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Discussion Starter #361
Anyone else like the fact that he has it on a lift AND on jack stands? :) Lucky bastard.
A four-post lift is good for working on exhaust (I got the lift out of an old Mineke shop), but if you want to work on suspension, you have to jack the car up from the lift - kind of a pain. (Are you feeling sorry for me yet?) Sometimes I can use jacks and jack-stands from the ramps, but sometimes I need a jack in the middle. I solved this by welding tracks along the inside of the ramps and then built a jack-bridge that can slide up and down the tracks the whole length of the car. I can then jack up or support something under the car. This pic kinda shows it.



I keep telling my wife, we REALLY need a 2-post lift in the other bay. :p
 

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Discussion Starter #362
In my haste to get the car ready for annual tech inspection and the first autocross two weeks ago, I didn't really give the car a proper alignment - which it should have had since I had the subframe out and all the suspension apart. Pressed for time I just eyeballed it. At the AutoX, I could tell we had front toe issues.

So after having the suspension apart AGAIN to replace the CA bushings, I figured I'd do it right in preparation for this weekend's AutoX shakedown. Turns out the front had a total toe-IN of 1/4" - definitely not what we want. I was surprised to find the left rear was toed out almost 1/4".

So now we have the front set at 1/8" toe-out and the rear at 1/16" toe-in. The camber is pretty close all around ranging from -2.2 to -2.5deg.

I have another co-driver for this weekend so we should get about 12 runs on the car. The weather looks better and we should get some video this time. If all goes well, our next event will be on a race track. :thumbup:
 

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CR, how'd you solve the back camber moving with the eccentrics?? You weld in some stops or something else?

Also, you ever hang your smart phone in there and log the G's through any of the corners??

I am not sure of the accuracy of the device (Droid HD using Torque Pro) but it said 1.4G's in a corner and the 6 didn't even break a sweat. So I AM Curious what you get having less weight, more -camber, toe, Tire, & MadSkillz and all that.

Good Luck on your upcoming events!


HAHA - >>> EDIT!!!!! First Question is ANSWERED RIGHT UP THERE Post #361 ! My Bad!
 

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I am not sure of the accuracy of the device (Droid HD using Torque Pro) but it said 1.4G's in a corner and the 6 didn't even break a sweat. So I AM Curious what you get having less weight, more -camber, toe, Tire, & MadSkillz and all that.
I highly doubt that is accurate.. unless it actually means 0.4G's.. even supercars typically can't corner over 1G.. F1 hits about 1.4
 

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Discussion Starter #366
Also, you ever hang your smart phone in there and log the G's through any of the corners??
I don't have any skidpad data - it would be the most useful and allow comparison to other cars or setups. It's an interesting question, so I went back thru my data from last fall at VIR and CMP and was surprised to find the following peak values:

At CMP:
Braking - 1.31g
Cornering - 1.63g
Vertical - 1.23g

I went back and looked at where these peak values occured on the track.
Braking peak occured entering T8 - up hill brake zone providing extra downforce.
Cornering peak was in T8 - uphill turn with some camber.
Vertical peak was jumping curbs. :p

At VIR:
Braking - 1.28g
Cornering - 1.53g
Vertical - 1.38g

Braking peak occured entering T14 - up hill brake zone.
Cornering peak was in T17 - turn at bottom of hill with some camber providing extra downforce.
Vertical peak was also T17.

Its Fun to look at the data, but without understanding the context the data isn't very meaningful. Keep in mind that my telemetry produces about 25,000 data points in a 25min track session, so 3 or 4 hrs on the track in a typical weekend generates a ton of data. Where its useful is comparing my laps from session to session after signifcant changes to the car or driving technique - just takes alot of time. Hoping to get some skidpad testing in this year.

CR
 

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I don't have any skidpad data - it would be the most useful and allow comparison to other cars or setups. It's an interesting question, so I went back thru my data from last fall at VIR and CMP and was surprised to find the following peak values:

At CMP:
Braking - 1.31g
Cornering - 1.63g
Vertical - 1.23g

I went back and looked at where these peak values occured on the track.
Braking peak occured entering T8 - up hill brake zone providing extra downforce.
Cornering peak was in T8 - uphill turn with some camber.
Vertical peak was jumping curbs. :p

At VIR:
Braking - 1.28g
Cornering - 1.53g
Vertical - 1.38g

Braking peak occured entering T14 - up hill brake zone.
Cornering peak was in T17 - turn at bottom of hill with some camber providing extra downforce.
Vertical peak was also T17.

