Mega RX-7 "Roadster" build (pics)
 

Well, It's time for the "official" thread regarding my car's most recent project. Goals are:

Major weight reduction, Full race prep(cage, gutting, etc)
Miata IRS
FC front suspension w/R&P PS conversion
Right hand drive swap
Wide Body kit
Removed roof and back hatch (Roadster)
Fiberglass body pannels (doors, hood, fenders,etc)
Full engine rebuild (yes, it's a V8......)

Sounds fun huh? Here are some pictures of the tear down so far. I need to take some more but this is what the car looked like last week.

http://memimage.cardomain.net/member...289_8_full.jpg

http://memimage.cardomain.net/member...289_1_full.jpg

http://memimage.cardomain.net/member...289_2_full.jpg

http://memimage.cardomain.net/member...89_11_full.jpg


I'll keep the progress updated here, but you can also follow the cardomain site here : http://www.cardomain.com/id/drivergt5

All sounds cool except one thing. Too bad you had to put 8 pissed-ons in the car. Shame...

It woulda been much cooler with a PP 12A or 13B.

I would be fine with a v8 if it was something cool like a Lexus 4.0 V8

Uh, no. A pissed-on is still a pissed-on.

a pp 12a or 13b would have even less low end torque, the V8 is a good engine. If it makes the car go fast... then its good in my book, at least he's not putting a 4 banger in it.... which engine is going in? I was thinking of a 351 windsor, since my 12 a, doesnt like to run in the rain anymore

ive seen 3500 hp big block V8 engines with no "NOS" ive never hurd of a rotary doing that..... what are the HP numbers on the pro street RX7 rotarys? im not trying to rattle anyones cage... im just curious

Looks Like it will be a very neat build up. Cant wait to see pics of it.

One of the Drag guys is at about 1500HP on a No "NOS" motor.

Jesus Padilla runs I think high 8's low 9's from 1.3L, N/A, No Juice. All motor. That's with what, 87 CI? Compared to 500+ CI. You can't compare. Let me see any V-8 do that. Only thing I know that is way more sick, but'll never fit in a car is a 12 cyl diesel that runs 708,000 hp, and 3,000,000 lb/ft. of torque....at 108 rpm. It's a cargo ship engine.

man i wish i had the money to make my rotary do 1500 hp..... that would be so cool!
But as a student, im stuck with junkyard parts, and a pp13b wouldent show up at the pick your part
oh well

ok... here is the way i see it..... hp/CI isnt worth anything if you believe that it is, go buy a honda S2000..... HP/MPG and HP/weight is much better...... i honestly think that the rotary engine is awsome, if mazda engineers sat down and worked hard on it, they could make an engine which could rock the world..... but, 1.3 letres with a 20mpg fuel efficiancy is not that good.... i can spend the same amount on gas, and have 100 extra hp on tap if i switch to a V8..... and if i turbocharge my 12a, my mpg goes down so to be honest... whats the point!
plus.... parts for a V8 are a dime a dozen, a rebuid kit is like $500..... but a rebuld kit for a rotary is upwards of $1500...... I like to spend less and go faster than the honda boys... this seems like a good way

You're absolutely right. But why be like everyone else? That's why we have rotary's. I don't wanna be a I4 guy. I dare to be different, and as little as I have in my car, i can run close to 14's, and still get 20 mpg. RB SP Exhaust, Holley intake kit, Holley Blue fuel pump, and pressure regulator. Mild SP.

1500 for car, exhaust came with it, the motor was 900, and came with the intake/carb. Pump was $50 on ebay. I can't complain.

thats my biggest problem.... I want my stuff to be unique, but i dont like spending loads of money.... so im stuck between the street port primaries, periferal port secondaries idea, and giving in to the V8..... i still havent decided yet
regardless, this car that '85 GSL 302 is building should be a wickedly fast car! I cant wait to see what a roadster with a wide body looks like, i cant even begin to imagine it!

sounds sweet, i just don't understand why you're gonna use a miata rear end with all that torque? the rear will be nice suspension wise, but will it take the abuse your v8 is gonna give it?

...canadians...

hey..easy now

im with u guys, stick with the rotary...

although i gotta say, here in my city there's a guy with a 302 in a fb with a wide body kit, and every time i see this car, i almost shit my pants, its way cool...not my thing, but you can't say its not an amazing machine!!!

