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      12-04-2017, 08:24 AM   #67
bbnks2
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Originally Posted by spxxx View Post
I was running consistent 2:02s all day on a OTS 93 Oct map and my rear "APR" wing, I noticed I could power on earlier but my top speeds suffered and my high speed braking was AWFUL with the balance of the car. I pulled the rear wing and ran a 2:00 flat immediately on the Federal RSRR tires, this was the last run of the day (sooo close to 1:59 lol) - Would love to get a balanced aero package on the car as most folks say that it'll drop 2-3 seconds off a 2min lap time (Assuming it's dialed in)
Can you change the angle of attack on the wing at all?

I am looking at picking up an EBAY APR knockoff. It's only 7" tall vs the real thing being 9" tall, but otherwise it's exactly the same. In your pics, the angle of attack looks very aggressive and the extra height you gave the wing makes it even more aggressive. You might also want to consider front sub-frame bushings. We all change the rear because we love laying on the gas pedal, but the sloppy front bushings are no better for when you need to slow down...

I spent all summer at autocross every weekend dialing my car in. Having jacked up coil-over settings will absolutely make braking AWEFUL. I found If I had front rebound too stiff the car felt weird and it wandered. I run the rear significantly stiffer rebound-wise than the front now and it feels much better. (3/7 front and 5/7 rear with the YCW). with all the extra rear down-force you might need more rear rebound to control how quickly all that force shifts forward upon braking.
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      12-04-2017, 09:56 AM   #68
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Originally Posted by mabrahams View Post
So you effectively gained 2secs ONLY by removing the rear wing?

I’ll be honest; maybe getting the car sorted without aero would be good and then when you are at the limits; add aero. The problem you may run into is; not knowing what to change since there are so many changes. Not being a dick either. Great progress!

Any videos?
Yeah this is my problem, I'm stupid and don't keep everything controlled when I adjust things because I'm anxious at the track and want to see results asap. I also just added the coils and haven't gotten them close to dialed yet.

I reduced front rebound and removed some compression in the rear along with removing the wing. I'm anxiously awaiting a test & tune day at Buttonwillow where I can make tweaks one at a time without having to worry about sessions.

The group I ran with was pretty bad from a seat time perspective. I have some vids that I'm trying to smoothen out (loose camera mount = wild shaky video) I'll post some up soon.

I've been using this "guide" to dial in my shocks if anyone wants to use/critique it.
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      12-04-2017, 10:08 AM   #69
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Quote:
Originally Posted by bbnks2 View Post
Quote:
Originally Posted by spxxx View Post
I was running consistent 2:02s all day on a OTS 93 Oct map and my rear "APR" wing, I noticed I could power on earlier but my top speeds suffered and my high speed braking was AWFUL with the balance of the car. I pulled the rear wing and ran a 2:00 flat immediately on the Federal RSRR tires, this was the last run of the day (sooo close to 1:59 lol) - Would love to get a balanced aero package on the car as most folks say that it'll drop 2-3 seconds off a 2min lap time (Assuming it's dialed in)
Can you change the angle of attack on the wing at all?

I am looking at picking up an EBAY APR knockoff. It's only 7" tall vs the real thing being 9" tall, but otherwise it's exactly the same. In your pics, the angle of attack looks very aggressive and the extra height you gave the wing makes it even more aggressive. You might also want to consider front sub-frame bushings. We all change the rear because we love laying on the gas pedal, but the sloppy front bushings are no better for when you need to slow down...

