High Power Suspension setups

[jmauld]

But anyway. If it were me I'd go power, suspension, and then whatever else you need to do. From personal experience my car changed the whole bit as far as suspension goes cause of the added power from the v8.

What did you have to change?

In the process of going from 150whp to 300+, I'm thinking that I will likely need to focus on making the rear of the car much more stable?

So far my plan is to switch to softer springs, switch from Toe-out to toe-in and get more camber adjustment in the rear so that I can dial out some of the negative camber.

[McCoy]

I've driven Your Mom's 240sx on track, 8611(F)/yellows(R) and equal spring rates to mine (550F/400R), and at 350+ whp his car was fairly easy to drive on track even with 255 azenis out back. I'm scared to think what his car can do with more tire.

I would think slight toe-in and keep the camber at around -1.5 out back and you should be fine. I'm not sure what swaybars hes using, think ST, but the car felt fairly neutral in the turns even when putting down the power.

The real trick is controlling/training that left foot.

[jmauld]

The real trick is controlling/training that left foot.

You're d*mn right!

I've been running 285s on the car and with 150hp, you really just floor the throttle somewhere right before mid corner and let the rubber handle the rest.

[Longfellow]

I've been running 285s on the car and with 150hp, you really just floor the throttle somewhere right before mid corner and let the rubber handle the rest.

Thats what I do as well, but its a bad habbit.

I was on the throttle way before apex though out my entire mountain trip. Bad driving, but it was the only way to make the best of 255-40-17 tires and 130(ish)hp

[mmdb]

What did you have to change?

In the process of going from 150whp to 300+, I'm thinking that I will likely need to focus on making the rear of the car much more stable?

So far my plan is to switch to softer springs, switch from Toe-out to toe-in and get more camber adjustment in the rear so that I can dial out some of the negative camber.

V8 power comes on right away so acceleration grip will be a bit of an issue. I tuned the car to give a tad bit understeer. You can definitely make the car rotate/oversteer by playing with the sway bars assuming you have your spring rates around the your relative ballpark.

Since then I have changed my rates to 8kg and 7kg and the dampers have been valved according to the car's weight, unsprung weight, motion ratio, and ride height. I'm also running a wider front tire from 245 to a 265 and increased the total track width 28mm using spacers and 285 width tires out back. I've also added roll center adjusters via gp sports hyper knuckle (super knuckle will be fine as well). Rear diff is a s15 gear type with a 3.69 gear ratio. Sway bars are progress adjustable bars with spherical endlinks.

Grip is very good thus far. I'll be hitting Streets of Willow next week to see how the setup runs. As far as your current setup, you might like the rates you're running now. So I wouldn't get new rates yet. Also your setup is most likely different than mine, so that's another reason to tune things one at a time. What's your suspension setup so far?

[jmauld]

KA -> v8

[DuckyD]

The real trick is controlling/training that left foot.

Your gas is on your left foot??!?!

[mmdb]

Your gas is on your left foot??!?!

I think he means right foot hehe. Yeah good point. Throttle control is very, very necessary controlling the car with a v8 or any other high horsepower car. If you're having problems spinning or losing traction on corner exit you'd have to tailor your driving style to gas on later, go in at a higher gear, move your acceleration point, etc. The v8 is almost like an on and off switch as far as power comes on. I'd recommend going to a 3.69 or lower (3.54 maybe) as well.

[McCoy]

Your gas is on your left foot??!?!

Shibby, I even had a 50/50 chance on this one and screwed it up

If I had a V8 in my 240, which I probably never will, I'd probably be rocking 275/40's up front and 315/35's out back.

[jmauld]

I have a 3.54 gearset sitting in the garage, but I'm waiting to pick up a HLSD before installing it.

Why aren't you running 285s in the front? Was it to intentionally induce understeer?

[mmdb]

I have a 3.54 gearset sitting in the garage, but I'm waiting to pick up a HLSD before installing it.

Why aren't you running 285s in the front? Was it to intentionally induce understeer?

Nope. Running those wheels is another task in it's own. A new fender needs to used ($$). I'm using a vertex fender that's +12mm more and it still rubs a little between the outer wheel vs fender. Also, you'll need the right offset to prevent the wheel from rubbing on the coilovers, which possibly means custom wheels (more $$$). You will probably run into issues with the inner wheel rubbing the inner fender. To combat that look into running ground control caster/camber plates ($$$).

It costs a bit to do it right, and i didn't want to dish out another 3k to get custom wheels, tires, etc. But it's definitely possible

[jmauld]

I've got 285s on my car already. I have the stock fenders, $200 wheels that I got on ebay and bilstein shocks in modified stock housings.. The only time I rub is at full lock against the wheel well.

I was wondering if you avoided them for handling purposes.

[veilside180sx]

I've driven Your Mom's 240sx on track, 8611(F)/yellows(R) and equal spring rates to mine (550F/400R), and at 350+ whp his car was fairly easy to drive on track even with 255 azenis out back. I'm scared to think what his car can do with more tire.

I would think slight toe-in and keep the camber at around -1.5 out back and you should be fine. I'm not sure what swaybars hes using, think ST, but the car felt fairly neutral in the turns even when putting down the power.

The real trick is controlling/training that left foot.

Brian has Whiteline bars.

[mmdb]

Oh nice! My setup is different so that's good to hear. And yes my setup is tuned for a bit of understeer. It's definitely safer to drive with it rather than oversteer.

[racepar1]

Your gas is on your left foot??!?!

I think he means right foot hehe. Yeah good point. Throttle control is very, very necessary controlling the car with a v8 or any other high horsepower car. If you're having problems spinning or losing traction on corner exit you'd have to tailor your driving style to gas on later, go in at a higher gear, move your acceleration point, etc. The v8 is almost like an on and off switch as far as power comes on. I'd recommend going to a 3.69 or lower (3.54 maybe) as well.

Actually I think he might be talking about left foot braking. You can control wheelspin with a well trained left foot as well. Also trailing the brake with your left foot keeps the front end down too, which may help understeer in some cases.