I'm going with the miata rear end because it's an awsome design and everyone's been running around talking about Grass Root Motorsports's IRS comment. Since no one has ever actually tried it, I figured I'd give it a shot. It definatly doesn't work the way they thought it would, but I'm all for a challenge. I'm going with a T-bird 7.5" IRS diff, just like the V8 miata guys run. I figure it'll be good to 450 hp given the weight of the car, which will be pleny for me since I never intend to run the 1/4 mile on slicks anyways.

As for motors, I have been over this 1000 times before. I had the motor before the car, and the car I bought had no engine. Simple math really. I'd love to build a 12a or 13b FB, but time and money are not on my side. It's been an awsome car for over a year, so much so that 2 other people in my area have built 5.0 RX-7's, both are hard core rotary guys, both have a V8 and rotory powered FB. Kinda cool really. All I can say is don't knock it until you've tried it :)

i amost did it myself a while back. :D i didn't know about the t-bird 7.5" diff working in the miata irs setup. sounds SA WEEEEET! good luck

thats basically what my project car looked like a few months ago, stripped to the bone. I have no problems with the v8 like some here do, and as you know I'm very interested in following the suspension swap. But cutting off the roof? man not my thing, I hate convertables. but hey, to each his own right. Why right hand drive? just to have something different or what? good luck

E-mod minimum weight is 1500lbs. There are plenty of cars reaching it too. I have no chance, but I need to save the weight where I can. That's why the roof is going bye-bye. Purely for competative reasons.

As for RHD, I can get a JDM clip for much much less than I can find the FC parts for here. That means to save money, I have to convert to RHD, something I've always wanted to try anyways.

take the storage bins out!!!! unless you plan one hiding a 450hp shot in them :D

you really think it will hold?

well that answers my questions. The one thing I would like to comment on though is this. In the other thread you said you weren't gonna do the miata front suspension swap because of diminishing returns (crap its econ 211 all over again :D) yet your willing to chop the roof and hatch and go through the trouble of making it presentable (I would hope anyway) Now, if it were me I'd take a first gen Miata, gut it, and drop the v8 in that and be done with it. I'm sure you could get it lighter, its already got better suspension and rack and pinion and would be much less work and probably cheaper. I'm not saying your fb project is a bad idea by any means, I'm just curious why you're choosing this route, when you've stated that money and time are important factors. I'm just curious is all, still waiting with baited breath for pics of that irs swap.

i'd say to be different swap a 3 rotor sp webber turbo, i was thinkin bout this latley how no one has done that b4 at least i dont think so, or a 12a pp would b nice

hell, put a TDi in if you want to be different...


fwd and all










matt
turbo 302 FB in progress

:(
why the hate

Sounds really cool... but it sounds like you could have everything you want (roadster, light weight, 302, IRS) if you just built a monster miata. Seems like it could also be a lot less work and if you got a good deal on a body, potentially more money since you wouldnt be doing as much R&D as this project would require.

Either way, I think its cool as hell and look forward to seeing more progress on it!

give you $100 to let me drive that thing around the parking lot on a milk crate ;)

You can drive mine for 100 bucks.

Nothing wrong with 4 bangers :) See website

http://www.eville140.com

Later
Randy

If you are going with the roadster concept for weight loss, you may need to rethink that. If it's for a visual statement, fine.

With the torque of a V8, and the loss of the roof structure, you will have a lot of twisting and flexing. By the time you get the body finished off with some sort of rool bar or cage, the frame strengthened and a rear deck fashioned, chances are the car will be heavier than leaving the roof intact.

well to anwser that make it a hard top that is removeable and have the cage in there for strength...........man im all up for whatever u do when my motor goes to heaven im droping my friends trans am engine in or his spare camaro engine by what i have heard and seen of u this will turn out bad ass lookin

Well, I understand and respect you desire for more HP and originality. I have a 93' ranger that I converted over to v-8. (hence my username). I don't know how much you know about the 302's, but I have been eating, drinking and sleeping them for the last 6 years, so I can give you lots of good info on them. Just pm me!
Ken

indeed, a first gen turned to a convertible, if done properly, will gain at least 80-100kg. Plus the extra wheight of the engine, in this case.
but a roadster will be highly original indeed... just a pitty this one will be no Seven anymore: Miata/MX5 supension, V8 engine, tranny/diff non-RX,...

