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Old 08-06-2002, 03:29 PM   #1
TractionCircle
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Default JIC's, review and preloading question

Hey guys,

I just installed the JIC's this last weekend and all I can say is WOW. Car takes my "test on ramp" at 10mph faster with less tire noise, and this is with my messed up alignment. After installing, my rears have WAY too much negative camber, and my fronts are too positive. Alignment is in my near future.

Install was a snap, everything fit perfectly. I set the fronts on full positive to make changes at the track fairly easy.

With all four corners set to full soft, the ride was pretty bouncy, nothing like my friend's Tein RA's (shameless plug for Dori Dori!) but still more than I wanted. I have turned them up to full stiff and it is still fairly bouncy around town.

Here's my question: is it possible I preloaded the springs too much? That would increase the dynamic spring rate and cause the damping to have less of an effect, I would think. The way I did it, with the car off the ground, I raised the spring perch until the spring wouldn't move AT ALL, then added 1/4 turn. I see people posting that they just raised it till the top and bottom touched the perches. Is it possible I pre-loaded too much?

Would love to hear from the people in the know on this one, as I am close to giving in and buying the softer springs (I have 8/6 now).

Thanks in advance,

Jay
02 Blue WRX, just like everyone else
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Old 08-06-2002, 08:22 PM   #2
ellisnc
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Did someone say track day

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yeah that's about where I have mine...

until the perch reaches the spring then turn it a little more by hand

I just think you want to avoid cranking on them with the wrenches is the idea

hope this helps, PM me and we can share setup ideas
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Old 08-13-2002, 11:55 PM   #3
TractionCircle
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Hey man,

I PMed you and didn't get any response so I'll post here.

After driving the car for a while, it is WAY too bouncy for me. I have tried changing the damping and no matter where I set it, it always feels the same. I have the 8/6 springs by the way.

To anyone else running ANY coilover and 8/6 springs: Is your setup bouncy at all on the road?

Thanks in advance,

Jay
02 Blue WRX just like everyone else
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Old 08-14-2002, 02:33 AM   #4
whiterabbit
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try stiffening the dampening...it helped for me.
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Old 08-14-2002, 06:07 AM   #5
ellisnc
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Did someone say track day

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that's right

I have the damping cranked up pretty high as I didn't like the feeling when it was around the middle

I don't think you can get away from the bouncy feeling, but a lot of it is your seat too... If you had some racing buckets, I don't think you'd feel it was too bouncy. However, I've seen GT3 Porches in race trim at Mid Ohio and going through the pits they seem to bounce and I'm sure they're running much higher rates than we are.

The high rates and stiff damping don't really start to feel good until you're tearing around on a track or back road.
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Old 08-14-2002, 10:20 AM   #6
Kartoffel
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Heavy damping and bounciness are mutually exclusive. If your suspension is bouncy, it is underdamped. Ellisnc is right about the bouncy feeling being subjective. However, if your car really is bouncing excessively something is wrong. Might want to make sure the damping adjusters are working properly.
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Old 08-14-2002, 10:23 AM   #7
TractionCircle
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Is it possible it is oversprung rather than underdamped? I was thinking of going with a softer spring, say a 6/5 setup.

Your thoughts?

Jay
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Old 08-14-2002, 01:01 PM   #8
Kartoffel
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Quote:
Originally posted by TractionCircle
Is it possible it is oversprung rather than underdamped? I was thinking of going with a softer spring, say a 6/5 setup.

Your thoughts?

Jay
My thoughts exactly. Not to knock JIC (looks like top quality stuff), but you have to take their Japanese suspension settings with a grain of salt.

DMS found out through trial and error that GD and GG Imprezas work best with close to the same springrate front and rear. On GC8s everybody kept the fronts stiffer than the rear, but since the coming of the new age Impreza it seems that most suspension manufacturers have not gone back to the track and found ideal settings.

Note that Elgorey, Gary Sheehan and others have talked about going to even front/back springrates or even stiffer in the rear.

I've been meaning to call up JIC USA and talk about what they've found. Everybody says you can custom spec JIC shocks with whatever springrate you like.

My thoughts: keep whatever valving comes with the 8/6 setup and swap in 6/6 springs. I'd be real interested to hear from FLT-A2 owners who have played with different spring rates.
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Old 08-14-2002, 01:30 PM   #9
Dori Dori
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Hey Jay, do you mean too stiff (bumpy) or too bouncy? I have confused i-clubbers before by saying bouncy when I really meant bumpy....

Anyway, I've got to ride in your car now. I'm really curious how these feel compared to the RA's. I'm getting to the point that I am really ready to sell these... I love how they handle, but I get a headache everyday on my ride home from work (I95 construction).

Are you going to TS this Friday? You haven't seen my wheels yet either.
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Old 08-14-2002, 01:37 PM   #10
TractionCircle
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Anthony,

I'll be there Friday. You can go for a ride, but my car is DEFINITELY over sprung. 8/6 is just too much for the street, or at least that is what I am learning anyway. I am trying to source a set of 5's, so that I will have the 6/5's.

Other than the spring rate, I LOVE these coilovers though. I'll show them to you Friday. I'll be getting there around 7:30ish.

