Lowered Cars Please Read - Bump Stops!!!

[Galavoxx]

I'm running the TRD (KYB) Sportivo absorbers with Springtech 1.8 inch lowering springs, I've had this recurring problem where at least once a week, I bottom out the front suspension on large bumps. And I mean I realllly bottom out the suspension, like @#%THUDDD!!!!#^%$. This cannot be good. The springs and absorbers feel great otherwise, just the big bumps and in fast bumpy turns is it bad.

When I installed my setup I cut the bump stops down as recommened by the spring company. This was also recommended in the Tanabe DIY by Chris07LB. The rear of the car doesn't have bump stops so no change there. I never bottom the rear.

So my bumps are currently about 1.5 inches long, maybe 2 inches. Having a bump stop that is half of or less than half of the original height can't be good. I understand that we don't want the stock bump stop limiting our suspension travel but we also want a bump stop that works and does what it is supposed to i.e., provide safety from bottoming while adding some progression at the end of the compression stroke of the main absorber. The bump stop is just an inactive miniature shock absorber and by cutting it, it's original qualities of absorbsion are lost. So I've been looking around for aftermarket replacements.

So I spoke to a a local autocross suspension tuner and he confirmed my "research" that cutting the bump stops is very bad in that it eliminates that final bit of progressive travel that the bump stop is meant to supply. He also confirmed that the bump stop is a crucial part of the suspension system. This is especially true in fast and heavy turns where a car will actually rest on the bump stop, not only preventing the suspension from fully bottoming but actually adding a very fine level of absorbsion for smaller bumps within the turn.

At this point, I have no final bit of progressive travel. It is gone. I go from suspension working good to... THUD. Supposedly, you can get back about an inch to an inch and a half of travel using these aftermarket bump stops. I already supplied this local tuner with my absorber info and he is going to try to get something together for the Yaris.


Let me know if anyone is interested. The price has not been specified but should be around $50 for a set of four. The price will be halved if you only want the front. I'll try to get him on here to answer questions once the kit is available.

I would also like to ask if any of you have used any of the aftermarket Koni bumps or if your suspension kit might have come with bumps? If you did a self install of the TRD Sportivo kit WITH SPRINGS, did the kit include instructions about the bump stop? I would think Toyota would speak to this in their instructions since the bump stop is an active part of the suspension, not just a stopper to prevent the absorber from banging into the shock hat.

Feedback?

[HTM Yaris]

Yo , put the stock springs back with the stock bumps in conjunction with the TRD shocks . You will be pleased , very pleased . I do very , very well in H stock class . The choice is yours , look cool or be fast . My Yaris won first place in HS and took 9th overall last month @ the autox . That was on stock suspension . This Sat ( Mar 17 ) I will get to use the TRD shocks with stock springs . The car feels REALLY good . I'm excited about putting distance on my competitors . I'm shooting for a top 5 overall .

[Galavoxx]

I realize the TRD absorbers waaaay outperform the stockies but that's not the issue here. I like the car lowered and honestly, it should handle even better with the lower center of gravity, which is does. And yes, I would also like to autoX.

Now about those bump stops... anyone else?

[jamal1984]

Yo , put the stock springs back with the stock bumps in conjunction with the TRD shocks . You will be pleased , very pleased . I do very , very well in H stock class . The choice is yours , look cool or be fast . My Yaris won first place in HS and took 9th overall last month @ the autox . That was on stock suspension . This Sat ( Mar 17 ) I will get to use the TRD shocks with stock springs . The car feels REALLY good . I'm excited about putting distance on my competitors . I'm shooting for a top 5 overall .

I'm planning to get new shock for my sedan, because my stock shocks is not that good. Is TRD is the best stock out there? how much is it run? i just want some kind of shocks that i smooth like camry when you go to holes or bumps ...

[Galavoxx]

I'm planning to get new shock for my sedan, because my stock shocks is not that good. Is TRD is the best stock out there? how much is it run? i just want some kind of shocks that i smooth like camry when you go to holes or bumps ...

That's for another thread. Right now, I want to talk about bump stops. So... anyone else want to talk bump stops?

[jamal1984]

That's for another thread. Right now, I want to talk about bump stops. So... anyone else want to talk bump stops?

Sorry man, i'm forgot. :thumbup:

[HTM Yaris]

Hey Gala , try . http://energysuspension.com/ They might have a bump you are looking for .......

[Galavoxx]

I have a line on the bump stops, just wondering if anyone has tried any aftermarket stuff or is interested in getting a set from the place I'm ording from?

[OxyG3nE]

i had the DF 210.. and i know i hit a few time the bump stop.. i cut it half like chris wrote in his thread but if you didnt cut it you would be running the bumpstop almost all the time?

[Galavoxx]

...which is why I also cut the bumps. Running on the bump stop is not good unless you're near the limit of the suspension travel.

[OxyG3nE]

im curious to know if when toyota install the lowered spring that they offer .. if they cut the bumpstop .. so i guess we should change the entire suspension :p

[cleong]

It was a long story to read to find that you're basically trying to sell the idea of a group buy to others so that we'd all get a discount on bump stops.

Anyhow I'm on TTE springs, and there wasn't a note to cut the bump stops.

[largeorangefont]

ill try a set of fronts if you come up with something. Bumpstops are usless in the rear. You get coil bind before the shock is out of travel. That is why there are none there from the factory.

I haven't had any problems with the stock shocks bottoming out hard. In fact, I can't recall them bottoming out ever. It took only 30 minutes to install the springs so I don't remember exactly how much I cut off the OEM bumpstops, but it was slightly less than an inch. I left alot more than half (2\3) mabye.

Ashley

[07typeS]

But you gotta understand that you are lowering where the shock sits at a normal sitting position. so ultimately you have an inch and a half to 2 inches less travel because of the lowering springs. cutting the bump stop a little gives you a little more of the suspension play back and does this decently because the coils have a higher spring rate meaning they arent as soft hence the "rougher" ride. the aftermarket shocks are a little firmer, accomodating for a shorter spring but also allowing for stock springs. the firmer shocks will match up perfectly with some drop springs. im sure aftermarket shocks and springs with aftermarket bump stops is the ideal combo........but money always plays a factor......especially when all this at once isnt necessary.

its been covered before you definately shorten the life of your stock shocks by putting lowering springs on, but most people know that. you just get what you can out of them and when its time for new ones, time for sweet aftermarket ones.

as far as you bottoming out i dont know what to say. i havent hit any dips that hard. im well aware im dropped and take more notice to dips and bumps like most of us do......

[Galavoxx]

Ok. Well it sounds like no one is interested. I plan on autocrossing at some point so I think I'm going to get this over with now rather than later. I'll let you all know if I notice any difference. And I am well aware of the loss in suspension travel when lowering but I don't buy the "shocks wont last as long b/c they are subject to severe conditions". With a properly set up suspension, the shocks should last the same amount of time as an OE setup. As I mentioned above, adding these bump stops will actually give travel back by creating a progressive compression ratio at the end of the piston stroke as opposed to the quick bottoming that I am now experiencing. San Francisco has a bunch orf hills and crap roads.

[PetersRedYaris]

With Sportivo shocks/struts, I don't believe your supposed to cut the bump stops. They are made for lowering springs (hence, they are shorter) and cutting the bump stops may accually allow the strut to fully compress. When the strut fully compresses the piston rod bottoms out. If this happens with enough force it will bend the rod thereby destroying the strut. Cutting the bumps only applies to stock shocks/struts with moderate drop springs. I would put full length bump stops back in there before you ruin them. Just my thought...

[punch]

With Sportivo shocks/struts, I don't believe your supposed to cut the bump stops. They are made for lowering springs (hence, they are shorter) and cutting the bump stops may accually allow the strut to fully compress. When the strut fully compresses the piston rod bottoms out. If this happens with enough force it will bend the rod thereby destroying the strut. Cutting the bumps only applies to stock shocks/struts with moderate drop springs. I would put full length bump stops back in there before you ruin them. Just my thought...


exactly, its not the bumb stop getting hit, its the strut bottoming out.

[Nimble]

We're interested, it's just that cutting the bumpstop in half is what's needed to maintain *any* sort of ride comfort when lowering with the stock length shocks. It's not magic here, just the physics of reducing the length of the BS so the shock has mre travel. Mine's fine.

