Author Topic: Advice on my link calc #s. (Read 3645 times)

MRHilux87 · « **on:** Mar 06, 2014, 03:56:42 PM »

Ive been working on my rear four link. First link setup ive done. Needs to drive well down the road. Still want some capable flex. Its going to be a flat/tube bed that I will build around the suspension, so as far as space goes its wide open. The only handicap is to fit everything up front my frame is around 26in.
If the picture isn't clear enough here is some numbers:
Upper link length: 45.
Lower link length 40.
Static anti squat: 139
Travel anti squat 139
Roll axis angle is 1 degree of oversteer.
Roll center height is 27in.

Advice or help wanted. Id like to get the anti squat number down a little bit but I need to maintain my vertical separation at the axle(300hp and 450ft lbs) and I don't want brackets hanging too low.

jrock · « **Reply #1 on:** Mar 06, 2014, 04:21:34 PM »

First you have to fix your vehicle specs. Set them to your street setup. Your rolling radius is very low.

Then raise the frame side uppers 2"... $.02

MRHilux87 · « **Reply #2 on:** Mar 06, 2014, 04:30:22 PM »

Ok thanks. i changed my rolling radius to 18. If I raise the upper frame mnts my anti squat goes to 100. Little better. id like it down in the 50-70 range.

jrock · « **Reply #3 on:** Mar 06, 2014, 08:38:13 PM »

100 is a good starting point. Leave up and down adjustments in the upper frame mount. You can lower or raise you AS based on how it works for you.

Also, the AS will change depending on where your actual center of mass is. Most use the hight of the upper bell housing bolts at this point.

MRHilux87 · « **Reply #4 on:** Mar 06, 2014, 09:38:55 PM »

Ya thats the point that I used. I imagine that number is not very accurate. Depends alot on roll cage, frame, engine, and bed weight.

TacoRunner · « **Reply #5 on:** Mar 09, 2014, 10:45:49 AM »

why are you afraid of losing ground clearance. most of the pro buggies out there are around 19"-21" bellies.

HogCanyonHopper · « **Reply #6 on:** Mar 09, 2014, 10:58:21 AM »

whats a good resource for learning about all things "links"? I want to understand what all the terms mean and why they are important yada yada yada. Not trying to thread jack, just want to have a better understanding of what i am reading. I want to link my first gen some day just for shits and grins.

helipilot77 · « **Reply #7 on:** Mar 09, 2014, 01:51:35 PM »

best website around is TacoRunner's. The link is in his sig. He has sections on terminology and different theories. he also wrote an article for the 2010 July/August issue of 4WD Toyota Owner Magazine that was amazing.

HogCanyonHopper · « **Reply #8 on:** Mar 09, 2014, 01:55:59 PM »

Thanks. I have seen that article on his website and forgot all about it. Some good reading for a rainy day

MRHilux87 · « **Reply #9 on:** Mar 09, 2014, 03:52:19 PM »

Quote from: TacoRunner on Mar 09, 2014, 10:45:49 AM

why are you afraid of losing ground clearance. most of the pro buggies out there are around 19"-21" bellies.

I was hoping you would chime in. Thanks. I just have everything else tucked in above the frame besides my rear driveshaft so I thought it would be dumb to have my link mnts hanging way down there. But now that you mention it I guess they would help protect my driveline. Have to make adjustments.

MRHilux87 · « **Reply #10 on:** Mar 09, 2014, 03:53:18 PM »

Do you think my roll axis is okay or should I make sure I have understeer dialed in so Its more road friendly?

TacoRunner · « **Reply #11 on:** Mar 09, 2014, 09:42:42 PM »

Did you read the suspension write up?

Edit:

Try and get the lower links flatter to the ground. That's rule number one.

MRHilux87 · « **Reply #12 on:** Mar 13, 2014, 09:12:16 PM »

Ive read it several times. I soak up a little more each time. Ive got the lower links almost flat now, and Im happy with the numbers. Whatever I don't like hopefully I can adjust out of it. Heres a question for you Tacorunner: How do the antisquat, roll center, ect numbers average out between front and rear? Ive seen many many threads about four links and three links, but I haven't found a lot about how the rear suspension affects the front and vise versa. If you have several degrees of understeer dialed in the rear, but your front is kinda jacked up due to space constraints...
Obviously this isn't a one paragraph answer, but I appreciate all the info you put out there to help us rookie builders.

TacoRunner · « **Reply #13 on:** Mar 14, 2014, 05:15:33 PM »

Anti Squat: If the rear end of your vehicle is lifting during takeoff then it is also helping to keep the nose of the vehicle down. But the more anti squat or dive as it's called in the front, that you have the harder it is to keep the nose down.

The opposite is also true for the front of the vehicle. The more you have in the front the more it affects the rear.

This is why I don't like anti squat.

Roll steer plays not part in this.

Author Topic: Advice on my link calc #s. (Read 3645 times)

MRHilux87

Advice on my link calc #s.

jrock

Advice on my link calc #s.

MRHilux87 [OP]

Re: Advice on my link calc #s.

jrock

Advice on my link calc #s.

MRHilux87 [OP]

Re: Advice on my link calc #s.

TacoRunner

Re: Advice on my link calc #s.

HogCanyonHopper

Re: Advice on my link calc #s.

helipilot77

Re: Advice on my link calc #s.

HogCanyonHopper

Re: Advice on my link calc #s.

MRHilux87 [OP]

Re: Advice on my link calc #s.

MRHilux87 [OP]

Re: Advice on my link calc #s.

TacoRunner

Re: Advice on my link calc #s.

MRHilux87 [OP]

Re: Advice on my link calc #s.

TacoRunner

Re: Advice on my link calc #s.

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