alignment for track using stock suspension

[OLDE GUY]

I don't understand this. It's common (even with a proper alignment) to experience significant wear on the inside of the front tires. Not the rears. My rears have always worn evenly across the tread.

My cars with significant rear camber (Porsche 994 T and 928 S and NSX) have all tended to wear more on the inside. If you track the car with the same tires, it seems to balance out and isn't so noticeable because of the increased outside tire wear which occurs on the track.

However, my first set of rear SO3s (255x17) wore most in the middle because of too much pressure (38 PSI street) even with track events. Go figure

 

[Larry Bastanza]

Q,

The first question I have is what is your driving experience?

I agree with the advice in regard to alignment, but your alignment should be set based on your skill level, tire choice, and usage.

Track tires, and competition level driving call for a totally different alignment then a novice with street tires. Not that you cannot use the agressive alignment, but it will not be beneficial IMO, and just add tire wear for no reason.

If you are a novice driver, set the car to a 1994 OEM specs and get some seat time.

JMHO,
LarryB

 

[Q]

Q,

If you are a novice driver, set the car to a 1994 OEM specs and get some seat time.

JMHO,
LarryB

I agree. I believe in doing small changes at a time to coincide with my skills. I initially started with the car stone stock, with the same '94 alignment settings. For my own situation, I believe now I'm at the level where I can start tweaking the stock settings slightly.

 

[Larry Bastanza]

In that case follow the recommendations above

Regards,
LarryB

 

[DCNSX]

OG- If memory serves, I believe I read an old post about your 944 having the unidirectional tires erroneously mounted at the track?? It resulted in major woes as I recall. Your comments about re-mounting the tires on opposite wheels make sense. I'll keep that in mind for a future set if my inward-wear continues. But not in my case at the track next time, as you already mentioned.

As for my track experience, I have two dozen+ track days under my belt, mostly in a '79 Rx-7. I've had 5 track days on the NSX. Otherwise the car just gets weekend street use (not aggressive).

Ken- my rears have always worn on the inside- before I started tracking the car and also on this current set with only 5 track days over the last 2 years.

Two questions:
1. What tire pressures do you run at the track (on street tires)
2. Any recommendations for new tires with a limited budget in mind? I'm fine with the Yokos again, but open to suggestions. thanks.

 

[nsxtasy]

1. What tire pressures do you run at the track (on street tires)

With street tires on the track, I just use the pressures recommended for regular driving (33F/40R, measured cold) and it works fine. This is with the OEM Yokohama A022H tires.

When I'm using track tires, I forget exactly, but it's somewhere around 31F/34R with the RA-1, measured cold, and a couple psi less with the A032R.

2. Any recommendations for new tires with a limited budget in mind? I'm fine with the Yokos again, but open to suggestions.

Well, the OEM Yokohama A022H is an excellent tire and gives a great feeling of precise handling. The OEM Bridgestone RE010 is similar and somewhat less expensive.

There are a lot of excellent top-of-the-line tires out there, including the Goodyear F1 GS-D3 and others, but they tend to cost as much as the OEM tires.

If you want to spend less, you have to step down in performance from the OEM and aftermarket top-of-the-line tires. Take one step down in price and performance and you can consider the Kumho Ecsta MX and the Toyo T1-R. Take another step down in price and performance from those, and you can consider the Kumho Ecsta SPT and the Yokohama AVS ES100. All of these tires are as good as you can do in their respective price ranges. And these are all summer tires, not suitable for use on snow or in extreme cold.

 

[DCNSX]

Thanks, Ken. Tire recommendations duly noted. AVS ES100's are on the car now.

 

[OLDE GUY]

.....Toe-in in the rear makes the car more stable at high speed, under braking, and when adding power exiting a corner. More toe-in isn't always better.....Bob

Let me throw out this experience with REAR toe-in. In 1999, I had the Bilstein coilover suspension put on my Porsche 944 Turbo along with adjustable anti-sway bars, monoball rear joints, rollbar, 5 point harness, etc. by Autometrics in Charleston, SC. They have a lot of experience with Porsches of all types. Three years ago their Porsche came in 19th at the Rolex 24 hours of Daytona in GT. His son had previously campaigned a 944 then 944T in Porsche Club and SCCA. Point being they should know what they are doing.

Anyway, they set the 944T up for street/track with about 3 degrees of negative camber all around and REAR toe-in of 0.1" (2.5mm) on each side for a total toe of 0.2" (5mm) - nearly the same as the 1991 NSX recommendations. So I have felt that the 1991 NSX toe alignment was not excessive for street/track. I do understand that it IS excessive for street only.

In any case, it has worked well for me and I find the rear of my NSX to be quite stable - not at all "tail happy". As for rear tire wear, because I use SO3s for street and track, the outsides are always gone before the insides so it is not an issue.