[Galavoxx]

Bottoming out like I have been is obviously not a problem for most people. And no I am not grossly overweight. But I think you're missing the point. As I said, we can all cut our bump stops but once we do, their original properties are lost. I am not planning to add just any old bump stop back into the mix. I want to find a bump stop that will work specifically for lowered Yarii. We have to make sure the stop isn't too long or too short. It's going to sit where the old stops sat i.e., in the shock hat. Rears will probably not be necessary but might be a good idea if you're running the Tanabes or the Teins since those springs do drop the rear even more than other setups. It's going to be at least two weeks before everything is figured out and I install. I'm hoping for improved cornering by eliminating the "hop" that I experience now. I also want the bottoming to stop.

[rwseattle]

I recently installed the Tanabe NF210. Wheel and tire set up 16" 205/45/16. I've not yet experienced any problem with the bump stop. I did cut the bump stop about 1.0. in the front because the Tanabe NF210 drops the car 1.0 in the front. The back drop is 1.3 but no bump stop needed. I defiantly would be interested in after market bump stops, but only if its really necessary. Please keep me posted on this subject? It's interesting!

[Blenjar]

I guess I wont cut mine :/

-- Blen

[OxyG3nE]

i cut mine because i will change everything anyway when it will be break .. so maybe can save 1-2 year but if you have good road you wont hit the bumpstop too often...

[Nimble]

I guess I wont cut mine :/

-- Blen

you might consider it, otherwise adios front struts.

[Blenjar]

even with the sportivo?
I'll consult with my toyota dealer part guy...hes the one who gave me ideas about his TRD upgrades and son's xA TRD upgrade. I'll ask him about the bump stop.

-- Blen

[501]

when i had my set up(df210-trd struts)installed they had forgot to cut the bumpstops. when the car was set down the front was still at stock hieght, which i could tell that the strut was sitting only on the bumpstop. i had to drive for a week like this, the ride was harsh up front and the car wanted to skip around in turns if pushed at all. after the bumpstops were cut the front end dropped into its travel and the ride was night and day better. now the car does not bottom out every where like before.

when running springs you will always shorten the life span of the struts.
another note is that the trd shocks were designed to work in conjunction with the trd lowering springs, and with that combo you should not lose hardly any of your total suspension travel.

[Blenjar]

How much were your shocks?
and where did you buy them?

-- Blen

[Galavoxx]

I have to agree, you either need to cut the bump stops or get some aftermarket items. I was actually going to start another thread on this because I just installed aftermarket bump stops and spacers last weekend but...

As I mentioned earlier in this post, I cut off too much of the bump stop and was bottoming out at least once a week. After installing the aftermarket bump stops, the difference really is night and day. On Sunday, I Got my alignment done with a little negative camber thrown in and I actually went out looking for a way to bottom the suspension. I drove highway 1 south from San Francisco and turned up through Bonny Doon Rd to Felton to Boulder Creek to Skyline and back to SF.

The drive was great but the best part is that, there is no more *THUD* when bottoming the suspension. In one section of my drive there was a good half-hour of tight fast turns. Even in turns with the suspension compressed and riding on the bump stops while hitting a pothole or bump, the car stayed settled. All I can say is, it's amazing how much difference these damn bump stops make!

Anyway, I would recommend these as opposed to cutting.

However, if you must cut, you should leave enough bump stop to do the job it is intended to do. The aftermarket items I got are a hair over 2 inches long including spacers (52mm).

I actually did my front and rear bump stops but you should really only need the fronts. If you do the rear, you'll have to pop the stock hard black rubber stops out with a screwdriver and possibly cut the dust boot.

Here is a link to the site where I bought mine:

http://www.fatcatmotorsports.com/FCMstops.htm

The guys name is Shaikh and he autocrosses Miatas. They are about the same weight and hp as the Yaris. He is planning on making a Yaris page if enough people want these. But for now just tell him Randy sent you. :biggrin:

The Yaris setup:

Front: (2) 47mm strut-style bump stops $24
(4) 9mm delrin spacers, drilled to 21mm $20

Rear: (2) 40mm non-strut (shock) style bump stops $24


extras: $5 each for 3mm slotted spacers, drilled to 16mm, used to tune over/understeer on rear of car. I didn't try this yet but may do so in the future. The car already handles great with maybe a little too much understeer. But this is a front wheel drive car.

