Quick Engine Clarification requested
 

i was just wondering, having recently joined the FD world...

i was lookin at pics...

comparing my "stock" engine to others..

how come some have black "hot pipe and cold pipes" for their SMIC

and some have silver?

take this for example..

http://rx7.apneablue.com/photos/engi...nsform/001.jpg


and then here's my very dirty engine

https://static.flickr.com/31/54954019_20bb3fe292_o.jpg



oh and my Second Q... how do I know if i have an R1 or R2?

i have front and rear strut barts, dual oil coolers, no leather, no sun roof, no bose sound system...Vin number doesn't give a hint...

any ideas?

Diff. color piping probably reflects Mazda changing suppliers midway through production, as they did quite a few times for various components of the vehicle. No real significance. I'm inclined to say the silver piping was on earlier years, and the later years were black. But I can't verify this for sure

Re: R1 vs. R2, what year is your FD? ;) R1s were only in '93, and R2s were in 94 & 95. Go here: http://rx7.voodoobox.net/infofaq/bguide3g/bguide3g.html for more info of the various trims the FD came in, as well as a bunch of great info. I'd read that site as well as the FAQ sticky on the top of the 3rd gen section. You'll find virtually every question you have already answered in there ;)

Oh, and congrats on getting the FD.

~Ramy

PS: Also read this post: https://www.rx7club.com/showpost.php...59&postcount=2 It has some really important info that you need to know NOW before it's too late... ;)

http://www.mazdausa.com/MusaWeb/disp...ersHome.action

you can go there and register your vin and it will tell you the model you have... and some other things about your car

You have an R1.

As for the pipe colors, I dunno - Ramy's suggestion makes sense. Keep in mind the aluminum "Efini" Y-pipe is also silver, but looks a little different from the original one. The blue couplers are aftermarket.

Dave

HOLY SMOKES! You have what appears to be a '93 State Inspection Sticker (looks awfully like a VA inspection sticker, at that). Was this car sitting for a decade??

yea that's the sticker (i think ur right, it is a VA one)

the car is no longer in the states.. it was exported my a Navy guy when he came over sea's and he sold it after his tour was done... changed hands here a few times.. no rotary mechanics around here to fix it, ended up getting abandoned... left in the sun and dust for like a year, the last owner (whom also happend to be navy) was leaving and heading back home...

got a Running FD, with an exhaust leak, clunking rear end, a small amount of rust... and a shit load of dust for $2500 59 K on the ODO and a JDM engine in it...


so i can't complain :p


i think they left the sticker as a reminder kinda thing...

Wow...what country are you in? I'm guessing Kuwait or Saudi?

Holy Crap!!! How come I've never seen this before??? Arigato Taikutsu-san!
Yuichiro

They told me I had an R2 and 5-speed, but that's about it.

Dave

Ditto... but it does let me know what the original co;or of the car was! So guess what...there IS a way to verify if a CYM is really a CYM, or just a respray! And if the interior was swapped from one color to another. Badass...

As for my FB, they have no IDEA what it is LOL. All it says is 1984 RX-7. Transmission: Unknown. Engine: Unknown. Exterior: Unknown. Interior: Unknown. And it won't even let me manually change that... =-/

After I bought my FD, I suspected it was either a base model with add-ons, done by/how whoever, or a PEG. The site confirmed I have a PEG! So I'm happy.

Silver plastic tube out of IC to throttle body was '93, production went to black after. Pipe into turbos was black plastic, I do not know of a silver colored plastic version.

For the overseas '96 and on models, the design changed to the smoother flowing and more robust "silver" aluminium Efini Y-pipe.

I always wondered about this, just never really cared enough to find out.

Ditto. Plus, I've seen exceptions to every rule so far

- R2 with leather
- 94s with non-reinforced wheels (mine included)
- 94s with R12 (mine included)
- 95s with 96 ABS Units

So I'm sure there's a 94 somewhere running around w/ silver pipes, or a 93 with black pipes :p:

I just used a little paint remover and some brillo pads on my elbow (got an efini crossover pipe now)

In general, the 93's have the silver intake pipes. I think Mazda just realized they could save money by not painting them, and that the paint gets scratched and crappy looking in short order. I do seem to recall seeing a later '93 with a silver TB elbow and black crossover pipe, though. All '94s and '95s I've seen had all black.

I've heard the AC thing with '94s, but I think all proper '94 models have R12 AC. My '94 is a fairly late one (going off the VIN) and has R12. Blows damn cold, too :).

I think some of the other weirdnesses, like R packages with leather, are from previous owners. Dealers will do a lot to please a customer, and if a customer wanted to buy an R package on the lot but wanted leather, I'm sure the dealer would swap in some leather seats to make the sale. Happens quite often. Or, a previous owner could have got some leather seats and swapped them out.

Dale

Man, I'd love to find a dealer with a pile of unused R2 seats because of customers who wanted leather...

Dave

How dare you! Blasphemy!!! It wasn't to save costs...it was to save WEIGHT!! Every mg counts!! :p: j/k. But you gotta admit, the Mazda guys are really something. They actually drilled the pedals to save weight. Talk about weight freaks. Ya gotta hand it to 'em... In fact, I think FD's had the lightest pedal set of any production car at that point!

