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Thats fantastic. Perfect for track days. Except the weight needs to be like 150 less for the hp and tire size. Sadly that will be tough. 250 lbs total without making it look like a straight race car is tough.

 

Finspeeds (in order) and non run flat tires save 100lbs

AP brakes will save another 100

lithium battery saves 40.

those are our next mods. Stock Comp seats, stock interior. Not quite a track rat yet.

 

Love to see the math on the wheel/tire weight savings. For the brakes you think there’s that much, even with carbon rotors?

 

Z51, no CCB.

 

Rear tire and wheel is just shy of 70lbs. Finspeed with hoosier is 47, Finspeed with Pirelli slick is 42.

brake rotors are just shy of 30lbs, AP is 17, and larger diameter. That doesn’t even include the caliper weight, which is usually 5-7lbs per caliper.

it’s just bench racing, but those estimates are not far off. Obviously we don’t have the parts yet because the cars are barely a few weeks old.

 

Not trying to hi-jack the thread, just sharing for reference. My 275PS2 on a 9.5” rim and your 100treadwear 255 probably have similar grip, think your car is similar in weight though more powerful and has less drag. The mag ride is definitely better and the C8 even more powerful than LS3 or LT1 as well as has a faster trans/better gearing with similar rear tire. You’ve got more seat time at MSR than me, was the 1:23 with the procharger?

 

I've found MSRC to be very similar to TWS in that there are times the track is fast when the weather is right and it is rubbered in....and there are times when the grip is simply not there and times suffer.

When you start bench racing times, if it isn't same day and same session there simply is too much margin for allowable grip. Sure, you can use them as generalities, but when folks start tossing times as absolutes it seems very inexperienced to me.

If you follow SRFs or SpecMiata over a race weekend, you'll see a solid differentiation in times from Friday test on a green track to race pace Sunday afternoon after a weekend of no rain and LOTS of cars rubbering in the track. I'm not saying we shouldn't benchrace, but I do think a lot of folks think lap times on different days directly compare and they are flat wrong.

Regardless, the C8 is shaping up to be a fun track car and here are my thoughts on driving it in anger the first time!

http://witchdoctormotorsports.com/ch281.htm



Costas
cars and such...

 

The rear Hoosier is going to be 29-30, so a 19 or 20 x 11 or 12 Finspeed wheel is only 17-18lbs.? That seems optimistic?

What alignment settings did you guys end up with?

 

got a pic of an 18x12 Finspeed on a scale? And a 18x335 or 345 hoosier on a scale? My notes say 20.x for the wheel and 27.x for the tire.

this is bench racing. It’s just a goal. “Paint with a wide brush” as we say.

 

I understand and DA is going to have an affect on lap times as well as track conditions when you get into that window of a second, it’s hardly ever an apples to apples comparison as a certain driver may be more accustomed to a particular platform even jumping in and out of multiple cars on the same day as well as leave some time on the table being it isn’t their’s like you mentioned. Great write up and thanks for sharing results even given the relatively short amount of time on a green track, do you feel the C8 is easier to drive at the limit than the C7? Glad to hear the comp seats worked well and are being swapped mainly for weight savings it sounds like. Bench racing is unfortunately all most of us can do with the Coronavirus going on:-/

 

Have scaled many a wheel and burned through many a set of Hoosiers, though even if I never had, it wouldn't make the 100lb any more attainable

I'm a fan and potential customer and wish you all the best in achieving your goals.

 

Paul, did you try running the car in D instead of manually shifting? Am curious how the car's software behaves, particularly on downshifts.

 

thats fantastic, we hope to keep you entertained and will sharpen the pencil . Until we actually bolt on the new shoes, it’s all conjecture as you know. Finspeed fired over that they have completed the engineering, we can’t wait to test them!

Next, we wonder how much the mid glass weighs between the cockpit and the engine?

 

manual mode every time. Will try auto mode next outing.

manual mode does indeed do what you ask it on track, which is wonderful.

 

Thank you for the kind words and I'm glad you enjoyed the writeup. I feel blessed and honored that Louis lets me play in the new toy! It is a *damn fun* car to drive and I'm looking forward to the development. Good comment on the DA stuff, I was mostly just noting 'track grip' and how it varies enough for well over a full second. I remember summer days at TWS where you could not come within 2 seconds of your morning time after 3pm!!

I have very little time in a C7 and so making that comparison is tough. A C5 or C6 comparison is pretty easy for me however. I have a substantial amount of track time in both traditional front engine (over 50% on front) and optimized front engine (51-52% on rear) as well as mid and rear engine cars (Lola Sports2000, various PCars, McL, Fcar, etc). I feel pretty versed in how these different cars carry weight into deep trail braking and then 'taking a set' and then deal with forward bite while tracking out.

As for ease at the limit, yes I felt Slick was pretty easy at first and then with Louis' "step 1" alignment it not only got faster but also became easier to go faster (if that makes sense). Especially after the additional change in the rear, the car was then MUCH more telegraphic and felt it was in a more "happy place" when cornering near the limit. When Louis and I have tuned a car in the past with real-time-tire-temp sensors, every time we make the tire happier we end up going faster and the car is easier to drive and thus the driver is happier. With the phase 1 and phase 2 alignment changes, the car was more solid and lap times fell....a best of both worlds combination.

