Ke1X Rear Suspension Options Hard Soft?? Suit Street/track

[camerondownunder88]

Hi RC,

      Been mucking around with my sprinter lately and been wanting to get back into

tinkering with it since moving house.

 

Now my suspension in my KE15 is mmmm seen better days front end bottoms out shocks dead etc.

 

Rear I have standard leaf springs and TRD 8 way shocks set on about 3 atm.

 

Now I was in at road and Track in Ipswich yesterday and started looking at

a KE17 that is in the shop atm that is being prepped for circuit racing.

 

Eventually I want to do some track days in the KE15 then just have it as weekend fun car.

 

So I'm looking into doing suspension.

 

Now Terry at road and track said for the KE17 circuit car they softened the rear leafs.....

 

I was thinking of going harder...

 

SO I am after RC's thoughts on suspension. Car will be mainly weekend fun car and some track days at QR.

 

Front suspension as it probably should all be matched I just finished making a set of camber tops and

Picked up some brand new KP61 TRD yellow inserts (as KP shocks fit KE1X struts) For get there rating

off top of head I have it in a  book so front will be stiff getting new coils made and remove the leaf spring

and I have a white line sway bar to fit to the front also.

 

So can use that as a rough guide.

 

Also as a note to the rear end I am fitting an LSD centre to the diff so that will also affect how rear end handles.

 

Cheers

Cameron

[styler]

See if you can find a few books to read on suspension, well worth it in my opinion...

Don't lower the car too much, the rear roll centre is fixed unless watts type 2 installed.

[kickn5k]

I had the 11 on the hoist at Peders today going through some options. It does appear to have one leaf moved above the main leag to soften the rear of mine.

My 11's current suspension setup.

Front.

Transverse leaf removed.

Ke20 struts(coming out soon for 1x struts to chase some neg camber).

Peders ke20 lowered springs.

Peders ke20 sports shock inserts(out of production now).

Signature Stabiliser Bars 22mm front swaybar.

 

Rear.

Peders comfort gas(very similar spec to the old sports series)

Std rear leaf pack with apparently one of the support leafs moved above main leaf to soften.

 

It handles reasonably well with yoko ao21r semis. But it could have better turn in so I have a 16mm rear swaybar which will be fitted next weekend. I'll post how it changes things then.

 

I'm also looking into a different rear spring setup ATM too. But I'll be keeping that one to myself until I know if its a goer or not.haha

[camerondownunder88]

Hi,

Ill have a look see what books I can find must read up on this.

 

Stu thanks for the information from you KE11 :)

 

Few questions...

 

When you floor the noise maker pedal with your rear softer rear leafs does the car squat down much etc or stay sitting at a fairly constant level and jsut move etc any info on how the rear end reacts etc?

 

So to add information to what I'm going for here is follows:

Front struts I have stock KE10 iteam 3 bolt bottom etc.

Camber tops I made to suit KE1X 3 bolt pattern.

I will use KE20 strut tops ditching KE10 2 part tops

Front inserts I have KP61 yellow TRD inserts part number: 48511-kp652, specs are:

Lenght Max: 555mm

Length min: 395mm

Dampening force: 140Kgf/70KgF ------> stock KP61 is 88/32kgf

Springs: Got a set made (meassured wrong 1 inch to short :( ) so getting another set done to suit shocks, TRD use this shock with springs around the K=2.1-2.2Kg for rally,dirt,trail,street.....if it is for tarmac TRD used K=5.0-5.1kg springs with same shocks so....front springs I'm thinking around the 2.5kgf/mm so thats 24.5N/mm so stiffer but not CRAZY.. and again this will match the shocks.

Then I have a white line sway bar to install and remove front leaf and I made some new LCA bushes for cross member.

 

So from this front low slightly stiffer. Reason I used KP info is the KP61 was curb weight of 749kg KE15 is 710kg. So there a tad shorter but prob similar and KP had a K motor hanging over front shocks and a light ass end same as a KE15.

 

So now rear end:

I run stock springs (kinda need a reset they sit flat when parked in driveway and nothing in car. And the anti squeak pads made from asbestos inbetween leafs has fallen away over time and leaves rivets are loose etc there dead.

Shocks: TRD 8 way adjustable greens don't have there specs on hand. Set on about 4 half way as any softer I run 13 inch wheels on 15 now will bottom out over some bumps due to leafs being dead.

 

So rear end jsut for some info on a KP61 stock rear springs were rated at: 1.9kgf/mm TRD rally dirt springs are 2.2kgf/mm and tarmac are 5.0kg/f.

 

TRD in rally spec run rear end slightly harder by 0.1kgf/mm across all options while in tarmac racing run rear 0.1kgf/mm softer across all spring options.

 

So idea in my head is if I run 2.5kg/f front springs possibly go 2.4kgf/mm leaf springs in back........

 

Now for hard part anyone in brisbane know who can reset add or remove leafs from packs taking about an inch from ride height AND being able to build them to a spec spring rate? Or am I dreaming?