 

[DCNSX]

OG- Thanks for the input. I'll probably PM you when I get the new tires- or perhaps before my next track session. I'm a neophyte when it comes to all this suspension/alignment tuning.

 

[OLDE GUY]

Thanks, Ken. Tire recommendations duly noted. AVS ES100's are on the car now.

Judging by your Avatar, it seems that you have a 1995 NSX or later with 16 and 17 inch wheels. I would suggest taking a look at Bridgestone SO3s front 225x45x16 and rear in 255x40x17 - 1 cm wider. They fit well - no rubbing.

As I have not used Yoko OEM, I can't comment on them. But I can say that the SO3s in this size are vastly better than the OEM Bridgestone RE 010 which get slippery when you are driving hard on the track. Others have written the same thing. My last set was $50 off each tire about this time of year at TireRack.

 

[nsxtasy]

OG- Thanks for the input. I'll probably PM you when I get the new tires- or perhaps before my next track session. I'm a neophyte when it comes to all this suspension/alignment tuning.

Remember what Larry said. If you're not all that experienced, just set the alignment to the recommended specs and don't worry about it.

Judging by your Avatar, it seems that you have a 1995 NSX or later with 16 and 17 inch wheels. I would suggest taking a look at Bridgestone SO3s front 225x45x16 and rear in 255x40x17 - 1 cm wider. They fit well - no rubbing.

I would avoid buying the S-03, since Bridgestone is in the process of discontinuing them. This means that in the event of one or two tires needing replacement, you might not be able to get them.

For street tires for 16"/17" wheels, the OEM tires are great. Another good all-around choice is the Goodyear F1 GS-D3, which I recommend in 205/45-16 and 245/40-17 - excellent dry traction, excellent wet traction, excellent treadlife, and less expensive than the S-03. If you want even better dry traction, and you don't mind living with so-so wet traction and rapid treadwear, then consider the Falken Azenis RT-615 in 215/45-16 and 255/40-17.

But I can say that the SO3s in this size are vastly better than the OEM Bridgestone RE 010 which get slippery when you are driving hard on the track. Others have written the same thing.

I've never heard that before. Was it posted on NSXprime? Could you provide a reference, please?

 

[OLDE GUY]

.....I've never heard that before.....

That's exactly what you wrote the last time this was posted on NSXPrime by me and VBNSX (Xavier) who does about 20 DEs a year. Pay attention :wink:

As I recall, you have written that you have never used Bridgestones RE010, only OEM Yokos, and have no personal experience with them - or SO3s for that matter. Feel free to contact VBNSX who like myself has used both - on the street and the track - for further info about the comparison of Bridgestone RE010 versus SO3s. He has also posted about them a few times.

 

[nsxtasy]

That's exactly what you wrote the last time this was posted on NSXPrime by me and VBNSX (Xavier) who does about 20 DEs a year.

Wrong; I didn't post anything like that. But thanks for the reference to VBNSX, which made it easy to find the previous topic in which he posted about them. Also, you mischaracterize Xavier's experience; at the time he posted in that topic, he had done approximately half a dozen events, total, which is not a whole lot of track experience.

For the record, here's what I did post in that topic:

I suspect what you're feeling is the difference in your inputs, rather than a difference in the tires themselves.

If you still have the RE010 tires on a separate set of wheels, you could bring them with you to the track and try switching back and forth between the two sets of tires in different sessions. If, OTOH, the S-03 replaced the RE010 on the same set of wheels, that's not an option...

 

[OLDE GUY]

Bridgestone SO3s

DCNSX - If you think that you might be interested in learning more about oversize SO3s, here is a link with commments from 5 or 6 track drivers who have used them. The problem with RE010 is that they become quite slippery after about 12 minute of hard driving on the track. So it is difficult to keep the NSX on the race line that one uses in the first half of a track session during the second half of the session. Adjusting the tire pressure doesn't correct the problem. On the other hand, SO3s hold their adhesion very well throughout a 20 to 25 minute session - you can use the same line though the entire session. This is why I prefer them to RE010s having used each in quite a few track events.

http://www.nsxprime.com/forums/showthread.php?t=44260

 

[nsxtasy]

If you're really looking for a street tire to do double-duty at track events as well as in street driving, I highly recommend the Falken Azenis RT-615. It's designed to be basically a cross between a street tire and an R compound track tire, and as a result provides great dry traction for track events and holds up well to the heat of the racetrack. Its downsides are so-so grip in wet conditions and relatively short treadlife (but tends to be better in those aspects than true R compound track tires). It's available in the '91-93 stock sizes for 15"/16" wheels, in 215/45-16 and 255/40-17 for 16"/17" wheels, and in 215/40-17 and 265/35-18 for 17"/18" wheels.

