Spring rate selection (GA61) *HELP, NEED REAR SPRING RATE*

[mullett]

Thinking about picking up a set of coilover sleeve kits from Otomoto, they'll be for the front of my GA61. It'll be mainly a street car, with koni shocks, swaybars and new bushings. I need it to be compliant enough not to be jittery, without diving a lot under brakes, but still firm and resonsive...

Is 5kg/mm enough? Or too much...

Edit: See last post

-RM.

[skin]

i would have thought you would have been safe up to 6

[mullett]

I've got a choice of 4 and 5 i guess 5 will be the go then, I can buy some heavier springs if I need later on...

-RM.

[GUN METAL]

From the small amount of experience i have had with changing springs is the spring rate has very little to do with ride comfort (unless you go from one extreem to the other like saying going from 2 to 8 kg.

The main factor will be suspension travel and effective bump and rebound damping.

Also keep in mind if you only change the front and say you increase the front rate only you will most likely increase understeer, or in otherwords reduce oversteer, is that what you want ?

if you want less dive maybe check the anti dive geometry first and or get dampers with more bump damping.

Are the konis existing or will they be new ? the critical part is matching the rate with the dampers ( and everything else for that matter) to work well together.

What is it in particular you hope to gain by having the coilovers ?

I know didly squat about GA61, but have a fair bit of suspension engineering and design under my belt.

If you can find other who have done a particular set up and you want the same result do that as working from scratch can involve significant amounts of time, effort and hitting ones head againts the wall.

I can understand what you mean by this comment "need it to be compliant enough not to be jittery, without diving a lot under brakes, but still firm and resonsive..." but be aware they are really contradictions. the best way to acheive what you are after is design as much tunability into the selection of equipment as possible.

So adjustable sway bars, adjustable dampers (preferably with seperate bump and rebound) if you can get the suspension shop to dyno the exisitng dampers that way you have a baseline to work from.

regards,

GUN

[mullett]

Thanks man. The shocks are new Konis, yellow adjustables. I should have cleared up the rear suspention in the first post...that's also going to have adjustable shocks, and king springs (for now, because I've already got them), so I guess the real question is: Is this going to be too much of a mis-match of spring rates. I don't want to go too stiff, because I imagine the konis are designed for a certain range, and i don't want to go outside that. Bump and rebound shocks are out of the question, but the rest I'll have

Coilovers because I want to play with camber adjustment, and it leaves more room for this, also because springs and height are easier to set, and they look cool behind the wheels

-RM.

[RONA]

I ran 9kg upfront in mine & it was still streetable. Daily drove it for a while when my Falcon was in the shop. I had Koni yellows & adjustable swaybars as well.

You could easily run 7.5kg & it'd still be very streetable. I had 6kg in the rear.

[mullett]

I ran 9kg upfront in mine & it was still streetable. Daily drove it for a while when my Falcon was in the shop. I had Koni yellows & adjustable swaybars as well.

You could easily run 7.5kg & it'd still be very streetable. I had 6kg in the rear.

Perth roads=

7.5 might be ok....How did you find the swaybars? Good investment? And which ones did you get?

I'll give it a go with the 5kg, until I get some heavier springs for the rear I guess anything else is too stiff, and 5kg comes with the kit anyway What's a set of custom-wound rear springs worth, and where's a good place to get them?

-RM.

[RONA]

Sydney roads are far worse then anything in Perth ask Cruzida & JCMO from their experience when they came over for Toyotafest.

My car was used by whiteline to develop the adjustable bars so it was the only one with the correct length end link as everyone else that got them in the group buy commented that the end links weren't long enough.

They made a great improvement. I already had the coilovers & custom rear springs when they were installed. With swaybars in, turn in was alot sharper & the car felt alot more balanced. It gave you greater confidence to push it further/harder as you knew exactly what was happening.

My whole suspension package sans swaybars was sourced through AJPS, so not sure exactly on the breakup of costs per item.

[JustCallMeOrlando]

Perth roads=

Really? They're a godsend compared to most roads around the country, especially Sydney!

[mullett]

No worries, so that's the 27mm front and 18mm rear bars you had? From the pics on whiteline it looks like they come with end links...should I get in touch with them and make sure they're the right length, or did that get sorted after the group buy?

-RM.

[mullett]

Really? They're a godsend compared to most roads around the country, especially Sydney!

Haha...really? Can't say i've been there...melbourne roads=teh awesome, likewise NZ...not just smooth, but twisty and narrow too

-RM.

[RONA]

Correct (Point 1 & 2). No idea (point 3), you'd have to find someone that has bought them recently to find out if its still an issue.

[mullett]

haha, no worries, sounds like I'm onto a good thing

-RM.

[CrUZida]

Perth roads=

Neg, Perth roads = some of the best in the country.

[CrUZida]

My Whiteline bars fitted with no issues. They were bought with the group buy.
I just think they had a 4 year old making the parts and packaging them, as pretty much everybodies were slightly different to other peoples.