what can we learn from the McLaren MP4 to better understand the FD?
 

McLaren recently released some new info on their world beater supercar and i of course see everything through the FD prism.

the MP4 is a carbon fiber structured chassis. (see pic below). wow CF weighs next to nothing and is diamond rigid.

it must be alot lighter than the FD.

MP4 2866 dry weight.

FD 2862 Touring model as per Mazda spec

hmmm

take a look at the beautiful aluminum upper front A arm in the picture. gee, it looks like an FD piece.

but what's the deal w the weight? 2800 is actually a skinny number. don't believe me? just look around and you will be surprised. so how come our FD is so light?

did you know that during the design process Mazda formed two teams and charged each with taking weight out? that was their only job for a year. they were forbidden to talk to the other team. if you really look at the car you will see the fruits of their efforts... sometimes humorous... like the swiss cheese front swaybar mount.

the absence of weight is very close to Godliness. weight hurts acceleration, deceleration, cornering as well as creates HEAT.

lack of weight is one of the key design features of the FD.

another is suspension geometry... true racecar... camber gain on bump, i could go on but i am pretty confident that the MP4 and the FD share the same appreciation in design for racecar physics. i KNOW the FD has it and it is a good bet the MP4 does too.


http://img51.imageshack.us/img51/613/mclarenmp4.jpg

o k so they are the same weight. how about hp?

the twin turbo V8 MP4 makes 592 flywheel hp V 255 for the FD. supposedly it runs 10 point something in the quarter at 134.

so the title of the thread is what can we learn.... not some thread to equate the two cars. we are here to learn.

the MP4 has a 3.8 L V8. that's 232 cubic inches. at 592 flywheel hp that is 2.55 hp per cubic inch.we all well know w turbos all you have to do is turn up the boost. at some point the party stops. hopefully before rods protrude from blocks or apex seals shatter.

the motor is scratch designed by McLaren. McLaren in it's purpose built $250,000,000 racing HQ. McLaren, no stranger to yearly F1 operating budgets of over $50,000,000.

dry sump, titanium everything... all the tricks. and they chose to draw the line at 2.55 hp per cubic inch.

guess what gang, that's the equivalent of 344 rear wheel FD hp! do the math. 159cubic inches X 2.55 = 405 Flywheel which roughly converts to 344 rear wheel.

what do we think of 344? 400? 450? oh that's medium power range for a modded single turbo setup.

500, now you are talking... and 500 is 575 flywheel/ 159 = 3.61 hp per cubic inch, a full 42% more power output than the best 2011 technology that McLaren offers.

add to the burden w the following factors:

a rotary requires 30% more air and fuel V a piston engine to make similar power.

the rotary makes best power at around 1650 F EGT V a piston engine at 1320F.

the rotary is a 2 cycle so there is no (every other) non-power cooling event.

and we wonder why our FDs blow engines???????

of course it doesn't have to be this way thanks to the addition of AI which delivers vast cooling. if you aren't running AI you'd better get busy.

here's the link:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/making-case-rotary-powered-fd-fix-806104/

BTW, to put a period on the state of tune...

Corvette ZL1 638 hp 376 cu in 1.69 hp/cu in supercharged intercooled

Nissan GTR 485 hp 232 cu in 2.09 hp/cu in twin turbo

Merc AMG SL 65 661 hp 365 cu in 1.81 hp/cu in

the point is that's where the above builders drew the line. none of these cars use AI of course.

so if you are a real nutcase you can crank up the volume on your 2800 pound FD, add an 80 pound per minute turbo, some real brakes and coil overs etc and you have something that will run closer than you might think to the newest worldbeating option from what might be the single greatest purveyor of auto-tech in the world.

not bad for a 15 year old car.

of course you wouldn't have the disco doors:)

thank God.

howard

You just made me feel so happy for owning an fd. Not that I wasn't already but now more so then ever. I don't feel bad about how much money I've spent haha, seeing as how its still a bargain compared to what that thing costs.

I see what youre saying, but you didnt address factors like torque and gear ratios. Those play a huge role as well.

That horse is currently being beaten to death in the the Defined Auto 3-rotor recap.

I think this is more of a commentary on just how ahead of it's time the FD was. Or, maybe an OpEd on how heavy modern cars are and the limitations of pump gas and Combustion Chamber Pressure relative to the FD.

I've always used the same comparison for years with a F40 because it was about as close as you could get at the time weight wise. You don't really need much more the 450whp in these cars. As far as amazing weight comparisons go. I like this... http://blog.leasetrader.com/archive/...Auto-Show.aspx

"you didnt address factors like torque and gear ratios. Those play a huge role as well."

you are absolutely correct. the MP4 has a flat torque curve that starts around 2000 rpm. pretty nice. the engine redlines at 8500.

midrange torque/hp is a key to uprated engineering for the FD. it is hp under the curve that wins races. here the FD w only 159 cu inches is at a disadvantage of course. much of my engine research is directed to midrange hp as when we shift we are back to 5000-5200. i try to get 400 SAE rw at 5500.

i am not trying to make the case the cars are equal, just that the FD is more competitive than one might think.

hc

A team to work on weight reduction and yet they give you a 5 foot long, 40lb catalytic converter :scratch: well done guys.

Great post Howard!

NCZ13 - dont get started on the torque argument!!
Power is power, and torque is just a factor of that power.
HP wins races not torque, otherwise we would all use low revving diesels.