I spent all summer at autocross every weekend dialing my car in. Having jacked up coil-over settings will absolutely make braking AWEFUL. I found If I had front rebound too stiff the car felt weird and it wandered. I run the rear significantly stiffer rebound-wise than the front now and it feels much better. (3/7 front and 5/7 rear with the YCW). with all the extra rear down-force you might need more rear rebound to control how quickly all that force shifts forward upon braking.
I'm actually running 7" risers and the AOA is pretty modest, I'm starting to think I just need to dial in my shocks. I mean, seat time cures all issues so I'll probably go the seat time and shock tuning route and throw the wing back on once I feel the car is more dialed in
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      12-04-2017, 09:19 PM   #70
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Quote:
Originally Posted by spxxx View Post
I'm actually running 7" risers and the AOA is pretty modest, I'm starting to think I just need to dial in my shocks. I mean, seat time cures all issues so I'll probably go the seat time and shock tuning route and throw the wing back on once I feel the car is more dialed in
Yeah for sure. My car felt all sorts of screwed up when I tried to run high front rebound.

The assumption I now operate under is that the rear requires significantly more rebound due to the stiffer rear springs. While motion ratio does dictate that the springs aren't effective at leveraging the weight of the chassis, the rear springs still have enourmously more return force for when weight shifts forward. Maybe this is wrong but the car 100% feels better with more rear rebound lol

EDIT: I think the issue is more that the spring and rear shock have different motion rations since it's not a coilover setup. That might explain why you need additional rebound in the rear even when you keep the springs at an even wheel rate like I do...

Where is that chart from? I disagree with a few of the suggestions... Like corner entry oversteer.. how would increasing front rebound and reducing rear rebound possibly help that scenario? All logic points to increasing front COMPRESSION and increasing rear rebound not reducing it... This would keep more weight over the rear wheels on entry and reduce the oversteer. I would think mid-corner/exit oversteer would warranty less front rebound (in order to allow weight o transfer rearward on power). The internet is a blessing and a curse when it comes to information...

Last edited by bbnks2; 12-12-2017 at 01:24 PM..
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      12-04-2017, 11:34 PM   #71
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Quote:
Originally Posted by bbnks2 View Post
Quote:
Originally Posted by spxxx View Post
I'm actually running 7" risers and the AOA is pretty modest, I'm starting to think I just need to dial in my shocks. I mean, seat time cures all issues so I'll probably go the seat time and shock tuning route and throw the wing back on once I feel the car is more dialed in
Yeah for sure. My car felt all sorts of screwed up when I tried to run high front rebound.

The assumption I now operate under is that the rear requires significantly more rebound due to the stiffer rear springs. While motion ratio does dictate that the springs aren't effective at leveraging the weight of the chassis, the rear springs still have enourmously more return force for when weight shifts forward. Maybe this is wrong but the car 100% feels better with more rear rebound lol

Where is that chart from? I disagree with a few of the suggestions... Like corner entry oversteer.. how would increasing front rebound and reducing rear rebound possibly help that scenario? All logic points to increasing front COMPRESSION and increasing rear rebound not reducing it... This would keep more weight over the rear wheels on entry and reduce the oversteer. The internet is a blessing and a curse when it comes to information...
I believe it's from ASTs site. I posted it hoping for criticism - I wish there was a definitive handbook on shock tuning (by handbook I mean one-pager) haha
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      12-07-2017, 07:29 AM   #72
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Quote:
Originally Posted by bbnks2 View Post
Yeah for sure. My car felt all sorts of screwed up when I tried to run high front rebound.

The assumption I now operate under is that the rear requires significantly more rebound due to the stiffer rear springs. While motion ratio does dictate that the springs aren't effective at leveraging the weight of the chassis, the rear springs still have enourmously more return force for when weight shifts forward. Maybe this is wrong but the car 100% feels better with more rear rebound lol

Where is that chart from? I disagree with a few of the suggestions... Like corner entry oversteer.. how would increasing front rebound and reducing rear rebound possibly help that scenario? All logic points to increasing front COMPRESSION and increasing rear rebound not reducing it... This would keep more weight over the rear wheels on entry and reduce the oversteer. The internet is a blessing and a curse when it comes to information...

That is really weird. (Preface: I have Koni DA's) I have always run really high front rebound, and really low rear rebound. I set the rear first, and use braking. I dial in just enough rear rebound to keep the car from nose diving under braking, then I do the front. I start at full-ish rebound and work down till the rear end stays planted.