Its Fun to look at the data, but without understanding the context the data isn't very meaningful. Keep in mind that my telemetry produces about 25,000 data points in a 25min track session, so 3 or 4 hrs on the track in a typical weekend generates a ton of data. Where its useful is comparing my laps from session to session after signifcant changes to the car or driving technique - just takes alot of time. Hoping to get some skidpad testing in this year.

CR
Wow that is interesting. Would you say there is more in it "grip" wise or is that at the threshold of friction and loss of grip? So it sounds like you're using a laptop and some elaborate hardware than an Android!

Also, I'd think the diet plan your car is on has to be helping it. But I'm at a loss as far as payoff for section width vs total weight. i.e. what is the point of no return on grip vs width. I expected a higher number than those posted. If your hardware is not a phone, how is it calibrated?

Thanks for sharing!
 

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Discussion Starter #369
Wow.. well now I'm confused. Guess I'll have to look further into this..
Your earlier comment is spot on - published lateral Gs are based on what the car is able to SUSTAIN at a given speed on a constant radius (ie: skidpad). I'm confident my car is not capable of sustaining 1g on a skidpad - some number above a stock Mazda6, sure, but not supercar territory.

That's why I said you have to understand the context. Almost any car going thru T17 at VIR will pull more than 1g. The track transitions from downhill to flat so the suspension compresses and you get tons of grip. By contrast in T10, I am well under 1g because it is at the crest of a hill and the car gets light - no grip. So just because there are instantaneous data points above 1g, it doesn't make my Mazda a SuperCar (sadly). ;)
 

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Discussion Starter #371
Wow that is interesting. Would you say there is more in it "grip" wise or is that at the threshold of friction and loss of grip?
I would assume that since these are the peak numbers of over 200,000 data points, they are probably pretty close to the threshold for that particular location of the track. There are some corners you can determine the threshold - T5a at VIR for example. I almost always slide the car in that corner so when you look at the data, you see the Gs increasing then abruptly decline as the tires break loose.

So it sounds like you're using a laptop and some elaborate hardware than an Android!
Nope, just an iPhone running a killer app. At its highest data aquisition rate, it'll kill a fully charged iphone in about 45min.

Also, I'd think the diet plan your car is on has to be helping it.
Reducing weight improves acceleration, braking and cornering. Like Lotus sayes: "Simplify and add lightness."


I'm at a loss as far as payoff for section width vs total weight. i.e. what is the point of no return on grip vs width.
There are many, many variables and at the end of the day it is always a compromise. Probably the most important is the tire compound. I could run a much softer compound and gain significant grip, but they would last only one weekend (read expensive). My strategy is to run a harder compound that I can get a whole season out of, and run as wide a tire as possible. It's a compromise.



I expected a higher number than those posted.
Thanks for sharing!
I was actually surprised how high the numbers are based on my tire compound. I would have guessed 1.2g max.

CR
 

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Your earlier comment is spot on - published lateral Gs are based on what the car is able to SUSTAIN at a given speed on a constant radius (ie: skidpad). I'm confident my car is not capable of sustaining 1g on a skidpad - some number above a stock Mazda6, sure, but not supercar territory.

That's why I said you have to understand the context. Almost any car going thru T17 at VIR will pull more than 1g. The track transitions from downhill to flat so the suspension compresses and you get tons of grip. By contrast in T10, I am well under 1g because it is at the crest of a hill and the car gets light - no grip. So just because there are instantaneous data points above 1g, it doesn't make my Mazda a SuperCar (sadly). ;)
Ahh ok that makes sense.. I guess I didn't catch that the first time. So then @finalImpact's reading could in fact be accurate in terms of peak lateral G's.. I just didn't realize peak is what it was reporting.
 

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^^ perhaps instantaneous G's.. .. ..
Let me add some where and how I got those numbers. These are in banked S turns with a very uniform radius in terms of switching. On my bike the transition is beautiful from right peg in the ground to full left peg in the ground and then switch back again twice. Its a fun stretch of road on anything at speed. Yes, everything was flying in the car but it held its line and the tires let out barely a whisper. There's also a section of road with a near flat 200 degree radius. It was 1.2 past the apex. All I can say is this is the best handling car I've ever owned and for being sedan! Impressive!

