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My STU build

Old 01-11-2015, 06:17 PM
  #21  
Z1NONLY
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First event with my new OBDII device. I did a quick calibration of the throttle range that ended up showing only 94% throttle when floored but it still gives a good idea of what I'm doing with the throttle. The RPM's seem correct though.

I am really looking forward to some fresh rubber. I checked the data from State, and saw that there was more lateral grip on wet asphalt then, than I had on dry concrete today.


Last edited by Z1NONLY; 01-11-2015 at 06:27 PM.
Old 01-12-2015, 07:41 AM
  #22  
3hree5ive0ero
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What OBDII device are you using? Is there any lag between your throttle input and what is recorded?
Old 01-12-2015, 09:27 AM
  #23  
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OBDLinkMX.

Just going by ear while watching the throttle indicator, it seems pretty close.
Old 01-18-2015, 05:21 PM
  #24  
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Love seeing this car scoot around the track.

I need to corner balance my car. I am glad I am finally out there with you and jorge.

Chris
Old 01-19-2015, 04:02 AM
  #25  
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For autox, I'm not sold it makes a huge advantage....I never corner balanced my car until this year. It might make the car a bit more consistent, but in the end....not sure it really translates to quicker times...
Old 01-20-2015, 04:25 PM
  #26  
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Originally Posted by NA&CH
Love seeing this car scoot around the track.

I need to corner balance my car. I am glad I am finally out there with you and jorge.

Chris
I still have the scales...


Originally Posted by 03threefiftyz
For autox, I'm not sold it makes a huge advantage....I never corner balanced my car until this year. It might make the car a bit more consistent, but in the end....not sure it really translates to quicker times...
I think the benefit of corner balancing is largely dependent on how "close" the car was before it was balanced.

If the starting point is not that far from where it needs to be, the final result won't make much of a change.
Old 01-25-2015, 05:29 PM
  #27  
MrZ1987
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Op nice setup I have the same for my 370z but haven't installed it yet. For the front how much did the 6 inch springs drop your car? If you wanted could you get to within an inch of stock ride height? I have 6 inch springs with shortened shocks and I am worried that the drop will be too much and that I may need to swap for 7 inch springs.

Also I see you plan to run a lot of negative camber up front. Do you know if that will cause bad tire wear? I am trying to get a feel for how much camber I can run w/o wearing my tires out too fast.
Old 01-25-2015, 06:49 PM
  #28  
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Originally Posted by MrZ1987
Op nice setup I have the same for my 370z but haven't installed it yet. For the front how much did the 6 inch springs drop your car? If you wanted could you get to within an inch of stock ride height? I have 6 inch springs with shortened shocks and I am worried that the drop will be too much and that I may need to swap for 7 inch springs.

Also I see you plan to run a lot of negative camber up front. Do you know if that will cause bad tire wear? I am trying to get a feel for how much camber I can run w/o wearing my tires out too fast.
My first guess at the ride height was way too high....It was so high that I thought I had left something under the car when I lowered the jacks and the car was still mostly "up". (I'm talking mini-van fender gap)

I do wear the insides faster that the outsides, but I rotate the tires front-to-back a lot so I'm not sure if it's the camber or the toe-out (up front). The track time wears the outsides of the tires though, so the insides are not that far ahead of the outsides in wear. The Rivals seemed faster with lower air, so the middle fared better than the sides. I have a fresh set of RS3's in the garage and I hear they like more air.


Suspension-wise, I recently lowered the rear a bit and rebalanced it. I'm going to try 1/8" toe-in in the rear and a little more camber back there too. (I will stay under -3)

I hope I can get back to consistently using my throttle out of turns without having to resort to trailer-queen camber.
Old 01-26-2015, 08:17 AM
  #29  
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Good to hear I was worried that I my car would be too low. At least now I know that theres more of a chance that I will get the height I want.

I can't rotate my tires so I guess I will have to run less aggressive camber up front, maybe -2 with 0 toe.

As for putting power down coming out of turns don't you want less camber in the rear? I had -2.2 camber in the rear and I couldn't put the power down out of the turns. I then went to -1.6 and now I push and have a hard time getting the back end to step out.
Old 01-26-2015, 02:48 PM
  #30  
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Originally Posted by MrZ1987
As for putting power down coming out of turns don't you want less camber in the rear? I had -2.2 camber in the rear and I couldn't put the power down out of the turns. I then went to -1.6 and now I push and have a hard time getting the back end to step out.
I drove the car a few times on the street between when I moved to the new suspension and got the current alignment.