That said, I rarely if ever, adust shocks, unless it is raining, or I am using different tires, and even then, not always. You will be miles ahead if you find a good setting, and leave them there, so that you can gain experience and build confidence in what the car is doing.
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      12-07-2017, 09:16 AM   #73
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Originally Posted by bionicbelly View Post
That is really weird. (Preface: I have Koni DA's) I have always run really high front rebound, and really low rear rebound. I set the rear first, and use braking. I dial in just enough rear rebound to keep the car from nose diving under braking, then I do the front. I start at full-ish rebound and work down till the rear end stays planted.

That said, I rarely if ever, adust shocks, unless it is raining, or I am using different tires, and even then, not always. You will be miles ahead if you find a good setting, and leave them there, so that you can gain experience and build confidence in what the car is doing.
I guess it would depend on the spring setup... I run a neutral 6k/16k setup. Most out-of-the-box spring rates are nowhere near that. Most setups run significantly stiffer (relatively) front springs like a 10k/12k setup.

Edit: as edited above as well, the rear shock is less effective than the front. Front shock is same motion ratio as the spring which is close enough to call 1:1. The rear spring and shock are separated. The spring mounts inboard of the shock which makes it much less effective (.36). The shock itself mounts outboard closer to the wheel and has a motion ratio of .7. so, if you run neutral wheel rate like I do it then it makes sense the rear shock would need a bit more rebound than the front strut needs to achieve the same damping.

Last edited by bbnks2; 12-13-2017 at 08:10 PM..
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      12-07-2017, 09:55 AM   #74
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Quote:
Originally Posted by bbnks2 View Post
I guess it would depend on the spring setup... I run a neutral 6k/16k setup. Most out-of-the-box spring rates are nowhere near that. Most setups run significantly stiffer front springs.
What kind of tire do you run?
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      12-07-2017, 10:53 AM   #75
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Originally Posted by bionicbelly View Post
What kind of tire do you run?
I have 275 40tw (Z214) on the car now but ran 255's in 200tw for a while.
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      12-07-2017, 12:35 PM   #76
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I have 275 40tw (Z214) on the car now but ran 255's in 200tw for a while.
Nice. Damn. That is a serious bit of rubber.
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      12-07-2017, 02:09 PM   #77
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Shock tuning is mysterious shit. My clubsport dampers are set around medium, front and rear, top and bottom.
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      12-07-2017, 02:15 PM   #78
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Shock tuning is mysterious shit. My clubsport dampers are set around medium, front and rear, top and bottom.
I would do dirty dirty things to just let some pro driver rip on my car and dial-in my shocks perfectly. Sorry for continually making gay references to shock tuning. We're also talking about Buttonwillow which isn't the smoothest track, I'd say it has the most aggressive berms in CA.

How are the clubsports? I personally wish I just had a single adjustable coils at this point after fiddle fucking with my 2-way KWs and not seeing much of a change in driving behavior. I spoke with MCS and might go that route in 2018 - single adjustables. Or Bilstein/Ohlin, really anything that only has 1 knob for me to screw up.
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      12-07-2017, 02:16 PM   #79
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Whoops-I take back the gay reference... plenty of professional female drivers than could do the job too
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      12-19-2017, 10:06 AM   #80
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Welp I set my goal to break 2minutes at Buttonwillow by the end of the year. Went down last weekend and the car was exiting turns very bouncy added a little rear rebound/comp and comp up front and I hit a 1:59.4 on the first hot lap of the next session... before being pushed off track by a couple sketchy Mclaren drivers at which point I called it a day.

Really cool seeing the small changes in the car having such an effect on track. Understeer is still a problem so my goal over "winter" here in CA is to figure out how to run 265/275 square and build me a nice splitter package

IG: spx.tunes for pics and video
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      12-31-2017, 12:26 AM   #81
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Edit: Christmas for me...

