Dallas J

iTrader: (1)

Because the front roll center and effective stiffness is lower than the rear we generally dont have any issue with inside lift, its all outside dive. I do have some pics of lifting a front tire but thats more attributed to swaybar pulling it up and not droop limitation. I dont worry about the lack of droop up front at all.

I dont remember without looking in my book but I know I have enough compression to tuck the wheels in the fenders maybe an inch before hitting bump stops. Basically spring rates are high enough that bump stops are never an issue.

hispanicpanic

How much travel do your rear tenders provide? Do you just have 1 swift tender? Or two stacked?

Dallas J

iTrader: (1)

The reality is I didn't really care how much extra travel total I got, I just wanted to get about another inch for dealing with bumps. I have a big set of rail road tracks to go over 1/2 mile from my house I have to go over so it was pretty relevant and makes a huge difference reducing that jarring effect.


IIRC, there is about 1" of droop added by the tender in the shock, so 1.5" at the wheel. When I did my math I chose a rate that was low enough my swaybar could nearly compress it when rolled over so I still get the benefits of inside wheel lift except when rolling on throttle. The closer to square rates with relatively bigger rear bar I run also help in that.


The tender rate is also fully compressed with <1/2 the corner load so I know its not effecting the rate under normal load ranges. I cant remember what rates I bought, but I think they're 4k or 5k. And just 1 tender on each side.

hispanicpanic

Thanks. I wasn't sure if i was going to be lifting an inside front so i got a set of helpers up there. I'm going to be on 335 slicks on a roadcourse and with these stiff rates, i wasn't sure what would happen. I'll probably run without the tenders up front and see if i lift a wheel. I know some FR and MR platforms lift an inside front if they're really stiff. No idea if FF's or AWD's do.

I also had a goal of preventing lifting a rear wheel. Main reason is because i will be running a full compliment of aero and **** gets sketchy quick when you have a lot of slip angle on aero stuffs. I have a feeling 800lbs won't be enough for the rear and ill be stepping up to 1000lb springs quick. If that's the case, i may double up on some softer tenders out back.

CaptainSquirts

iTrader: (3)

I am having same issues with going over railroad tracks or anything with a big uneven change in the road where my rears won't have enough droop and takes a good 2-4 bounces for the rear to settle back to normal. I am running fortune auto 510's 10k front and 11k rear. Is something like this would help increase my droop a little so the rears wouldn't leave the ground?

http://www.evasivemotorsports.com/mm...ASSIST_SPRINGS

Dallas J

iTrader: (1)

I dont recall the exact spring I run, but its quite possible thats the one. Basically you want something thats fully compressed at a good 1/2 the actual corner sprung weight, which is somewhere around 500lbs. Taking into account the motion ratio, that fits the bill.

The reason you want it fully compressed is so on normal cornering it does nothing. Just want it to come into play when the car gets excessively unloaded.

CaptainSquirts

iTrader: (3)

I know my rear corners weigh about 650 lbs give or take 10 lbs. Which would you think would be better for me, the 4 or 5k assist springs?

Dallas J

iTrader: (1)

I would go with 4k. Remember, your 650lbs is corner weight, also have ~100lbs of unsprung weight there.

CaptainSquirts

iTrader: (3)

Thanks!

CaptainSquirts

iTrader: (3)

Btw do you get any noise from the help springs?

I asked Fortune Auto about them prior to this and they said...

"While they do offer rate support during extension, they make a little bit of noise them selves. The helper springs are Flat coils to be compact so when the extend and then compress they make a thud or bang as all the coils collapse on each other."

Dallas J

iTrader: (1)

lol, That seems like a stretch. I'll tell you this, they make a hell of a lot less noise than having your spring either unseat and reseat or shock run out of travel.

deeman101

iTrader: (34)

Pretty interesting idea here. I was considering the same more for ride comfort since I feel like my ohlins have negligible rebound travel with 10k front and 12k rear springs. Definitely not the 1+ inch you seem to have. So just to clarify, you run 6" springs (what rate?) up front with no tenders and basically don't see it unload, and you're now running 7" 900lbs rear springs with a 1" 250lb tender?

Do you think there would be any ride comfort benefits (if not track times) to running the tenders in the front too if it cleared your wheel/tire?

Dallas J

iTrader: (1)

I wouldnt worry too hard on which tender to use, it should never really come into play on track just when hitting big bumps and needing that rebound travel on the street. So it ideally wouldn't have any effect on track. Purely a comfort thing to get that extra droop. I seem to remember early on deciding the softest rate with maximum preload was the best bet.

My setup is a 6" spring up front and 6 or 7" spring in the rear (I have both, so what ever I stuck in there). At the 900lbs range travels are so low that it just didn't matter. It only changes where the perch sits.

CaptainSquirts

iTrader: (3)

So from an autocross prespective, did the tender springs change the rear rotation of the vehicle? Normally I'm going to assume most evo's tend to have rear inside wheel lift in certain scenario's. Now with the added droop, will the rear rotation be less compared to without the tender springs?

Dallas J

iTrader: (1)

Shouldnt have any effect unless your setup is pretty odd. I can think of ways it would change things, but thats if you are getting oversteer induced by the shock of hitting shock travel limit.