FT86 as a 2-seat sports car

[Irace86.2.0]

Originally Posted by HKz

isn't 50/50 a bit overrated? I never quite understood this as I would imagine a moving car would have more weight pushed towards the rear, yes?


2000GT still the best looking 2 seater, everything else to me looks stubby. In general, I prefer the longer 2+2 GT style.

50/50 is overrated and is good too. Assuming no aerodynamic effects, no, the car at speed is identical to static. If it was positively accelerating then yes. If it was negatively accelerating then no by a lot because it would shift to the front and not the rear.

This is definitely the right proportions for hood to cabin length...sitting on the rear wheels is nice, but the overhangs are big and the wheels seem like they need to move back slightly because that rear overhang looks like a Porsche:

[DarkSunrise]

Interesting. I thought I’d like it visually, but the 2+2 looks much better IMO.

Still like the idea of a 2 seat FRS though (even if it wouldn’t work for my usage case).

[ZDan]

Originally Posted by HKz

isn't 50/50 a bit overrated? I never quite understood this as I would imagine a moving car would have more weight pushed towards the rear, yes?

"50/50" is not "perfect" weight distribution. For a rear-drive track car, more *rearward* than that would be better. (for an fwd track car you want a lot of *forward* bias)

Street usage, 205hp/2800 lb. FR car, 55/45 is no big deal. For track usage and if tenths of a second matter, it's more of a big deal. Without even getting into ability to put power down (yet), the 55/45 FT86 is murder on the front tires at the track while taking it relatively easy on the rears. At 50/50 the rears would contribute more and the fronts would be less overloaded, and I'd have more total lateral grip for cornering. Faster...

Braking is another area where 55/45 is objectively worse. Under 1-g braking with 18" c.g. height, 73% of the load is on the front tires and only 27% on the rears. Same deal, fronts are more overloaded and not developing as much stopping grip per load as grip/load curve is not linear. At 50/50 under 1g braking, it'd be 68% front and 32% rear. May not seem to be a lot, but the 50/50 car will have an advantage in braking grip with the rears contributing a lot more and fronts on the more linear portion of the load/grip curve.

And the 3rd area is of course ability to put power down. At stock power/weight, 55/45 isn't the end of the world. If you were to add power it would begin to be more of an issue. I'd feel a lot more comfortable adding power to a 50/50 (or better, more rearward!) car vs. 55/45.

Should note that a 55/45 car puts not 5% less, but 10% less load on the driven wheels vs a 50/50 car.

Yes, under acceleration the rears are loaded up somewhat, still better to have more rearward weight bias if you want to be able to put more power down. 50/50 static distribution will be able to put down significantly more power than 55/45.

2000GT still the best looking 2 seater, everything else to me looks stubby. In general, I prefer the longer 2+2 GT style.

2000GT, 240Z, Cobra Daytona, Ferrari GTO, 275GTB, Daytona, etc., pre C8 corvettes, etc. etc., FR sports cars wanna be cab-rearward for 50/50 or BETTER (more rearward) weight distribution. Styling is another question, but the benefits of cab-rearward for weight distribution are so ingrained into me that 2+2 FR cars like the 240SX and FT86 just look *wrong* with the rear wheels shoved way aft!

[ichitaka05]

Did great job on photochopped. But it won't be THAT short in the rear. iirc when I was talking with Tada-san, about what if kinda thing and he said if 86 was 2 seater, it would of been fraction shorter in front & rear.

[Red-86]

I prefer the styling of the 2+2 twins to the chopped versions, personally. If you are going for a cab rearward design, the bonnet needs more length to run with that aesthetic. Looks too stubby with the standard bonnet length and chopped rear.

[ZDan]

Originally Posted by ichitaka05

Did great job on photochopped.

Thanks! I didn't do much really, it was a lot easier and more straightforward than expected, at least to give a decent impression

But it won't be THAT short in the rear. iirc when I was talking with Tada-san, about what if kinda thing and he said if 86 was 2 seater, it would of been fraction shorter in front & rear.

The approach I took to improve the f/r weight distribution by making it a 2-seater was to move the rear wheels forward as far as possible, making it a much shorter-wheelbase car, ~93".

Another approach to making it a 2-seater with about the same wheelbase and overall length as the current 2+2, you could keep the wheels where they are and move the driver/passenger and engine/transmission way aft relative to the wheelbase. Could still easily achieve 50/50 or better this way, and really I'd be fine with 50/50 cab-rearward 2-seater on the existing 101" wheelbase But that exceeds my ability to make a reasonable-looking photoshop image!

2nd approach would address people's concerns about the front looking too stubby as moving the passenger cabin aft effectively lengthens the front.

[beltax90]

Originally Posted by ZDan

Nah, more SP2

Corrado is cab-forward FF architecture, with 2+2 hatch bent roofline

touche

[ZDan]

OK, don't kill me, I love Lava FR-S, but:

[SUB-FT86]

I think the roofline needed to be more low slung to match the shorter dimensions.

