REVHED

Why are you quoting a peak torque figure? Give us the torque and rpm so we can have something meaningful... hp.

Blue Goose

But they shaved off a half second in the quarter mile and cleaned up at the track when they went to the 8...

futant

Here is a graph of a 5.0 running a 150 shot with less engine mods than me. This is conservative, I should make more. I don't know why you demand that i supply a hypothetical amount of power it produces anyway. I cleary stated soon I will be at the dyno.

Are you implying hp is more meaningful than torque? Unless you spend all your time above 5250rpm.......
What is important is the area of the curve.......

Zulu

Now, what rotary owner thinks it's fun below 5krpm?

it's the 6 to 8krpm range that's exciting

mar3

iTrader: (8)

See what happens when ya want to be like Mike? Point taken...observe my new sig, but y'all go to your new home, now, OK?

Winnipeg85GSL

NEVER!!!!

rotorhead

jeeeeezus! it's all well and good to poke fun at our pissed-on , i mean piston brethern, but some people seem genuinely pissed off about it! i mean, it's THEIR CAR for chrissakes, they can do whatever the hell they want to! if somebody stuffed a v8 in MY car, then i'd be pissed. unless i asked 'em too.... cuz then i'd be reeeeally fast. what's worse? having some grease monkey convert his car(which he loves, don't we all?) to pistons, or have it go to some schlub that doesn't give a rat's *** how cool the 7 is. then they'd be tempted to run it over with their bigass redneck 4x4! for those who haven't seen it, yes, it has been done. as long as you love your car, do what makes you happy! also, i can't promise i won't make fun of ya for doing it! but i will respect that choice.

" 'NUFF SAID " ~ stan lee

Eville140

I know for a fact, that if I had not hauled of the rx7 that I did the 4cyl swap on it would be nails by now.

Later
Randy

rotorhead

thanks for saving a 7 randy! even if you did bastardize it

Manntis

There is no 8 in an Elise, and Lotus only put a V8 into the Esprit when GM took over for a brief time, their marketing gurus believing people think only V8s have any power... the half second gain, one could argue, had as much to do with re-engineering the spaceframe to contain more aluminum components, regearing the transmission, and other upgrades as did swapping the power plant...

Maguire

iTrader: (1)

This is what i dont understand. If you wanted to make big power in a small car. Why not drop a v8 in a datsun 280zx or even a early 300? Put a piston engine in a piston car. Why "bastardize" a 7, as rotorhead put it? And yes i do agree that swaping a 13b into a 12a car, isnt much better. But AT LEAST IT STILL HAS ROTORS!!! im sorry, but I just dont see the point.

Manntis

You'll notice there's not a whole lot of Europeans, Asians, or Aussies doing these conversions.

Americans have been trained by decades of Big Three marketing that the bigger the engine, the bigger the output (though there's not a lot of large blocks and hemis anymore...), and plenty of North American 240zs and 280zx chassis end up with V-8s in them (a shame, really, as those inline-6 engines were torquey and smooth as-is, just a low top-end hp output)

Elsewhere in the world people concentrate on wringing out every bit of horsepower they can from smaller displacement engines, with the exception of V10 and V12 powered exotics (Don't even get me going on Lamborghini - as a former tractor manufacturer selling 'performance cars' with no racing history and poor handling, it's no wonder the company keeps getting sold).

The arguement for putting a V8 into a ReX could go either way, though, as the main issues are

1) cost
2) complexity
3) torque gains, especially when compared to (1)

1) cost - Chevy and Ford V8s are in so many trucks that they're dirt cheap. I've rebuilt 350s for less than $390 CDN (not counting the cost of the engine, but blown blocks are cheap)

2) complexity - RX-7s, especially 1st gens, don't have a heck of a lot to remove, and the long snout seems engineered for a far larger engine than the li'l-breadbox-that-could that Mazda put in there. Yes there are crossmember and mount mods, and a new tranny, etc. but that's true of virtually any engine swap.

3) torque - I love rotaries for their output per physical size, but there's not a heck of a lot of low-end grunt (mind you, the same is true of Honda boingers) For those who love off-the-line snap this is a relatively easy way to obtain it.

Me, I've gone to great lengths to keep the serial numbers of major drivetrain parts in my car matching, and the appraised value reflects that. Right now Pamela is only putting out 160-170 hp but I'm enjoying her as-is, andlove having such a different powerplant.

However, there are those who have completely different goals with RX ownership, and some of 'em drop in V8s.

Not my thing, but whatever floats your boat...

fatboy7

Hp is important!! I don't understand why you all think torque is the do all and say all. When it comes to comparing cars that have entirely different gearing, Hp is the think to look at. I hate it when people take Shelby's comment out of context, he was talking about peak Hp, which IMO is a 'bragging rights' but otherwise useless statistic.