 

Also for those at home here is stock KE1X in general spring info: (I say KE1X general as KE15/17 had harder springs stock and KE10 4 door and some sedans had softer springs etc Toyota played a bit here)

 

Front Shocks:

Max length: 644mm

Min length: 453mm

Stroke 191mm

dampening force: 32-48kg in dampening and 34-46kg in rebound (dam soft as a stock KP is 88kg dampening/32 rebound so rebound softer here)

Front springs:

Leaf:

two leaf pack

1.65kg/mm spring rate (stock KP springs are 1.8kg/mm)

Coil springs:

4 coils

0.59kg/mm rate

 

So again very similar to KP so I'm leaning towards kp kinda settings see how I go.

 

Also Stu got info on a rear sway bar? If I fit LSD have a feeling ill need one...

 

Cheers

Cameron

[kickn5k]

Nah it doesn't squat much at all. It had good grip in a straight line though. You had to be agressive with the clutch pedal to get the rears to turn even with the blown setup. But I'm only going by what the guy at Peders told me so I could be wrong. I'll get some photos up tomorrow so you can see if he's right. I wouldn't know what a std leaf pack looks like.

 

The swaybar is a 16mm ke1x kit I got from my local Peders. I'll have the right bracket kit by the weekend and get some photos and reports then. I only have a single pegger at the moment so ill have to suck it and see I think.

 

Oh yeah I'm not 100% sure on what brand it was ill ask next time I talk to them.

Edited November 10, 2012 by kickn5k

[coln72]

Felt my 20 handled better with a softer rear spring pack. I had all but two leaves removed. Worked well for what it was used for, reduced the oversteer that it had on dirt.

[altezzaclub]

I'm not familiar with the Ke15, but generally-

 

Shocks have two valves in each direction, one for slow shaft-speed bleed which controls cornering, and one for high shaft speeds which controls bumps in the road. We're looking for high-speed specs inth rally car, you'll be doing the opposite and looking at slow-speed numbers for roll control on smooth tarmac.

 

Similarly, we want lots of resistance to the car going down and want it to come up quickly, while nearly all shocks (esp modded ones) go down fast and come up slowly. There will be stacks of options for your shocks.

 

Overall, the stiffer the springs at either end, the less grip the car has as it can't transfer the weight to the outside wheel.. So a stiff front end or stiff front sway adds to understeer, same for rear.

 

A car is designed to take 4 passengers and 4 big suitcases, often to tow a trailer too, so the rear end is usually far stiffer than what a driving enthusiast needs.

 

Long soft bump stops become part of the spring system as just rolling into a corner will make them work, and they can hold an attitude of roll for you. They stiffen very quickly in an asymptopic curve, while springs are meant to be linear in stiffening and shocks constant.

 

Same for sway bars, cut off the lower top seat & you can make sprung mounts so they allow you a couple of inches of progressive roll before they stiffen up 100%.

 

Those two factors let you get good turn-in then hold the car steady from further roll.

[ke70dave]

In my limited experience, it seems that "stiffness" is all about the shocks.

 

perhaps try stiffening up the spring too see if you like it, but you might be better off going for some custom built shocks?

 

Go to a race or rally suspension mob and tell them your requirements and see what they can offer?

[kickn5k]

Go to a race or rally suspension mob and tell them your requirements and see what they can offer?

 

This is what I've been doing lately.

 

Between my local Peders and a mate that makes those red open wheeler things handle. We seem to be getting there slowly but surely.

 

[Ical]

Where does one get TRD shock's from???

 

Cheers Ian.

[camerondownunder88]

Sourced my new in box KP61 TRD front shocks and my new in box TRD green rear shocks from japan. Wasnt cheap but bolt into KE15 and for what you will pay a nice shock asorber and I like how the rears are valved and easy to adjust.

[altezzaclub]

Nice gear!! Up with the $400/corner Bilsteins I assume, expensive, but good.

[wagn]

Also as a note to the rear end I am fitting an LSD centre to the diff so that will also affect how rear end handles.

My KE20 runs TRD green shocks on 3rd click from softest with standard leaf pack with second from the bottom leaf flipped on top of the pack (temporary) adding my TRD 2 way seemed to make the rear end feel like it pulled around corners better as in less pushing in the front end.there is definitely more cornering grip as well as traction you would expect and predictability its nice to know what the rear is going to do once it does let loose.IMO the LSD is a good addition to improve handling not only just traction. hope this helps

[Ical]

Sourced my new in box KP61 TRD front shocks and my new in box TRD green rear shocks from japan. Wasnt cheap but bolt into KE15 and for what you will pay a nice shock asorber and I like how the rears are valved and easy to adjust.

 

Any chance of a link pls.

 

Thanks Ian.

P.s nice work....:)

[camerondownunder88]

Wagn, Thanks for that info is good to know. ATM I will try running a stock leaf pack and I have the greens on 4th click (middle playing it safe.lol) yet to put LSD in car jsut got diff back from powder coaters and waiting to get back to work so I can build center up and fit. But good to know it adds traction. After LSD I think ill do steering box in KE15 then better wheels then motor.....list is growing..lol

 

lcal: Link sorry can't do :( Just trawling the net and working in the airline industry helps a tad getting parts on the ground so just keep your eyes open and you will find. Also keep in mind old TRD gear is called TOSCO the CDI I got in the KE15 is a TRD/TOSCO branded unit. Also old TE27 era adjustable TRD shocks are usually the compress and twist adjust method. Pain full. So if you see them get but I personally would avoid as the later easier to adjust stuff fits and travel limits is suited to the car.