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Self stiffening !
andy996tt - 31/5/13 at 06:45 PM

I've got a Tiger Avon set up for racing. But I think the suspension is a little soft. In the bends there's quite a bit of roll. Have a look at the picture in the link.
Rather than taking it to a specialist to set up the suspension. Could I compress the springs an equal amount on each corner ?




[Edited on 31/5/13 by andy996tt]


big-vee-twin - 31/5/13 at 06:55 PM

Have you thought about stiffer springs,what have you got fitted


andy996tt - 31/5/13 at 07:00 PM

Not sure what springs I have but they're Avo shocks. The springs at the front aren't compressed at all. The ones at the back have been squeezed by only an inch. There's a lot more travel on the collars


Theshed - 31/5/13 at 07:07 PM

Winding up the platform or putting in a spacer will adjust pre-load but not rate. You will alter your ride height. Once the roll exceeds the pre-load you will get the same roll as before - change the springs


Talon Motorsport - 31/5/13 at 07:25 PM

nobody thought about turning the adjuster knob (if fitted) that makes the coilover stiffer?


jacko - 31/5/13 at 07:26 PM

Thought about a torsion roll bar ?


big-vee-twin - 31/5/13 at 07:26 PM

The springs will be stamped with their stiffness-poundage


andy996tt - 31/5/13 at 07:51 PM

quote:
Originally posted by Talon Motorsport
nobody thought about turning the adjuster knob (if fitted) that makes the coilover stiffer?



Is that the little red knob on my photo. Do I tighten it to the right to make it stiffer ?


bi22le - 31/5/13 at 08:07 PM

As said before, winding preload ( winding up the big red collar to compress the spring) up will adjust ride height and reduse wheel drop. As a guide line 100mm from ground to under front chassis cross bar is about right. 125mm for rear.

Turning the inviting little red nob change rebound and compression ratio. Essentially changes how fast the wheels react to contours. This will slow the lean but not prevent it. Not necessary solve your problem.

Spring strength will reduce roll and is the only way. Anti roll bar are another science and commonly not used on kit car race cars. Just because you have one it don't mean its easy to set up and fit!!

Just because it feel like it leans are you loosing traction on the inside wheels? Some body roll is good.


big-vee-twin - 31/5/13 at 08:20 PM

As said stiffer springs the damper stops the springs bouncing I.e. up and down once when in a hole not -up down, up down, up down.


SCAR - 31/5/13 at 08:28 PM

The car does look to have quite a bit of roll in the photo. First I would find out what springs are fitted then uprate as required this will make the car harsher over the bumps but will reduce roll in the corners. If you want to go further then fit an anti roll bar (the clues in the name) get the right strength bar and this will keep the car flatter through the bends. find out what others with the same car are using as a best place to start as you wont want to keep experimenting with different kit.


snakebelly - 31/5/13 at 08:35 PM

Andy where are you? Have you signed up on the tigerownersclub forum?


andy996tt - 31/5/13 at 08:42 PM

Yep. On the Tiger forum. Will ask there too.

Never dabbled with suspension before. Can't see any markings on the springs.
Don't mind if the car is stiff as its track only.
What springs would people recommend and where would u buy them ?


rodgling - 31/5/13 at 08:47 PM

The car is at quite a big angle in that photo, I agree. Have you tried holding the camera straight?


rick1962uk - 31/5/13 at 09:13 PM

just one word of warning most springs are set at 1" of compression its best to get a stronger spring rather than just screw the adjuster up as for every other inch the spring is screwed up it doubles the rating and this will not match the damping and will feel like there is little damping
spring set up is a art form its well worth going to the experts it can save you a lot of money in the long run


twybrow - 31/5/13 at 11:16 PM

quote:
Originally posted by andy996tt
Yep. On the Tiger forum. Will ask there too.

Never dabbled with suspension before. Can't see any markings on the springs.
Don't mind if the car is stiff as its track only.
What springs would people recommend and where would u buy them ?


Go and get it setup my someone who knows what they are doing - you wont regret it....!