Later,

Jay
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Old 08-14-2002, 01:47 PM   #11
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Before you change those s/r's, talk to Jic...find out how much strut travel they have. The RA's only have 2"...that makes me worried about putting in too low of a s/r. Maybe I'm way off here...but just some food for thought.
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Old 08-14-2002, 01:47 PM   #12
magicman
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Hey guys, I think the supreme spring rates for the JIC FLT A2 set up is 7 kg/mm front 5 kg/mm rear. Pre-load...... there should be no pre-load on springs at all. they should be snug between spring seats but not pre loaded. ride hieght should be adjusted by lower bracket and not by lower spring perch(seat).
If you need more help call me at 562-803-6122

Terry H.
JIC USA



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Old 08-14-2002, 02:04 PM   #13
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Quote:
Originally posted by Kartoffel


My thoughts exactly. Not to knock JIC (looks like top quality stuff), but you have to take their Japanese suspension settings with a grain of salt.

DMS found out through trial and error that GD and GG Imprezas work best with close to the same springrate front and rear. On GC8s everybody kept the fronts stiffer than the rear, but since the coming of the new age Impreza it seems that most suspension manufacturers have not gone back to the track and found ideal settings.

Note that Elgorey, Gary Sheehan and others have talked about going to even front/back springrates or even stiffer in the rear.

I've been meaning to call up JIC USA and talk about what they've found. Everybody says you can custom spec JIC shocks with whatever springrate you like.

My thoughts: keep whatever valving comes with the 8/6 setup and swap in 6/6 springs. I'd be real interested to hear from FLT-A2 owners who have played with different spring rates.
you know that JIC USDM and JDM settings are totally different from each other. not only S/R but dampening is also changed.

same rate springs don't work as well as you think. and stiffer rear spring is the way you set up a front driver (integra) so that it will rotate around like a real... oops I mean rear driver. The gd chassis cars still have more wieght in the front than the rear and still behaves much like a rear driver. if you set it up like an integra it may induce a false drift much easier but it will ride really bad and it will understeer badly for any experienced driver.
JIC uses 8&6 kg/mm rates for high performance and
7&5 kg/mm for a street set up. We have done a lot of testing with pkZero (a So Cal suby specialist).

your friendly neighborhood magicman
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Old 08-14-2002, 02:35 PM   #14
TBreu007
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Dori, are you interested in trading for my HA's plus me giving you money?
I'll even do the swap

Tim
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Old 08-14-2002, 03:09 PM   #15
TractionCircle
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Tim, figured it wouldn't be long before you piped up

Magicman:

Finally, an answer from the source! So then for a daily driven car in an area where roads have the texture of Schwarzenegger's six pack, would you recommend 6/5 or 7/5? My friend (see above) has the Tein HA's with 7/6 and his car still gets some skipping over uneven pavement, wondering if 6/5 would be better for "real world" driving.

Anthony, if you are still listening, I am about 2 potholes away from peeing blood myself.....time to go wussy, I mean softer.

Jay
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Old 08-14-2002, 03:31 PM   #16
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Not to thread-jack, but I'm selling my JDM-spec (I think they're JDM... the instructions definitely aren't in English) FLT-A2's with 8F/6R springs. Under 2k mi, 1 autox, perfect condition, and $1450 shipped.

I've been driving on this setup through Manhattan every day. As long as I remember where all the potholes are, I don't have a problem. Handling at the limit with the front camber maxed out is beautiful... totally neutral, and not what you'd expect with 8 kg/mm springs in the front and 6 in the rear.
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Old 08-14-2002, 05:49 PM   #17
Kartoffel
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Default Front/Rear springrate bias

Terry/magicman, thank you for the excellent feedback. I checked out JIC USA's recommended springrates and found some weird things.

Recommended rate for WRX is 8 kg/mm front, 6kg/mm rear, for a ratio of 1.333. I threw all the FLT-A2 models into a spreadsheet and looked at what kind of front/rear ratios are being used on different cars. Here's a list of various fitments sorted by the front/rear springrate ratio:

0.71: mid engine RWD car, Toyota MR-2
0.89: front engine FWD car, Acura RSX
0.89: front engine FWD car, Honda Civic ES
1.00: front engine AWD car, Mitsubishi Lancer Evo 4
1.13: a 50/50 weight biased RWD drive car, Mazda Miata
1.14: front engine AWD car, Mitsubishi Lancer Evo 7
1.20: front engine AWD car, Nissan Skyline
1.33: front engine AWD car, Subaru WRX
1.33: front engine RWD car, Mazda RX-7
1.40: front engine RWD car, Toyota Supra
1.40: front engine FWD car, Nissan Sentra
1.40: front engine AWD car, Mitsubishi 3000GT
1.43: front engine FWD, Acura Integra
1.50: front engine RWD, Nissan 300zx
1.60: front engine FWD, Mitsubishi Eclipse

Except for the oddball tailheavy MR-2, most RWD cars tend to be stiffer in front and lighter in the rear.

AWD cars have a range around 1.0-1.4. Some Lancers are dead even front and rear while the 3000GT has the biggest difference.

FWD cars are all over the spectrum. The RSX is set up like magicman suggested an Integra should be set up (stiff rear, soft front). Strangely, the Integra is one of the most stiff-front-biased FWD cars on the JIC list.

Anyway, based on the way I've seen DMS-equipped WRXes handle and the comments from other people on this forum (elgorey, Gary Sheehan), I still believe the best setup for the WRX will have close to equal springrates front and rear.
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Old 08-14-2002, 05:54 PM   #18
Kartoffel
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Quote:
Originally posted by TractionCircle
My friend (see above) has the Tein HA's with 7/6 and his car still gets some skipping over uneven pavement, wondering if 6/5 would be better for "real world" driving.
Less compression damping, more rebound damping.

Drive the car over cobblestones to test. If it hunches down and squats too low, back off on the rebound.
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