Wanting the more aggressive look of 6’’ wheels but not to compromise
the E-type’s nimble handling I opted for both the wider wheels and
the 185HR15 Vredesteins. I kept a 5’’ wheel as my spare, mated to
the same tire. This is the profile view of the two configurations
laying side by side on a table:
and closer up:
Unloaded width of the tire on the 5’’ wheel is 7 1/4’’, on the 6’’
wheel it’s 5/8’’ wider. The centerline of the two configurations is
about 1/4’’ wider on the 6’’ wheel so a track increase of 1/2’’. Tread
width is of course identical. The tires will fatten up a bit once
they’re supporting the weight of the car but I expect the 5/8’’
differential will be maintained or increased marginally.
Surprising to me was the difference in weight between the two. The
6’’ wheel and tire weigh in at 43 lbs 2 oz while the 5’’ tire is at
43 lbs 3 oz, so there will be no affect on unsprung weight. A
little better in fact with the wider wheels. I expect no difference
in handling.
Objective achieved?–
Nick Saltarelli - 1968 E-type S1� OTS, 1954 XK120SE OTS
Niagara, Ontario, Canada
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Wanting the more aggressive look of 6’’ wheels but not to compromise
the E-type’s nimble handling I opted for both the wider wheels and
the 185HR15 Vredesteins. I kept a 5’’ wheel as my spare, mated to
the same tire. This is the profile view of the two configurations
laying side by side on a table:
and closer up:
Unloaded width of the tire on the 5’’ wheel is 7 1/4’’, on the 6’’
wheel it’s 5/8’’ wider. The centerline of the two configurations is
about 1/4’’ wider on the 6’’ wheel so a track increase of 1/2’’. Tread
width is of course identical. The tires will fatten up a bit once
they’re supporting the weight of the car but I expect the 5/8’’
differential will be maintained or increased marginally.
Surprising to me was the difference in weight between the two. The
6’’ wheel and tire weigh in at 44 lbs 2 oz while the 5’’ tire is at
43 lbs 3 oz, so there will be no affect on unsprung weight. A
little better in fact with the wider wheels. I expect no difference
in handling.
Objective achieved?–
Nick Saltarelli - 1968 E-type S1� OTS, 1954 XK120SE OTS
Niagara, Ontario, Canada
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Nick S. sent Tue 28 May 2013:
Correction, weight of the 5’’ wheel is 44-2 vs 43-3 for the 6’’ wheel.–
Nick Saltarelli - 1968 E-type S1� OTS, 1954 XK120SE OTS
Niagara, Ontario, Canada
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Nick S. sent Tue 28 May 2013:
That looks like a really good setup. I think that the wider wheel
will reduce the slip angle of the tire a little, and so you should
actually notice a little better handling.
I assume the weight difference is less due to the lack of a tube in
the 6’’ wheels, right? That is another good point!
The weight highlights a conundrum with the E-Type: they went out of
their way to reduce unsprung weight to the minimum with the rear
suspension and inboard brakes, but then they put on boat anchor
wheels! The mid-'80s 911 had stock wheels that even though wider
weighed 10-15 lbs less. When I was looking for autocross tires I
found that the pseudo-Dunlop alloy wheels actually weighed about
the same as the wire wheels, so I went for the wires.
Jerry–
Jerry Mouton '64 FHC 889791 ‘MIK Jaguar’
Palo Alto, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Nick S. sent Tue 28 May 2013:
as it turned out in my situation I have 6’’ on the rear and 51/2 on
the front with the 185 verdestines…would like to think that the
additional rubber on the rear is beneficial…any comments???–
Peter Willetts 62 OTS
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from PeteWilletts sent Tue 28 May 2013:
Pete,
The racing wheels were wider in the rear. OTOH, the car on stock
wheels is perfectly balanced so I don’t think wider tires are
needed on the rear. Could increase understeer a little, but I bet
not much, especially with the same tires.
Jerry–
Jerry Mouton '64 FHC 889791 ‘MIK Jaguar’
Palo Alto, California, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from mouton sent Tue 28 May 2013:
Putting 185 tyres on 6’’ wheels has the effect of stiffening
the side walls which can improve handling at the expense of
a slightly firmer ride. I fitted 5’’ Borrani wire wheels with
Michelin XVS 185VR15 tyres to my car and they are 9lbs
lighter per wheel than standard thanks to alloy rims and
thinner spokes. The reduction in unsprung weight is
immediately noticeable with better steering feedback and
more precise reaction to input. Big difference and beautiful
to look at as well.
Jaguar specified 5.5’’ rims, on the rear only, for racing but
personally I think the car is better balanced with the same
width all round. It is quite easy to alter the balance
simply by experimenting with front/rear tyre pressures and I
have settled on 35psi rear and 30psi front (slight
oversteer) as best suiting my driving style. However I only
get about 8,000 miles out of the rears partly due to over
enthusiasm and partly due to the very soft compound Michelin
use on their XVS tyres. Seems their biggest and intended
market is Historic racing cars where cost is not an issue
and they were designed accordingly. They handle superbly
though!
Regards
David–
The original message included these comments:
The racing wheels were wider in the rear. OTOH, the car on stock
wheels is perfectly balanced so I don’t think wider tires are
needed on the rear. Could increase understeer a little, but I bet
not much, especially with the same tires.
–
David Jones, S1 OTS
Nottingham, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
The “E” is almost perfectly ballanced as is (that can be said of almost NO other car of its vintage). In that case, I would imagine that it will introduce understeer.
If you do need a bit more understeer (for low speed racing) then you are going about it the wrong way. You need to stiffen the front end with shocks and sway bar.
LLoyd
Insofar as mathematics applies to
reality it is not certain and
so far as mathematics is certain
it does not apply to reality.
Einstein----- Original Message -----
From: “PeteWilletts” pjwilletts@hotmail.com
To: e-type@jag-lovers.org
Sent: Tuesday, May 28, 2013 10:16:29 PM
Subject: Re: [E-Type] 185HR15 Vreds on 5" and 6" wheels - a side by side comparison
In reply to a message from Nick S. sent Tue 28 May 2013:
as it turned out in my situation I have 6’’ on the rear and 51/2 on
the front with the 185 verdestines…would like to think that the
additional rubber on the rear is beneficial…any comments???