Torque is defined as the moment of force, for rotating bodies. if you take torque 'ft-lbs'(lbs of force X feet) and devide by the radius of a wheel, for instance, you get force in lbs. With that said, gears could be called torque multipliers.
Let me make a point.If you just took, even your 450lb-ft monsterous V8 and attached it directly to the wheels and had tires with a radius of a foot, you would only have 450lbs of force trying to move a 2700 lbs object, but redlines at 5500RPM at the crazy speed of 392.5MPH. Now take a 12A ,100lb-ft, in with a first gear ratio of 3.662, and a final drive of 3.909, take the torque and multiply the three numbers: 1431.5 lbs-ft seen by the wheels divide again by 1 foot, and you get 1431.5 lbs of force, 3.18 times as much as the V8, but relines 7000 RPM at 34.9MPH. Which situation is better? Depends on desired speed. The 12A in this situaltion accelerates much faster, but the V8 goes much faster in the end. Horse power seen at the wheels of each is the same regardless of gearing: 471 HP for the V8, 133.3 HP for the 12A(assuming constant peak torque to redline).
I could take my 12A, stick a 9+ final drive on it(tree-stump puller ), and out accelerate almost any car (and redline it in fifth at 68MPH).

My point is horsepower@all RPMs is useful for comparing cars, and torque@all RPMs is useful for comparing engines.

So my question is, what trannies & final drives are you using? That will tell me a ton more about what you V8 RX-7's are capable of.

Manntis

To back up the torque vs. hp statement above, the MLVW I drove in the army (bigass 6 wheel drive transport truck seen in most army movies) has 167 hp, but can go up a 30% grade, fully loaded, without slowing down.

However, as important as gearing is, engine torque is important to start the wheels turning under power, and for snappy acceleration.

Directfreak

iTrader: (2)

Agreed. This is why with my Old 13B Streetported SE, I could beat Mustang 5.0 in the 1/4 mile no problem, but rolling from 50-90 was a much closer race because of their instant torque.

Even Third-Gens are vulnerable on rolling races for the first few carlengths to V8's. The V8's have the Torque to get it rolling, but it's Turbocharged High Horsepower that passes them by immediately after.

fatboy7

I agree fully.

mar3

iTrader: (8)

Torque gets you off the line and HP seals the deal at the top end. The Holy Grail of motoring is to have both in abundance which is a trick for any engine...

rotary emotions

HP AND torque are important, but only in a certain way. If you take a car to dragstrip it's only important to get to the end of that 1/4 mile as fast as possible. So mayba a V8 makes sence. If you are a real driver, you'll take your car out on the track. And not an oval!
What counts is the balance, the handling, the overall car. Smaller, less powerfull cars often outperform bigger beasts on such an occasion. We all remember the legendary Mini, yes? It won the monte-carlo rally in front of many more powerfull, faster cars. Why? Because it was a better car, overall. It was light, cornered very well, and was reliable. If you put 200lbs extra on the front axle, and you're going to a track, you will notice the difference. If not you can't drive, and should have the car tested by someone who can. Don't think Michael Schumacher is gonna believe you if you say 200lbs doesn't make a difference, do you??? Drag racing is fun, but it's far less racing then a difficult track (let's say Le Mans, Spa-Francorchamps..)is. Let's try your V8 beast there.

Maguire

iTrader: (1)

Dont get me wrong here. The datsun 280 is easily my favorite car next to the 7's. And it is a shame that they get ripped apart also. But i sure see alot more datsuns in my area than i see rotories. So i dont have as much compasion for them. Some day ide like to own a clean stock 280zx.

White84SE

Well, I do actually take my little 12A out on a track, although since I don't have a competition license yet, I'm not allowed to go wheel to wheel with anyone. Oh, and I would much rather be in a road race than a drag race.. Obviously, 200 pounds won't make a difference to Schumacher.. they've done it already and hasn't impacted him... And you want to see a V8 at Le Mans... gee, Corvettes don't count AT ALL do they?

--Danny

EL PAALO

I still don't understand why so many RX7 owners are OFFENDED by pistons.



It is my car, right? At least I don't want a park bench on the back and vinyl all over her, just more power for less money.

Acuspeed

Yep. And when you boil it all down, that's all that really matters. You should do what you want and not worry about what others say/think/feel about it. In fact, I think that's pretty good advice for life in general...

rotary emotions

Corvettes do count, but eh, how many of you use a C5R engine??? You guys use a block that was intended for a ******* truck!!! So try at least to use the C5R then. Might be slightly overpriced though :-)

MIKE-P-28

iTrader: (1)

Well just a few thoughts on this, I like what I got right now, its untuned but runs really nicely! I am however very unhappy at the amount of money i spent to get there.. If I had to do it over I would get something else... I have spent a freaking fortune, almost enough to buy a new car and forget this HP madness...

So in closing i dunno if I will do another car, and dont know if it would be a v8. But if i did another one, the cost would be an issue this time. So draw youre assumptions from there..

Directfreak

iTrader: (2)

Mike,

It's not what you spent to get the HP you wanted.

It's the money you spent to Get what you wanted.

You and I both know a Blow through Turbo 13B could easily put out well over 300 HP to the wheels, and it would have been cheaper than a V8 conversion, (and much cheaper than a Cosmo swap.)

I am using 300 as a figure because you feel that's about what you're putting down.

I know several 12A (Blow-Through) Turbos that run 11's all day, and a few that run high 10's. They have less than a third into their system than what I have into mine so far. And when I am finished, they are still going to give a hell of a run for my money.

I had a budget, blew by it, and then just decided to keep going until I got what I wanted. What I want is not a High HP FB, I wanted a High HP ROTARY TURBO FB.

It's not what it costs, it's what you're willing to spend.