[ZDan]

Originally Posted by SUB-FT86

I think the roofline needed to be more low slung to match the shorter dimensions.

Should note that the modded pics are chosen because they're almost a dead-on side view from a height about half the height of the car to make it easy to do the short-wheelbase mod in photo editor with simple cut/paste operations. The cars do not look like this to humans more than 2'6" in the real world.
Lower roofline with the rest of the car remaining fixed would squash the greenhouse too much. I'd only lower the roof if also lowering the line from the nose to fender arches, tops of doors, hips, tails. Basically remove a ~1-2" section of body from around the whole car. Which would be cool! But beyond my skeeelz.

I think the swb orange FR-S already looks kick-ass and 1" lowering just at the suspension would achieve 85% of the desired "lower" look from there.

[bfrank1972]

Originally Posted by ZDan

"50/50" is not "perfect" weight distribution. For a rear-drive track car, more *rearward* than that would be better. (for an fwd track car you want a lot of *forward* bias)

Street usage, 205hp/2800 lb. FR car, 55/45 is no big deal. For track usage and if tenths of a second matter, it's more of a big deal. Without even getting into ability to put power down (yet), the 55/45 FT86 is murder on the front tires at the track while taking it relatively easy on the rears. At 50/50 the rears would contribute more and the fronts would be less overloaded, and I'd have more total lateral grip for cornering. Faster...

Braking is another area where 55/45 is objectively worse. Under 1-g braking with 18" c.g. height, 73% of the load is on the front tires and only 27% on the rears. Same deal, fronts are more overloaded and not developing as much stopping grip per load as grip/load curve is not linear. At 50/50 under 1g braking, it'd be 68% front and 32% rear. May not seem to be a lot, but the 50/50 car will have an advantage in braking grip with the rears contributing a lot more and fronts on the more linear portion of the load/grip curve.

And the 3rd area is of course ability to put power down. At stock power/weight, 55/45 isn't the end of the world. If you were to add power it would begin to be more of an issue. I'd feel a lot more comfortable adding power to a 50/50 (or better, more rearward!) car vs. 55/45.

Should note that a 55/45 car puts not 5% less, but 10% less load on the driven wheels vs a 50/50 car.

Yes, under acceleration the rears are loaded up somewhat, still better to have more rearward weight bias if you want to be able to put more power down. 50/50 static distribution will be able to put down significantly more power than 55/45.

2000GT, 240Z, Cobra Daytona, Ferrari GTO, 275GTB, Daytona, etc., pre C8 corvettes, etc. etc., FR sports cars wanna be cab-rearward for 50/50 or BETTER (more rearward) weight distribution. Styling is another question, but the benefits of cab-rearward for weight distribution are so ingrained into me that 2+2 FR cars like the 240SX and FT86 just look *wrong* with the rear wheels shoved way aft!

All 100% true - I think, however, the moderate front weight bias also contributes to the overall excellent and approachable handling characteristics of 86. Not optimized for ideal performance under braking or putting power down, but you can really explore the limits of these cars without a sphincter workout.

[ZDan]

Originally Posted by bfrank1972

All 100% true - I think, however, the moderate front weight bias also contributes to the overall excellent and approachable handling characteristics of 86. Not optimized for ideal performance under braking or putting power down, but you can really explore the limits of these cars without a sphincter workout.

I don't think 50/50 should feel less stable necessarily. My 987.2 2.9Cayman didn't feel more twitchy at the track with 45f/55r weight distribution. And less twitchy on the highway! I still like my BRZ better tho...

[WolfpackS2k]

My Cayman felt considerably more twitchy than my S2000 (to me at least).

But that's not a straight F/R weight distribution comparison. The Cayman has a very low polar moment of inertia since the mass is centralized.

[ZDan]

Originally Posted by WolfpackS2k

My Cayman felt considerably more twitchy than my S2000 (to me at least).

But that's not a straight F/R weight distribution comparison. The Cayman has a very low polar moment of inertia since the mass is centralized.

Suspension geometry has more to do with it than weight distribution. Cayman is designed to be very stable/benign. S2000, especially AP1, is designed to *rotate*. My AP1 and my 240Z had the same weight distribution, but very different handling characteristics. The Z was a lot more linear, and I could drive it with utter abandon even when I had it set up poorly with too much oversteer. AP1 handling is nonlinear due to rear suspension monkey motion (toe change with bump). Do the wrong thing and the handling behavior changes instantly. Not as quick to recover.

Wait, your Cayman felt *more* twitchy? Was your S2000 an AP2 (ah, '07, so yeah)? AP2 eliminated absurd rear toe-change-with-bump the AP1 had, big improvement.

Cayman definitely felt no more twitchy to me on track vs. BRZ, which is definitely less twitchy than my AP1 was.