The comp seats are NICE. Part of me wishes we could remove the shell and just put it on mounts bolted to the floor! The seats are comfy and incredibly supportive. That whole "seating IN the seat" instead of "on" the seat type of feeling.

We are hopefully testing the next round of changes in a few weeks....but I'm happy to answer anything I can in the meantime.

Costas
cars and such...

 

LOL! I had that SAME thought as I was driving home that night.

Honestly, I was trying to save tires most of the time and limit the number of times I hustled them through a corner. They are certainly the weak link and I did not want to put any more wear on them than necessary so I didn't try a lot of different things.

As Louis said, yes, we'll try it to see how it behaves. I drove in TRACK mode around the area and under aggressive braking (following all local laws and ordinances of course...) the car will downshift quickly/sharply to where IT SEEMS like it is always ready for you to stab the gas and get moving quickly. I'm anxious to try it on track, but if it extrapolates to what I found on the street, I bet it will be nice.

I cannot WAIT to get some real play tires on this car that can take some abuse and bang out a LOT of laps trying different modes and steering feedback and apparently there is a whole "performance traction management" system with options and such....I need to dig into that. We want to provide feedback on all the options and such so entry level folks and experienced folks alike all have a good understanding of what should happen (at least approximately) before they slide on a helmet and drop into a C8.

Of a personal note I typically downshift very late....I get all the braking done and I don't downshift until I'm pretty close to needing power. This allows me to focus on the threshold braking (in this case, just before tread squirm) and put the car as close to where I want to be....and not worry about doing anything else. It will be interesting to see if the AUTO mode does it different and if that upsets/bothers anything.

More soon!

Costas
cars and such...

 

Appreciate the update. Most of us - even the lucky few who've received cars - are pretty tightly locked down, so we'll be living vicariously through you guys.

As Slick descends into slick-shod racecardom, I hope you guys make a stop at a "gentleman's track day" tire, with something like a GY Supercar 3 or 3R, or Sport Cup 2, or the like, on proper-width wheels. This is more indicative of what most track-goers will use, so the data collected there will greatly add to the community's collective sense for the point at which the stock braking (and cooling, and, and...) systems give up, and what other supporting mods might be needed.

 

We'd LOVE to find 200TW tires that fit the OE wheels but it looks bleak. Pricing is also a consideration as well (duh!).

The Nankangs have a rear listed but fronts might be an issue. We know enough WRL teams who have liked the 'kangs and I feel that would be a good tire that would be consistent over 10+ hours of track use. THAT would allow us to test many more settings (mechanical and electronic) and provide a lot more feedback (and find weak spots and engineer solutions for them!!). You're spot on....that information will be more valuable across a wider base than pure-slick data.

However, the call of the hoosier is truly a siren to those of us that play in that arena...and I'm the first one to beg for a set on the incoming Finspeeds! If they had not changed the freaking bolt circle there is a really good chance our final session would have been on borrowed Pirelli slicks on C5 wheels (offsets work), but that small bolt circle change had us worried.

Costas
cars and such...

 

were working hard to go the route that most who track the car will go. If you have a tire suggestion, we can run it up the flag pole and see what the consensus is. It would be nice if it fit stock wheels, but we understand (as many do) that we might need wheels. (Aside from the hoosier shod finspeeds- they are 18x10ish and 18x12ish, fwiw)

 

I have 18x10.5 and 19x12 with Goodyear Supercar 3 (275 & 325) on my car right now, but understand most probably won't want to go that wide in front.

The tires I would consider are the non-runflat PS4S, the Goodyear Supercar 3 (not the R), or the Continental ECS. They all have a 325/30-19 you can use in the rear and a few different front options that keep the f:r circumference ratio close enough to stock. These are all popular choices for tires that can be driven to/from the track, and the car should work well on them at stock spring rates. There are other options but they are either too far behind the times in diameter (like the BFG Rival) or not available in big-car sizes (Bridgestone RE71R, Yokohama A052).

Once you go below 200 treadwear (like a Michelin Cup 2, Goodyear Supercar 3R, Toyo R888R, Pirelli Trofeo R), grip goes up a bunch but foul-weather suitability goes away and the car will probably need some supporting mods, including a trailer in bad weather. How the car works on them will be very interesting to learn, but might be better as a future step in a progression.

I've had good experience tracking the non-runflat PS4S, though the tire was well supported with good wheel width and alignment. Something in common with all these 200+TW tires, they're not going to have the race-tire style construction of something like a Hoosier - they're going to need relatively wider wheels and greater negative camber to perform their best and keep from nuking the outside shoulder.

Finspeeds are indeed superb, among the best $ can buy. The 18s will save a lot of weight but people may not like the look on the street on something that originally came with 20's. If history serves, most Corvette owners will be hitting the track on inexpensive rotary-forged style wheels. If you put together a 10" front/12" rear package on one of those good 200+ tw tires and stays closer to OE diameters, I bet you'd save 50lbs. in wheel/tire weight and take another 1sec/60 off lap times - and then proceed to sell lots of them