Wheels: Motegi MR116, Offset: 18 X 8 +45, Tires/Brand/Model: Federal Steel 595, 225/40/ZR18 88W (tires are sipped), camber front -0.5, rear -1.5. Toes are 0.0625"
 

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Discussion Starter #374
Although driving the car with the tail out is great fun, I'm tired of spinning the car and I REALLY don't want to end up in the tire wall. So out with the 27mm rear swaybar and back in with the stock 19mm swaybar. I'm thinking the 19mm may be too soft. plus I like being able to adjust the rear bar for more roll resistance. So we'll modify it a bit.

Here's the stock bar end. Not much material there to provide a slot.



We don't want to make the bar any longer, that would make it softer. We want a slot that travels from the end, back toward the main bar. So we cut the stock end off and fabricate a new end.



All we have to do now is cut a slot in it and weld it to the bar.

Here you can see the cutoff end for reference. The finished bar will be no longer.



Still gotta do the other end and cut the slots. Stay tuned!
CR
 

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Discussion Starter #375
I think this will work nicely. :thumbup: Can't wait to try it out.



CR
 

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curious how that looks and how much room that slot has by the bar once it's welded. The pics make it look like the slot is way close to the bar- closer than the bolt head or washer will allow, and the weld won't help matters.

I would have been more comfortable if the bar had a mating groove in it for strength rather than the new bracket being surface welded only.
 

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Discussion Starter #377
curious how that looks and how much room that slot has by the bar once it's welded. The pics make it look like the slot is way close to the bar- closer than the bolt head or washer will allow, and the weld won't help matters.
Turns out I was way optimistic with the length of the slot. There is only enough room to slide the endlink back a little over halfway down the slot. Here's the final welding, grinding and priming product - compared to the RB bar.



New poly bushings. :thumbup:


I would have been more comfortable if the bar had a mating groove in it for strength rather than the new bracket being surface welded only.
I'm pretty confident the new end slot is at least a strong as the 10mm bolt that connects to it. :D I'll let you know how it works out.

CR
 

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Discussion Starter #378
Fender Flares!

OK - Time to increase our tire clearance. :D We start on the front because it will be easier than the rear. You may remember that we were pretty tight on the front. On the inside, we were almost touching the knuckle.



On the outside, this is as far as the suspension could go before the tire rubbed - there was still a couple more inches of travel available before hitting the bump stop.



I added 6mm hub-centric spacers to provide more room at the knuckle. Here's the spacer:



Here's the increased room at the knuckle:



Unfortunately this pushes the tire further out toward the fender. That just means we'll be trimming more sheet metal. :p

Step one, tape off the fender so we don't scratch the paint as we cut the sheet metal. This is the rear, I forgot to snap a pic of the front, but you get the idea.



Then we tape the flare in place where we think we want it. I started with the flare opening aligned with the stock fender opening. Again, I forgot to snap a pic of this step, but this shows about where I want the flare.



I traced the outside of the flare and then drew a cut line about an inch below that, tapering to the ends. We don't need any more room ahead or behind the tire, just above. The tick marks are where the screw holes will be. Then begin cutting. The sheet metal we removed is sitting on the rotor.



Next I pulled the spring/strut assembly out so we can move the suspension throughout its entire range of travel with the tire on to check for interference. With the suspension fully compressed, here's what we got:




I didn't take a pic, but when we turn the wheel lock-to-lock, there is no interference.

Now we tape the flare back on again - aligned with our original trace line and tick marks. It looks good with the wheels straight, but there is serious rubbing with the wheel turned (remember this is with the suspension at full compression).



So we re-position the flare about 1.5" up - notice the original trace line at the bottom of the flare. Now we can turn lock-to-lock, with the suspension fully compressed, with no rubbing.



Below is where I estimate the normal ride height to be.




A bit monster truck-ish now, but when we lower the car with coilovers we'll appreciate the room.

Stay tuned,

CR
 

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You are the F'n man CR! Comming along very well, still waiting for the fender flare source. :D


Sent from AutoGuide.com App
 

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VERY nice CR - What metal did you use for the spacer? As I've heard those aren't typically the safest things in the world to install if you're going to be using the car for performance. Maybe I'm way off, but I heard they weren't always the best idea.

Definitely a bit of needed breathing room though on the knuckles, so I guess it had to be done either way.

Oh and I'll say it before anyone else - TOO MUCH 4x4!!!!11!1!!! :lol:
 
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