[DaveC113]

Originally Posted by jwisjw

So the turn-in lock up feel or decel is isolated from the diff tune, fwiw. It is the calibrated engine torque that is created from the different modes that you want to run, touring, sport or track. The corvette experiences a lot more "lock up" on decel feel with track so we run touring and also the ediff is a lot happier with lock up on exit to help us rotate under power.

Surprised that your friends non-1LE spins up one wheel given it is a clutch type diff? I would suspect something is up with the setup of vehicle.

The amount of lock on turn-in is greatly effected by the GMPP tune, it's actually in the GMPP description and it's very noticeable in some situations, it opens the diff more quickly on turn-in and locks it more quickly on throttle. I do agree the eDiff changes it's behavior depending on many factors, but the GMPP tune is only active in track mode with all nannies off, and under 70 mph or so.

It's best to tune for it with the roll bar setup, otherwise you may end up with a bit too much oversteer. It's also too abrupt for the OEM tires and can unsettle the car. With 200tw autox tires you just don't notice it unless you do something wrong, like overslowing for a slalom then getting back on the gas as you enter the slalom, when it locks up the car will shift position a bit which isn't ideal, but I figure that's just my poor driving.

Of course my friend's car may not be setup optimally, but he's had it since '16 and has won ESP at Nats. He says it's the venue's surface. It is an odd one, PPIR in Fountain, CO. It can get hot enough that times actually start falling off in the afternoon.

My car is pretty much a F-Street SLE with an alignment, wider wheels and the
autox diff tune, and it's been keeping up with or beating cars with a lot more prep lately. My codriver managed to beat a CAMC car that trophied at Nats. I do think the eDiff tune is contributing.

[DaveC113]

Originally Posted by VR Baron

Stock tune probably also contributes to my lazier turn in.
Dave, on a side note, remember when we talked about the cost of the tune? A guy up in NoCal just got it done. Cost $730! Gm charged 280 but dealer charged 450 for 1.5 hours. Didn’t think they were to charge extra, customer beware I guess

Ooof, that's a big tax for what's really 15 minutes of labor, but the Dealer has to call GMPP with the VIN and then they send them the tune. I paid about $300-350 or so, it was about 4 years ago now though.

[jwisjw]

Originally Posted by DaveC113

The amount of lock on turn-in is greatly effected by the GMPP tune, it's actually in the GMPP description and it's very noticeable in some situations, it opens the diff more quickly on turn-in and locks it more quickly on throttle. I do agree the eDiff changes it's behavior depending on many factors, but the GMPP tune is only active in track mode with all nannies off, and under 70 mph or so.

Of course my friend's car may not be setup optimally, but he's had it since '16 and has won ESP at Nats. He says it's the venue's surface. It is an odd one, PPIR in Fountain, CO. It can get hot enough that times actually start falling off in the afternoon.

Sorry, not trying to be that guy but the person that created the autocross diff tune told me that what you are feeling is "drag torque" and is completely isolated from the autocross diff cal itself.

It definitely sounds like you are talking about Darden and I don't think our setup and his setup are even in the same league fwiw.

[jwisjw]

Originally Posted by VR Baron

With sq stones or now the nankangs , Nannie’s off in track and stock front bar, The only really annoying time with the EDiff was oversteer out of tight turns onto straights. On a very bad autoclub lot six surface with low grip. With the hotchkiss front bar set soft I now use, have no issues with the EDiff, or Should I say the EDiff and sq tire oversteer combo(?) I can focus on the now lesser steering response with the bigger bar and lazier crs turnin on the tight all turns no straight very grippy lot we now have, and never have to give the rear a second thought. Not sure what else I should be noticing with ediff behavior, the car just grips everywhere.

I can totally believe that for sure! Makes the magride do so much less and prevents it from nosing over as much.

autoclub lot... tire grinder haha, you should be happy that you can't run there anymore. Have you ran at Lake Elsinore?

[DaveC113]

Originally Posted by jwisjw

Sorry, not trying to be that guy but the person that created the autocross diff tune told me that what you are feeling is "drag torque" and is completely isolated from the autocross diff cal itself.

It definitely sounds like you are talking about Darden and I don't think our setup and his setup are even in the same ball park fwiw.

That's fine, there must be a misunderstanding somewhere and it could easily be mine, but the "unlock on turn-in" thing is specifically mentioned in the GMPP description of the tune, and it's very noticeable in some circumstances.

I do agree that drag torque has a major effect on eDiff lock up, you can see this when you run the eDiff lockup display on the dash, but I disagree the eDiff tune has no control over the eDiff's behavior on turn-in. I've had the eDiff tune for 4 years now, it's really a night and day thing at times.

I'm not comfortable naming names if they aren't here to participate in the discussion, but you may be right. The car's running Hotchkis ft/ZLE rear bars and MCS suspension.

[VR Baron]

Originally Posted by jwisjw

I can totally believe that for sure! Makes the magride do so much less and prevents it from nosing over as much.

autoclub lot... tire grinder haha, you should be happy that you can't run there anymore. Have you ran at Lake Elsinore?

That our new home! Since autoclub and nmca went away some of us expats have been running with Porsche club LA. Kicked out of Angels stadium, then kicked out of San Pedro..lol 11/4 will be my third time at Storm stadium. My buddy Will Flores has been trying to me to run scca sd with him but I am to old and lazy now and don’t want to work..lol

[joelster]

Got the trifecta last weekend at MBR SCCA in PA.



Car is a '15 Z/28 with great power, stock brakes, stock suspension except for camber plates.

[apexit53]

forgot to share this one. Went to st louis last weekend for their cam challenge event. Needed some seat time in the new camaro. Went better than expected. Day 1 was in third over all still figuring out the car on stones. day 2 in the morning was qualifying for the challenge, first run was enough to safely keep me in the challenge so used the remaining runs to push the limits. ended up taking off about another .8 of second..... once i found that rhythm all i needed to do was be clean. ended up winning the Cam c bracket and wont the cam challenge over all. fun event with a good crew at st louis region.

[DaveC113]

Congrats Joel and Mike!!!

I need to start taking some video. I've never felt it would be all that useful as a beginner, it's really obvious what I do wrong and nobody cares. I'm getting a little faster though! This weekend was a BMW event in the rain, I got 5th fastest raw time and 5th overall. I was running my PS4S tires, but those on REs seemed to do well too. RT660s seemed off pace, a couple good drivers on them didn't do well.

Anyone have any comments about the Nankang CRS? Rotis seemed to do well with them, and Tire Rack recorded a faster time than Yoks. I ordered a set of 335/30/18, going to run them square on 18x12s. They'll take about month to arrive so I can cancel them. I'm pretty happy with my 295/35/18 REs, but 335 is a larger number than 295.

Here's a couple pics of the Camaro... the hood wrap and flag vinyl were replaced by a flip color that is satin black base but flips dark red and gold metallic. Adds a little bling! I also replaced the oem hood vents with Race Louvers.

[joelster]

Originally Posted by apexit53

forgot to share this one. Went to st louis last weekend for their cam challenge event. Needed some seat time in the new camaro. Went better than expected. Day 1 was in third over all still figuring out the car on stones. day 2 in the morning was qualifying for the challenge, first run was enough to safely keep me in the challenge so used the remaining runs to push the limits. ended up taking off about another .8 of second..... once i found that rhythm all i needed to do was be clean. ended up winning the Cam c bracket and wont the cam challenge over all. fun event with a good crew at st louis region.

GREAT runs! I was watching the live timing as it was happening.

Serious question here......

How many damn cars do you have? LOL, I know you had a 1LE, then had/have a Mach 1, and now you're back in a 1LE?

[clyde]

Originally Posted by DaveC113

Anyone have any comments about the Nankang CRS?

They seem to be good in cold weather.

Originally Posted by joelster

GREAT runs! I was watching the live timing as it was happening.

Serious question here......

How many damn cars do you have? LOL, I know you had a 1LE, then had/have a Mach 1, and now you're back in a 1LE?

[apexit53]

Originally Posted by joelster

GREAT runs! I was watching the live timing as it was happening.

Serious question here......

How many damn cars do you have? LOL, I know you had a 1LE, then had/have a Mach 1, and now you're back in a 1LE?

lol. I have an integra daily and my 1le 😂. Traded the mach1 for this Camaro. Just like the 1le more.

[VR Baron]

Originally Posted by apexit53

lol. I have an integra daily and my 1le 😂. Traded the mach1 for this Camaro. Just like the 1le more.

Ok wait, you got rid of the blue one and now in a white one?

[VR Baron]

Originally Posted by DaveC113

Congrats Joel and Mike!!!

I need to start taking some video. I've never felt it would be all that useful as a beginner, it's really obvious what I do wrong and nobody cares. I'm getting a little faster though! This weekend was a BMW event in the rain, I got 5th fastest raw time and 5th overall. I was running my PS4S tires, but those on REs seemed to do well too. RT660s seemed off pace, a couple good drivers on them didn't do well.

Anyone have any comments about the Nankang CRS? Rotis seemed to do well with them, and Tire Rack recorded a faster time than Yoks. I ordered a set of 335/30/18, going to run them square on 18x12s. They'll take about month to arrive so I can cancel them. I'm pretty happy with my 295/35/18 REs, but 335 is a larger number than 295.

Here's a couple pics of the Camaro... the hood wrap and flag vinyl were replaced by a flip color that is satin black base but flips dark red and gold metallic. Adds a little bling! I also replaced the oem hood vents with Race Louvers.

Dave, racing a friend monthly with his zl1, he has 305/30/19 crs’s. More camber than me but I have the bigger front bar. My 285/35/19 RE71s so far seem to be as fast, no advantage over each other. He recently had to change to 305/30/19 falcons and depending on the course length time wise I picked up .2-.4 seconds. Probably more as I was overdriving some really tight hairpins.

Rick