You can read more about the RT-615 on the Falken Tire website here. Dealers include Vulcan (UT), Edge Racing (FL), and Discount Tire.

Once you start building up a lot of track experience, you'll probably want to get an extra set of wheels and use R compound track tires for the track, and other tires for the street. Until then, the Falken RT-615 is a nice meeting point between the two.

 

[OLDE GUY]

OG- If memory serves, I believe I read an old post about your 944 having the unidirectional tires erroneously mounted at the track?? It resulted in major woes as I recall. ......

Not me, fortunately. I did swap my unidirectional front tires+wheels a couple of times while at tracks with the 944 Turbo but there were no adverse consequences.


What I was referring to was swapping the front wheels+Bridgestone RE 010s on my NSX once on the 250 mile drive from Charlotte, NC to Roebling Road near Savannah, GA - thinking that I might try them on the track that way. I could tell immediately on lane changes on the I-77 and I-95 that the crisp turn-in and precision of the RE 010s were gone. The NSX handled like a different car. Apparently the bands within the tire are wraped in different ways for each corner to work with the suspension to improve handling (see FAQ). When you swap the wheels+tires side to side, they run backwards which distroys this built-in benefit.

When I got to the track, I swapped them back to their normal position. So don't swap the corner specific OEM tires to get more tire wear.

 

[Q]

After AOB aligned my car, I did an HPDE event at Gingerman last Monday. WHAT A DIFFERENCE!!! The car has much better turn-in, with just a slight, slight bias towards oversteer. The tendancy to push in the corners was greatly reduced. It felt great. Here are my current specs with 170 lbs in the drivers seat:

Front camber left: -1.2
Front camber right: -1.1

Rear camber left: -2.0
Rear camber right: -2.0

Front caster left: 8.1
Front caster right: 8.1

Front toe left: -0.07
Front toe right: -0.05

Rear toe left: 0.09
Rear toe right: 0.09

 

[OLDE GUY]

I am glad that you are happy with the alignment. Now perhaps 1 cm wider front tires and the NSX-type R front anti-sway bar?? As mentioned above, I can't tell that the 225 front tires rub while driving but there is a little scuffing of the fender liner.
Were you pleased with your SO3s?

 

[Q]

I am glad that you are happy with the alignment. Now perhaps 1 cm wider front tires and the NSX-type R front anti-sway bar?? As mentioned above, I can't tell that the 225 front tires rub while driving but there is a little scuffing of the fender liner.
Were you pleased with your SO3s?

The problem is the availability of a 225/40/17. My next upgrade will be the entire suspension, probably in a year or so. I want to get as much out of the stock setup before I move on.

I really love the S03. I was very pleased with them on my stock 15/16 setup, so I went with them with my 17/18 combo. They've got very good grip and have predictable break away. Very easy to modulate. They seem to hold up well to heat too. Since they don't make them anymore, for my next set I'll try the Falken RT-615. I seriously think I got one of the last sets of 215 and 265 S03s left!!

 

[DCNSX]

Everyone- thanks for all your input.

OG- my '91 looks like a '95+ since it is a non-factory conversion targa. it has the updated OEM 7-spokers. Suspension is all stock, except the conversion co. (Newport Automotive Engineering in SoCal) did brace the underbody by adding a square-tube aluminum (!) brace beneath the car to give back some of the stiffness. Not sure if they reinforced the cowl. ...and yes it leaks- I need new seals, they're one-offs-- and it has some cowl squeak, which I overcome with high RPM's and/or loud stereo :biggrin: )

Anyway, It's my weekend car that I track 6-8 days/year. My "track" budget is very limited so I just have Axxis ultimate pads front and rear. I plan on adding Dali brake deflectors (?) and removing the rain shield. Other than new tires (the Falkens are intriguing- I don't plan to switch tires/wheels for the track ...for now.), speedbleeders and SuperBlue fluid, that's about all I'll do for this year. ...and Larry B has graciously sent me some CG locks. What a guy!

...and yes, VBNSX is quite the track whore. I think he lives in a culvert near VIR. :wink:

 

[Q]

...I just have Axxis ultimate pads front and rear...

Curious, have you been to the track with those pads yet?

 

[DCNSX]

yes- several days of HPDE with the Axxis on the fronts only (rears just added). I had OEM pads my first two track days a coupla years ago and had horrible shudder. I did nothing to the rotors- but just made sure I bedded in the Axxis well, per their instructions. The shudder went away completely and I've experienced little fade- but I take it relatively easy on the brakes- drifting the last hundred yards or so on the main straight before braking. Any recommendations for upgrading the front pads (keeping in mind I have new Axxis Ultimates in the rear now?) Kinan mentioned he loves Project U pads.

Hopefully adding the Dali deflector and removing the rain shield will help cooling a bit.