H&R Spring Suspension Modification

I just got a quote of $221.40 for the H&R springs from local dealer http://www.achtuning.com
That's real fair for a special order, but 8 week lead time. I'm pulling the trigger. Will report back on whether they fit the portly US model and what the effects are, around Christmas time

jray3 said:

I just got a quote of $221.40 for the H&R springs from local dealer http://www.achtuning.com
That's real fair for a special order, but 8 week lead time. I'm pulling the trigger. Will report back on whether they fit the portly US model and what the effects are, around Christmas time

Click to expand...

Any updates? Would love to hear how this turns out.

melloyello said:

jray3 said:

I just got a quote of $221.40 for the H&R springs from local dealer http://www.achtuning.com
That's real fair for a special order, but 8 week lead time. I'm pulling the trigger. Will report back on whether they fit the portly US model and what the effects are, around Christmas time

Click to expand...

Any updates? Would love to hear how this turns out.

Click to expand...

I got the springs, they look like they'll fit my car, but I haven't tackled the install yet. These come with a purple coating, so it's easy to keep track of OEM vs aftermarket!

jray3 said:

I got the springs, they look like they'll fit my car, but I haven't tackled the install yet. These come with a purple coating, so it's easy to keep track of OEM vs aftermarket!

Click to expand...

Can't wait to see how this turns out. I'll be the next to try it if it does.

I'm finally installing the H&R springs. Teamed up with the local High School Auto Shop, and stayed on hand to supervise.
Rear springs were a piece of cake, simply remove the shocks and hand-tighten the spring clamps while the suspension is compressed (a gorilla hanging off the trailer hitch helped too), and they practically fall out when the body is jacked up.
The rubber spring pads were a perfect match for the new springs, though the part # and F or R designation was printed upside down on the springs (yup, sure of that, they only go in one way!). Effective drop was 1 3/4" (though my rear is heavier than most, carrying the 40+ lb trailer hitch). Will see if it stays there during 'break in'. It looks good, and from the short test drive, my butt-o-meter swears that the ride is smoother rather than rougher, as feared. More testing to come to see if I should've shortened the bump stops or other measures. Photos to come, and the front end is on tomorrow's agenda (Yup, the car currently has reverse rake- so it looks REAL FAST). :lol:

Though my buttometer is finely tuned, I intend to use an iphone vibration app to quantify this claim of a smoother ride...

So as expected, my experience with the high school auto shop was less than one would expect from a professional shop, but a learning experience for all. The rear springs were easy. Just remove the rear shocks, hand-tighten the spring clamps while the suspension is loaded (put folks in the back seat and a gorilla in the cargo hold for extra effort reduction). Then when you jack up the body, the restrained rear springs practically fall out on their own. The new ones went right in place, and the springs fit their pads and perches perfectly. The effective drop was about 1 3/4" and looks good. However, I noticed a vibration in the rear under heavy acceleration, mainly between 40-50 mph. The driveshaft angle was indeed changed, (shallower, practically flat), but I think that may just be exposing a problem with my CV joints. The inboard joints on the tranny have significant play in them.

The fronts are another story. The shop manual says to remove the headlights, and to do that you remove the bumper. That's nonsense. As long as you use small hands , it's easy to undo the two nuts holding the top of strut to the fender well. All the other bolts are accessible from below. The springs were so small as to be a challenge for the shop's wall-mounted strut compressor, and the spring retaining nut on top was quite difficult to remove (spark plug wrench with an Allen wrench thru the middle to keep the piston from spinning worked). Kids also forgot to reinstall the nut on the steering knuckle that was unnecessarily removed, which I luckily found upon final inspection. We then overtorqued and rounded off the nut upon re-installation.
The front springs apparently aren't compressed enough in the strut and are loose enough to rattle around on the rebound. I can recreate the sound by pulling down on the spring itself (not the wheel) with the front suspension at full droop. IT doesn't appear loose until one pulls straight down on the spring

So, it appears that a spacer will be needed to 'stretch out' these springs a bit, or add a washer over the top plate to push it down a bit more. The Auto shop teacher used bored-out hockey pucks as strut lift kits back in the day....

More to come,
Jay

Thx for update, eagerly awaiting to hear more! I hope those front springs turn out OK..

So, jray3, let me make sure I understand this: you're going to all this trouble to lower your i-MiEV, whereas Tesla recently did a software update to raise their car. What a great example of old-tech vs. new-tech! Hope you don't have any loose chunks of metal on your roads... :roll: Looking forward to your photos, and let us know how she handles.

Ha ha Joe, Here's some real numbers. The Tesla that got fired by a hitch on the highway was at 5.11", and their normal clearance is 6". MR BEAN now clears 6" under the bumper and 5" under the tow loop. Total drop after 50 miles of run-in is 1.5" exactly, both front and rear! with precisely 13" from center of wheel to top of the fender arches. There's still about an inch more air over the front tires than the rears. To remedy my rattles, I'm inclined to try shims under the front strut nuts in 1/8" increments to tighten up the spring, and wouldn't mind up to another 1/4" or so of drop up front. Tis funny, but with apologies to our metric members- the suspension seems to prefer inches!
With our super short nose, I have no problems with the tallest speed bump in my area (but haven't measured it yet). Standards say that some speed bumps may rise 6" within 3'.

So, stepping forward and back. The rear axle vibration is perfectly described here:
http://www.vibratesoftware.com/html_help/2011/Diagnosis/Propshaft/Failed_CV_Joints.htm
A third order vibration caused by excessive driveline angle. Three bumps for each revolution as the joint hits it's limits. Well, under acceleration the rear squats, increasing the angles. I measure the half shaft angle now as 4 degrees UP bubble at rest. That's right, tranny is now lower than the axle. With 5 degrees being the maximum working angle of a CV joint, that'd be rather likely to be exceeded under load.

I got some rubber "dog bone" style spacers to test the loose spring theory up front, and a quick insertion improved the knocking springs, but hurt the ride quality. Time to try shims between the upper spring perch and top nut. This'll lower the front a tad more but preserve the most travel.

Looks like I need to raise the rear to remedy the driveline angle. Will test with the rubber spacers, then decide whether to go all the way back to stock height or use a doughnut-style spacer to just add back 1/2 or 1". I won't mind raising the rear, as the rear fender gaps are an inch smaller than up front. The front, I still want low. Even with clicking springs, cornering is greatly improved. Rain finally returned to Seattle after a 3-day drought, and the understeer is definitely reduced. It wasn't just transient traction caused by dry pavement!

Lastly, I prefer the feel of progressive springs. Smaller bumps are smoother and the car no longer crashes off speed bumps or into potholes. Rebound is more energetic though, will study on shocks more once the spring situation is settled.

Okay, you'd think I'd be good at this by now. Took the struts off again today and added a 3/8" spacer between the strut nut and the upper spring perch, pushing the spring down. Theory was to tighten up the spring, preventing it from rattling around on the strut at full extension. Somehow, we made it worse. Struts rattle like crazy now. I put a 1" rubber dogbone coil spacer in the rear springs to address the driveline angle issue, but haven't measured the angle or highway tested it yet.

Of additional note, the auto shop teacher was 'driving' while the car was up on the lift, trying to feel the rear driveline vibration. Turns out that the pulsation I felt at full suspension droop was just the stability control getting freaked out above 10 mph without any rev signals from the front wheels. Spin the front wheels a bit by hand, and the rear brakes stopped pulsing. Then, he stomped on the accelerator for just the briefest moment, and the drivetrain shot up to an indicated 88mph before he could react and let off. :shock: That woke up all the idiot lights and the car shut down, but thankfully the lights reset after (but not during) a short test drive. That's right, the error messages reset on the second restart.

This weekend I made and installed test spacers above the rear springs- plywood donuts 3/4" thick. The 3/4"rear drop would now only be noticeable to a connoisseur, but I greatly prefer the feel of the progressive springs. Driveline angle measures only about 1.5 degrees now (angled up to the wheel), so that should be well within cv joint specs. Driveline rumble is almost gone, though I still perceive a faint vibration- so slight that I wonder if it's a ghost, and nothing that would be noticeable in a gasser with the engine on! Gotta measure the angle with a full house, then I'll leave the rear alone 'till the front end fix is determined. For a permanent rear end fix, I'm thinking to cut donuts either from heavy rubber sheet and glue em to the desired thickness, or a block of high density polyethylene I have on hand. The HDPE wouldn't spread over time like some mystery rubber might.

I'd appreciate it if anyone can post their stock axle angle (I used an iPhone app that's been checked against my dial inclinometer.), though I should be able to measure a virgin i at Tuesday night's Seattle EVA meeting.

After first discussing this with jray3, this evening I moved the H&R spring posts from the Norwegian I-Miev "Black Edition" topic into this dedicated thread.

Thanks Joe. So as suspected, there's nothing wrong with applying the H&R springs up front, just a loose nut behind the wrench. What made my miev into a rattletrap were the front swaybar linkage nuts. The ball-joint studs that secure these nuts have an allen key socket, so you can steady the stud while torquing the nut, but that prevents the use of a normal torque wrench. Turns out, the ball joint starts spinning in it's socket right about the time the torque wrench wants to click, so a shadetree mechanic may have no clue that his nuts aren't torqued right. That explains why the rattle was bad with any tiny bump, yet the swaybar seemed firm to hand pressure. The studs then loosen up quickly if insufficiently torqued, and only about 30 miles after a visual re-inspection and firm hand pressure on the swaybar, one nut had vibrated loose and completely fallen off! Luckily, the stud's threads weren't buggered up, and a scrap Toyota Corolla swaybar linkage had the same nut...

