GM Z06 & Z51 Track Preparation Standards/Recommendations

[John]

Including track alignment settings. UPDATED PRINTING:


Posted in page form (12 pages) in next post.


2023 Corvette Track Preparation Form_081722_v5.pdf

[John]

Including track alignment settings. Again, this is an UPDATED PRINTING (discard earlier version of yesterday).

[brad66]

PDF added as attachment to first post.

[AzDave47]

Thanks much, John.

I thought the break-in RPM for the LT6 was around 6500 RPM (Owners Manual). Section 1 indicates 4000 RPM and does not differentiate between the LT2 and LT6 engines.

[Egon]

Interesting that the recommended track alignment settings are not as aggressive as the base car. Only -2 camber up front compared to -3, and -2 versus -2.5 rear. Yet, all accounts I’ve seen say there is tremendous front grip. I’m sure the wider track helps.

[John]

Egon, please are you referring to the Stingray as the “base car” please? If so that is because the wider track just as you suspicioned is a major part of it. Other learnings and Z06 parts changes such as tires, different bushings, spring rates, etc, and its more recent development sure contribute to the less aggressive settings. And yet as we learned from the 20+ auto-media’s Pitt track experiences and reviews, it corners far better.

[Paul Christian]

Question for the group regarding the Z07 underbody strakes. The document shows they should not be bolted onto the car for street use. My question is why not? I thought the underbody strakes reduced underbody turbulence and therefore reduced drag and created more efficiency. Wouldn’t that be a benefit for both track AND street use? So why are the strakes not recommended for use on the street?

[John]

The document uses the word “inspection.”

I believe its exact wording is to check that they are properly installed before track usage. I am interpreting it as “might yours have come partially lose in your daily driving,” so check that they are installed correctly before you go out onto the track.



As to whether the strakes should be PDI installed for all, I and others are still exploring that exact question. In my mind still ambiguous and why we are working to learn more.

[SullyC8er]

Thanks John, definitely looking forward to the day I need this!

[Paul Christian]

The document uses the word “inspection.”

I believe its exact wording is to check that they are properly installed before track usage. I am interpreting it as “might yours have come partially lose in your daily driving,” so check that they are installed correctly before you go out onto the track.



As to whether the strakes should be PDI installed for all, I and others are still exploring that exact question. In my mind still ambiguous and why we are working to learn more.

Look at the actual chart for ZO7 performance package. Under street driving columns, it does not include underbody strakes. That indicates they should not be on for street driving. Then if you look at the track columns for ZO7 performance package, it states to install strakes.

[John]

Thanks Paul. You are correct and I appreciate your educating at least me, e.g. track use only. THANK YOU!

[Paul Christian]

Thanks Paul. You are correct and I appreciate your educating at least me, e.g. track use only. THANK YOU!

you welcome but back to my question if anyone can answer it. If the strakes reduce turbulence and therefore improve aerodynamic efficiency, why would they not be recommended for street use? That seems odd to me. Are they only off the chart for street use because GM is afraid that they could get damaged on the street (uneven pavement or large pot holes)? Otherwise, it does not make any sense.

[Ragtop 99]

. Are they only off the chart for street use because GM is afraid that they could get damaged on the street (uneven pavement or large pot holes)?

that would be my assumption too. Same with the Z51 rear brake ducts - they hang down, so GM says not to install them for street use.

[John]

you welcome but back to my question if anyone can answer it. If the strakes reduce turbulence and therefore improve aerodynamic efficiency, why would they not be recommended for street use? That seems odd to me. Are they only off the chart for street use because GM is afraid that they could get damaged on the street (uneven pavement or large pot holes)? Otherwise, it does not make any sense.

that would be my assumption too. Same with the Z51 rear brake ducts - they hang down, so GM says not to install them for street use.

GM mentioned that was not an issue of road damage due to their being flexible and tucked onto and being immediately under the flat undertray. Unlike the rear Z51 air ducts that hang down about 2 1/2” to 3” underneath that flat plane, the max aero string depth is 1”.

Perhaps GM’s thinking is if you already have permanently mounted dive planes and the high wing (along with the he standard rockers and some sized splitter), there is not place other than the track that any beneficial aero advantages of the underfloor aero stings is literally on a track — for just those aforementioned piece will provide more downforce than one could use say up to 125 MPH and we should not be doing that on any street.

Nevertheless I will ask down the road when the opportunity arrives if had not previously done that.

[Paul Christian]

GM mentioned that was not an issue of road damage due to their being flexible and tucked onto and being immediately under the flat undertray. Unlike the rear Z51 air ducts that hang down about 2 1/2” to 3” underneath that flat plane, the max aero string depth is 1”.

Perhaps GM’s thinking is if you already have permanently mounted dive planes and the high wing (along with the he standard rockers and some sized splitter), there is not place other than the track that any beneficial aero advantages of the underfloor aero stings is literally on a track — for just those aforementioned piece will provide more downforce than one could use say up to 125 MPH and we should not be doing that on any street.

Nevertheless I will ask down the road when the opportunity arrives if had not previously done that.

It was my interpretation that the underbody strakes are there only to reduce drag/turbulence under the car, allowing the car to travel more efficiently. They reduce drag creating greater efficiency. Will be interesting to see what GM says. Its odd that they mount the front drive planes permanently, which absolutely increase drag and is bad for the street, yet the factory does not mount the underbody strakes, which reduce drag and makes the car more efficient.