Noob tuning question

[Jujubean]

Okay, so I am a long time GT fan, but most of the tuning I have done up until this point has been trial and error, and very imprecise (increase spring rate, lower ride height, set the gear ratios, and you're ready). Now I am trying to get more systematic about things and actually diagnose problems and fix them rather than just saying, 'oh that car is just trash.'

So my question is concerning my Camaro SS '69. I had been tuning it up had dialed out the understeer by adjusting spring rates, ride height, and camber, but I realized the inside rear wheel was spinning like a mad man when accelerating out of corners. My intuition tells me this is a differential problem, so I go to adjust it, and lo and behold, I still have the stock diff. I did a trial run with the LSD installed, and now the outside wheel is causing far more harm that the inside was before. I tried increasing the Acceleration sensitivity for the LSD, but that only made it worse, so then I started decreasing it. I have it all the way down to the minimum setting, but I am still smoking that tire on the exit of (especially) slow corners.

Is this just something that my heretofore less critical inner tuner never noticed, is there something else I should adjust for this, or am I just hitting the throttle too hard too soon?

Thanks in advance.

 

[nomis3613]

Yep, we're aware of it. https://www.gtplanet.net/forum/showthread.php?t=203009

Much different to GT4, eh?!

 

[Adrenaline]

I did a trial run with the LSD installed, and now the outside wheel is causing far more harm that the inside was before. I tried increasing the Acceleration sensitivity for the LSD, but that only made it worse, so then I started decreasing it. I have it all the way down to the minimum setting, but I am still smoking that tire on the exit of (especially) slow corners.

When you say 'that' tire, are you referring to the outside tire still?
If you're smoking the outside tire, with the Accel setting at 5, then your initial is way off. What are your full LSD settings right now?

Based on what I know about the Z28 (I assume the SS can't be far off)
You'll want to start with an initial of 10-15, Accel of 30-40 and DeAccel of 10-20. Stock is probably 10/40/20 and you said you disliked that, so my next jump would be 15/20/15 and then slowly work your way from there. If your issues continue, I'd venture to say you need to take a look at rear spring rates, ride heights and quite possible your transmission gearing.
Remember, these cars are running solid rear axles with leaf springs, there's only so much you can tune out of it.
Am I to assume you're on racing softs?

 

[Motor City Hami]

I am finding that camber can also affect the glowing red tire. If the LSD doesn't solve the problem, it is something else in the tune. Try different camber angles and different shock damping.

 

[Jujubean]

From the GT4 tuning thread:

* Accel. Settings:
Locking (higher value) Increases traction out of corners by limiting wheel spin. Limits the car’s ability to turn, particularly in tight corners.
Opening (lower value) Reduces traction out of corners by increasing the chances of wheel spin. Improves the car’s ability to turn, particularly in tight corners.

That doesn't corroborate with what I was experiencing, which was higher settings making the outside wheel spin even more, and any gas at all while not in a straight line having disastrous results.

When you say 'that' tire, are you referring to the outside tire still?
If you're smoking the outside tire, with the Accel setting at 5, then your initial is way off. What are your full LSD settings right now?

Based on what I know about the Z28 (I assume the SS can't be far off)
You'll want to start with an initial of 10-15, Accel of 30-40 and DeAccel of 10-20. Stock is probably 10/40/20 and you said you disliked that, so my next jump would be 15/20/15 and then slowly work your way from there. If your issues continue, I'd venture to say you need to take a look at rear spring rates, ride heights and quite possible your transmission gearing.
Remember, these cars are running solid rear axles with leaf springs, there's only so much you can tune out of it.
Am I to assume you're on racing softs?

You are correct assuming that is referring again to the outside rear tire. I will try your LSD settings. I am aware that this is a 43 year old hunk of metal I am working on, so it won't be perfect. I am on SS, but I only have power up to ~400HP (I am aming for 500PP).

I am finding that camber can also affect the glowing red tire. If the LSD doesn't solve the problem, it is something else in the tune. Try different camber angles and different shock damping.

I was thinking a touch of rear camber might help; I haven't tried that yet.

Thanks to those with suggestions. I am just trying to learn bit by bit about tuning. I will post up here any updates or good news concerning this tune.