Lotus Elan

Bill's 26S

PostPost by: 1owner69Elan » Fri Jun 22, 2018 11:35 pm

Just to comment on a few issues raised in this thread:

Bill308:
I expect the tire will contact the anti roll bar a full lock before it contacts the master cylinder blister. S3-S4 rack stops plus 0.120 inches will be fitted to my new rack, then trimmed in situ to just prevent contact with the anti roll bar which has not yet been fitted.


Trimming the rack stops in situ sounds challenging. I used clip on nylon (delrin?) rack stops (Ford Mustang) to easily dial in the right amount to avoid fouling the ARB. Trivial to put on and remove, in different sizes, multiples. After much research it turned out that the Mustang part was the right size for the Elan rack.

img_7556.jpg and
img_7554-2.jpg and



Bill308: I just weighed one of my unmounted wheels on an old bathroom scale. This scale read 5 lbs with nothing on it and 17 lbs with the wheel weight, so 12 lbs +/- 1lb I’m guessing.

My TTR 26r wheels (5 inch, aluminum) weigh 13 lbs. I went with aluminum instead of magnesium thinking the AL might be more robust for street use. The 26r alloy wheels actually weigh a bit more than the original steel knock off wheels. (11.5 lbs)

img_8027.jpg and



Rohan’s comment:
You will find that the wheel hits the body at full opposite lock with bump compression of the suspension with body roll. I find that even with my smaller tyres and have the cracks to prove it !


An additional data point:

I am running 185/60r13 Toyo r888r on my stock body (no flares) S4 with 26r wheels (5”) and hubs, TTR front shocks and 125lbs TTR front springs ("Fast Road"). I have straight lower arms, height adjusted to make them horizontal.

This current setup does not foul the wheel arches and rides well on the road. But, previously on stock suspension and wheels the 175/70 tires caused the damage (at full lock and bump) described by Rohan which I haven't yet repaired:

img_0161.jpg and
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PostPost by: Davidb » Sun Jun 24, 2018 6:10 pm

I am stunned at the weight of those replica 26R wheels!
My Revolution 6 inch rims are 9.25 lbs which isn't a hell of a lot more than the magnesium 26R wheels which I believe weigh 7lbs or so?
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PostPost by: 1owner69Elan » Sun Jun 24, 2018 7:16 pm

I agree with you on the weight of the TTR aluminum 26r wheels. I was a little surprised as well.

But, they do seem to be robust and the 26r screw in pegs are quite robust compared to the pins on the normal hubs. Not that the pegs should be used for anything but locating the wheels on the hubs. Certainly not for transmitting power.

I suppose I rationalize the extra weight (6 lbs over the 4 x pressed steel) to greater strength, consistent with the stresses from my wider tires and on the rear, a substantial increase in hp/torque. I am also using billet shafts.

I factored in the extra weight from the wheels in the overall reductions achieved elsewhere (magnesium bell housing, lightened flywheel, alternator, battery,...) and I still have around 65 pounds less than stock.
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PostPost by: bill308 » Mon Jun 25, 2018 4:45 pm

Hi Rohan,

Thanks for your insight. I too experienced the full opposite lock tire contact on the lip failure when I went off track on the right hander, just before the bridge at Lime Rock Park, during a time trial with my S2 using 165/70R13’s. This seems to be a common failure mode. Just before the car stopped, weight transferred
back to the inside wheel, on full opposite lock and took out a chunk of fiberglass.

Hi 1owner69Elan,

I really, really like the Mustang rack stops you used. These look like the perfect solution. Can you provide some more specifics as to part number and sources for these items? How do they attach and held in place? Are the OEM rack stops removed completely?

Hi Davidb,

Does Revolution make a center lock, aluminum wheel for the 5-pin ko hubs? I knew going in that the Kelsport wheels were not particularly light weight, but they looked good and more importantly they fit my hubs, were likely to be stronger and geometrically more accurate (round)? TTR and possibly others offer lighter wheels but of a different design. I believe magnesium is not a good material for a road wheel. While light and strong, corrosion is likely a much bigger concern.

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PostPost by: Davidb » Mon Jun 25, 2018 5:26 pm

Bill, My Revolution wheels were originally bolt on, I converted them to fit 26R hubs with the help of a tame machinist and a little thought.

Revolution do advertise a wheel to fit 26R hubs but I don't know if they make them to fit 5 pin Elan hubs.

I would be concerned about adding unsprung weight if I used those replica 26R wheels-I had no idea they were that heavy.

On a similar note, I had a discussion with a forum member recently who had ordered 26R style wheels from Image Wheels and was so disappointed with them that he sent them back and had Image pay the return shipping from the West Coast--so they must have agreed with him!
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PostPost by: 1owner69Elan » Mon Jun 25, 2018 5:53 pm

A mitigating factor with the 26r replica aluminum wheels is that the 26r hubs and knock-off spinners have less weight than the stock items. The apparent 6 lb additional unsprung weight (compared to stock steel wheels) is reduced by more than half.

(1.1 lbs reduction - spinners, 1 lb - front hubs, and I believe at least 1 lb - rear hubs - but I don't have that last measurement at hand).
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PostPost by: 1owner69Elan » Mon Jun 25, 2018 6:09 pm

Regarding the Mustang rack stops:

I kept the original rack stops in place and then just added the Mustang rack stops to incrementally increase the total rack stop dimension on both sides.

