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GT40 Tech - Chassis,Brakes,Tires,&WheelsChassis and Handling.
The car is in the garage and the more time i spend looking at it, i´m sure that i won´t stay with the narrow rear body. I just like the look of the race cars ( original or non original).
Therefore i decided to look for tire options.
I would love to use some of the Vintage Dunlop CR 82 race tires, but my TÜV engineer will probably get a hardattack, if i ask him to approve this ( and i need him alive for all the other things ).
By looking for alternatives i found i difficult to compare different tires out of different lists in terms of DIAMETER, TREAD WIDTH, SECTION WITH and so on.
Finally i put the datas i found in a simple excel table. Most of the datas are from tiredealer sites. Where they where not available i calculated them. So no guarantee for the very last 1/10 inch.
The list helped me a lot. For now i decided to go with the PIRELLI 345/35-15 on 12 " wheels (i will have the very nice vintage wheels provided with the kit widen by 2") plus the +2" wide track suspension in the rear. Front will be a 225/50-15 Pirelli or Toyo ( whatever is available, Toyo has a wide range of them with different compounds, so that a fit to the rear should be managable). I hope to achieve a look like this:
The rear tire would be a little less high, but the difference is not to big ( 12mm, 0.5 inch in tire height, 1" in tire diameter)
Find onby the tirelist for your usage. Feel free to add tires and to correct datas if they are wrong. Please repost it than, so that all of us can have a quick overview about the possible options.
Thanks Tom, that's some very good and helpful information. I've been thinking about ditching the BF Goodrichs (which didn't even make your list and rightly so) for the Avon CRs. The BF Goodrichs do come in the same 295/50/15 rear and 215/60/15 front that is seen on a lot of GT40s but they're not so good on the track unfortunately.
IMHO the BF Goodrich are a POS if you talk about realy wanting to use the potential of this cars. I cannot imagine doing a 5 min lasting high speed run on german autobahns (with my porsche i did once permanent 270- 290 km/h for about 10 min in the slipstream of a fast porsche biturbo) with the BF´s. Also there griplevel are just not on the level they should be. Pure showcarstires, therefore i did not serious took them in account. I think the AVONs CR´s are a very good choice, would just love to know how far they are with the development of the 235/55-15 front tire.
Tom,
If you look at your list you have the Goodyear Blue Streak tires "rear" as 8.0x15. All the sites I am familiar with list the tire as 26.5 x 10.0 with a R655 compound. It doesn't list as a G-7 or G-12, but as a "Cobra" if any type is listed. The front tire is 26.5 x 8 with the same compound. If you know them to be G-7 or G-12 then they are. I just haven't seen it. I am definitely in the market for 15s and would love to have the mammoth tires that some of the guys have. I just have to draw the line somewhere on expenses. Will save them, the wheels, and the body mods needed for later. I think your listing is very good for those of us in the market. If I were going to alter your spread sheet, I would add a price range or a price and dealer(source/web site) with the caveat that prices are subject to change.
Bill
__________________ DRB#5
351W/408 DIS TWM F. I. 930 Porsche LSD
Thanks for your comment. I was not quite sure about the Blue Streaks, because the website i have the information from is just mentioning the CAN AM´s as Blue Streak and not the cobra type.
I added the cobra " blue streaks" to the list.
find onby also the website i sourced the info from.
Ordered my pirellis today, will put them on 12" BRM´s ( send out the rims for widening as well). Onby some pictures how the 345/35-15 Pzero look like on 14" wheels.
Sorry i did´nt ask before post. Die 225 sollen angeblich in 2 -3 Wochen wieder verfügbar sein. Sagt zumindest der Reifenhändler meines Vertrauens. Angeblich hätten die bei Pirelli direkt welche kaufen können, war aber angeblich zu teuer. Laut deren Aussagen gehen sie jetzt über quellen im Ausland. Klingt alles etwas strange. Ich werde in 14 Tagen mal nachfragen was der Stand ist. Meine 345er sollten nächste Woche hier aufschlagen.
Thanks for your comment. I was not quite sure about the Blue Streaks, because the website i have the information from is just mentioning the CAN AM´s as Blue Streak and not the cobra type.
I added the cobra " blue streaks" to the list.
find onby also the website i sourced the info from.
it will always be the mix of width and diameter, which defines the clearance. From what i saw on some cars the tight point is the rocker panel, in the moment the tire is turning in during steering.
If you take the AVON 9,1/23.5-15 for example, it is one of the tires with the widest thread width, but also the tire with the smallest diameter. Following Bill D´s comments it is a tight fit but fits.