Just pulling out of one of my favorite corners seemed to hook up better, with > -3.5 camber, than it did on the same corner after I took it back down with the alignment.

Now, I never put it on a track with all that camber in the back so my observation is not scientific.

I know I would want almost no camber for straight-line drag racing but when pulling out of turns, with the car loaded up laterally, I think negative camber (and toe-in) is beneficial up to a point.
Old 01-27-2015, 05:19 AM
  #31  
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Originally Posted by Z1NONLY
I drove the car a few times on the street between when I moved to the new suspension and got the current alignment.

Just pulling out of one of my favorite corners seemed to hook up better, with > -3.5 camber, than it did on the same corner after I took it back down with the alignment.

Now, I never put it on a track with all that camber in the back so my observation is not scientific.

I know I would want almost no camber for straight-line drag racing but when pulling out of turns, with the car loaded up laterally, I think negative camber (and toe-in) is beneficial up to a point.
Gotcha, the fun part is finding that sweet spot.
Old 01-30-2015, 05:58 PM
  #32  
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The 285 RS3's are on.

I scanned the BP STU thread and couldn't find anything on tire pressures. (I thought there was something in that thread?)

Anyone have recommendations for 285/35-18 RS3's on a 10.5" wheel?
Old 01-30-2015, 08:21 PM
  #33  
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Originally Posted by Z1NONLY
The 285 RS3's are on.

I scanned the BP STU thread and couldn't find anything on tire pressures. (I thought there was something in that thread?)

Anyone have recommendations for 285/35-18 RS3's on a 10.5" wheel?
34 hot is what I run them at but I use them on the roadcourse
Old 02-03-2015, 07:21 AM
  #34  
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Just took it to an old-school alignment shop. (No laser beams or computers).

Seems the computer alignment was over-estimating camber. It said I was at -2.9 and -2.2 but but it was more like -2.75 and -2.

I left the front camber alone and had them bump the rear camber to -2.5

Front is now 1/16" toe-out and the rear is 1/8" toe-in. And for the first time in months, my steering wheel is straight when the car is going straight. (It wasn't pulling to either side before either, but the steering wheel wasn't centered)
Old 02-03-2015, 08:46 AM
  #35  
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I recently discovered how much better a proper old school alignment is over a laser. Quite a difference. I had my brothers mustang on a laser alignment and had .3 degrees of negative camber and .05 of toe in on the rear solid axle...
Took it to a old school shop and they said the rear was square (as it should be with a solid axle)
Old 02-09-2015, 01:45 PM
  #36  
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Mike text me that shop. Local I assume.

How do you like the RS3? Did you use them at this last event?

Chris
Old 02-10-2015, 12:41 PM
  #37  
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Originally Posted by NA&CH
Mike text me that shop. Local I assume.

How do you like the RS3? Did you use them at this last event?

Chris
Sent you the text. And you have a PM about your wheels.

Fresh RS3's are apparently about 1.5 seconds faster on a ~60 second course, than old, heat-cycled Rivals.

Plenty of reference drivers showed up, and we all ran in the same heat....

I'm now just a hair off the pace I was hoping for when I began my prep, and the current setup is just the first "good" reference point I've identified on dry pavement. I may have gotten lucky and just tripped over "the sweet spot", but I suspect that the setup and the driver can get a few more tenths with some adjustments. (and a little luck)

Front shocks were about 15 degrees softer than the half-way point, and the rear shocks were 3 swipes stiffer than the softest setting. Air pressure was 33psi cold. Tires are coming over to just shy of the arrows on the tire.

Alignment:
F -2.75 camber, 1/16" toe out
R -2.5 Camber, 1/8" toe in.

I was starting to worry a bit about not going double-adjustable because traction out of corners on the worn-out rivals was very inconsistent, but I had no such issues on these fresh tires. Better shocks would probably deal with the issue better than my custom singles, but the custom singles seem to work well-enough when given good conditions. (good tires, smooth surface)
Old 02-10-2015, 01:23 PM
  #38  
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Checking cone-proximity on the passenger side (still didn't calibrate the OBDII):


Last edited by Z1NONLY; 02-10-2015 at 01:24 PM.
Old 02-11-2015, 08:29 AM
  #39  
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What do you mean by calibrate? I mean, what can be done?
Old 02-11-2015, 09:55 AM
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Originally Posted by 3hree5ive0ero
What do you mean by calibrate? I mean, what can be done?
The software (solo storm) has to be "told" where "0" and "100" percent throttle are.

Once it's set to calibrate the variable, you're supposed to floor it for a second or three and then bring the throttle back to zero.

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