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PostPosted: July 8, 2015, 10:26 am 
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how well does your shifter work?? Are you retaining the stabilizer bar? Mine kind of sucks

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PostPosted: July 8, 2015, 6:43 pm 
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Thanks robvious, it may have been cheaper to just have it bent at a shop.

TooBusy, I can move the pickup point for the bottle jack and get closer to 90 degrees. I think it works ok for my application. I only needed a 40 degree bend.

Mjalay, I am running the stabilizer to a polyurethane bushing on the transmission housing. I also modified the motion ratio of the shifter lever so the throws are VERY VERY short. About 1" throw from 1st to 2nd gear. I think the grooves retaining the detent ball is worn, and it's a little tricky to find neutral. I rebuilt this entire GSR YS1 transmission 5 years ago, but did not touch the detent grooves on the selector shaft. Other than having to work my lever somewhat hard, I think my shift lever feels pretty good. (Hold the jokes.)

Also, thanks for the offer for the HF dies, I figured out a solution on the cheap with what I had on hand.

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PostPosted: July 16, 2015, 12:07 pm 
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LateralScience wrote:
Thanks robvious, it may have been cheaper to just have it bent at a shop.

TooBusy, I can move the pickup point for the bottle jack and get closer to 90 degrees. I think it works ok for my application. I only needed a 40 degree bend.

Mjalay, I am running the stabilizer to a polyurethane bushing on the transmission housing. I also modified the motion ratio of the shifter lever so the throws are VERY VERY short. About 1" throw from 1st to 2nd gear. I think the grooves retaining the detent ball is worn, and it's a little tricky to find neutral. I rebuilt this entire GSR YS1 transmission 5 years ago, but did not touch the detent grooves on the selector shaft. Other than having to work my lever somewhat hard, I think my shift lever feels pretty good. (Hold the jokes.)

Also, thanks for the offer for the HF dies, I figured out a solution on the cheap with what I had on hand.


Would you be willing to share how you did your shifter mounting? Show the shifter and the transmission mounting?

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PostPosted: July 18, 2015, 11:44 pm 
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Sure thing mjalaly. I cut the OEM honda shift lever above and below the the ball, and cut an inch off the top and relocated that below the ball. Essentially, this decreases the mechanical advantage of the lever, but decreases the displacement of the shift knob. The motion ratio can be tuned which affects both lever displacement and shift effort. (Maybe a turnbuckle beneath the shift lever rotation point to tune feel to your liking?)

I have pictures posted on page 20 a bit less than half way down the page of this build log. I placed the shift knob high and right next to the steering wheel such that my hand doesn't travel very far when changing gears.

The grooves in the selector shaft are what sometimes become worn. The "hills" between the valley of the grooves get worn down over the years, and the transmission shifts from 1st to 2nd or 3rd to 4th too easily.

See item #80 below:
Attachment:
Detent grooves for Honda B series GSR YS1.jpg
Detent grooves for Honda B series GSR YS1.jpg [ 229.85 KiB | Viewed 1327 times ]

Item #74 is the ball bearing that rides in the grooves that is spring loaded. Increasing this spring rate (or preload) will will increase shift effort to move from 1st to neutral, 2nd to neutral, etc...

I plan on slightly opening up the middle groove slightly, such that neutral is easy and obvious to find. Also, if you do not use the stabilizer rod (the service manual calls it a Change Extension), then shifter feel is dependent on the stiffness of the engine mounts and chassis tubes. Essentially the shifter linkage ball housing must attach to the stabilizer rod, such that a tensile force from the shift rod is equal and opposite selector rod.

I like to think of this as a punch to the stomach is more effective if you HOLD the guy with one arm, instead of not holding him--strange analogy...I know.

I made my selector and stabilizer rods from 5/8" OD .035 wall 4130 tubing ($1.96 per foot from Aircraft Spruce), and still pretty light. I have no bends in these long two rods such that shift feel is stiff.

What transmission are you running BTW?

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PostPosted: July 20, 2015, 10:21 am 
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LateralScience wrote:
Sure thing mjalaly. I cut the OEM honda shift lever above and below the the ball, and cut an inch off the top and relocated that below the ball. Essentially, this decreases the mechanical advantage of the lever, but decreases the displacement of the shift knob. The motion ratio can be tuned which affects both lever displacement and shift effort. (Maybe a turnbuckle beneath the shift lever rotation point to tune feel to your liking?)

I have pictures posted on page 20 a bit less than half way down the page of this build log. I placed the shift knob high and right next to the steering wheel such that my hand doesn't travel very far when changing gears.

The grooves in the selector shaft are what sometimes become worn. The "hills" between the valley of the grooves get worn down over the years, and the transmission shifts from 1st to 2nd or 3rd to 4th too easily.

See item #80 below:
Attachment:
Detent grooves for Honda B series GSR YS1.jpg

Item #74 is the ball bearing that rides in the grooves that is spring loaded. Increasing this spring rate (or preload) will will increase shift effort to move from 1st to neutral, 2nd to neutral, etc...

I plan on slightly opening up the middle groove slightly, such that neutral is easy and obvious to find. Also, if you do not use the stabilizer rod (the service manual calls it a Change Extension), then shifter feel is dependent on the stiffness of the engine mounts and chassis tubes. Essentially the shifter linkage ball housing must attach to the stabilizer rod, such that a tensile force from the shift rod is equal and opposite selector rod.

I like to think of this as a punch to the stomach is more effective if you HOLD the guy with one arm, instead of not holding him--strange analogy...I know.

I made my selector and stabilizer rods from 5/8" OD .035 wall 4130 tubing ($1.96 per foot from Aircraft Spruce), and still pretty light. I have no bends in these long two rods such that shift feel is stiff.

What transmission are you running BTW?


Yeah i couldn't squeeze the steering stabilizer in. Would you be able to take a pick of where the stabilizers meets with the ball?

Right now the issue i have is that is too hard to get into 1&2. I can adjust that but then 5th and rev are hard t get into. In the back I have two issues. The shift lever needs more swing somehow but every time i do that it hits either the lower tube or the oil pan.

FYI, i had a GSR tranny until the Trooper made me hand it over... now i have an LS tranny i believe.

I will continue this here so not to bog down your build log.

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PostPosted: July 21, 2015, 10:03 pm 
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Mjalaly, below is the ball housing:
Attachment:
image.jpg
image.jpg [ 223.41 KiB | Viewed 1240 times ]


The ball housing is an OEM Honda part, which forms a plastic enclosure (or race) around the ball. The housing then connects to the stabilizer rod. I made the stabilizer rod's ball housing a bolt-in piece, such that I can remove the rod if I need to fix something.

Let me know if you have any questions.

That sucks to hear about your GSR transmission. The LS gearing is not as short. I can't bear to part with my cable GSR transmission, as the rebuild parts, and multi plate clutch pack adjustable LSD are worth several times over the value of the transmission.

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PostPosted: July 26, 2015, 7:43 pm 
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To beat a dead horse...

In revisiting the front and rear ride frequencies, and looking at the prevalent usage of motorcycle shocks, I reran a few hand calcs investigating the feasibility of using R6 shocks at the front ONLY. For the rear, R1 and R6 shocks simply have too short of a stroke and simply won't work. But for the front...

Please feel free to check my sanity:

FRONT:
R6 shock travel: 2.44" (without bumpstop)
Installation Ratio: 0.6
R6 spring rate: 550 lb/in
wheelrate: 198 lb/in
Front corner weight: 225 lb
Corner ride frequency: 0.938 Hz
Total Front wheel travel: 4.06"
Wheel displacement at rest: 1.13"
Remaining wheel travel from rest: 2.93"

REAR:
660 shock travel: 4"
Installation Ratio: 0.9
660 spring rate: 300 lb/in
wheelrate: 243 lb/in
Rear corner weight: 425 lb
Corner ride frequency: 0.756 Hz
Total Rear wheel travel: 4.44"
Wheel displacement at rest: 1.74"
Remaining wheel travel from rest: 2.69"

Front to Rear ride frequency difference: 0.18 Hz (Stiffer front)
From what I recall from OptiumumG Kinematics, the front ride frequency should be higher than the rear, to maintain a "flat-ride" aiming for a 10~20% split front to rear.
http://www.optimumg.com/docs/Springs&Da ... _Tip_1.pdf

Note that I am not building a teeth rattling ride (2Hz+), as I do intend on driving this on the public roads. I recall our FSAE car had rather soft wheelrates with alot of damping and ended up having alot of mechanical grip with very communicable body motions but very stable and responsive in fast transients inputs.

From these numbers, this appears to me it IS feasible to run R6 shocks at the front for a rear engine/mid engine application. This is primarily due to the front components weights are mainly due to only the following components:
-Radiator
-Fuel Cell
-Steering Rack
-Steering column
-Battery
-Master Cylinders
-Nose cone

Is there something that I'm perhaps overlooking in my numbers? I recall Kurt B. is very adamant motorcycle shocks simply do not work. The build quality of R6 shocks, and ease of packaging and very low cost is very appealing.

Attachment:
R6 Shock.jpg
R6 Shock.jpg [ 174.97 KiB | Viewed 1205 times ]


Thoughts?

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PostPosted: July 26, 2015, 8:23 pm 
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Not exactly. I said I couldn't get them to work but other people had. It's all about the final installation ratio (after its squared) and whether the resulting stroke is adequate. Also, bikes have wildly differing strokes and spring rates. The R6 shocks I tested had 550 lb springs.and 1.8" stroke and for MY design it wouldn't work, but for other designs it might.

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PostPosted: July 26, 2015, 8:35 pm 
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LateralScience wrote:
Front to Rear ride frequency difference: 0.18 Hz (Stiffer front)
From what I recall from OptiumumG Kinematics, the front ride frequency should be higher than the rear, to maintain a "flat-ride" aiming for a 10~20% split front to rear.


It's the other way around.


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PostPosted: July 26, 2015, 9:34 pm 
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I think the big draw back of the R6 units is the stiffness of the springs and that can be changed.

I have them on all four corners of my Locost and I'm happy with them. No competition planned. The dampening seems quite adequate for street use.

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PostPosted: July 26, 2015, 11:09 pm 
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gregk wrote:
LateralScience wrote:
Front to Rear ride frequency difference: 0.18 Hz (Stiffer front)
From what I recall from OptiumumG Kinematics, the front ride frequency should be higher than the rear, to maintain a "flat-ride" aiming for a 10~20% split front to rear.


It's the other way around.


Good catch, I must have misread it. If I drop the front IR to 0.48, then the corner frequency differential Front to Rear changes it to 9% higher rear. Total front wheel travel then increases to 5.08". Wheel displacement increases to 1.75" (droop) from rest.

I could slightly lower the spring rate, however aftermarket springs for an R6 aren't very inexpensive. Does anyone happen to know where I could find dyno shock plots for R6's or R1's?

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PostPosted: August 15, 2015, 4:49 pm 
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After much toiling in regards to springs and shocks, I'm finding the R1 and R6 shocks have ALOT of preload. I want to run essentially zero preload--but just enough to stop the spring from coming loose. Also, the very low motion ratio of 0.6 in the front would necessitate a bell crank and pushrod system--which IMHO is simply a pain in the neck to package. The lack of the threaded shock body would make ride height adjustment difficult.

In looking at the multiple packaging issues with the large diameter ATV shocks, 3.2" OD springs, 2.2" shock bodies, and the external piggyback reservior, it is VERY tough to thread the needle between the A-arms, tie rods, toe links, and axles. The 45 degree angle of the shock body spherical bearing presents an additional challenge.

Furthermore, a coworker of mine had a coil spring break on his car after hitting a bump and the sudden change in steering, pulling the car towards oncoming traffic. :shock:

This got me thinking in regards to using 13 year old springs on the Yamaha 660, and the fatigue life of the spring steel. Plus, the degradation of old shock oil over many years isn't likely to help.

The recent rework of the front suspension and steering to accommodate full lock with the 13" wheels and 10" wide Hoosiers decreased the splay between the front LCA members, making it further difficult to package the ATV shock. Also, the lack of a fully threaded shock body such that the spring perch can move closer to the spherical bearing reduces ride height and preload adjustment.

So, after much more research and reading, I pulled the trigger on GAZ Gold adjustable shocks (13" extended, 9" closed) with 1/2" ID spherical bearings. Much slimmer design with 1.75" body, and 1.9" ID spring, but still giving me a 4" stroke.
Attachment:
GAZ Gold 13 inch.JPG
GAZ Gold 13 inch.JPG [ 209.66 KiB | Viewed 1081 times ]

I am finding the GAZ shocks are standard on the Brunton Super Stalkers, and they also make units for Caterham and Westfield. Granted they are not Ohlins, or Penske, Nitrons, or Koni shocks, but I've read good reviews on them for the most part. Yes, I am loosing independent high speed and low speed compression damping adjustment, and independent rebound adjustment, but I simply can't justify $2,000 on shocks for a toy car.
The QA1 PromoStar Double adjustable shocks (which I believe Kurt B. is using on Midlana?), look like precision units but were still much more cost than I could justify to upper management.

