MR2 Roadster Owners Club

What's the definitive solution to this if there is one ?

I have a megillian mid and FL front lower brace which have made a slight improvement, but it still feels shakey to me and more so with the roof down.

I've checked all the front bushes etc and while not new are all very solid.

Anyone got to eradicate it totally without fitting a hardtop ?

It IS a convertible, so total eradication is not possible. You could try adding a decent quality front strut brace.

That's about it.

I think I saw a post by you on f/book.  General consensus is that the underside mid brace has the biggest effect, & 2nd is a front strut brace. But before you spend more money on it maybe you should get an experienced owner to feel your car to give a 2nd opinion?

I'll add for anyone else reading this that he has Dev's blocks fitted too.

I do get that it's a convertible and fully understand what that means in terms of chassis stiffness.

I have previously owned convertibles and never had scuttle shake (VX220 & Z4)

I do also appreciate it could just be an MR2 thing, but thought before throwing more money at it, I would ask on here to see if that's just how they are first.

Quote from: panderoo on August  6, 2020, 10:23What's the definitive solution to this if there is one ?

I have a megillian mid and FL front lower brace which have made a slight improvement, but it still feels shakey to me and more so with the roof down.

I've checked all the front bushes etc and while not new are all very solid.

Anyone got to eradicate it totally without fitting a hardtop ?

Your bushes whilst looking "solid" are in fact at min 14 years old.. they are past their best. If you don't want scuttle shake don't obviously go with polys, I would suggest replacing your front wishbones (buy the  yaris ones for £40) and you'll get new bushings that way.

As Carolyn said, put in the front strut brace, that'll help to remove some of the rattles etc and make the car feel "bigger and more solid" over bumps. I also found an improvement in adding snelbaards breastplate combined with the mid under brace.

You can also add more rubber insulation to the area between the windshield and the front dash - give it a whirl, it's a cheap trick, it works for some.

Basically have a look on you tube for earlier 2000's videos of MR2 in dash footage (that isn't race related) and decide for yourself if an original suffered from scuttle shake or not, I bought mine when it was 14 years old so am not qualified to say.

Hope that helps.

Do bear in mind that the VX220 is more a targa than a cabrio so not quite comparable.
The Z4... well, that is not a throw about; it got seriously out of sorts through the corners in the mountains here.
So neither is a gold standard of comparison.
The crux is that YOÚ experience ´scuttle shake´.

I have a front strut brace, Snelbaard´s mid brace and Dev´s door spacers; stock shocks & springs. I drive the properly heated up AD08Rs on Enkei RPF1s to over the limits and find the car reassuringly rigid enough.
The softish suspension and slight flex in the chassis give very good compliance on the real world mountain roads here.

Soft top up or down makes NÓ difference in stiffness of the tub. Up gives just a bit less ... disturbence from the loose hood in the back on rough surfaces. Nothing to do with any shaken scuttles though.

The hard top will make a difference IF bolted down. The clamps are too flexible to make a real difference.
So there you have the solution; Snelbaard´s hard top brackets  8)

Bottom line; try a front strut brace, the door spacer and start rubbing grippy rubber  ;D

Enjoy!!

Quote from: Petrus on August  6, 2020, 17:13Do bear in mind that the VX220 is more a targa than a cabrio so not quite comparable.
The Z4... well, that is not a throw about; it got seriously out of sorts through the corners in the mountains here.
So neither is a gold standard of comparison.
The crux is that YOÚ experience ´scuttle shake´.

I have a front strut brace, Snelbaard´s mid brace and Dev´s door spacers; stock shocks & springs. I drive the properly heated up AD08Rs on Enkei RPF1s to over the limits and find the car reassuringly rigid enough.
The softish suspension and slight flex in the chassis give very good compliance on the real world mountain roads here.

Soft top up or down makes NÓ difference in stiffness of the tub. Up gives just a bit less ... disturbence from the loose hood in the back on rough surfaces. Nothing to do with any shaken scuttles though.

The hard top will make a difference IF bolted down. The clamps are too flexible to make a real difference.
So there you have the solution; Snelbaard´s hard top brackets  8)

Bottom line; try a front strut brace, the door spacer and start rubbing grippy rubber  ;D

Enjoy!!

Actually the hard-top does make a difference if the clamps are properly adjusted.  Petrus you know not of what you speak...

I think so as well, i run with it on all the time,  on the 2 days a year i remove it for some open top motoring i think the scuttle shake is worse...

Thanks for the suggestions everyone..

To be honest I wasn't looking to make a comparison with anything else.

I was just looking to see from the wealth of experience if there was a definitive solution to the evident shake/wobble everyone seemingly experiences to a more or less degree. (Most likely only differentiated by personal expectation or experience)

It seems that the only current solution is to throw as much bracing as your pockets/wallet can manage and then grin and turn a blind eye to the remaining shakes/wobbles.

I guess I just need to go through it all and see what I can find and fix anything that's actually faulty or not on my car. I just couldn't find anything last time I had it in the air.

Quote from: Carolyn on August  6, 2020, 17:47Actually the hard-top does make a difference if the clamps are properly adjusted.  Petrus you know not of what you speak...

