(adsbygoogle = window.adsbygoogle || []).push({});

@Jouni, checking that Art Morrison probably later today/tonight. Now checking if finding any real life data for that car. Just having some memories at ie did tune something on that car earlier, it wasn't bad to drive.. Probably made some quick tune then..

Suspension Type Toe (Inches) Camber (Deg.) Caster (Deg.)
Deluxe IFS 1/32 to 1/16 (In) 0 to -0.25 +1.5 to +3.0
55-57 GT Sport (Street) 1/16 to 1/8 0.0 to -0.5 +5 to +5.5
55-57 GT Sport (Track) 1/32 (out) to 0 -1.0 to -1.3 +5 to +5.5
Corvette C6 (Street) 0 to 1/16" (in) -0.5 +5 to +5.5
Corvette C6 (Track) 1/32 (out) to 0 -1.25 to -1.75 +5 to +5.5
C6 Sport (Street) 0 to 1/16" (in) -0.5 +4.5 to +5.5
C6 Sport (Track) 1/32 (out) to 0 -1.25 to -1.5 +4.5 to +5.5
Sport IFS (Street) 1/32 to 1/16 (In) -0.5 +5.5 to +6.5
Sport IFS (Track) 1/32 (out) to 0 -1.25 to -1.5 +5.5 to +6.5

"Driver's Impression - On The Autocross Course
This car had incredible power and good traction, but the threshold between stability and scary was very narrow and took some getting accustomed to. I had to use a delicate touch, "point and shoot"-type of driving style to get it around the autocross course, and never really felt comfortable behind the wheel. Part of this was the pedal position as the accelerator pedal was located more in the center of the foot-well with the other two pedals off to the left-definitely something the driver needs time to get use to. At the speeds this car could generate, the brakes couldn't get it slowed down fast enough for my liking. The car didn't like any throttle application at an apex, skittered through corners, and the technique required to drive it was throttle, brake, turn, and then back to throttle until the next corner. Luckily, it was relatively easy to turn with excellent steering response. With a softer, more compliant suspension and more responsive brakes, this could be a very fun autocross car. I hope to drive it again after these changes are made. - Mary Pozzi

Read more: You must login or register to view this content.
"

Good post.

It probably need track suspension because this car might need toe out and camber - to get understeer in control. The choice of tyres is important.

The drivers impression was intresting. I agree most part but I wouldn't say that steering response is excellent.

Edit: With above suspension and therefore limited possibilities to adjust toe out and camber, the replica version might be really challenging - to eliminate understeer will be difficult. I tested little bit of this car and it looks like I have biggest problems with understeer.

Jouni

It has that IFS Sport front suspension, and solid rear axle.. Gonna check more.

Spring Rate % 8” # 10” # 12” # 14” Spring Lenght
125 lbs 59080125 59100125 59120125 59140125
150 lbs 59080150 59100150 59120150 59140150
175 lbs 59080175 59100175 59120175 59140175
200 lbs 59080200 59100200 59120200 59140200
225 lbs 59080225 59100225 59120225 59140225
250 lbs 59080250 59100250 59120250 59140250
275 lbs 59080275 59100275 59120275 59140275
300 lbs 59080300 59100300 59120300 59140300
325 lbs 59080325 59100325 59120325 59140325
350 lbs 59080350 59100350 59120350 59140350
375 lbs 59080375 59100375 59120375 59140375
400 lbs 59080400 59100400 59120400 59140400
425 lbs 59080425 59100425 59120425 59140425
450 lbs 59080450 59100450 59120450 59140450
475 lbs 59080475 59100475 59120475 59140475
500 lbs 59080500 59100500 59120500 59140500
525 lbs 59080525 59100525 59120525 59140525
550 lbs 59080550 59100550 59120550 59140550
600 lbs 59080600 59100600 59120600 59140600
625 lbs 59080625 59100625 59120625 59140625
650 lbs 59080650 59100650 59120650 59140650
675 lbs 59080675 59100675 59120675 NA
700 lbs 59080700 59100700 59120700 NA
725 lbs 59080725 59100725 59120725 NA
750 lbs 59080750 59100750 59120750 NA
800 lbs 59080800 59100800 59120800 NA

Using that on US cars would make realism, how much spring length is under static weight loaded etc.. But you might get point.


