Why are 7's so good at handling? I know weight has something to do with it, but what else is there?

 

50/50 weight distribution.

 

Mazda spent a lot of money on R&D. The RX-7 is unique in design because it has a lightweight, compact engine, allowing it to be placed very far behind the wheels as compared to other designs. Mazda and few other companies call this placement a front-mid mounted rear wheel drive layout(I think). The placement allows them to get a near perfect weight ratio(50.2% and 49.8%) with a high horsepower engine as a powerplant. The rotary/front-mid layout also allow for a very lightweight chassis, and while we didn't really see that in the FC, the FD is a shining example of it's potential. So this should sort of give you an idea why our layout is particularly effective and makes for a great handling, compact sports car.

Steve

 

What does a FD weigh?

 

well what do you mean we dident really see that in the FC? It still has nearly perfect 50/50 weight distrobution and its power to weight ratio is pretty damn good. Did you mean the FD?

 

FD weigh like 2800 pounds

 

50/50 weight distribution, lightweight, and RWD.

 

what does a FC weigh?

 

about 2800 lbs for an fc

 

If you have a TII and FD with the same features, etc. the FD is a bit lighter.

 

For a T2 maybe... but most of the FC NA series 4 cars were under 2700lbs and most closer to 2600 lbs.

Which is what I though the FD was... around 2600lbs?

It wasn't until the lower production numbers series 5 cars did most of the NA cars get to 2800lbs

 

I'm looking at an ad that says 2789lbs for the FD, Brian Long reports 2917lbs for the touring with auto.

 

The series 4 N/As were between 2600-2700
The series 5 N/As were between 2800-2850
The verts were- s4 3000, s5 3150

 

Combine all that with roll center height, spring rate, camber gain, Ackerman, anti-lift rear suspension geometry, anti-roll bars, minimal bump steer, proper camber and toe control, and the infamous DTSS! (Or Weissach rear axle, for the Porsche enthusiasts.)

 

An FD weighs somewhere in the neighborhood of 2700-2800 lbs.

What I meant was, while the FC is blessed with a very good, stiff chassis design for its time, it is also a little heavier than perhaps it should be. 3000 lbs is a lot of weight for a Turbo II. Compartively, 2700 lbs for an FD is very light. So while yes, its weight ratios are excellent(as are the FDs), the power to weigh ratio could have been better if Mazda had slimmed down the car a little instead of going crazy with the luxury items found within. Bottom line: The FC is a GREAT sports car. The FD is a thoroughbred.

Steve

P.S. It's not really fair to compare the FC and FD chassis, as one has about 7 years of R&D on top of the other. Chassis stiffness takes metal, and a lot of it, but refinements in the way the chassis is constructed can reduce the amount of metal needed to construct a chassis with better stiffness. But in addition, rather than blaming the few extra pounds on R&D, it seems to me that when they designed the FD, they were being very conscious of the car's final weight, whereas with the FC, they designed it with more creature comforts.

 

The secret to the FC is "KANSEI ENGINEERING".

 

Nobody here, but you, a half dozen others, and myself are old enough to remember that marketing phrase.

 

Whats the skidpad on 2nd gen?

 

86 n/a: .88g

 

Wow

 

the engine is not lightweight and compact like everyone says unless it was n/a

a turboed 2 rotor weighs hardly less than a lt1 especially an ls1.

and it had alot of stuff in front of the steering rack and wheels.unlike n/a's with just a radiator.

an rx7 is one of few cars ive seen with even a battery upfront(also supra).

corvette doesnt handle as good and the engine is pushed behind the steering rack and into the firewall.

even though some say ,imo i think a supra handles great.and it has half an engine over the steering rack.explain that.

im not sure cuz im not mazda but i believe the handling comes from the limited slip/independant rear suspension/stiff suspension/compact design.

lightweight is not always the key.going around some corner in the 7 can flip it at high speeds.as where if u were in a tank it will hold to the ground.how i know?i rode in enuff cars.

 

Old? Whose old? (as I quietly pluck another gray hair)

For the younger set:
"Kansei Engineering. Designing an automobile to fit the feelings of its driver. It's what happens when engineers get together with kinesiologists and psychologists to design a car....."

 

I remember hearing that. Its a recognized form of car design isnt it?

 

"even though some say ,imo i think a supra handles great.and it has half an engine over the steering rack.explain that. "

They had to push it forward to balance the extra tonnage of the supra. ie 3000#+

Unless your trying to pull a boat, less weight is better.

My 86 N/A (~2400#) handles better than the 88 TII's I've driven (both stock)

 

good weight dist. ( I think only 3gens have 50/50 though), rwd w/ind. sus., and limited slip for the lucky ones of us