I háve a hard top remember. Even use it during winter.
And the clamps are adjusted tight.
As I write, yes a difference, still not much of a difference. Imo it is more the extra weight lowering the frequency of movements than a limitation of them.
But hey, perception is reality and we can agree to differ.

Quote from: panderoo on August  6, 2020, 18:27Thanks for the suggestions everyone..

It seems that the only current solution is to throw as much bracing as your pockets/wallet can manage and then grin and turn a blind eye to the remaining shakes/wobbles.

No and yes.
No to the money/bracing as there is something like too much of a good thing and in mý opinion bracing is such a thing but again opinion differ.
Yes to the grin. The thing really is a throwabout. The best ´mod´ is to get the grippiest tyres allowed on the public roads. For the MR2 nothing beats high grip tyres for grin factor.

My 2p.

I found shake significantly reduced when I done a suspension refresh.
I had a mid "matt" brace on the tired suspension. And removed it, just to see. After having the new springs n shocks. Never bothered putting it back on and sold it.

Quote from: Ardent on August  6, 2020, 19:48My 2p.

I found shake significantly reduced when I done a suspension refresh.
I had a mid "matt" brace on the tired suspension. And removed it, just to see. After having the new springs n shocks. Never bothered putting it back on and sold it.

My car will benefit from new shocks/springs so I´ve called first dibs on Boris´s Sportivo set if/when he gets/does his Cusco upgrade.

The definition, perception of ´scuttle shake´ is leaving a bit of room for confusion btw. Your 2p. point that out to perfection imo.: Rattles and such are not neccessarily tub flex.

Just a thought, has anyone on here driven a roadster from factory miles to know if it suffered with scuttle shake from new ?

I've had mine from new...2004 FL and standard when I got it.  There has always been a shake, especially with the roof down.  I don't have any extra braces underneath or between the axles, apart from standard, the only thing I have done is fitted HK Automotive springs which lowered the car by 30mm...standard shocks still fitted.
What has made some difference is running with a hard top, but by far the best improvement was fitting Dev's door bushes - car now done 69k. They basically lock/jam the doors into the door frame making the side of the car a solid unit which can't shake.  These have virtually eliminated the scuttle shake & its now a joy to drive the car hard with roof down on even the worst road surfaces....the cobbled streets in my local town really showed up the improvement. From previous feedback, it would appear others have seen great results too & not an expensive modification.  ;)

Thanks for sharing the from new experience.
As Carolyn observed; it´s a cabrio so the tub is compromised, period. Open both doors with the roof down and it is appearant.

I agree with the Dev spacer observation. They stiffen the door, making them relatively high placed tub braces.
As to their effectiveness, Schnazzles experience is epic imo.

The front strut brace, though effective in improving the steering feel, does nóthing to that effect. Again easily seen with the roof down, doors open; it does affect what you (not) see only very indirectly.

p.s. I stíll distinguish between rattles and tub flex. Stiffer springs will increase rattles, not make the tub more/less flexible.

An interesting topic about one of the car's biggest bugbears. My 2 is a PFL on its original suspension. It's nimble enough and is certainly comfortable but there is evidently a lot of flex in the body. I will concur that the hardtop makes a significant improvement to this. I'd like to drive an FL back to back to see how improved the later stiffened cars are, as it certainly needs it!

My 2 replaced an MG TF, a car that is objectively inferior to the MR2 in many ways but has a far stronger body (thanks in part to its whacking big subframes front and rear that contribute to its 100kg+ weight disadvantage). However, even with its stiffer standard suspension set up, scuttle shake is much lesser apparent in the MG as a result.

@LeRich - when I switched from FL to pfl I noticed the flex on twisty roads. See post no'3.

An FL's 'parallelogram' front underbrace (4 tubes) can be added, but they're not easy to get in sound condition. There are some aftermarket makers though.

Can someone elaborate on what exactly "Scuttle shake " is? Is that where the car feels like it "skips" sideways in hard  bends?

Just to pull this to a conclusion for my car.

I have a Megillian Mid Brace, Face lift front under body brace and Dev's door bushing s and still had quite a lot of lateral shake over man hole covers / un-even road surfaces / road repairs ... basically any kind of lump or bump in a road would make the steering wheel shake. (not that same shake as badly balanced wheels)

I lifted the car up and checked bushes, track rod ends, lower ball joints.

It's has brand new front dampers & tein springs within the last 500 miles

I've personally fitted and balanced 2 sets of wheels and tyres.

But today I pulled the frunk plastic and decided to have a quick check of the top mounts and managed to tighten up the off side front 19mm top mount nut by about an 1/8 of a turn.

The difference seems to be night and day.. scuttle shake is 95% gone and now at a perfectly acceptable level.

No idea why it would be slightly loose as I did tighten them both when fitting the springs and dampers, but it obviously pay's to double check areas that you might not think would have any effect.

The only other symptom which led me to look here was that i had started to notice a slight rattle on full lock when maneuvering.

I bet your car feels good now!

Congrats on solving your issue.

