gannieevo9

iTrader: (6)

Thanks everyone for the input on the front differential and sorry for the delays getting the tire wear pics to show how big of an impact having that inside front tire spinning in the air with even some power being sent to it. The top tire is the one I used on a Saturday and then rotated to the rear on the Sunday. The one on the bottom is the one I used on the Sunday and pushed pretty hard. This bottom tire looked like the ones in the middle in the AM....



I'm going to do the following to help alleviate this situation (wear management):
1. Rotate tires more often - possibly after each session
2. Work harder on trying to get the car rotated harder and faster so that I am more straight as I feed on throttle
3. ACD reflash
4. Look into an upgraded front differential during the winter when I get the transmission serviced

kyoo

iTrader: (29)

^ Yeesh. What is your mod list again? Suspension setup? Rear diff? etc?

fwd_josh

iTrader: (2)

Speaking of the front diff, does any one know what LSD Shep installs when you have him put one in the 03-04's?

heel2toe

iTrader: (41)

If I had to guess it would be from an 04 rs.

killerpenguin21

iTrader: (20)

maybe its just me, or the picture...but those all look more worn in the center to me...

Nimpoc

iTrader: (17)

Yeah, check toe for sure. And maybe too much rear bar. If you're picking up / unloading one tire then spinning the other it'll come around quick.

I had a couple mid-corner 'mystery' spins at neutral throttle and high cornering loads that I attribute to tricycling. Adding a FSB seems to have eliminated it. A more correct solution would be more spring, but I didn't want to go there with a street car.

Nimpoc

iTrader: (17)

I'm not sure what you're overall goal for the car is nor constraints based on class rules, etc, but it seems like you're heading toward reducing tire wear with expensive diff tuning rather than maybe focusing on keeping the tire on the ground... For about the costs of an ACD flash and Cusco front diff, you can have a set of Ohlins. The suspension solution could be a whole lot cheaper if you're already on coilovers and just want to try stiffer springs / FSB.

Just a thought.

gannieevo9

iTrader: (6)

Mod list is:
Power: basic bolt ons with supporting fuel components for 334whp and a speed density tune.

Drivetrain: Competition Clutch Stage 2 Unsprung Clutch with the TRE max lock diff.

Suspension:
Stance GR+ Coilovers (in the dry, I usually set up with 1-2 clicks more stiffness in the rear than in fronts, these are 1 way adjustable only)
Whiteline Rear sway bar
Whiteline roll center adjustment kit
Whiteline bumpsteer kit
Perrin Positive Steering Response System
Alignment is set at -2.8 fronts, -1.8 rears and zero toe all around
Corner balanced

gannieevo9

iTrader: (6)

This is my TT3 track only car so suspension and drivetrain mods are pretty open and only have a set of Stance's because I've had them for a while and have gotten the job down until possibly now.

Disclaimer, I am a relative suspension set up noob and thus have stuck with basic changes (dry versus wet solutions). By a better set of coilovers, I'm assuming you are alluding to the ability to change rebound as well compression?

And by a stiffer spring you mean, in the rear to not allow the car to squat as much under hard acceleration?

FSB = ?

Thanks!

gannieevo9

iTrader: (6)

Yeah, I noticed that too a couple events ago and have been careful about monitoring the tire pressures to make sure they aren't too high. Have been consistently running them at around 38-39psi hot.

Don't have a pyrometer so haven't measured actual temps. No squirminess in mid-corner as you guys described and beyond the tire wear and associated inability to get the car straight on tight turns in question, really no complaints about traction at all.

R888's might not be the stickiest things out there but damn they are predictable, even at the limit. Here's a session from a couple months ago, check out lap 6 and you can hear them starting to howl a bit in the high G load turns and they held on well.

http://trackattackapp.com/?raceid=89...b-4e8e0a583625

gannieevo9

iTrader: (6)

ah, I just got the FSB = Front Sway Bar. What an idiot, was obviously online too late last night.

I have the OEM FSB right now and can see now how that can help now that I'm pushing the car this hard.

The car comes back next week with a full weld in cage, prepped to meet NASA wheel to wheel racing requirements plus a little more. Would the additional overall chassis stiffness help or still do the FSB?

Nimpoc

iTrader: (17)

Probably best to move this over to Motorsports as it's far from Rear Diff talk now. That said, the cage is likely to make a huge difference in the balance of the car and effective wheel rates. Since it's a proper race car for tarmac use I personally wouldn't add a bigger FSB, but rather add spring rate to keep the tires planted. Something else to consider is running a bit less damping in the front. I'm not sure what the Stance knob is adjusting, but it's probably low speed rebound and/or compression. If rebound, and you're having wheel spin issues with the front, less rebound should help reduce lift of the inside tire. Again, I'm just making an informed guess here, but you don't want to use compression damping to try to keep a tire down steady state.

gannieevo9

iTrader: (6)

Agreed, and actually where I spend most my time on Evom. All the hawt talk is on the motorsport thread. Here is my build/journal on there:


https://www.evolutionm.net/forums/mo...-build-10.html


Good input, really appreciate it. I'm going to be extra sensitive to that with the cage in the next time I'm out in a couple weeks. I'll also be on BFG R1's (first time on this sticky of a tire).

siikEvo92

iTrader: (5)

Gahh reading this made the decision between tre and shep so much harder. I live 5min from sheps house and have picked his brain about my needs (track only car, nasa build, ohlins, yada yada) but it seems the tre maxxlock is just so well liked.

heel2toe

iTrader: (41)

Hmmm that is a tough call. Im not sure I will be able to offer much assistance to you however I can say that I am 100% satisfied with my TRE Maxxlock rear diff. Jon was fantastic to work with and I know for a fact that his product offers more that what Shep brings to the table.

Its tough for you bc you are so close to Shep so I see the desire in terms of convenience and saving without having to deal with shipping.

At the end of the day you need to think about your priorities. Both products will certainly facilitate power oversteer. Personally I think TRE has a better product so that would be my vote.