- MCS 1WNR coilovers for the 135i
- E46 M3
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      01-02-2018, 12:15 PM   #82
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Big fan of MCS singles. Had double remotes on an S2000, now singles on an ND. If I end up keeping the 128 around a whole lot longer I might go that route again.
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      01-03-2018, 01:34 AM   #83
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Big fan of MCS singles. Had double remotes on an S2000, now singles on an ND. If I end up keeping the 128 around a whole lot longer I might go that route again.
Great to hear, figure the superior design and larger piston will more than make up for lack of compression adjustability that I currently have with my KWs.
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      01-03-2018, 09:17 AM   #84
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Originally Posted by spxxx View Post
Great to hear, figure the superior design and larger piston will more than make up for lack of compression adjustability that I currently have with my KWs.
Out of curiosity, do you have any pictures of them? What size springs are you going with / camber plates?

I say this after a series of interesting bits learned from my 128 STX build.

1. The JRZs had zero problem with travel, nor diameter of the shock itself. But to run with the 6in springs required for the upper perch to clear the tire, I was at the VERY top of the height adjustment range on them (which makes sense, as they wanted to maximize travel). I'm curious how the MCS are in this regard.

2. After turning this into more of a casual car, and watching a friend do well on some revalved Megan Racing (same internals as all the chinese mess), the biggest issue with them is that the diameter of the strut tube is substantially larger than the JRZs, which requires a larger spacer for the tire to clear it. Which then can likely create interference from tire -> fender (I am not sure 255s on a 9 would fit anymore, while they did with zero rub before).

If you have pictures of the shocks that you could post showing both the strut tube diameter (towards the bottom where they actually slide into the knuckle), or have a caliper you could use, that would be great. Also, what camber plates / springs are you using?
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      01-03-2018, 12:42 PM   #85
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I run MCS 2 way remotes on my FRS. They are absolutely amazing - Great at handling bumps with no drama
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      01-03-2018, 04:20 PM   #86
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Quote:
Originally Posted by RyanDavies View Post
Quote:
Originally Posted by spxxx View Post
Great to hear, figure the superior design and larger piston will more than make up for lack of compression adjustability that I currently have with my KWs.
Out of curiosity, do you have any pictures of them? What size springs are you going with / camber plates?

I say this after a series of interesting bits learned from my 128 STX build.

1. The JRZs had zero problem with travel, nor diameter of the shock itself. But to run with the 6in springs required for the upper perch to clear the tire, I was at the VERY top of the height adjustment range on them (which makes sense, as they wanted to maximize travel). I'm curious how the MCS are in this regard.

2. After turning this into more of a casual car, and watching a friend do well on some revalved Megan Racing (same internals as all the chinese mess), the biggest issue with them is that the diameter of the strut tube is substantially larger than the JRZs, which requires a larger spacer for the tire to clear it. Which then can likely create interference from tire -> fender (I am not sure 255s on a 9 would fit anymore, while they did with zero rub before).

If you have pictures of the shocks that you could post showing both the strut tube diameter (towards the bottom where they actually slide into the knuckle), or have a caliper you could use, that would be great. Also, what camber plates / springs are you using?
They're being built now by MCS, Im also out of country for a bit. I'll update the thread once they arrive and I can compare them to the KWs along with full measurements. That's my biggest concern is trying to run 265 square with the larger diameter shaft
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      02-27-2018, 11:43 AM   #87
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Love the build! Really intrigued by your experiences with experimenting with aero. Your car is definitely an inspiration for my build.

Just a minor thing, what tow hooks are you using?
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      03-02-2018, 09:30 PM   #88
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Just got out to Laguna for my first day of the year... It was dumping rain but honestly might have been the most fun I've ever had at Laguna. I ran a solid 20min session on track as the ONLY car which was great practice for car control, really put that LSD to work.

I had one semi dry session but I wanted to note that I have fitted 265/35/18 RE71R on 18x9 et42 wheels with 5mm front spacers and 5in 400lbs front springs.

Yes, it rubs... Not for long because it's eating my bumper and I have a full 1M conversion on order so that's my next project!

Cheers for track season!
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