Also, I have a spare set of front bump stops with spacers for sale if anyone wants them. I had them installed on the rear of the car for about two days but the inside diameter was too big and they were flopping around so I swapped them out for a smaller I.D. $25 shipped.

[Chris07LB]

My DIY showed STOCK struts being used with the Tanabe DF's. If you have the TRD's they are SHORTER then the stock struts, so of course if you removed the same amount off the bump stop, it would be bottoming out.

I guess I should note this for others installing different struts while following my DIY.

[Galavoxx]

I am using the springtechs with about 2" of drop. So I took off 2 inches of bump stop.

[Chris07LB]

Whats the spring rate of those SpringTech's up front? Softer then DF's?

[Galavoxx]

You know, I'm not even sure. I had the numbers at some point but I looked for them a few weeks back and couldn't find the e.mail. Base on feel alone, they are sort of like goldishox: not too hard and not too soft, juuust about right!! :bellyroll: haha. Actually, they could be a tad more stiff, just a tad.

[brickhardmeat]

when i had my set up(df210-trd struts)installed they had forgot to cut the bumpstops. when the car was set down the front was still at stock hieght, which i could tell that the strut was sitting only on the bumpstop. i had to drive for a week like this, the ride was harsh up front and the car wanted to skip around in turns if pushed at all. after the bumpstops were cut the front end dropped into its travel and the ride was night and day better. now the car does not bottom out every where like before.

when running springs you will always shorten the life span of the struts.
another note is that the trd shocks were designed to work in conjunction with the trd lowering springs, and with that combo you should not lose hardly any of your total suspension travel.

I used shitbrand springs. I did not cut my bumpstops and the set up is only temorary. The front is 2 inches lower without cutting the bumpstops.

You are saying not cutting the bumpstops with the DF and the TRD Shocks installed that your car was not lower than stock? Huh?

I am planning to use the same set up as you since there are no shock options except for the TRD but I am not yet commited to the idea of butchering the bump stops.

[Blenjar]

Whats the spring rate of those SpringTech's up front? Softer then DF's?

Hey, if I use the TRD sportivo with the stock shocks/strut...what do you recommend?

-- Blen

[brickhardmeat]

Hey, if I use the TRD sportivo with the stock shocks/strut...what do you recommend?

-- Blen

Toyota isn't going to chop the stops nor are they going to tell you to do that.

[Galavoxx]

Hey, if I use the TRD sportivo with the stock shocks/strut...what do you recommend?

-- Blen

Don't do this!! Save your money and get a full setup. You're going to be bouncing and rolling like your Yaris has tourette's.

And I agree, Toyota isn't going to tell you to cut anything. And quite possibly, you don't need to if you use their setup. The TRD springs have a very high spring rate so you may never bottom out.

[Blenjar]

damn...not sure now....cut or no cut..g.rrr n I dont wanna pay 85 bux an hr for that....
I got the TRD spark red spring...
any1 got them? bump stop cut off?!?!

-- Blen

[brickhardmeat]

damn...not sure now....cut or no cut..g.rrr n I dont wanna pay 85 bux an hr for that....
I got the TRD spark red spring...
any1 got them? bump stop cut off?!?!

-- Blen

Why don't you call TRD and ask them? I am pretty sure I know what they will say.

[Galavoxx]

I agree. Just call them. They are going to tell you that no cutting is necessary with the full TRD setup.

[Blenjar]

"Hi,

Okay, when installing lowering springs on Struts, you cut the bump stop the same amount that you're lowering the car and in this case I believe that's going to be 1.2" so we're talking about 6/10's of one inch. Talk to you later.

Ken"

That was Ken from TRDspark, the RED TRD springs.
Now all I need to do is get a math major to help me cut this.

-- Blen

[Galavoxx]

"Hi,

Okay, when installing lowering springs on Struts, you cut the bump stop the same amount that you're lowering the car and in this case I believe that's going to be 1.2" so we're talking about 6/10's of one inch. Talk to you later.

Ken"

That was Ken from TRDspark, the RED TRD springs.
Now all I need to do is get a math major to help me cut this.

-- Blen

Hmmm, I never thought toyota would sell something where they actually ask the customer to just "modify" a part to make it work. I was sure they would either provide a new piece or use the intact old one. Guess I was wrong.