Soon editing all earlier replicas springs, I had error on calculation.. Foot mixed with inch.. Shit..

125 lb 2.232246
150 lb 2.678695
175 lb 3.125144
200 lb 3.571593
225 lb 4.018043
250 lb 4.464492
275 lb 4.910941
300 lb 5.35739
325 lb 5.803839
350 lb 6.250289
375 lb 6.696738
400 lb 7.143187
425 lb 7.589636
450 lb 8.036085
475 lb 8.482534
500 lb 8.928984
525 lb 9.375433
550 lb 9.821882
600 lb 10.71478
625 lb 11.16123
650 lb 11.607679
675 lb 12.054128
700 lb 12.500577
725 lb 12.947026
750 lb 13.393475
800 lb 14.286374

I'm using values from counting back those numbers, so 0.01 differences may seen on my replicas.

@Jouni, here's quick base setup for Art Morrison Corvette, there is toe counted on assumption of work diaries of Morrison stating front/rear width of tires being 265/295 on 18" wheels, and closest diameters of those wheels are:
669.2mm front 265/40R18
663.7mm rear 295/35R18
Difference between tire diameters are bigger on any other choice, making front tire "remarkably" bigger than rear, so my guess can be really close to truth, my -0.09 is rounded up from -0.08high.
Rear lock is 40/20%, values can be altered on own feels, like if you want plant rear totally, but having slightly more understeer you can go on 12/28/8, but that 11/29/9 leaves you more room to manipulate throttle, prefer it.
Didn't change lot on suspension, just dropped to Morrison diary stated 5" height, and stiffened overall dampers and arb, and counted springs to closest aftermarket spring rates from those PD's values.

127/127
20.54/17.42
4/4
4/4
4/4
1.4/0.0
-0.09/0.00
5/5 bb

LSD 11/29/9

What tyres?

Car is surprisingly well balanced, much better than I thought. There might be something to adjust more, but this isn't a car just for better lap times. It's a nice car to learn how to help steering with throttle. Those who can drift might like this type of car - I don't drift, so it's just a guess.

It's great fun to put the car a little slide whenever You want and it's still under control. There is huge amount of power reserves to use all the time. It's probably first time for me when I noticed how many different throttle positions there are between zero and full. I also noticed how many different sides there are in this game to enjoy, there are races, setups, but also much more.

Jouni

@Jouni, that works best on SM and above, when adjusting LSD, keeping sum 40/20 it can be used from CH and above. Tuning itself was on default SS tires. I have run it with 10 to 12 preload(init), depending compound, total lock sum staying 40/20.

Steering with throttle, yes, also giving lessons to start braking early enough for corners, coz this monster collects crazy speeds when flooring throttle.

Ps. This car turns to undriveable if you hit wall, traction of bended body is really bad, or makes you really much work with wheel.. Really expensive car to drive

First time on Nordschleife with it, practising car manners, as seen on video, barely staying on track


Next project, real pedal practising machine.. Gonna tune this until it dances into corners like Senna made it dance.

@Ode
Excellent videos. Nice driving with Art Morrisson, actually very impressive driving. There is something in Your driving skills that I still don't understand. I have a setup, I can see it on the video but I still can't do it. There is very good coordination between your steering and footwork.

Lotus is good project. Looks like You know Ascari very well, driving is so smooth. Did You change something on the wheel, or is it steering sensitivity still 6?

I don't know well this track, but now is time to learn. It's good that You choose a very reactive car, it's interesting to see what are You making different to decrease reactions of the car.

Jouni

@Jouni, no changes on wheel or other settings. Same 6/6/10.
Tried Lotus on Nordschleife, RH/noABS/offline first pull 5:45.515. And always keeping that grip reduction real.
Currently only changes on Lotus are ride height, toe, LSD and brake bias. (Just noticed at I have made 4th and 5th gear slightly longer, change made way back when car was introduced on GT6, didn't remember that )

Good videos. Nice to see such fluent driving.

Sennas little formula would also be nice to do among this project.

Jouni