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Thread: P11 Auto-X Setup help

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Posts: 1-10 of 220
2012-11-14 20:30:47
#1
P11 Auto-X Setup help
I am having some difficulty deciding what to do next with spring rates.
I currently have Tein SS with Eibach 8" 600lb springs up front and the 7" tein 400lb est. in the rear all mount on custom top hats.

Front sway bar is stock and a addco sway bar in the rear all with custom rod end links. Front bar has an extra an extra hole drilled further back for a bit more resistance and the rear is also adjustable.

My problem is that I feel the car still has a bit to much body roll and can be better, my idea is to get some 800lb 7" front springs(8" will be to tall, front coild are at its lowest setting) and use the 600lb for the rear. and to lower it maybe another 1/2" to an 1". photo for height reference:


Is this too much of a spread between the rates and is the 800lb too stiff?(not worried about street comfort here). Currently it feels fairly neutral with some understeer so with the 800/600 the feeling should feel similar just stiffer overall. Or would a 650/600 work better?
2012-11-14 20:57:31
#2
Are the Tein SS valved for those stiffer spring rates?

Addco makes a rear bar for a 91-96 P10. They do not have one for a P11. I do not know what rear bar you have, but it is not Addco. Take pictures, please.

The front bar you said is drilled, how is it drilled in relation to the mounting part for the end? In other words, is the custom drilled hole closer to the ends of the bar or closer to where the bar begins to bend to go around the chassis parts? This influences stiffness and is rather important.

To further clarify, this is USDM P11, right?
2012-11-14 22:03:42
#3
to answer your questions:
1. This is a JDM P11.

2. The SS are not re-valved for the springs rates but they feel good and are note bouncy other than I have stiffer springs and would normally be a harder ride. the 800lbs may be pushing it though but not sure.

3.The rear sway bar was for a maxima. can't really recall if addco but it is 20mm solid bar. and it is mount like on a solid axle on the chevy, fords.etc.:
The pics i have of the bar, no full pics:



4.Front Sway bar is drilled closer to wher it starts to bend. so mounting it on the custom hole would stiffen the bar. making it 3 way adjustable.
Last edited by cayman_primera on 2012-11-14 at 22-04-34.
2012-11-15 01:32:42
#4
I'm not really well versed in P11's yet, but if I had to guess my answers would be:

800 isn't too high for a caged car. Without a cage, you're probably turning the whole tub into a spring. point of comparision, my NX is on 500/600 and I can feel my bolt-in autopower move independent from the body. You also need better dampers. The Teins just don't have the rebound. Depending on your rules package, consider a clutchpack diff. that will allow the use of a bigger front bar. I'd also look at more rear spring also.
2012-11-15 01:48:49
#5
Some other issues with the rear of the P11.

The link, Scott-Russel link connects the chassis to the beam. Upon compression, it actually forces the wheels to move horizontally upon extreme lowering or compression whatever you want to call it. This makes the car "dog-track" where the rear wheels no longer follow the front wheels. It creates an unbalanced car since it will now handle differently in left hand and right hand turns. Also, the rear has static camber and toe and the toe-in the car has hurts its ability to rotate. Sometimes, a few have bent the rear beam to zero toe using a railroad iron tie, three brackets, some strong chain, and a hydraulic jack.

I rather like that rear sway bar installation. I can see the welds are a bit squiggly, was that your idea or someone else? Did you buy the car like that? This is the proper way to attach a rear sway bar on the beam-based suspension.

Along with everything @Blair said. Those little Teins are not helping those stiff springs so you are mostly riding on springs.

I think one company, Tanabe has made a Primera P10/P11 front sway bar. I can't find one, let me know if you can.

The front, there is someone who makes shortened Upper Control Arms to gain more negative camber to better utilize the tire contact patch under heavy/heard cornering. LoCo Performance | Select Parts for Select Vehicles E-mail him, he has lots of goodies.
2012-11-15 03:20:11
#6
All very great ideas, the teins are ready for a refresh or maybe even swap out completely. Would it be worth it to send them to get revalved or should i setup a custom koni G/C coilover sleeve type thing?

@Blair, I know what you mean about the chassis flex, just from jacking up the car in the front the rears doors are harder to close, I do plan on doing some under chassis bracing like this:

well maybe not that much but basically the braces that run down the entire length. Not sure if a cage is in the budget right now, and the good thing with our rules are they are very open right now, only the tires decide what class you are in

Do you think a b14 rear roll cage can be modified to fit?

@Kyle, I came up with this idea when i actually saw a chevy trial blazer driving in front and I saw how the sway bar was setup. If its good for OEM then its good for me! plus a lot of research with american cars made me see that this was a very common setup and it makes the sway bar a lot more responsive. The welds are pretty bad. had to do it with the car on jack stands so could not get good angles to weld. i will be re-doing the links shortly and the mounts.

Not sure if neg. camber would help much with the auto-x, right now the tires do not roll much, i normally mark the sidewalls to see how much they roll and i am happy with it, might take away some of my traction being turbo n all.

I have another P11 that I can salvage the beam from to do the bending thing incase it gets messed up because you can tell on my sway bar mounts just behind the exhaust how much movement you are describing.

Well, the next and last event for the year is this weekend, and then I have a couple of months to change some stuff up, I may just try out the 800lb spring and bracing to see where i am at. I like to try stuff out one thing at a time to really feel the difference if any then follow up on the dampers. or if i can find a front bar then get a 650lb spring and go from there.
2012-11-15 12:10:47
#7
I think USDM and JDM rear suspension are same, but EUDM is different. We dont have that problem. Mostly stock P11 works awesome in terms of handling, balance, corner speed... very neutral to oversteer feeling. Almost zero understeer.

I dont think any sway bars actually help. Id rather do new bushings, joints, etc. I dont feel changing springs on coilovers. Also stiffer doesnt means better. Front negative definately helps turn-in... but as your car is lowered it can be all messed up. Is you car turboed? Thats extra weight in front, torque-steer,...
2012-11-15 13:22:48
#8
It is turbo so yea, more heavy up front and torque steer, all the good stuff.lol I use 235 40 17 R1Rs up front for help with traction, might go up a size to 245 next time and see how it goes.

When I changed the front springs to 600lb it help a lot, did not have any problems with travel at the lowest settings, used a zip tie to measure travel on stret driving and I have at the least 1/2" left. thats street driving with all the big bumps and bangs, so I am very confident in the travel when doing auto-x.

my idea is to get a stiffer spring and go even lower. honestly with the couple changes i did this month, this final event will help me decide what i want to do from how the car will perform. If it does great then I may just look at other areas of intrest.
2012-11-15 13:51:24
#9
I forgot to ask what tires you are using. My head automatically thinks Hoosiers, and somtimes I forget about the rest of the world. It *is* possible to be over sprung for the tires. (My NX is terrifying on street tires.)
2012-11-15 14:18:37
#10
Ahh, makes sense. I right now i use 235 Toyo R1R up front and 225 potenza re050 not the run flat. got the toyos and the potenzas, i know mixing like that is good for balance because of different grip levels but they seem to work well as is. If i use R compund or less than 140 treadwear then I will be in the unlimited category. If I did not use this as my daily then i would actualy like to see how it does with stickier tires. I can see where the effect of the stiffer spring would be greater on the track(race course) than auto-x. we run in a tight space a barely see 60mph
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