>I think
>that people are missing the point when they say that studies show that
>drivers can't tell the difference between 65# and 80# on a load E. I would
>like to see if they could tell the difference between a 65# load D (which I
>believe is the recommended pressure) and an 80# load E. I suspect that they
>would. This would only be of academic interest to me except for the fact
>that I feel that my GMC should be smoother (in the front) going over bumps.
>I dropped the pressure in my XPS E's to 65# and couldn't tell the
>difference. I suspect the problem may be that I installed Caspro shocks
>with neoprene bushings rather than the softer rubber bushings. I also used
>neoprene bushings in the sway bar but I doubt that it would have much of an
>effect. Any comments on this issue?
One of the problems that we have as GMC owners is determining what exactly
has made a difference in our ride and handing because we often make more
than one change at a time.
Shocks effect on Handling & Ride
When we first bought our Palm Beach we had the worn out shocks replaced
with BIlsteins and the brakes reconditioned to "new" plus a sensitized
booster and larger mid-axle cylinder. As with any vehicle that has worn
shocks, the new shocks, were, well a shock. Where the old ride had been a
lot mushy, the new ride was stiffer (a lot more "road feel.")
Tire effect on Handling and Ride
The PB originally had LR D polyester tires on steel wheels. The switch to
LRE steelbelted radials made the biggest difference in ride. The new tires
made the ride much stiffer. Bumps that used to be a sort of "mushing" over
the ridge became a bit of a lurch. The question of tire effects was
answered when we bought a ROyale. It had LRD steel radials on it. With the
same Bilsteins as on the PB, the ride was pretty much the same over the
same course at the same speed.
So, I have a few personal observation points: PB - poly D with and without
Bilsteins and Bilstein plus G159s. Royale with steel D and Bilsteins (will
have same coach with G159s later this month).
My experience with LR D vs E relative to ride harshness is consistent with
what Wes has published in his newsletter and what tire manufacturers have
said about their tires. Poly sidewalls give a smoother ride than steel.
This is due to the differerence in sidewall flex.
Sway Bar Bushings
I ahven;t changed mine yet, but I can tell you that changing from rubber to
neoprene on my x1/9 made a huge difference in handling. I don't know what
the effects would be on your coach. Maybe one fo the racers on teh liost
could comment.
That's my experience with two coaches and a variety of tire/shock
combinations. My subjective analysis - but you can count of the "harsher A,
harsher B" as what I perceived.
As a side note, I've posted earlier about the 4-bag system. The 4-bagger
was installed by Jim Bounds in August on teh PB after all of the above was
done. If you don't like the ride on your coach now, take a test drive in a
coach with the 4-bag.
Henry
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
>that people are missing the point when they say that studies show that
>drivers can't tell the difference between 65# and 80# on a load E. I would
>like to see if they could tell the difference between a 65# load D (which I
>believe is the recommended pressure) and an 80# load E. I suspect that they
>would. This would only be of academic interest to me except for the fact
>that I feel that my GMC should be smoother (in the front) going over bumps.
>I dropped the pressure in my XPS E's to 65# and couldn't tell the
>difference. I suspect the problem may be that I installed Caspro shocks
>with neoprene bushings rather than the softer rubber bushings. I also used
>neoprene bushings in the sway bar but I doubt that it would have much of an
>effect. Any comments on this issue?
One of the problems that we have as GMC owners is determining what exactly
has made a difference in our ride and handing because we often make more
than one change at a time.
Shocks effect on Handling & Ride
When we first bought our Palm Beach we had the worn out shocks replaced
with BIlsteins and the brakes reconditioned to "new" plus a sensitized
booster and larger mid-axle cylinder. As with any vehicle that has worn
shocks, the new shocks, were, well a shock. Where the old ride had been a
lot mushy, the new ride was stiffer (a lot more "road feel.")
Tire effect on Handling and Ride
The PB originally had LR D polyester tires on steel wheels. The switch to
LRE steelbelted radials made the biggest difference in ride. The new tires
made the ride much stiffer. Bumps that used to be a sort of "mushing" over
the ridge became a bit of a lurch. The question of tire effects was
answered when we bought a ROyale. It had LRD steel radials on it. With the
same Bilsteins as on the PB, the ride was pretty much the same over the
same course at the same speed.
So, I have a few personal observation points: PB - poly D with and without
Bilsteins and Bilstein plus G159s. Royale with steel D and Bilsteins (will
have same coach with G159s later this month).
My experience with LR D vs E relative to ride harshness is consistent with
what Wes has published in his newsletter and what tire manufacturers have
said about their tires. Poly sidewalls give a smoother ride than steel.
This is due to the differerence in sidewall flex.
Sway Bar Bushings
I ahven;t changed mine yet, but I can tell you that changing from rubber to
neoprene on my x1/9 made a huge difference in handling. I don't know what
the effects would be on your coach. Maybe one fo the racers on teh liost
could comment.
That's my experience with two coaches and a variety of tire/shock
combinations. My subjective analysis - but you can count of the "harsher A,
harsher B" as what I perceived.
As a side note, I've posted earlier about the 4-bag system. The 4-bagger
was installed by Jim Bounds in August on teh PB after all of the above was
done. If you don't like the ride on your coach now, take a test drive in a
coach with the 4-bag.
Henry
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