Procomp


MikeCapon - 1/6/13 at 06:27 AM

If you need to know the spring rate you can calculate that by measuring the spring. PM me your mail and I'll send you an Excel spring rate calculator.


britishtrident - 1/6/13 at 07:15 AM

We bit sanity guys


As somebody said early on in the thread winding extra pre-load on to the springs won't alter the spring rate.
To reduce roll in steady state cornering the only options are (1) Fit stiffer springs or (2) Fit an Anti-Roll Bar or (3) raise the roll centre.
On the rear the only one of those that is viable is to fit stiffer springs.

You can't reduce roll by altering the damper stiffness because damper stiffness only effects roll under transient conditions for example turning in or exiting the corner.

The problem with fitting stiffer springs to the rear only is it will cause a change in the roll couple distribution that will increase oversteer. This is because stiffening the rear moves wheel vertical load (ie weight) from the inside rear wheel to the inside front wheel, in effect robbing the rear of grip and transfering it to the front.

To get the car back into balance you will probably end up stiffening the front as well by either stiffer stings or fitting an anti-roll bar.


[Edited on 1/6/13 by britishtrident]


britishtrident - 1/6/13 at 09:02 AM

Spring rates in lbs/in are usually etched on the flat seating area at one end of the spring.

When building any car it can save hassle later on if you know the spring rates and spring free length at each end.


procomp - 1/6/13 at 01:55 PM

Hi

Theres a lot of miss information in the above. Before even thinking of changing springs, Do you even know what those dampers are doing. Youll find those paticular items will have farr to much compression and little rebound. IE wrong ratio for the application. The dampers need stiffening, But in rebound not compression.
But untill you have tested the dampers changing springs is pointless. ;-)

Cheers Matt


ElmrPhD - 24/8/13 at 12:38 PM

"Miss information"? Who is she? Prettiest girl in Information?

Anyway, the bad information got corrected.

The discussion is really about roll stiffness, springs and possibly anti-roll bars.

You don't sell dampers for a living by any chance???

;-)


Steve, in the NLs


loggyboy - 24/8/13 at 12:44 PM

quote:
Originally posted by ElmrPhD
"Miss information"? Who is she? Prettiest girl in Information?

Anyway, the bad information got corrected.

The discussion is really about roll stiffness, springs and possibly anti-roll bars.

You don't sell dampers for a living by any chance???

;-)


Steve, in the NLs


why dig up a 3 month old thread to add no relevant information to it?


snakebelly - 24/8/13 at 12:47 PM

We have front and rear ARB's on our Avon from when we used to race, they weren't to difficult to make and fit and made all the difference.


loggyboy - 24/8/13 at 01:17 PM

quote:
Originally posted by ElmrPhD via u2u
I thought it quite relevant that the saying previous information was wrong (not entirely true) and that the first thing to do was replace the dampers(...which he happens to sell).

And what is the official expiry date by which one must no longer react to a thread?

Who pissed in your cornflakes this morning?


I suggest you do some research on who your questioning, procomp has one of the best reputations on this site (and further afield im sure) for both knowledge, ability and service for setting up cars.
he doesn't just sell dampers, he sells car setting up service and a whole lot more.


StrikerChris - 24/8/13 at 01:18 PM

Is it actually causing you an issue? My car is fairly soft and has a good ride.can push on alot faster than some of my friends who have stiff suspension bouncing all over the place.for example 2 friends have identical m3s bar one has fitted coilovers.the standard one was 1s quicker around anglesey circuit then the lowered one.which actually felt quicker . suspension setup is quite a science in my experience and without the experience and knowledge of a specialist (alot of whom aren't) trial and error methods can get expensive!there are so many varables its just not really viable to try everything on one car for your typical bloke.most fast cars ive seen on the rallying and circuit scene are normally afew years old with alot of tinkering behind them! If the 4 wheels stay on the floor and it goes around corners as well as your ability to drive can who cares what it looks like!just my opinion

Chris


PhillipM - 24/8/13 at 01:32 PM

Yes, roll in and of itself is not an issue.


jeffw - 24/8/13 at 04:33 PM

quote:
Originally posted by ElmrPhD
"Miss information"? Who is she? Prettiest girl in Information?

Anyway, the bad information got corrected.

The discussion is really about roll stiffness, springs and possibly anti-roll bars.

You don't sell dampers for a living by any chance???

;-)


Steve, in the NLs


Steve, in the NL....you need to search for Procomp and wind your neck in a little.