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Re: Pirelli P4000 Super Touring Update
Per my previous post in this thread, the tires will work better on 6" wheels than pre-'67 base 5.5" wheels, so the options are KO's or '67 Bolt-on optional wheels or 6" Rally wheels, which should accept the OE well covers on pre-'67s.
All have +0.60" offset (which includes the adapters for KOs), and there should be no interference problems other than possibly rubbing the steering gear bolt heads at full left lock, but be careful when entering steep inclines at an angle. Center the steering wheel!
If there are any fender interference problems, steering wheel straight ahead, your camber is too far in the positive direction, so you must readjust it in the negative direction.
A one-degree camber change in the negative direction will increase fender clearance by about 0.25", and in between it's linear, so a half degree adjustment in the negative direction will add about 1/8" clearance.
DukeLast edited by Duke W.; January 19, 2011, 02:48 PM.Comment
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Re: Pirelli P4000 Super Touring Update
I'm not sure what you are describing, but the fenders have a lip or flange around the periphery of the opening that strengthens/stiffens the fender and is typical of either steel or fiberglass bodies. At the top of the fender opening, the flange is horizontally oriented, and at the front fender the bonding strip flange is just above the fender flange.
This is the material I had to remove to achieve clearance - just the flanges at the tops of the fender openings, not along the front or rear of the openings. I essentially removed the entire fender/bonding strip flange at the tops of all fenders.
From the side view there is no change to the fender contour. One either has to get down low and look up to see where the material was removed or feel along the tops of the fender boundary to realize the flanges were removed.
Certainly it would result in a significant judging deduction. I wouldn't do it today, nor do I recommend it to anyone, today, but I did it in 1968 when modification attitudes were different. I never considered flares, but I had no issue with removing the fender lips, which didn't change the stock fender contour.
The bigger wheels/tires not only work better, but give the car a very aggressive look since they are pushed out to the limit of the body, and the wheel cover spinners stick out so far I could probaby do as much damage as the chariot in Ben Hur. Pedestrians who stand too close to the apex of the corner, beware! I will never go back as long as I own the car. I'll leave that up to whoever buys it from my estate!
I don't know what specific modifications were done to the Wingate car, but it's pretty obvious from visual inspection what has to be done to clear wide tires on wheels offset in the negative direction from OE.
Now, how about calling Baldwin before they close, today.
DukeLast edited by Duke W.; January 19, 2011, 09:44 PM.Comment
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Re: Pirelli P4000 Super Touring Update
Thank you for the explanation, I have been interested in how to accommodate wider wheels (e.g., the 7" 1968 Corvette rally wheels to maintain stock appearance) with slightly wider tires for a few years now, but I have not found much information about how to make it work. The only official information I have found on this subject is the August 1964 Chevrolet Service News (Vol. 36, No. 7) which describes (for coupes only) installing the rear inner wheel housings that were used in conjunction with the N03 big tank option to make room for wider tires (specifically, "7.10-7.60 x 15 tires mounted on RPO P48 Aluminum Knock-off Wheels (6" rim width)..."
I very much like that aggressive look, which I have seen occasionally on midyear Corvettes with 225/65-R15 or 225/70-R15 tires, that's why I wanted to find out how it could be done. I have read that the offset trailing arms allow the use of wider rear wheels without body modification, relocating the parking brake line, etc., but I have also read that these "fixes" don't really address the fundamental problem.Comment
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Re: Pirelli P4000 Super Touring Update
The reason the '68 Corvette has unique 7" Rally wheels is because the negative offset was required for inside clearance, particularly the spring end.
Some have claimed to use the zero offset 7" Rallys from the F and G body cars, but there was a reason GM engineers used those unique negative offset wheels on the Corvette - inside clearance, and the '68 body had larger/wider wheel openings to provide sufficient outside clearance, including the 8" Rallys that have -0.5" offset, but they had to modify the fenders slightly at the plant to fit the optional 255/60s late in C3 production.
