Suspension travel

[RPM016T]

Hey, just interested to know what kind of suspension travel people have up front (if they have measured?) from normal ride height to fully compressed?

Obviously it will be less critical the stiffer the setup is, and im looking at well set up street cars, but would be good to get some ballpark figures

cheers

[pandaah]

depends what tryna ride your tryna get.. on my gz20 soarer i think id really really struggle to force the shock and spring down 50mm with my coilovers... dunno if that helps?

[TTCorona]

I think this is one of those things that many people have many different ideas about...

I use my car mainly for the track, so it does have quite a stiff setup.
But still what I was told, and what I try to stick to is between 100mm - 150mm of travel.
At normal ride-height measuring total possible travel - i.e. distance until the bump stop hits.

[RPM016T]

We measured the datsport kits for 1600's on Friday and it was something like 125mm or 128mm total travel with 250lb springs. So once you install it in the car and it sags a little, that might drop down to about 90mm which is a bit under that, and the datsport kits to my knowledge work pretty well.

[TTCorona]

yeah a few of my mates have used the datsport kits for their 1600's with good results.

I suppose they have a fair bit of experiance with it, they should know what they are doing..

[30psi 4agte]

from memory ...... i have about 65-75mm off compression in my setup.

[mullett]

My VN sits on the bumpstops bro, it's sick.



-RM

*disclaimer: I don't have a VN. Ever.*

[takai]

In the race car i have 100mm of absolute travel before the chassis rail hits the ground. Only ever used 70mm though.

Road car im setting it up for 150-175mm of travel total, but bumpstopped at about 125mm.

[mullett]

Takai: you might be able to answer a similar question: I've got coilover sleeves on the front of my MA61, but the shocks are Koni Reds for an MX73, and the travel's just too much. To keep the springs captive (even with the helper springs) the ride height is higher than factory

The only solution I can come up with is to use a 'limiting strap' to tie the top hat down to the strut body, and limit travel that way. Thoughts?

-RM

[RPM016T]

Takai: you might be able to answer a similar question: I've got coilover sleeves on the front of my MA61, but the shocks are Koni Reds for an MX73, and the travel's just too much. To keep the springs captive (even with the helper springs) the ride height is higher than factory

The only solution I can come up with is to use a 'limiting strap' to tie the top hat down to the strut body, and limit travel that way. Thoughts?

-RM

Shorter shock inserts would be best or you could try a shorter main spring with longer helper to compensate (providing the main spring doesn't bind. You'll have to measure the distance between the top and bottom spring seats then compare that distance against the 'assumed' or 'measured' fully compressed length of both of the springs when used together.

[RPM016T]

In the race car i have 100mm of absolute travel before the chassis rail hits the ground. Only ever used 70mm though.

Road car im setting it up for 150-175mm of travel total, but bumpstopped at about 125mm.

I'm guessing that set-ups pretty stiff to only use 70mm though, right?

I guess when I compare the new set-up i'm planning on running, to the old setup I was running for years, regardless of the new travel length (70mm-ish) it's still going to be an improvement on the old setup now that it'll have shorter inserts. The older set-up wasn't all that bad.

It's pretty easy to get caught up with 'theoretical' numbers when you're trying to work all this crap out..

[mullett]

Shorter shock inserts would be best or you could try a shorter main spring with longer helper to compensate (providing the main spring doesn't bind. You'll have to measure the distance between the top and bottom spring seats then compare that distance against the 'assumed' or 'measured' fully compressed length of both of the springs when used together.

Shorter stoke shocks are definitely the best solution, but the ones I have are brand new, which seems a waste to throw away, and I'm not 100% on there being a suitable shock anyway (although I've heard SW20 rears work?)

The limiting strap is just a cheap, effective solution (if it works well)

-Rm

[RPM016T]

Dont know too much about what shocks are available, and a limiting strap would probably work. You'd probably want to use something pretty durable to movement though and have the two straps parallel to the wheel tho so it didnt end up in your tyre. Not sure how kindly RTA etc would take to it though??

[SeptemberSquall]

I have always set my cars up at around 150mm total travel distributed 1/3rd droop 2/3rds bump and has worked well for street use at moderately sporty spring rates.

(generally as a rule of thumb my spring rates have been around the "spring rate in lb = corner weight in kg" for street use.)

[mullett]

Making 5kg springs 279 pounds...maybe mine are a bit soft

-RM

[30psi 4agte]

FWIW
Im running 275lb on the front and 200lb rear. Cant tell you if its too hard or too soft havent tested it yet. Should be about right though....... id like to think i know what im doin LOL

Car weighs 900 kg

[takai]

Definately shorter stroke shocks for you mullett.

RPM: for the shocks you are thinking of, think about your DH suspension. Not sure what you ride, but most triples have rebound, and low and high compression adjustment, to balance it out, as well as the spring/air coil.
The 70mm of travel in the race car is ultra stiff on high compression, supple on low compression, and medium/high rebound, a chunk of which is assisted by the coil.
The road car will be medium on high comp, low-medium stiffness on low comp and low-medium rebound to try and cope with bump chatter (think cranking rebound up to max and riding a rock garden).

Race car runs 325lbs front 225lbs rear, weighs around 920kg fully wet.
Road car will be approx 400lbs front 275lbs rear, and about 1200kg wet (hopefully)

[RPM016T]

Well mines probably going to be 750-800kg and running 250lb so should be about the same..

Takai, good call.. my main concern was potholes etc, as that used to be the only time i'd experience bottom out, and thats a pretty rapid hit. So providing I run a decent shock abosrber, the shock should do all the work to stiffen things up and prevent bottom out happening.

[30psi 4agte]

TAKAI: Humor me............ what would you race car be like on the street?
IE with the suspension travel and bumps in the road + spring weights etc

It seems pretty similar to my setup.

[30psi 4agte]

my main concern was potholes etc, as that used to be the only time i'd experience bottom out, and thats a pretty rapid hit. So providing I run a decent shock abosrber, the shock should do all the work to stiffen things up and prevent bottom out happening.

That is my theory too.