In any event your coment serve as a useful backdrop to the inadequacies of the TRX tyre.
    That ferrari put this tyre on the TR which was a heavier and slightly faster car beggers belief. Clearly there was some disfunctional thinking at maranello when it came to their supercar tyres, especialy consdiering that lambo had gone to the p7 and the boxer chassis is actualy better off with better tyres.

    Even if you dont go fast, the improvement in stability, steering response and tactility make
    modern rubber a must. Do you leave a design flaw in a car for posterity, or do you correct it. Changing to modern rubber and wheels is not a modification as much as a correction of a serious design flaw.

    As to speed, any period boxer accleration figures need to take the following into account.
    The boxer clutch is not one for standing starts, the dogleg between 1st and secong is going to be slow. If you take these two factors into acount, then you realise that a modern with launch control and paddleshift will put down great paper numbers, but not be really faster in on road in gear accleration.

    Put a nother way, open up a well running obxer when rolling in 2md 3rd or 4th gear and accleration is going to be viceral and epic. True time will be lost on the slowish shifts, but working a winding road shift times are not really a factor, in gear accleratrion, tourque and the ability to micro meet out power is. In that regard a boxer has all the power needed and is a true throughbred.

    It is what I call a thinking drivers car. You have to think down the road, think of the gear you will need for the bend and comming out. Power needs to be meted in and used to balance the car mid corner with the wheel. You cant just jab at any of the controls, the car needs to be worked down the road, but rewards accordingly.

    Compare this to a modern, the shifts are kinda done for you, just keep the revs up. If you brake or accklerate too fast in a bend the nannies take care of it. Less of a choregraphed dance with the road and car, than a roller coaster ride. Which is more fun, and on the street, is that theoretical extra speed of a 458 useable anywhere, I think not. The boxer is the sweet spot of car design, power and handling in an anologue art.

    Just eliminate the design flaw, put real tyres on and unlock the beast within.
     

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