wstar's Journal

SPOHN

The VLSD is worthless when hot. And are diff gets hot quick.

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wstar

Yeah, my car loses cornering late in sessions. Some of that's from overheating the Conti DW's, but undoubtedly some of it's from the VLSD as well. Need a good 1.5-way on my mod list, but there are so many other things I need to get to first (like, fixing up my cooling situation, and getting a 4-pt + solid seats + harnesses into the car). Oh and adjustable suspension bits moved up the list. I need adjustable camber in the front.

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7AT Track Car!
Journal thread / Car setup details

sig11

I think I destroyed the VLSD completely last year because I didn't have problems like this except for a few corners a few laps in. I can't wait to get the NISMO diff and 350Z ready. :P

cv129

wstar, on the JRZ RS1, that small silver knob at the bottom, do you know what that is for?

sig11

It's the valve for filling the shock with gas/nitrogen.

wstar

^ What he said.

Random progress updates:

The APRacing/Stillen BBK + CL RC6E pads are physically on the car, but the old calipers are still sitting in the backs of the wheel wells and hooked up to the brake lines. Tomorrow's the planned day to swap to the fresh braided lines and bleed the system and bed the rotors, etc.

I've got (in the garage or in-shipment) a CSF radiator, a bunch of silicone coolant hoses, an upgraded 25-row series-9 oil cooler, a new thermostat (Mishimoto's, to replace the one cut out at the track), etc. I'm giving up on sorting out a Laminova-like cooling setup for now, because I need the car to get colder and work right for a pair of upcoming track weekends like now, and there's no time to experiment. This is just a rehab of all my cooling system, with the water, oil, and trans coolers all getting larger/better (my old 19-row oil cooler will replace the even smaller existing trans cooler).

Also have Z1's engine/trans mounts on the way, will replace those while the radiator's out. Also planning to gut the engine-bay side of the HVAC stuff while the radiator's out, but will probably just plug/cap the lines going to the interior of the car at the firewall for now, no time to dig apart all the under-dash stuff.

Next event: May 18-19 @ Texas World Speedway.

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7AT Track Car!
Journal thread / Car setup details

ChrisSlicks

You'll want some of these unless you like your dust boots extra crispy

DH586 Titanium Brake Shims for AP Racing CP7040 Caliper

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Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

sig11

Do they really work? I just had my brakes rebuilt and roasted them again the day after.

ChrisSlicks

I got them at the end last year but since my seals were already in a toasted state (refreshed in the spring) so I can't say yet. I will be replacing the seals and dust boots soon with high-temp parts and we'll see what happens.

<OT>
It's too bad they didn't design the kit with the CP5555 caliper, it has a recessed dust boot and a better bridge support. It matches up almost identically in specs, would need a just slightly different bracket since the caliper sits a couple of mm higher.
</OT>

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Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

wstar

Oh good thought, thanks! I actually have them on my stock front calipers, but I kinda forgot they were there

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7AT Track Car!
Journal thread / Car setup details

wstar

Yeah there are a lot of options w/ AP's custom racing stuff, or having Essex do the calipers or whatever, including stuff with no dust boots at all (but then I guess you're expected to clean/rebuild more often that way as well). Just you lose the "Stillen says it works on this car, and gives you the right brackets and rotors that fit correctly" part.

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7AT Track Car!
Journal thread / Car setup details

wstar

New pro pics from the last event, Apr 13/14 at MSR-Houston. You can see how much lower the car is sitting, and how much less body roll and nose-dive there is in these. While it feels like "zero body roll" in the car, and other drivers were commenting that there was virtually no body roll, in the still photos you can of course see that there still is some mild roll in the car. I guess that's always the case unless you weld everything solid . Not sure if damper settings affect that or it's just spring rate, so it's possible by bringing up the damper stiffness I could push some of that out, too. All through this event I had the rear Hotchkis sway at full-soft as well.

With notes on what's happening in each pic (This is MSR-H Clockwise):

This one's nearly done tracking out from a right-hander onto the pit straight, still accelerating in mid-4th-gear:



Midway through the second corner of Sugar-and-Spice from the rear, you can easily see the remaining body roll. I'd say at this point in the corner the car's about as laid over on lateral G's as it's ever gonna get on these tires:



This is at the end of the pit straight, a right turn again. I've started turn-in, but I'm not 100% sure whether I was off the brakes on this attempt or still playing with trailing them into it:



Not even sure where this is, too little context. Maybe Gut-check, maybe the straight before Bus-stop?



And this is near the end of Keyhole, a ~50mph-ish tight little circular section to the right:

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7AT Track Car!
Journal thread / Car setup details

ChrisSlicks

Just remember that stiffest isn't always fastest. You have to match the damping to the tires and the track conditions. Some weight transition is useful, it just needs to be controlled.

For my setup I run full stiff on DOT-slicks, about 2/3rds for R-comp 100TW tires (NT01/RA-1) and about 1/2 for sticky street tires as the starting point. In the rain on R-comp wets I run about 1/3rd. Different coilovers though so your settings will be a little different. If I'm not happy with the traction balance of the car front to rear I will make small adjustments to try and get it dialed in.

Probably the most important thing is that you keep a log of everything. Weather, tire pressures, damper settings, what you had for breakfast, oil temps etc. It will all be useful when analyzing your performance at the end of the day or even in between sessions.

Car is looking great BTW and love the data logging setup.

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Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

wstar

Yeah a log of all the conditions and settings is starting to become a necessity. At least I only have one type of tire setup at the moment. I can only imagine how complicated it gets when you're switching.

The data logging is pretty amazing, but it will be a while until I get into the hang of really using it well. What you see in the Youtube videos is just basic video + gauge overlay, but their software actually does a lot more than that when I'm at my desk analyzing data in it. Again, logs to go with the data would help, so that I can see things like "Hey changing that swaybar setting gains me 5mph at the traction limit in corner X" or whatever the case may be.

You can see a little slideshow about their analysis software here: Race-Keeper Software | Race-Keeper . Basically, you get graph data for everything that's synced with the track map and video, and you can do side-by-side video + full-data comparisons of laps from different outings or whatever and it syncs those up as well.

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7AT Track Car!
Journal thread / Car setup details

ChrisSlicks

I use this one. Not as fancy as yours, you have to record the video separately and combine later, but the data analysis suite is very similar.

AiM Sports - Solo overview

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Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms