[TheRealJA105]

Originally Posted by TrackClub

Good to hear on the bushings: congrats regarding your ingenuity and perseverance!
Thanks!
Regarding your set up:

1) It is extremely unorthodox to run a stiffer rear bar on a F engine car, especially one with an extra weight of a blower. I think this is causing you a F vs R roll stiffness imbalance on entry/mid corner and an obvious oversteer issue on exit (which costs you tons of time).
I realize it's unorthodox, but i really dislike understeer.
However I realize i need to do some experimenting and i think reversing my bars to full stiff front and middle rear will be a good comparison
2) Looking at your recent NCM vid you proly lose at least 3-4 secs having to correct for oversteer on exits and delaying benefit of your supercharged power. Case in point, Provoste was 2 secs faster in a bone stock SS 1LE except for DTC60s. Sir Jackie Stewart once said: "The corner exit is far most important than the corner entry in terms of smoothness". Colin Braun repeats that most recently in my post "Best track advice ever" with more detailed advice. It is so obvious, yet i think too many of us focus on getting this extra tenth on entry and forget about principle #1: good exit that will pay fat dividents all the way til the next braking zone . If i were you, i would fix that issue first.
Agreed, see answer to #1, but I would probably drop time if i could put the power down sooner
3) if you feel understeer on entry, then obviously your front is set up too stiff (yet i didnt see any corrections for understeer in your NCM vid, so perhaps it is mild?). Also, very clearly, your rear is too stiff. So...given the two comments above (and i know how fast Nicky Bobby is ) perhaps consider what they run bar set up wise, copy them, soften the bars and run them equally. Another fast guy, Ryephile runs the same set up as well if i recall correctly. Funny how marrying BMR sways with Hotchkis makes more sense than BMR only. Maybe BMR took a page from a Stang book, thinking a Camaro would benefit from a stiffer rear, but clearly it does not.
My initial idea behind getting the bars was to greatly reduce body roll and hopefully help my outside tire edges, oh and get more oversteer!
4) i see a wing on your mods list. Have you balanced it out in the front with a splitter/cannards/extractor hood/etc?
I have a Street Scene splitter which i feel is pretty aggressive, the Callaway hood is vented and ZLE front end (for both aero and cooling) is on my next years list if i don't switch out for a C6Z.
5) do the G3s just bolt on to your car, or do you have to use spacers? Changes in track width ratio F vs R can also change balance one way, or the other.
The MRRs just bolt on and i use a 5mm spacer up front to push them to 18mm offset vs 20mm on 1LE/ZL1
6) getting some toe out in F should lead to better turn ins (albeit i like my stock SS with 0).
Yeah but i like my tires to last, we know this battle
7) if you subscribe to Ross Bentley's Speed Secret Weeklies (and if you dont, subscribe today!!!), you can download his FREE e book on set up. It is short and excellent. Truly excellent.

Last comment: i havent competed for years (except for iRacing in off seasons ). I just arrive and drive and have fun. Yet, i am still very competitive regarding my PBs. Ive been happy with my PBs in the last 3 yrs. Then 2020 happened and my usual season went to shit. But that gave me an opportunity to contemplate my driving and look for improvement opportunities. I had decided to really focus my limited outings on carrying brakes deeper than usual (even though i always trail brake anyway) and most importantly: releasing them very smoothly. I only did 5 days this season and ran only 2 venues. Result? I beat my PB on both and almost immediately:
1 sec on a 1:20+ track (from 1:19 to 1:18) and 2 secs on a 2:00+ track (from 1:59 to 1:57). Food for thought regarding old dogs learning new tricks

Cheers and best of luck!

PS Re posted suggestion to try YYZ springs...save your money (so sorry Krops!).

Originally Posted by h018871

TrackClub, very nice write up / explanation

I like numbers, so.........
I put these together. For me it makes it much clearer what should happen and why. We're running different setups (springs/aero/tires/surface/pressures/etc), so a bar change for one person will not necessarily have the same results for another.

TheRealJA105 Considering sways only: you have ~ 23% front bias over the stock FE4 setup

I'm not running the Hotchkins, but your chart doesn't make sense to me. If i reverse my settings and switch the front bar to full stiff and rear to middle how does that decrease the front bias by 1% I think your bottom row should all say rear bias.

[h018871]

Originally Posted by TheRealJA105

I'm not running the Hotchkins, but your chart doesn't make sense to me. If i reverse my settings and switch the front bar to full stiff and rear to middle how does that decrease the front bias by 1% I think your bottom row should all say rear bias.

Thx for catching that The chart is updated for the first 2 columns to show the correct rear bias.
The firm/firm settings are a 78% increase in front and 77% increase in the rear for Hotchkis front and BMR rear bars when compared to the stock FE4 (ZL1) bars. This makes for a 1% increase in front bias, compared to FE4. Which is so close that I for one couldn't tell the difference and I'm sure is within the margin of error based on the initial numbers.

[TrackClub]

Originally Posted by h018871

TrackClub, very nice write up / explanation

I like numbers, so.........
I put these together. For me it makes it much clearer what should happen and why. We're running different setups (springs/aero/tires/surface/pressures/etc), so a bar change for one person will not necessarily have the same results for another.

TheRealJA105 Considering sways only: you have ~ 23% rear bias over the stock FE4 setup

EDIT: you don't have the Hotchkis front bar and I corrected the bias chart

Thanks for your kind words Geoff and thanks for prepping these excellent comparo tables. Awesome job!

Agree, that folks set ups may differ, due to aero, rims, tires etc. And as such a change in sways may produce different results. But, by and large, stiffer will produce more roll stiffness, which will result in faster transitions, but less grip. This will be especially magnified when running streets vs slicks, albeit the rule applies to both.
Additionally, it is important to maintain proper roll stiffness balance F vs R.

As you charts indicate, Hotchkis F with BMR R offers a much better pairing, as it offers an ability to increase the roll stiffness proportionally F vs R to start with: a la 1LE/ZL1 27% stiffer on both ends. Then it also offers a finer ability to tune either towards a slight understeer (a la Nicky Bobby set up), or reverse, with smaller bias increments. I think that's what you were getting after by mentioning a 1% bias. Cheers!

JA, obviously you have a fast car and equally *obviously* you know how to wheel it

But a car that understeers on entry and oversteers on exit is an absolute nightmare and points to a major imbalance. Id hazard a guess and say it means the car has too stiff roll stiffness on both ends and with your big rear bias, proly a bad F to R balance as well, provoking an over loose condition from mid corner onwards.

I have no idea how a non 1LE SS handles. The only thing i can say is my SS 1LE is very neutral. Perhaps with a very slight bias towards oversteer mid corner (I do think my 2020 has a bit more F grip vs my 17). But it is stupidly easy to push, with a great turn in (with trail braking to keep the weight on the nose) and has great traction on exits. Having said that, these cars have MRC and e diff. Not sure about yours.

It is easy to make a suggestion as it is your wallet lol, but I'd get a Hotchkis for your F end and see what happens with equal (F vs R) soft set up first. Basically mimicking a ZL1 set up but with a bit more roll stiffness. It may require deeper trail braking to rotate it, but that should not necessarily lead to loss of pace. Quite to the contrary. NB that's were proper pads that offer good modulation are absolutely key imo.

Then dial the rear up one notch and see what happens.
Ditto leaving the rear soft and turning the F one up (a la Nicky Bobby). I would not be surprised at all, if this actually resulted in much more stable car and faster pace. Anyway, such bar pairing would permit you to make more finer adjustments vs 2 BMR bars.

Just my armchair opinion here, so take it for what it is

All the best and cheers!

[TheRealJA105]

Or I can just move my settings to what I said with the BMRs (stiffest front & middle rear) and maintain the exact FE4 bias and be 55% stiffer on both ends.

[TrackClub]

Originally Posted by TheRealJA105

Or I can just move my settings to what I said with the BMRs (stiffest front & middle rear) and maintain the exact FE4 bias and be 55% stiffer on both ends.

You are absolutely correct and it would make perfect sense to try this first. I was looking kinda forward to another step of being able to soften both ends below 55%, given your understeer comment (which may get worse with even stiffer front). But who knows?
Bottom line, not spending $ unnecessarily is always a good thing Best of luck and cheers!

[TheRealJA105]

Hence why I'm confused and need to just experiment with my setup. We've already discussed the understeer in / oversteer out condition so it doesn't make sense how to fix it, but I can definitely benefit from putting the power down sooner. Maybe it will make it feel even worse to me, but if I go faster that's hard to argue against.

Also before I went BMR i ran FE4 front FEA rear stiffest and without a doubt went faster and liked the car better with my current BMR settings.

[TrackClub]

Originally Posted by TheRealJA105

Hence why I'm confused and need to just experiment with my setup. We've already discussed the understeer in / oversteer out condition so it doesn't make sense how to fix it, but I can definitely benefit from putting the power down sooner. Maybe it will make it feel even worse to me, but if I go faster that's hard to argue against.

Also before I went BMR i ran FE4 front FEA rear stiffest and without a doubt went faster and liked the car better with my current BMR settings.

Yep. You can also try both BMR bars in their softest settings and still have a stiffer rear, if you prefer such balance. Hence, that's what id do first and see what happens. Bottom line, softening (as in both ends) should improve grip (at both ends). Zero question. Increasing F stiffness even further will likely just worsen understeer. But, it may solve the F vs R roll stiffness balance. Won't know until ya try. Good luck!

NB Pairing BMR rears with the others up front would offer an equal, softer balance F vs R, but it is always prudent to see if the present kit can be adjusted before forking out more $.

[TheRealJA105]

Right, it's clearly not like the car is undriveable or I'm going slow. I'm just trying to go faster and you as well as others have pointed out how unconventional my setup is. I may see lower laptimes from corner exit traction and using my power than I am getting now with having the car rotate easier.

Or a may get rid of the car and get a C6Z. Idk what I want to do!!!!!!!!!!!!!!

[TrackClub]

Originally Posted by TheRealJA105

Right, it's clearly not like the car is undriveable or I'm going slow. I'm just trying to go faster and you as well as others have pointed out how unconventional my setup is. I may see lower laptimes from corner exit traction and using my power than I am getting now with having the car rotate easier.

Or a may get rid of the car and get a C6Z. Idk what I want to do!!!!!!!!!!!!!!

Nope: you're not slow by any means lol!!!
But your car is misbehaving, especially in slower corners, or so it seems to me? And i do think a bar would fix it. Perhaps with a change on how you brake, but no idea here, just a possibility - perhaps invalid.

C6Z is an awesome car, but LS7 can go boom and no doubt you've read countless threads on this subject.
Having said that, it seems that improving dry sump oiling goes a long way in that regard. The fix seems good, but it ain't necessarily cheap. Yet others are convinced it is a valve train...so go figure!

If i were you id experiment with the current bars and even spring for a new F one to see how far it takes ya. At least potentially, it is a small cost for possibly higher pace and a car that can give ya all it is worth.

Cheers!

[TheRealJA105]

LS7 issues are with the valve guides and I would be making sure those are taken care of right away if i go that route.

And honestly, though i love my car i miss a manual obviously (even though it's slower), and-being smaller and lighter like my old C5Z (which translates into consumables being way less money). Also I hate that it is Yellow and I have had loads of heat related problems being forced induction.

Still a good chance I'll be sticking with it, because I'm just not into throwing money away and it's a great car, so the C6Z will have to be the right deal/time/level of prep.

[travislambert]

Originally Posted by TheRealJA105

LS7 issues are with the valve guides and I would be making sure those are taken care of right away if i go that route.

And honestly, though i love my car i miss a manual obviously (even though it's slower), and-being smaller and lighter like my old C5Z (which translates into consumables being way less money). Also I hate that it is Yellow and I have had loads of heat related problems being forced induction.

Still a good chance I'll be sticking with it, because I'm just not into throwing money away and it's a great car, so the C6Z will have to be the right deal/time/level of prep.

I can put you in touch with engineers at C&R Racing who can help with the heat problems. They really helped with the heat issues on my car. Over the summer I worked with them to create an oil cooler that installs in place of one of the auxiliary coolers (to avoid pushing the heat load from the engine oil right into the primary radiator). I replaced the left aux cooler (used in stock form for supercharger) then upgraded my center heat exchanger using their unit. It dropped my oil temps by about 50 degrees on average without increasing the IAT2 temps. I know there are other units on the market, but C&R is the real-deal. They aren't cheap, but they make their coolers with the very best core designs available. They are an OEM supplier for Ford (new GT500) as well as Porsche, McLaren etc.

https://www.crracing.com/product/che...-ss-oil-cooler
https://www.crracing.com/product/che...heat-exchanger

For the trans/diff, the shrouding can be trimmed to expose more of the cooler and reduce temps there (which also helps the engine temps because the trans/diff fluid flows through the primary radiator.).

Another area they might be able to help with is the bricks inside your supercharger. I'm having them make me a set for my 2650 over the winter.

[TheRealJA105]

Originally Posted by travislambert

I can put you in touch with engineers at C&R Racing who can help with the heat problems. They really helped with the heat issues on my car. Over the summer I worked with them to create an oil cooler that installs in place of one of the auxiliary coolers (to avoid pushing the heat load from the engine oil right into the primary radiator). I replaced the left aux cooler (used in stock form for supercharger) then upgraded my center heat exchanger using their unit. It dropped my oil temps by about 50 degrees on average without increasing the IAT2 temps. I know there are other units on the market, but C&R is the real-deal. They aren't cheap, but they make their coolers with the very best core designs available. They are an OEM supplier for Ford (new GT500) as well as Porsche, McLaren etc.

https://www.crracing.com/product/che...-ss-oil-cooler
https://www.crracing.com/product/che...heat-exchanger

For the trans/diff, the shrouding can be trimmed to expose more of the cooler and reduce temps there (which also helps the engine temps because the trans/diff fluid flows through the primary radiator.).

Another area they might be able to help with is the bricks inside your supercharger. I'm having them make me a set for my 2650 over the winter.

Travis thanks for the help here. I'll text you to quit derailing my own thread

[h018871]

Originally Posted by travislambert

For the trans/diff, the shrouding can be trimmed to expose more of the cooler and reduce temps there (which also helps the engine temps because the trans/diff fluid flows through the primary radiator.).

Travis, where are you doing the trimming? In this area, or somewhere else?

EDIT: Apologies for the thread jack........

[travislambert]

Originally Posted by h018871

Travis, where are you doing the trimming? In this area, or somewhere else?

EDIT: Apologies for the thread jack........

Remove the plastic trim in the area of the green boxes to expose more of the cooler to airflow.