[brickhardmeat]

Hmmm, I never thought toyota would sell something where they actually ask the customer to just "modify" a part to make it work. I was sure they would either provide a new piece or use the intact old one. Guess I was wrong.

me too, quite surprised, I am still in the air on cutting mine with the new install, i'll probably do a lot of calling around

[churp]

The bumpstops sole purpose is to prevent the strut shaft from hitting its cylinder at the bottom of its stroke (and causing damage)....changing the spring does not change the bottom travel of the strut, so cutting the bumpstop will bring you closer to that destructive interference. There will be some leaway in the design of the strut that you can get away with it sometimes....but cutting the bumpstop doesn't alter the point where damage can be done. Aftermarket struts may be designed to allow for more downtravel, but myself I'd leave it alone with the factory strut. Hitting a rubber stop is much more pleasant than hitting steel to steel!

[Chris07LB]

Of course no cutting is needed with the TRD setup... it was designed to work together..

Now any aftermarket spring and STOCK shock setup will require cutting.

Do yourself a favor, call the manufacture of the springs you are buying, AND ASK! Lots of bullshit advice being spread around lately on this topic.

[d4w1]

I have a set of TRD lowering coil springs installed on my 2007 Yaris hatchback with TRD Sportivo struts and shocks. I found that Tanabe racing development installation instructions recommends how much to cut from the front bumpers on your front struts. Tanabe tells you to only cut 15mm to 25mm from the rubber bump. You can cut easily with a cutter knife after you spray lubricant oil on the rubber bump. Tanabe also has a note: Please consider number of passangers and carrying load. For my car I only removed the mininum of 15mm. I have not had any promblems of suspension bottoming out. Here in Texas the rual roads are not that great. Losts of uneven surface raods.

[Blenjar]

I cut mine...that first U shape, cut it there...I dunno wat's a buttom out but my ride is fine..looks better..i think it will lower more within the next two weeks.

-- Blen

[daddz07]

I have to agree, you either need to cut the bump stops or get some aftermarket items. I was actually going to start another thread on this because I just installed aftermarket bump stops and spacers last weekend but...

As I mentioned earlier in this post, I cut off too much of the bump stop and was bottoming out at least once a week. After installing the aftermarket bump stops, the difference really is night and day. On Sunday, I Got my alignment done with a little negative camber thrown in and I actually went out looking for a way to bottom the suspension. I drove highway 1 south from San Francisco and turned up through Bonny Doon Rd to Felton to Boulder Creek to Skyline and back to SF.

The drive was great but the best part is that, there is no more *THUD* when bottoming the suspension. In one section of my drive there was a good half-hour of tight fast turns. Even in turns with the suspension compressed and riding on the bump stops while hitting a pothole or bump, the car stayed settled. All I can say is, it's amazing how much difference these damn bump stops make!

Anyway, I would recommend these as opposed to cutting.

However, if you must cut, you should leave enough bump stop to do the job it is intended to do. The aftermarket items I got are a hair over 2 inches long including spacers (52mm).

I actually did my front and rear bump stops but you should really only need the fronts. If you do the rear, you'll have to pop the stock hard black rubber stops out with a screwdriver and possibly cut the dust boot.

Here is a link to the site where I bought mine:

http://www.fatcatmotorsports.com/FCMstops.htm

The guys name is Shaikh and he autocrosses Miatas. They are about the same weight and hp as the Yaris. He is planning on making a Yaris page if enough people want these. But for now just tell him Randy sent you. :biggrin:

The Yaris setup:

Front: (2) 47mm strut-style bump stops $24
(4) 9mm delrin spacers, drilled to 21mm $20

Rear: (2) 40mm non-strut (shock) style bump stops $24


extras: $5 each for 3mm slotted spacers, drilled to 16mm, used to tune over/understeer on rear of car. I didn't try this yet but may do so in the future. The car already handles great with maybe a little too much understeer. But this is a front wheel drive car.

Also, I have a spare set of front bump stops with spacers for sale if anyone wants them. I had them installed on the rear of the car for about two days but the inside diameter was too big and they were flopping around so I swapped them out for a smaller I.D. $25 shipped.

do you still have this front bump stops??

[Galavoxx]

I don't have them. Try FatCat, I think he's still around.

http://www.fatcatmotorsports.com/