I´m not quite sure about the blue streaks, because i´m not even sure if i have the right tires in the list. I know that fran using them on some cars, maybe he can confirm the size and the fit.
There was also a post about gulf wide front sections which should clear wider tires in straight direction. May be someone knows if the had also a wider cut back towards the rocker panels.
I received my Pirellis PZERO 345/35/15 last week. The front 225/50/15 should fit on the 8" rims without any issues. They are just not available yet. According to my dealer, production will happen soon, so i should have them end of march. As soon i have my rims back from widening and the tires mounted i will post some pictures.
As an idea i reworked the file and put a few columns in where on could put in his car/mods and the rim width to confirm the fit. save it and return it to the post, so we all can profit from it.
I am trying to find as much as I can about the Goodyear Bluestreaks. Does anyone have the part numbers or information about the various part numbers. I have found through Summit and Jegs that the numbers are 1756-7 for the fronts and I believe the 1758 is for the rears.
They all have different prefixes, but Goodyear list them as GDY-xxxx. The 1756 is for the 655 compound and the 1757 is for the hard compound. It is listed in the catalogs only as a 7-15 tire. The 1758 is for the 655 compound rear tire(I think), but I can't get any info other than that. They make a 1763 tire, but I can't find anything on it either. Maybe the g-19 type tyre.
I am trying to stay with standard 15" rims(8 &10). I may have to go over to the Cobra forums to find more.
Prices are running around $270-$280 a tire. Hoosier is the only one I have seen cheaper. Around $244. Avons about $373. All U S.
Anyone with anymore info??
Bill
__________________ DRB#5
351W/408 DIS TWM F. I. 930 Porsche LSD
Have you looked at these guys? Also you can call Shelby's Goodyear Racing distributorship (might be Nevada now) their was a fellow that was really helpful when I called a few years ago.
I have decided to take a different approach to tires, in that all I had asked in the past had come up with about the same info as on this list. My criteria for finding tires was based on the rear tire. I would like to have one like Bill D., but I don't have a Gulf flare rear clip, not to mention my wife is now in the market for a new car. Her 10 yearold BMW 5 series is about to give up the ghost. So I have to start making sacrifices for this year(hopefully this year only). So I am limited to one set of wheels. So all I have is about 14" of space to fill up. What I wanted was something along the line of a 315-335 type tire. I didn't relish the thought of driving around on tires that were not legal for the road. So I asked a few of the members what they were using(Bud, Roy Cobb, Fali, and Foowowee[Mike]). I got the typical answers that are out there. One with 17", one with Blue Streaks, one with two sets of tires and wheelsbut not sadisfied with his street tires(BFGs with a 295 rear). One however was different, and mentioned a tire I had not researched. Believe me I researched "almost" every brand out there. Mike told me of his Nitto tires. I Googled them and found them at Discount Tire and they have to send off for them out of Ohio. Nitto make a drag radial in their NT555R 325/50R15. What I also found from Discount was that BFG makes a G Force T/A drag radial as well in a P325/50R15.
The Nittos have a NT450 225/50R15 114V, but it is in a different style tread pattern. The closest they have in the same tire pattern is a 275.
The BFGs 225 is the same style, but it too comes in a different tread pattern as shown in the photos below. So here are the numbers on the tires I found on the manufactures list. They are a little different than the "List"
Nitto NT555R 325/50R15 114V
Dia.-27.9
Width-13.11 on 9-11.5 rim
Tread Depth(32nd)-5.0
Tread divided into 4 sections minimal groving in a slight arrowhead design
Nitto NT450 225/50R15 90V
Dia.- 23.86
Width-8.94 on 6-8.0 rim
Tread Depth(32nd)-9.7
Tread in an arrowhead design.
Price mounted and balanced-$658
G Force T/A Drag Radial
P325/50R15
Dia.-27.9
Width 13 on 10"Rim(9-12"rim)
Tread depth(32nd)-5.5
Tread(TT,DIR) in 3rds with outside 3rd treaded, middle slick
P225/50R15
Dia.-23.9
Width-9.3 on 7" rim
Tread depth(32nd)-5.5
Tread(NT,DIR) in a wavy design
Price mounted and balanced-$757.96
Mike told me he loved the way the Nittlos handled. Don't know much about the BFGs. They are a different compound than the regular T/As. Does anyone have any info on these tires?
Bill
__________________ DRB#5
351W/408 DIS TWM F. I. 930 Porsche LSD
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