From the 1994 Brochure:

"And because weight is the enemy of performance, we subjected every part, every design of the RX-7 to intense and thorough weight-reduction scrutiny -- but never at the expense of structural strength. In pursuit of every last extra gram, we even drilled out the aluminum brake and clutch pedals and shortened the spark plug lead wires." :eek:

Dale, I'm not quite sure what you mean by a proper '94? Cuz '93s have R12, '95s have R-134, and '94s seem to be a mix. From what I've read on the forum, most are R-134.

BTW...mine blows real cold too, and I love it. BUT, my friend who's a certified A/C installer & repair specialist was telling me that R-12 and I think R-22 are being completely discontinued. Before, you just had to be certified, and small quantities were available. Now, they've completely halted production, so the car and home A/C units using the older freon will eventually HAVE to convert to R-12. Either that, or use those fake R-12 bottles they sell at auto parts stores lol.

I'm sure that's the case as well.

I think you're backwards on your R-12 vs R-134 stats. From what I've seen, R-12 is in most of the 94s with a few at the end of the year switching to 134.

R-12 has been out of production for some time. There is old stock being used up.

Then I'm going to be blasphemous and say that drillng pedals doesn't make them lighter - not as much as a better design in the first place. Drilling holes is not as effective as simply redesigning the pedal to be lighter in the first place - perhaps a cast frame with a lighter weight inset might have been superior. Drilled holes looks high-tech since it's a actually poor-man's weight reduction technique used to modify existing parts - and Mazda knew that it would be recognized among the sports-car buffs.

But Mazda did really design a lightweight car - especially in unsprung components - I'll give them a lot of credit there.

Dave

I'm just repeating what I read on the forum. Big argument over a few threads (back in the day) about how only 93s have R12, and the rest have R-134.

Re: R-12...I guess maybe the old stock is almost gone?

Dave, would a cast frame with a lighter weight inset be lighter than an aluminum pedal? I thought aluminum is pretty much as light as it gets...? :scratch: And remember, this was pre-CF days haha.

As for shortening the plug wires...are they serious? :0

Cast aluminum...:)

And for those of us who have no idea what the difference is (between regular aluminum and cast aluminum)? Sorry, engineering isn't my steeze lol. I googled it, but found no explanation.

Aluminum generally comes cast or wrought. Wrought means it comes in bar/rod and gets cut to shape, castings of course are poured to the shape and optionally cut afterward. Cast parts are usually more brittle than wrought, and wrought parts can be heat-treated for extra strength after being shaped.

If weight was really an issue with the pedals, consider how ceilings and floors are made. Since we can't find a 2" thick slab of wood to make a floor, we make trusses and beams to divide the area and put a thinner slab on to cover the gaps. For a pedal, you could probably skip filling the gaps altogether and cast a lighter, stronger structure. Like a basic bicycle pedal. That would be cost-effective, and probably be as strong and lighter than the current Mazda design. I think Mazda didn't get too aggressive in going this direction since it had to look like it would support the weight of your foot. Or it would have required a lot more engineering hours than the grams were worth (as in, hours spent on another component would have been more meaningful).

Mazda did do some suspension components using "squeeze forging" which I think is just a deluxe casting. Extra heat/pressure probably reduces brittleness and improves strength.

As for using wrought aluminum, you could cut/drill a plate into a rather airy-thin design. This is expensive for mass production, but can be done in a one-off manner. So you will see many home-built race-car parts made this way. But the cost doesnt' go down as you get into mass production.

The ultimate solution would probably involve one-piece titanium - higher strength/weight than aluminum. But expensive as all get-out.

I have to say, Mazda did a hell of a job for a car stickered at $35k. But it's no Enzo.

Dave

Here's another exception. Mine's an early 93 model (build date 8/92) and it had a black crossover pipe and a silver compression tube. Go figure. I always thought that people painted them silver to look like the efini pipe.


There's a reason Ford owns the controlling interest in Mazda now :wink:

Joe

Interesting.

So pretty much structurally reinforce a less dense object, huh? There would be gaps and areas not as thick/strong/dense as the rest (not structurally important areas however).

Nice. Thanks for breaking it down for me. That gave me an excellent mental image :)

You're saying to use wrought aluminum (a bar), shape it, then thin it out in areas, and drill it out in others etc...basically removing some of the material to lighten it? And that isn't feasible to be done via mass production? Gotta be done one at a time, which is why the cost won't go down?

Whoooowweee. Titanium sure is expensive alright. Hmmm. I'm wondering now if the Titanium Pedal Set I have (an accessory offered on the FD in Japan) is real titanium or just looks like it?

Isn't the Enzo chassis made entirely of CF and aluminum honeycomb sandwhich panels? I don't think such technology was anywhere near affordable in the RX-7's day, and it's not very affordable now. NSX's are all aluminum chassis (is that plural as well? lol) and look how expensive they are. I'm sure you're aware of how expensive the Enzo and Porsche GT are with their CF structure.