I agree fully that I could build a better car than the RX-7. I do have some problems with the V8 miata's, mostly involving engine placment. The FB is a much better platform for the V8, plus I already have the car with the V8 installed, and it's been great for over a year now. Really, this project is to see how far I can go, both to challenge myself, and to build a serious machiene in the process. I may not take a national title, but I'll be there, that's for sure.

As for the roof, I think you guys are missing out on the logic behind some stuff. The car isn't purely an E-mod vehicle. It's also going to be used for track days, drift comps, and general street driving. I don't know about you, but I have ZERO intentions of driving a 2000lbs, 400hp car without a cage installed. So, the cage is going in, regardless of the roof. Now, with that said, the roof, windshild, door and back glass are all coming out. This makes for a nice weight reduction, and should counter the weight added from the cage, if not more. The only real sacrafice I'm making here is to install a full cage vs. the 6 pnt. I could technically get away with. As I said earlier, for what I intend the car to do, I'm opting to go for the larger cage for saftey. I figure it'll cost me about 100lbs, but I'm willing to make that sacrafice. You must understand a convertable requires much more metal for support because of the less than ideal location of the braces. The cage will essentially act as the roof, and because of it's location, can be more effectivly used with less of a weight penalty. Also, there are no previsions for windo glass, nor is there a roof assembly, or windshield. These alone account for aprox. 180lbs worth of material that would normally be on a convertable. The swap I'm doing is hardly compairable IMO to some of the amazingly complex things that go into a convertable FB.

If it makes anyone feel better, I'm going to test cut the roof off one of my parts cars and weigh it to get the hard numbers before I proceed. I should have numbers from that sometime next week or so.

I cant wait to see this done. Im not a big fan of piston powered RX7s, especially American V8s, but this will be very unique. Good luck man.

I think its a cool buildup.. tests your fabrication skills as well :)
Daryl

i saw u at us drift and u kicked dirt in my face...lol either way its a seven and this project will be tight

sounds like a great idea, and ya got tha respect, build that V8 and then race a built seven for sh!ts and giggles. V8 vs PP13b or 20b ? who would win

Time for some new pictures.

http://memimage.cardomain.net/member...89_16_full.jpg

http://memimage.cardomain.net/member...89_23_full.jpg

http://memimage.cardomain.net/member...89_17_full.jpg

http://memimage.cardomain.net/member...89_18_full.jpg

http://memimage.cardomain.net/member...89_15_full.jpg

You can see where the frame rails are going to be in the way. I removed the upper metal to expose the rail underneath. Soon I'll be extending the frame outward so I can install the IRS.

Be like me, I drive what car depending on the meet. My LE for the rotary meets, my Nova for the muscle car meets, and my DSM for the import meets. Sometimes I switch it up, show the import guys what happens when you have a 350 reving up and smoking them off the line in an automatic. they get pissed.

What if you just had one car for all three meets? ::evil laugh::

i just want to take the time to say.. your my god damn hero.

your car is amazing

What happens when you give a skinny kid a body saw and some free time?








































http://memimage.cardomain.net/member...89_33_full.jpg
http://memimage.cardomain.net/member...89_34_full.jpg
http://memimage.cardomain.net/member...89_35_full.jpg


I think I just added "pray to God" to my to-do list....

:eek: Im praying for you too. Good luck.

I've watched the vid that he had posted on here about 5 months ago. Anyone who is against piston engine swaps should watch it. The way the car is so easily manipulated is amazing. Just with a slight change of pedal pressure, you can control the car to any extent. I love the rotary, but if your one to do crazy burnouts and doughnuts all the time, use a V8.

I did some test drawings today. One is in "street mode" with the passenger seat and windshield installed, the other is in "race trim".

http://memimage.cardomain.net/member...89_39_full.jpg
http://memimage.cardomain.net/member...89_40_full.jpg

What do you think? I'm liking it.

Thats going to look sweet.

yea I saw that vid too, very impressive. And those drawings look pretty cool too. One thing I'm sure you're aware of but I feel the need to say anyway, is be VERY careful not to tweak the frame (or lack of in this case) when reinstalling things. Having cut that much out that car must be about as flimsy as a piece of cheese right now. You better brace everything up before you go welding that sub frame in. Anyway, I'm done :D

You may want to think about putting in a large amount of the cage (or vast quanitites of bracing, anyway) before you cut the roof off.

Lookin' good so far, tho.