The rack stops just clip on no further retention required. This is a standard approach, this is a Ford OEM part.

https://www.americanmuscle.com/ford-ste ... -7904.html

Here is the earlier post that I made on the rack limiters:

1. I ordered limiters from KAD which are actually for the original Mini. They have the correct ID. The kit also includes a pair of larger diameter ones as well - too big for the Elan.
2. I also ordered clip-on limiters used for the 1979-2004 Ford Mustang. I didn't know the ID in advance but took the chance as they are cheap. It turns out the ID is very close to the requirement: 27/32 inch (IIRC).

I used the Mustang clip-ons as the installation is trivial and does not require removal/disassembly of the rack. The KAD ones look like they would be challenging to get them onto the rack without taking the rack apart and slipping them on over the ends. The KAD ones don't appear to be "spreadable" like the Mustang ones. They also recommend putting a plastic cable tie around them - not sure why: "belt and braces"? Mini owners apparently struggled mightily installing these as indicated on various on-line Mini boards.


Mustang limiters in center, mini limiters each side:

fullsizerender-5.jpg and


I used two Mustang limiters per side to get the needed clearance. Easy to adjust by adding/subtracting limiters. The boots were slipped over them and then secured normally. Now, no rubbing of the tire on the ARB.
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PostPost by: bill308 » Mon Jun 25, 2018 7:28 pm

Hi Davidb,

I’m a little concerned with the wheel/tire weight too, especially since nearly everything else on my car is light weight. I got these wheels with spinners over a year ago, so they are not going back across the pond.

Hi 1owner69Elan,

My stock hubs are probably heavier than the real 26R hubs but I do have the aluminum spinners, which should save a bit of weight. Not ideal, but workable.
The rack stops seem to be a real problem solver for me. Thank you very much. Do the OEM versions come 1 or 2 per package?

I see at least one vendor offering 6/$20, but it’s not clear they are genuine Ford. I would think Ford engineered these pieces to be compatible with rack lubricant, but not sure if copies use the same material/care.

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PostPost by: 1owner69Elan » Mon Jun 25, 2018 7:48 pm

IIRC, there are two rack limiters per package. I bought 2 packages and used all four, which was just right.
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PostPost by: bill308 » Mon Jun 25, 2018 9:11 pm

Hi 1owner69Elan,

Is your rack fitted with the longer S4/Sprint length stops?

This may be a stupid question, but If there were no Elan stops fitted, perhaps like in a Spitfire, what would these Ford parts push against? The reason I ask is because the rack core to be used for my rebuild, came from a Spitfire.

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PostPost by: 1owner69Elan » Mon Jun 25, 2018 10:02 pm

I have the stock S4/Sprint rack stops and then added the Ford ones which push against them.

With just the stock rack stops my wide tires were hitting against the ARB at full lock. Thus, the incremental addition of the Ford Mustang ones to provide the needed clearance.

Hope that is clear.
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PostPost by: bill308 » Tue Jun 26, 2018 2:59 am

Hi 1owner69Elan,

Yup, that's clear. I Think you saved me a lot of aggravation. Thank you.

Bill
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PostPost by: bill308 » Sat Jun 30, 2018 3:49 am

Hi 1owner69Elan,

I changed my rack rebuild instructions to make the lock stops the same as yours, S4/Sprint length. I'll add and trim the Ford parts to fit.

The battle with the pedal box and associated gear continues.
Loose installation of the clutch master cylinder shows significant intrusion into the wheel well.
dsc02163d.jpg and
This is the view looking up into wheel well. The wheel is at full left lock and full bump where the travel limit is set by contact with the wheel arch lip. This is a lower bump limit than in the straight ahead position.

Lock is limited by contact with the clutch master cylinder (MC). I’m thinking a shorter MC is going to get me close to a clearance gap. The casting can be tilted inboard a few degrees for additional clearance. I want to get a blister to seal this feature This is also the best access for installation Tilton Engineering offers a version measuring 3.21 inches from the mounting surface to the end of the casting, versus the Girling shown here, which measures 4.10 inches to the end of the casting. It looks possible to chamfer at least another ¼ inch from the casting for additional clearance.
dsc02165d.jpg and
The height of the wheel rim is 29 ¼ inches. The height of the rim is 30 ¼ inches when in the straight ahead, max bump position.

dsc02168d.jpg and
This is the max bump full right lock view. I need to get an anti-roll bar mounted to see how this limits max lock travel.

dsc02172d.jpg and
This photo looks along the outer plane of the tire at full left lock and max bump. This would be the inside wheel positon when cornering left. This height of the wheel is about 1 inch below the max bump level in the straight ahead position.

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PostPost by: Davidb » Sat Jun 30, 2018 4:54 pm

Bill, I look forward to hearing more about this special rack-it sounds very interesting!
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PostPost by: el-saturn » Thu Jul 19, 2018 6:31 am

btw, folks: brand rims (at 4,5") weigh 1 KG less than a steel rim (= 4kgs weight loss; makes 4,5mio$ per F1 car!) sandy
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