In short, my struts now seem fine with the lowering springs, the front end is 1 1/2" lower, and anything from broken pavement up through speed bumps feels much more civilized than stock. Cornering feels much more confident. I wasn't able to measure any camber change with eyeball or iphone inclinometer, but intend to put the car on an alignment rack once I 'finalize' the rear end setup. (Though there is no front camber adjustment mechanism- would have to go custom.) Bottom line- if you have an annoying rattle in the front end- check the swaybar studs! The two nuts mounting each strut top to the fender never worked loose, and same with the bottom two strut nuts and the top nut on the strut's piston.

Rear suspension still has 3/4" plywood spacers, will revisit that later. I haven't decided whether to make permanent spacers out of something solid or elastic, and may add a bit more thickness to prevent CV joint rumble at full load. The rear springs sure smooth out bumps better than stock, so I wanna keep 'em even if it means stock ride height.

I would be getting back with H & R and rattle their cage for a replacement set - Springs made specifically for a certain vehicle should not require plywood spacers to make them function correctly. Get them to wind you a correct pair. I would think they would appreciate your input, since what they're selling isn't something they would be proud of

Don

Thanks Don, I'll take a crack at talking to H&R, at least to deliver the message. Fitment was not guaranteed on the North American version of our car, as they were wound for the Euro version. But, you'd think that the wider rear track would reduce the driveline angle change brought about by lowering. However, the springs are supposed to provide 30-35mm of lowering on an Euro version, while I measured a 38mm drop on my heavier car. I haven't been able to re-establish contact with jafo or another user of these springs to compare notes...

I have lowered my nearly new European i-MiEV with the same H&R springs through my i-MiEV experienced mitsubishi dealer and have it adjusted through him and I have exactly the same annoying vibrations from the back. The car is NOT driveable in this way. I fear I may damage the transmission by driving it like this.

However I noticed the same slight vibrations also on my 2x C-Zeros I had before (which is the same car) but on higher mileage and only very short on heavy acceleration.

I am really glad I found this thread. I thought I have to balance my rear wheels.

Tomorrow I will contact H&R to find out the problem. I am wondering why there or tons of ebay auctions for these springs and I only know 5 people on the planet who lowered their car: you, me, the Norwegian guy and 2x Rinspeed i-MiEVs.

Thank you Hornstudio- I hope that you can get a response from H&R, being in their home market. My vibrations are greatly reduced by adding spacers to raise the car back up, but my next task is to re-mount the original springs in the rear to see if the vibes go away, or if there's been some permanent damage to the CV joints. Interestingly, with the suspension at full droop up on the lift there were no vibrations, and that down angle seems more extreme than the up angle caused by these lowering springs. Oh well, now to eliminate that variable and continue the experiment. I'm loving the improved ride and handling on the front axle.

Update: H&R has never heard of a complaint and said they sold enough springs to know that there is no design fault. H&R said I should call Rinspeed who lowered the first two i-MiEVs in Europe.

So I called Rinspeed in Switzerland and they said they lowered them for shows and did not drive them at all. Then they said they gave these two i-MiEVs back to Mitsubishi Switzerland and that they still drive them in their car pool. The interesting thing is that I called Rinspeed two years ago and that these i-MiEVs were for sale (at a too high price).

So one of them does not say the truth.

H&R gave me the hint I should measure the center of the wheel cap up to the fender on my lowered and on my stock i-MiEV and get back to them that they could compare and tell me if the car is not TOO low.

So I asked how it can be too low when they make identical springs in series? He did not have an answer.

But when I picked up my car from the shop we were two adults in the front and nobody in the back and no vibrations. But now in my driving situation is mostly one child plus one adult in the back and I notice severe vibrations while acceleration and while regenerative braking. So that would explain exactly why it could be too low in the back and why vibration is gone when you put a spacer on the back and "lift it towards stock".

I will now measure and get back to H&R and listen what they say!

Another question: how does Mitsubishi itself lower their Pikes Peak i-MiEV? I may then return the H&R springs.

Excellent work. Your vibrations match mine. The more load on the rear axle and the more you accelerate, the more it vibrates. H&R did not respond to my email inquiries. I guess if they never read the message, they never got the complaint....

I'm hoping that a high-angle cv joint could be identified to use in a lowered i-MiEV. In my other world of aircooled VWs, it is common to substitute a Porsche 930 cv joint for lowered or off-road applications.