It also indirectly makes the point that true racecar construction is not of any commercial value in the general automotive industry. You could say it's ahead of it's time, but you could also say no other manufacturer has had the guts to attempt it since. Lotus used to be there but has already quit as far as I'm concerned, and Vettes are oversized and have too many features designed to suit receding hairlines. (You might as well put a Viagra dispenser in with the cupholders)

While the FD was ahead of it's time, others have learned that producing a high performer with racecar-like maintenance requirements and fuel consumption is not good for the company's bottom line. FD fans are among the few who will step up and address the limitations built in by popular demand and EPA regulations and convert one of the few racecar platforms into what it can be. McLaren budgets aside, you have to do it yourself with a better turbo setup and properly robust cooling and braking systems.

David

by all means my intention wasnt to debate torque lol

They cars deliver their power in a different manner. rotaries have a very progressive tq delievery, v8s have very flat torque curve through the rpm band, I didnt see it adressed in the OP, but i figured it was also something he didnt just forget about.

I would never discredit the FD as a capable racer. I was just watching that video the other day of the FD racing the F430 and absolutely decimating it.

I love these posts, thanks Howard

" As far as amazing weight comparisons go. I like this... http://blog.leasetrader.com/archive/...Auto-Show.aspx "

no disco doors.:(

thanks for sharing. both cars are clearly built for one purpose: pure performance. The FD was years ahead of its time, still looks sexy, and performs with some of the best sports cars today. The MP4-12C is ahead of its time, looks great, and is one of the best performing cars on the road today.

Wish it was a bit warmer so I could get my FD out of the garage :)

"Weight is the enemy; air resistance is the obstacle." - Alfa Romeo slogan from the '50s.

Great thread.

I read the Edmunds.com Inside Line first drive for the McLaren this morning. Pretty impressive considering no AWD. Too much electronic help though and they need to offer a manual transmission. They could probably get in under 200k without the elec. aids, dual-clutch, and carbon ceramic brakes.

NCZ13 - Would you post a link to that video of FD beating the F430?

This may be the video:
http://www.youtube.com/watch?v=ODFKv8r7_5A

The point by finally given at the 8:12 mark.

I was there that day running in a slower group part of a NASA event. The FD driver is Jon Schroeder who runs Trackacardia who set up an earlier meet there at Monticello back in April.

Here is my vid from back then following another FD rx7club member.

http://www.youtube.com/watch?v=Tps1rSVR6Tk

great track which they now require membership just to get on.

Howard why not compare the 20b instead since it's much closer to that MP4 in displacement? I know it's an engine swap but lets still give the 20b some credit when it comes to easy hi hp. I mean the way I look at it, Mazda didn't have to reinvent the wheel and spend a gazillion dollars on building a brand new engine. They simply engineered the new center plate and longer e-shaft and put the engine together with existing factory parts. 20b is your answer to the torque question and can easily make 600 rwhp on pump with the only internal mod being swaping out the exhaust sleeves. Hmmm not bad for a pieced together engine. ;)

I just wanted to add that according to the driver his FD has a GT3574 and that day he was boosting 1 bar @ 405 RWHP. Stock YES stock suspension with R888 tires.

Here’s the thread if anyone is interested.
https://www.rx7club.com/racing-kills-lounge-10/fd-vs-ferrari-f430-941174/

Somehow the styling of the new McLaren is uninspiring... the first one (F1) was so distinctive and timeless, and this one is a little bland. Sort of "Lamberraraudus". I sort of dug the centered driving position too, though i'll bet it was odd with the typical single passenger (super model arm candy) the average owner toted along.

Numbers notwithstanding, it seems more like a focus group-approved status toy for rich people than a singular expression of automotive vision that the F1 was. I'm sure they'll sell twice as many. But I digress.

Speaking of singular visions, there'll never be another car like the FD. Certainly not by a manufacturer for the rest of us.

I don't want to start anything I just wanted to point out to Howard this statement is in error, the rotary engine accomplishes all four 'strokes' separately (intake, compression, combustion, exhaust). It is not a 2 stroke engine.

-Sorry, pet peeve

Lol@disco doors

i consider the rotary most similar to a 2 stroke because every time the combustion chamber passes the sparkplug combustion/power is generated.

while other characteristics of a 4 cycle may be similar (of course it has intake, combustion, power and exhaust), IMO, the most important characteristic of a 2 cycle is power every stroke in contrast to a 4 cycle that delivers power every other stroke.

feel free to consider the rotary a 4 cycle if you wish... i don't.

howard

Howard as Im sure you will agree , this debate boils down to crank revolutions vs "power stroke". The rotary may have a combustion cycle everytime the rotor face passes over the plugs, but it is not once per crank rotation as in a 2-stroke, not every other as in a tradtional 4-cycle piston engine. Im not telling anyone anything new here, but depening on how someone cares to look at power cycles, you can make the argument either way.

Not to be pedantic but, by definition, the rotary is a 4-cycle engine. The most important characteristic of a 2-cycle engine (piston or otherwise) is that it had two cycles, not four. Just because a 4-cycle rotary engine doesn't have pistons does not make it a 2-cycle engine. More specifically, both piston and rotary 4-cycle engines are, in thermodynamic terms, Otto (not auto) cycle engines.

You guys are missing Howard's point. The rotary is both a 4 stroke with 2 stroke advantages because it sparks every rotation and not every other. As Howard stated on a 4 stroke piston engine the spark plugs fire every other top dead center of the piston (1 spark for every 2 revolutions). With a rotary, you do not have this colling off period as the plug fires every rotation. If takes 3 e-shaft rotations for the rotor to make 1 full revolution. In 3 rotations, that rotor will also have sparked 3 times.