What I did will also work on a disk brake C2, but the outside clearance is a little tighter due to the disk brake wheel mounting plane being slightly more outboard than the drum brake wheel mounting plane, which is why the disk brake C2 track is speced about 0.4" wider than drum brake C2s.
A friend with a '67 mounted the same 225/70 CN-73s on '68 Rallys and had no issues other than the previous cautions I mentioned.
The modifications to the inside fender with N-03 IIRC was to accomodate 8.20-15 racing tires and the issue was OD not width. That old tire size was 28-29" tall.
DukeLast edited by Duke W.; January 19, 2011, 09:47 PM.Comment
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Re: Pirelli P4000 Super Touring Update
[quote=Steven Amen (38372);531788]I just got off the phone with Diamondback Tires and asked them if they could put a whitewall on a Pirelli P4000. I was told that there is something in the Pirelli rubber compound that does not allow them to apply a stripe to these tires. Has anyone else heard that?quote]
Yes - I called them a couple of years ago the last time I thought about buying the P4000 and was told the same thing.Comment
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Re: Pirelli P4000 Super Touring Update
I just got a report from the '65 "327 LT-1" owner. His P4000s were made in Spain, too, and they are probably about the same age as yours, but he forgot to read the date codes, so I asked him to go back and look, again.
Can you check your date codes, George?
BTW, his Coupe, originally a L-76, has a 3.36 axle, and the engine has enough power (about 290 @ 6500 SAE corrected at the rear wheels with only a slight rolloff to 7200) to pull 7000 revs in top gear, which is about 161 MPH, but I don't think he's tested top speed, yet.
He's got a "new" (1964) Bonanza and a new (first) wife, so I think the Corvette may be getting lonely.
DukeComment
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Re: Pirelli P4000 Super Touring Update
Duke,
interestingly, I could only find the Made in Spain on one of the four tires. It was very small. I don't really know what to look for on the date coding, so if you could give me some direction, I'll take another look.
Regarding your tires, can you take a picture and post it. I'd be interested to see them, including the spinners.
Regarding the friend and his car, I have the same gear and about the same power. Mine drops off after 6400, and I haven't gone past about 6000 in top. It was fast enough.
GeorgeComment
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Re: Pirelli P4000 Super Touring Update
I don't have any modern gadgets to take digital photos, but I do have an old print. If I can find it, I'll scan it and email it to you.
The date codes are probably on the inside sidewall. The is a "DOT field" molded into the sidewall with some alpha-numeric codes. The last four digits (for tires made after 2000) is the week and year of manufacturer. For example 2604 would be the 26th week of 2004.
Prior to 2000 the year was only one digit, so for a tire that was in production for a decade or more, which was not many, you have to guess the decade.
DukeLast edited by Duke W.; January 20, 2011, 10:16 AM.Comment
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Re: Pirelli P4000 Super Touring Update
There are lots of places on the 'net that explain tire date codes. This one is one of the easiest to understand:
TerryComment
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Re: Pirelli P4000 Super Touring Update
IIRC, '63-'64 drum brake cars have a slightly narrower wheel track compared to later disc brake cars. Needless to say, on C2's, every little bit helps!. . . Should camber become an issue, seems it would not be as much of a problem in this instance.
Relating to the P4000's: These tires look to be a very well made. As well as the tread, the quality of the sidewall molding (letters, numbers, etc.) really looks nice - very crisp and clean.Comment
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Re: Pirelli P4000 Super Touring Update
I discussed the C2 drum/disk brake track difference in post #37 above.
It takes the best materials, tooling, and workmanship in the industry to manufacture a tire with a 168 MPH speed rating.
They should be good for at least 40K miles or at least 20 years, whichever occurs first for a collector car that spends most of its time in the garage and is only driven a few hundred to a few thousand miles per year.
DukeComment
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Re: Pirelli P4000 Super Touring Update
P4000's arrived two weeks ago. Made in Romania. Treadepot, $545.76 delivered.Comment
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