I think Mazda did an incredible job as well. I just wish it was as aerodynamically efficient as say, the new 911 Turbo, where it doesn't try and cut through the air; it actually promotes airflow through the chassis, enhancing downforce, cooling the brakes and motor, etc... amazing stuff. But again, you see the 911's pricetag, and you see the RX-7's pricetag. I think Mazda surpassed all expectations given their budget, and then some ;)

Here's a post w/ more info re: the 911 Turbo's amazing aerodynamics: https://www.rx7club.com/showpost.php...6&postcount=98

LOL. There you go Joe. Yet another exception. Like I told ya...I'm just not surprised anymore.

I remember I was shocked when I found out about the red interiors on silver FD's. Then I found a black FD with red interior (you have one, right?). On ebay a week ago, there was a WHITE FD w/ red interior! It never stops man...

Yes. Since a pedal mostly has to transfer the pressure of your foot without collapsing, it's what we refer to as bending loading. In bending, making something thick truss-like works better than a solid slab.

Check out this battle-bot thing: http://www.teammadcow.com/construction_summer_2002.htm
and jump down to 25 July. That's exactly how they're building this - take a chunk, hog out pockets, and leave material where you need it. It just take a lot of time under the milling machine.

In mass production, cast parts have a high up-front cost and delay due to making the molds. So it's generally out of reach of prototype and low-volume projects. But once it's going, it'll pop out parts very quickly and cheaply. To keep up with an auto assembly line, this is a popular approach.

Just be sure it's not 'titanium look' or 'titanium coated' or something. I dunno about Japanese accessory parts, but a truly superior titanium pedal would probably cost $1000 here. Give or take a grand. For reference, I had some titanium D-rings made once, (D-rings like the ones that shoulder straps clip into on a dufflebag). They were 10g apiece and cost $150/ea. So Ti is very expensive, very.

I've seen little bits about it. I have a article from an auto trade magazine describing the latest GT's chassis, I will try to dig it up. It mentioned how they shifted the CG down like 0.1" and all the stuff they did to acheive it. That kind of development requires a very stable platform and a whole lot of wind tunnel time to prove it out.

Plus, the economy of scale applies here. If Ferrari were only making 100 of a particular car, they may hog out wrought material rather than casting, since they don't make these cars particularly fast, and the hassle of molds isn't worth it.

Dave

Bending loading, huh? I feel like I'm in a materials engineering class hehe. Good stuff :bigthumb: Takin me back to my college days... (my roommate was an industrial engineering major).

Re: the titanium pedal, take a look at it, and tell me what you think. It clearly says "Titanium" (the name of the accessory), and the color/tint of the metal looks titanium gray to me (I was one of those 120 color Crayola guys :D). Don't have a weight on 'em, but price was $200. Pic: http://img.villagephotos.com/p/2004-...6/IMG_2953.JPG

Oh I see, they are a thin titanium plate that is set on the existing pedals for cosmetics. I can see that being real Ti for $200, since it looks like it's only 1/16th or 1/8th thick, and it has no structural requirements.

I was talking about replacing the whole pedal and pedal arm with a single titanium part. That would be much more expensive than a cover plate.

Dave

A complete pedal set replacement in titanium?!?! What...do I look like I have money I don't know what to do with? lol. Besides...the .5 lbs I'd lose by such a mod (if it existed) would just KINDA be offset by the 30 lbs I picked up w/ the lambo door hinges haha :D

~Ramy

PS: FYI, Guru Motorsports makes a lightweight pedal box w/ removable Alloy Pedal Pads. It weights only 2.6 kg (5.73 lbs)!

I never it made sense :)

:Wconfused

I meant, "I made never sense said is".

Bah, forget it.

LOL :rofl: Don, I saw it, and I thought eh...lemme let this one slide (even though Dave was quick to fault me on ONE misspelled word in a PM I wrote at like 4 am!! lol) :D

Nice one Dave :nono: haha

EDIT: On second read... What the??? Arruu?? I know what you meant the first try, but the second try... :scratch:

No its lighter

Non-reinforce wheels were continued in production past '93. (Mine, I bought my 94 in 95 through Mazda Motorsport, had to wait for shipment from Japan and know that a dealer didn't have time to screw with it). 5 spds came with lightweight and automatics with heavier set. What seems to have changed is the supplier since wheels manufactured in 1992.

From reading the various service documents '94's A/C's came with either R12 or R134, there must either be a cutoff VIN number or differenece between factory installed vs at the US docks installation by MANA.

Now a '95 with a '96 ABS unit would be nice. For that matter I would prefer a 95 in my 94

Julian, re: the R12 vs. R134, there may very well be a VIN cutoff, BUT, I spoke w/ Mazda directly, and they told me they can't even tell what A/C system I had. So either the agent I spoke with is clueless, or Mazda doesn't keep track of it, and it was MANA at the docks. Who knows.

As for ABS, what's the difference between the 94 and 95 units? I know the 93 and 94 units are definitely different (back in the day, everyone at PFS used to always crowd around my car, looking at the ABS unit, because they pretty much saw 93s all day long).