Thursday, January 08, 2009 - 04:29 pm, by: Dave Cazes(Cazman)
Ok, after seeing numerous peoples cars on here with people whinging about xyz problems, and others wanting some decent performance suspension, but not knowing what they are doing (I call this pedders syndrome where they sell you any thing they can just so they can take your money)
If you only care about having some fun in your car, driving it and you are happy to have a not so perfect suspension package, STOP READING NOW. Close this window and dont bother reading on.
I dont know where to start with this so.... If you cant be bothered reading, just look at the pics, it makes sence really
Your soarer once you have lowered doesnt have enough stroke/suspension travel. Before you say "I have only lowered it X inches" please think about it as " I have x Centre wheel to Gaurd (CWG)"
What this means is on bumps your car WILL: Make crashing noises Get very stiff on big bumps Unsettle your car mid corner mid corner if your already bottomed out through body roll and then hit a bump your in trouble You will get bump steer steering wanders through its suspension stroke Just to name a few
At any lower than 370CWG you will run into issues with bottoming out, and geometry issues. No you dont have a one of a kind special one, none of them do, not your v8, not your TT none of them. Your shock will bottom out on big bumps or high speed transitions.
I hear you saying " but I have a short stroke shock...." You most likely dont, KYB, Boge, pedders, monroe, gabriel, bilstein, koni - NONE OF THESE ARE ANY SHORTER THAN YOUR STOCK ONES. The other problem is short stroke shocks only hold the spring more captive, so they dont fall out, they dont give you and more stroke room to stop your car bottoming out.
Shortened body shocks are another story, but this STILL WONT HELP YOU. Your wheel will collide with your upped wheel arch before you get very far anyway. Almost every coilover has a shortened body, but as said, and as the pics show, your wheel will hit the wheel arch before you run out of stroke with shortened body shocks. What this means is you still need to run a big enough bump stop to stop the wheel coliding with the arch, which negates the use of shorter shocks.
Base height or double spring height shocks make both of these problems even worse.
I have attached some pictures to show/prove to you that you wont have an "optimum" suspension setup if your car is too low.
Yes it will still handle well, yes it will feel better than before and it WILL handle better than before, but your suspension package is compromised and not at peak performance
Now onto suspension stroke, Your shock stroke IS NOT equal to your wheel stroke, your suspension rate ISNT 1:1 You prob have between 100 and 120mm of total stroke as it is now when its jacked up, less if your running a coilover. once you put it on the ground you lose about 30mm, once you lower it from stock height you lose between 20 and 40mm etc.
As you can see at 360 CWG you have exactly half bump and rebound stroke, but the bump stop interferes with bump, so atm I have only about 30mm if that total bump stroke. I can tell you this its not enough. I have reached the limit of my current suspension setup with stock guards. Nothing can be done except raise the car up. All my measurements were done using a 235/45/17 tyre, if you are running a bigger tyre/ rim combo than this you are in even more trouble.
So what are your options? Get stiffer springs, I myself am running 15kg fronts and even at 360cwg it still bottoms out on big bumps. Raise your car to 370 or 380 cwg Some bilstein progressive bump stops will help alot, but its not a fix for the actual problem, Rather than them colliding it will slow the shock down progressivly before it bottoms out. Tub the car, and cut the original arches out completley.
Of the 3 dedicated race soarers in the world, (2 D1GP and 1 in the UK) they all run a full tubbed setup, and the green D1 car runs 26kg springs. This is what is needed for an optimum setup whether it be street or race use, The problem is i see alot of cars on this forum that are even lower than mine, and you guys must hae the worst handling soarers in the world.
Its not just me, If you do some research o the US forums you will see on the supra forums, and in the massive Gilmer Gixer suspension thread, that low cars arent a possiblity with soarers/supras, not if performance is your goal.
now I havent even mentioned your suspension geometry problems that you will get form being this low either, your roll centre will be out, meaning your car will bump steer and also it gets more body roll the more you lower your car.
Friday, January 09, 2009 - 04:23 pm, by: Grant Rowan(Booster13psi)
Hey David this thread could not have arrived at a better time! I installed some Tein HA's on the x-mas hols. I picked up my car from Fulcrum yesterday afternoon from a wheel alignment and hight adjustment. I said to them that I don’t mind it low but not at the expense of handling. I indicated to them that I wanted about 2cm of clearance between the guard and the tyre. When I picked up the car the tyre was level with the guard. Anyway so I took it for a drive around some twistys, and sure enough when it loads up in the corners it bottoms out.
So its back to Fulcrum on Monday
Should I tell them that I want 360cwg + Does this apply with the Tein coil overs?
Friday, January 09, 2009 - 04:42 pm, by: Ben Lipman(Ben12a)
Grant, I have Tein SS(Aus version) with 12kg/mm springs up front. At 350 CWG it bottomed out a couple of times loaded up in corners and then hitting potholes, road joins etc. At 360 CWG it has yet to do this, if it helps.
Inspection of the guard area showed it hit dead centre of the tyre on the top of the inner plastic liner. I was expecting the lip or inner guard...
Monday, January 12, 2009 - 09:53 am, by: Dave Cazes(Cazman)
Yes as answered above, i hate to say it as I am a tein dealer as my work, but the bumpstops are incorrect in the super street kits.
I myself would change them, but it isnt that cheap in reality. the bumpstops arnt too bad, but the time labour and alignment , just to install them will cost you quite a bit. Unless you are a DIY man.
Your car being higher can still bottom out, but it is GREATLY reduced now that it is higher, the problem with the tein SS is the bumpstops are NOT long enough, and i would recommend Bilstein progressive bump stops if you were to upgrade them.