After reworking my suspension calcs, I arrive at 200 lb/in front, and 280 lb/in rear springs. I went with new Eibach 8" length 1-7/8" ID springs, (similar but 2" shorter than below) which should give me enough room to run near zero preload.
Attachment:
EIBACH SPRING 10 INCH_001.jpg
EIBACH SPRING 10 INCH_001.jpg [ 124.07 KiB | Viewed 1081 times ]

With 4 springs and 4 shocks (with spherical bearings and spring perches) this came out to $753.42. :shock:
This is probably the most expensive part of the car, second to the engine.

I'm not a big fan of the Eibach hooker red, and may end up painting the springs black or silver. The springs are special order 3 week lead from Eibach through Summit, and GAZ shocks are about 1 month lead from UK.

Getting these small 13" Hoosier slicks is becoming rather challenging to clear, as it could have been easier to go with larger wheels/tires, but I'm certainly going to try my best to keep everything small and light.

Question: I have not confirmed this yet, but has anyone had issues fitting 1-7/8" ID (1.875") springs on UK made shocks which call for 1.9" springs? Can I assume the 0.025" difference is not an issue with European shocks which call for 1.9" ID springs? (If I need to make a small relief on the spring face to clear the spring perch, it shouldn't be a problem--but I'd rather not.)

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PostPosted: August 15, 2015, 5:28 pm 
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Quote:
Question: I have not confirmed this yet, but has anyone had issues fitting 1-7/8" ID (1.875") springs on UK made shocks which call for 1.9" springs? Can I assume the 0.025" difference is not an issue with European shocks which call for 1.9" ID springs? (If I need to make a small relief on the spring face to clear the spring perch, it shouldn't be a problem--but I'd rather not.)


The difference is 0.025" or about the thickness of 8 sheet of paper. I'm fairy certain it is just the rounding off difference. This might be about the thickness of the spring coatings (paint, powder coat, or whatever). I don't think you'll have a problem, but.......Why not just order the springs from GAZ while you are at it? That way there will be no question if the springs fit. GAZ coilovers can be purchased here in the USA thru Jack McCornack (Kineticvehicles.com) or from Dennis Brunton (coilovershocks.com). As I understand it, they are custom assembled at the factory in the UK to order and shipped here thru Dennis.

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PostPosted: August 15, 2015, 5:42 pm 
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rx7locost wrote:
Quote:
Question: I have not confirmed this yet, but has anyone had issues fitting 1-7/8" ID (1.875") springs on UK made shocks which call for 1.9" springs? Can I assume the 0.025" difference is not an issue with European shocks which call for 1.9" ID springs? (If I need to make a small relief on the spring face to clear the spring perch, it shouldn't be a problem--but I'd rather not.)


The difference is 0.025" or about the thickness of 8 sheet of paper. I'm fairy certain it is just the rounding off difference. This might be about the thickness of the spring coatings (paint, powder coat, or whatever). I don't think you'll have a problem, but.......Why not just order the springs from GAZ while you are at it? That way there will be no question if the springs fit. GAZ coilovers can be purchased here in the USA thru Jack McCornack (Kineticvehicles.com) or from Dennis Brunton (coilovershocks.com). As I understand it, they are custom assembled at the factory in the UK to order and shipped here thru Dennis.


Good points. I could probably sand and polish off 0.025", but it's likely literature rounding.

Regarding sourcing, I went through Shocks Direct on ebay, and this was $139 per shock with shipping. I looked at Brunton, and they are charging $257 per shock with shipping.
http://www.coilovershock.com/GAZ%20Coil%20overs.htm
It says $171 for polybush, add $29 for spherical bearing, add $86 for Gaz Gold.

Also, Kineticvehicles.com is $200 per shock with spherical bearings, ($800 for a set of 4), whereas I paid $556 for a set of four, saving me $244.
http://www.kineticvehicles.com/parts.html

I was thinking of using Gaz springs as well, but they are about the same price as Eibach, who has certainly alot of experience making quality springs. Also, if I can use 1-7/8" springs, that opens up the world of roundy-round circle track springs.

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PostPosted: August 15, 2015, 9:13 pm 
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Well, you did find a steel! Congratulations. I checked your seller on eBay. Looks like you got the only GAZ shocks he had. I'd be looking at other mfg'r shocks in that case too. :cheers:

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