Yes, I can actually feel the car now without suffering vibration white finger  :-[  :))

Glad that you found it. I've never read a 'current time' thread before of someone finding that, but in researching suspension changes & aspects, I have.  Does it have a spring washer under it or have you threadlocked it?

Quote from: Gaz mr-s on August 11, 2020, 09:57Glad that you found it. I've never read a 'current time' thread before of someone finding that, but in researching suspension changes & aspects, I have.  Does it have a spring washer under it or have you threadlocked it?

The OE fitting is a Nyloc type nut. Best practice is to use these once only and replace. Mr T charges highly for replacement but other sources are available.

Quote from: Gaz mr-s on August 11, 2020, 09:57Glad that you found it. I've never read a 'current time' thread before of someone finding that, but in researching suspension changes & aspects, I have.  Does it have a spring washer under it or have you threadlocked it?

It doesn't have either, but i don't think they are required.

I will likely fit a new nyloc nut as i had re-used the original nut when i swapped out the dampers & springs, that should hopefully be enough.

If i do get any shake again i will know quickly where to look this time.

Good you found it.
Confirms my observation about ´scuttle shake´ btw  ;)

I trust you (re-)packed the top mount bearings with grease.

Nylock....I should have remembered that. Koni supplies a thick spring washer.

Quote from: panderoo on August 11, 2020, 09:54Yes, I can actually feel the car now without suffering vibration white finger  :-[  :))

Next, delete the p.a.s.

Quote from: Petrus on August 11, 2020, 10:19

Quote from: panderoo on August 11, 2020, 09:54Yes, I can actually feel the car now without suffering vibration white finger  :-[  :))

Next, delete the p.a.s.

I have already looked into this and did the power off/on whilst driving and didn't personally like the feel with it off.

If someone finds/makes a proper manual rack i would consider it, but i don't like the modified PAS to manual rack option. 

Quote from: panderoo on August 11, 2020, 10:23I have already looked into this and did the power off/on whilst driving and didn't personally like the feel with it off.

If someone finds/makes a proper manual rack i would consider it, but i don't like the modified PAS to manual rack option. 

Just switching it off sees you pump the fluid through the system. Shortcircuiting it feels much more direct. The biggest diffence is conncting the two sides of the piston withing the rack.
All easily done and reconnected. Basically a extra complicated fluid change.

I lóve it: Now I can féél when the grip of the front rubbers is ever so slightly less. Even the rear going is noticeable so much earlier than with the bum.

I don´t need to navigate city traffic though and nor hardly ever park in a tight or complicated spot.

Quote from: panderoo on August 11, 2020, 10:23

Quote from: Petrus on August 11, 2020, 10:19

Quote from: panderoo on August 11, 2020, 09:54Yes, I can actually feel the car now without suffering vibration white finger  :-[  :))

Next, delete the p.a.s.

I have already looked into this and did the power off/on whilst driving and didn't personally like the feel with it off.

If someone finds/makes a proper manual rack i would consider it, but i don't like the modified PAS to manual rack option. 

  I have done the PS delete a very long time ago. There is a big difference between turning off the PS vs removing the PS pump and looping the lines. 

 Just turning off the PS is horrible and very difficult to turn because there is too much resistance in the small passages of the PS pump. Once its removed and you connect both lines together it feels completely different. 
It reminds me of a VW golf GTI that I owned in my youth that had a manual rack but better because it has a shorter steering ratio. I now have much better feel of what the front tires are doing and the car feels tight. 
  I have got so use to it over the years  I often forget that its a manual until I drive someone else car at a meet and then I feel like the steering is way over boosted with disconnected road feel. 
 

Is there guide or do you have pics of what you have done with looping the lines ? @Petrus @Dev

Quote from: Dev on August 11, 2020, 13:02that had a manual rack but better because it has a shorter steering ratio.

Yup. The pas rack is shorter ratio than a manual would be so deleting the pas is win-win imo but, and it can be a butt even, not if you need to tackle a lot of slow city travel and parking.

Over here where tarmac gets literally scorching hot, the grip can be very tricky. For one the tarmac is hard,  because of that often worn smooth and lastly because of 300 sunny days/year can be réal grimey and when it gets wet UFFFF.
Having direct feel of the rubber is só much safer. I can now feel the traction; feel when the car is nearing the limit instead of having to react to it going óver the limit of grip. I can respond to the front getting lighter or the rear pulling befóre the car actually goés.

Quote from: panderoo on August 11, 2020, 13:08Is there guide or do you have pics of what you have done with looping the lines ? @Petrus @Dev

I put it in the members ride section in Southern Belle´s thread Incl. photos on page 6 and 7. May have mentioned more earlier.

I'm currently investigating scuttle shake, so this has been a really useful thread, thanks!

I will check the nuts on the front struts ASAP, then report back when I've sorted some door bushes and a lower mid brace (already have upper front brace which has helped a bit).

If anyone has managed to check the front strut bolt torque settings whilst the strut is in the car please let me know how you managed to stop the shock rotating? thanks!

 :))  I just went to do the same job and found the same. Figured its tight enough if its trying to rotate the lot.