Coilovers going in - got questions.

[SGOS252382]

The issue of XA settings came up in the latest GM High Tech Magazine.

GM High Tech Mag put Pedders XA coilovers and Nitto NT05R tires on their shop car and it ran slower (on average) than it did stock around the road course. They admitted they needed more time to try to dial in the coilover settings. But the fact that the car felt unstable and ran slower than stock proves a major point. You can't just throw XA coils on your car and expect it to perform better than stock.


I really don't think the basic XA coils are the best setup for a serious racer. They'll will work fine for someone wanting to lower their vehicle for daily driving, but I'd invest in something else if you're really into road course type racing.

[amanc96]

Originally Posted by jeremywes

I know that pedders reccomends 10mm's of preload but I think that is way too much and it reduces the effectivness of the dampening. The result is an uncontrolably bouncing ride or a very stiff ride because you have to max out the dampers to the point where they are no longer allowing enough rebound and compression.

... and yes I am aware you need to time the factory bushings after you change the ride height.

What did you go with for your preload?

[IPT]

Originally Posted by Doc

I've got basically the same size and tire setup that L99cama2011 does and I've been running 12 front 10 rear on the street, and 20 front 14 rear on the track but now that I've seen what IPT posted about Pete's recommendations I'm a bit mystified about his road course settings. Are you sure he recommended 18 front and 28 rear? It wasn't the other way around; 28 front and 18 rear??

Do you have the link for his recommendations?

Man, I looked at so many I'm not sure exactly what thread it was grabbed that from. I'll take a look after work and see if I can find it again.

[jeremywes]

Originally Posted by amanc96

What did you go with for your preload?

I used zero preload (the first point that does not allow vertical movement in the spring) with pedders XA 2.5" springs on Megan racing coil overs.

[The Stig]

Originally Posted by jeremywes

I used zero preload (the first point that does not allow vertical movement in the spring) with pedders XA 2.5" springs on Megan racing coil overs.

Is it possible to change preload without removing the coil over?

[jeremywes]

Originally Posted by The Stig

Is it possible to change preload without removing the coil over?

Yes absolutely! The preload is adjusted by the two lower nuts below the spring base and the ride height is adjusted by screwing the whole damper cartridge up and down in the strut housing.

You can even experiment with track specific settings by loading one side. Or front and rear balance to match track rotation etc. there are some really good books on the subject like "speed secrets"

[L99CAMA2011]

Originally Posted by Doc

I've got basically the same size and tire setup that L99cama2011 does and I've been running 12 front 10 rear on the street, and 20 front 14 rear on the track but now that I've seen what IPT posted about Pete's recommendations I'm a bit mystified about his road course settings. Are you sure he recommended 18 front and 28 rear? It wasn't the other way around; 28 front and 18 rear??

Do you have the link for his recommendations?

Neutral or oversteer keep the rear setting stiffer than the front, if you want to add in understeer then bringing the front setting closer to the rear is the answer. The range of adjustments is wide as J Lo $#$$%#%. My Eibachs suck but handle great and has a huge range of ERS or Hyperco springs to make my car handle how I want. Also remember that you can use tire pressure to further alter the balance or even make the ride more compliant.

[L99CAMA2011]

Originally Posted by SGOS252382

The issue of XA settings came up in the latest GM High Tech Magazine.

GM High Tech Mag put Pedders XA coilovers and Nitto NT05R tires on their shop car and it ran slower (on average) than it did stock around the road course. They admitted they needed more time to try to dial in the coilover settings. But the fact that the car felt unstable and ran slower than stock proves a major point. You can't just throw XA coils on your car and expect it to perform better than stock.


I really don't think the basic XA coils are the best setup for a serious racer. They'll will work fine for someone wanting to lower their vehicle for daily driving, but I'd invest in something else if you're really into road course type racing.

Ha Ha Ha. Actually it goes deeper than that. Pedders XA are not bad at all. Here is the thing and it is why I just bought the Pirelli 295-35-20 a few days ago to replace the Nitto NT05. Nitto NT05 are really you get what you pay for tire and is W rated(168mph). I had to pump the Nittos to 48 psi in order to match the Pirellis 36 psi. You can't put stiff coilovers on a car and then put soft sidewall tires on the car and expect the car to perform well. My car now with the stiff Eibach R1 are no longer the weak point like the stock suspension, the Nitto NT-05s are. For drag racing good tire, for road course on a 3800lb car with stiff is heck coilover setting not good. If you are running stiff track like coilover settings you also need a tire that can handle the pressure because as the suspension gets stiffer the tire becomes the weak point , that's why the car GM used handled worse than stock but if they had put a DOT rated tire on the car like a Hoosier brand tire then the results would've slaughtered the stock time. This is the exact same issue I am now having and is why my front Hankook tires are on their way off my front rims as well as the Nitto NTO5s. Michelin Super Sports are on their way in.

[sting808]

NT05 and NT05Rs are different. R's are for drag with soft sidewalls.

You'd think the reviewers would know that. Not to say the NT05 is all that... But good bargain for autoX.

[L99CAMA2011]

Originally Posted by sting808

NT05 and NT05Rs are different. R's are for drag with soft sidewalls.

You'd think the reviewers would know that. Not to say the NT05 is all that... But good bargain for autoX.

Yup NT05Rs are softer. I still think NT05 street are still too soft as well, that's why I am taking them off.

[sting808]

Originally Posted by L99CAMA2011

Yup NT05Rs are softer. I still think NT05 street are still too soft as well, that's why I am taking them off.

I need to run them at 45 psi for autox. Looking at pilot SS, but now Rivals as next tire. Btw, running XAs at 14 and 10. Have stiffer springs due to FI weight up front.

[IPT]

Originally Posted by Doc

I've got basically the same size and tire setup that L99cama2011 does and I've been running 12 front 10 rear on the street, and 20 front 14 rear on the track but now that I've seen what IPT posted about Pete's recommendations I'm a bit mystified about his road course settings. Are you sure he recommended 18 front and 28 rear? It wasn't the other way around; 28 front and 18 rear??

Do you have the link for his recommendations?

Doc - post # 22 from this thread: http://www.camaro5.com/forums/showthread.php?t=248324

[L99CAMA2011]

Originally Posted by sting808

I need to run them at 45 psi for autox. Looking at pilot SS, but now Rivals as next tire. Btw, running XAs at 14 and 10. Have stiffer springs due to FI weight up front.

Toyo has a Y rated 285-35-20. Tirerack.

[Doc]

Originally Posted by IPT

Doc - post # 22 from this thread: http://www.camaro5.com/forums/showthread.php?t=248324

Thanks! Don't know how I missed that thread. I wonder what sport he considers to be "sport front"... autocross? And is he recommending these settings with the stock sway bars or Pedder's sways?

Wish I had the time and access to a place where I could do some track tests to see what the different settings feel like.