If you cant afford them then a superpro bumpstop is still the next best brand to use.
Good to hear this has helped, as this took me a few hours to write at work, dont tell the boss....
Monday, January 12, 2009 - 07:33 pm, by: Ben Dowdell(Ben)
I have my CWG at 360mm so i am happy about that.... i am not so happy that it still a rough ride, harsh over bumps and does tramline (mainly when i dont have enough air in the tires)..... I guess its time to do some bushes.....
Tuesday, January 13, 2009 - 08:54 am, by: Dave Cazes(Cazman)
You only need to change the front pair, and they are $65 a pair + freight, These are a bilstein part too, where as at pedders you would probly pay $95 for a cheaper alternative.
You only really need worry if you are lowering your car alot, but these are progressive stops also, meaning: Rather than the suspension bottom out and "crash" it kind of soft lands it and as the bump stop compress' it gets harder, so your car is slightly more compliant. This helps prevent brake lock up if your car is ultra low too.
Andrew McKellar TryHard NSW Soarer Sports Sedan (well, nearly); '84 MA61 Supra.
Tuesday, January 20, 2009 - 10:25 am, by: Dave Cazes(Cazman)
^ watch out, I have looked into this extensivley, its nor as easy as some nissan crap.
The upper wheel well is part of frame, cutting into it removes alot of strength from the front end, look at the D1 cars to understand more. The best way to over come this is to run low offset wheels so that you only actually have to tub in about 60 mm towards the shock absorber, if that makes sense.
What ever you do, dimple die the whole lot for strength
Sunday, March 22, 2009 - 08:32 pm, by: David Samuel(Thenavigator)
justin . have they changed the specs on the springs mine are marked front 9kg rear 5kg. thought i had better have a look to make sure. i have changed the front to 11kg ,specially made by king springs. its a really nice balance now. also changed the bump stops and add a 10mm spacer. dave is spot on about running a low ride hight, not only does it f&%$ the roll center it also inhibits the weight transfer of the front sway bar and you get vibration on the unloaded wheel.
Wednesday, March 25, 2009 - 01:17 pm, by: Dave Cazes(Cazman)
tein SS should have 10 & 6 Its off because even the Tein S tech springs have 13.x & 6.7 progressive
I would use 12 & 7 non progressive in them, but I like my soarer a bit harder than most. I am running 15 & 9 atm, and its dead on the limit for street use.
Monday, March 30, 2009 - 05:39 pm, by: David Samuel(Thenavigator)
hey dave my fronts were genuine tein part # c090-icg... which i am told are 9 kg springs . i have replaced them with 11 kg king springs [non progresive] i am interested in getting more rear grip...she wants to step out mid corner on tighter corners. if you have any ideas i would love to hear .
Wednesday, April 01, 2009 - 02:04 pm, by: Dave Cazes(Cazman)
its your rear alignment. Without spending stupid amoounts of money you can fix it either. The car has heaps of dynamic camber, and i dont think toyota designed it to run on the bumpstops either.
Bigger tread will help, and your already running fairly soft rear springs.
Whats your definition of step out?
Flooring it in 2nd you get copious Wheelspin and bash the limiter?
Wheels only just spin but the car gets a tiny bit sideways? (enough to unnerve you)
Or mid corner it just wants to drift/get side ways when you step on the gas mid corner?
There are numerous ways to get more traction too, but ill wait to hear what you mean.
(adj traction rods, new subframe bushes, new subframe angle, these are the 2 biggest upgrades anyway)
Wednesday, April 01, 2009 - 02:36 pm, by: Dave Cazes(Cazman)
"The roll bar lifts the inside wheel, allowing the car to settle in a flatter position. A stiffer roll bar will lift the inside wheel more"
I use an aftermarket swaybar in my soarer and for drifting its too soft really. I would actually prefer to run a stock bar and correct my roll centre, but its not gonna happen for under 3k.
I get lots of inlift, I have just learnt to put up with it in tight corners. The only other way to fix it is a new diff, the torsions are great except they seem to be a bit unpredictable.
You have very little other options except the usual options. Raise your car, put softer rear springs in, put bigger tyres on, wider rims, more offset, fix some camber issues as the inside tyre is the worst off here, it effectively will have a bad contact patch anyway due to our cambered roads.
Try to correct your rear camber, and see if they can do a dynamic camber test on their aligner, im sure they will say no. You have to align it, then use ratchet straps to strap the car down to simulate squat/cornering. Then you will see how much camber your car gains as it corners.
The easiest solution is to add understeer to your current setup. While people complain about this, in reality 95% of people want understeer. Why? Becasue its safe, any one can see it coming and all they need to do is brake and turn the wheel a little bit more. Oversteer is not for the faint hearted, im not talking aobut 2nd gear maccas •••• either, im talking 3 gear 120+kph and the rear end just looses itself and you poo your pants. If you dial understeer in you will never have this happen to you, but you wont have the most optimum setup. This is the main reason almost every car leaves the production line with a heap of factory understeer.
Wednesday, April 01, 2009 - 06:26 pm, by: Ben Lipman(Ben12a)
Dave Cazes wrote on Wednesday, April 01, 2009 - 02:36 pm:
3 gear 120+kph and the rear end just looses itself and you poo your pants.
Oh. For a second there I thought you were talking about what I had last track day, but that was 4th gear at 176kph, so it can't be the same thing, right? I was like
*For the record, a WRX had just blown an outside wheel bearing to smithereens, so there may have been a little something on the track. (because there weren't nothing in the WRX)*
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