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03-13-2007, 04:31 PM | #1 |
Lowered Cars Please Read - Bump Stops!!!
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? |
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03-13-2007, 05:23 PM | #2 |
resident senior
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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 .
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03-13-2007, 05:32 PM | #3 |
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? |
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03-13-2007, 05:34 PM | #4 | |
The Beautification of Car
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Quote:
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03-13-2007, 06:03 PM | #5 |
That's for another thread. Right now, I want to talk about bump stops. So... anyone else want to talk bump stops?
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03-13-2007, 06:14 PM | #6 |
The Beautification of Car
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03-13-2007, 06:16 PM | #7 |
resident senior
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Hey Gala , try . http://energysuspension.com/ They might have a bump you are looking for .......
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03-13-2007, 06:53 PM | #8 |
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?
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03-13-2007, 06:56 PM | #9 |
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?
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03-13-2007, 07:26 PM | #10 |
...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.
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03-13-2007, 07:29 PM | #11 |
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
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03-13-2007, 08:54 PM | #12 |
Parallel Parking Pro
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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. |
03-13-2007, 09:11 PM | #13 |
Break'em off some.
Drives: 07 Yaris LB, 04 Cobra Join Date: Jan 2007
Location: So Cal, OC
Posts: 854
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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 Last edited by largeorangefont; 03-13-2007 at 09:22 PM. |
03-13-2007, 09:58 PM | #14 |
Drives: 2007 White Toyota Yaris Type S Join Date: Dec 2006
Location: Southern California
Posts: 439
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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......
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TRD Springs w/ KYB Struts and Shocks, Custom CAI w/ K&N filter and pre filter wrap, Weapon R Header, Stock 15 inch alloys, Dezod Performance pads, Tanabe Front Strut Bar, 35% front door Tint and 20% Rear doors back Tint, De-Badged Ass, Custom painted flat black interior, Pioneer deh-p6700bt w/ IPOD hookup, Infinity components up front with custom mounted tweeter, Inifinity 6x9's out back, 1 12" kicker comp cvr........ |
03-13-2007, 11:18 PM | #15 |
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.
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03-14-2007, 12:11 AM | #16 |
Drives: 2005 Scion xB Join Date: Nov 2006
Location: The Black Hills of South Dakota
Posts: 1,059
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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...
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03-14-2007, 10:01 AM | #17 | |
Drives: 2007 Yaris Sedan "D" package Join Date: May 2006
Location: Barrie, ontario
Posts: 852
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Quote:
exactly, its not the bumb stop getting hit, its the strut bottoming out. |
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03-14-2007, 01:24 PM | #18 |
Modification Condoner.
Drives: 2007 Black Sand Liftback Join Date: Jan 2007
Location: Chicago, IL
Posts: 360
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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.
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Tanabe DF, Debadged, stripped, Black emblems |
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