JoeD

Oh my God...how can someone actually think that sounds good?

Unless you were joking...then nevermind.

rx7lover0147

first of all u should definatley take off ur badges because rx means rotary expirament. it is no longer a rotary and should no longer be known as an rx-7. second i think it is alright what ur doin i don't really approve of it 100% but oh well it's ur car do what u want to it. second i have seen a turbo for a rx-7 that will give u a little over 700 rwhp on a rotary engine. so u havent tried everything.

YayeR

he was being sarcastic.. he was trying to prove a point that the rotary engine sounds worse when pumped up than a 4-banger. I disagree, it all depends on with what taste you modify your car.

JoeD

Ok...that's what i thought.

tnt

You know as well as I do that it take alot more than just a particular turbo to achieve 700 on 13brew, those #'s have only been put down by a few people and are not realistic for a street car, as far as the debadging i am not going to take them off except for the front bumper because it is not stock.....

I ran out of material today but the new mounts for the steering rack are in and I am getting ready to do the finish welding i still have to make new mounts for the sway bar because it is staying in the stock location and the stock mounting bracket interferes with the steering rack, I will posts some more pics tommorrow...

Shaun

FDdRIFTER2

sorry to be off topic here, but what would be the difference in putting the 3sgte than the sr20? ive heard that the 3sgte is one of the best 4-bangers out there. have you ever thought about it?

rpm_pwr

Here's something I prepared earlier. Notice:
a) In 2 revs it displaces 2.6litres
b) 4 firing events every two revs
This is where SAE get the 2.6Litre four from.
c) Although it displaces 3.9l before repeating, it takes 3 revs to do so - hence the 3.9L has no comparason with other engines.
d) 270 degree powerstroke.
e) In 1 rev both rotors have inhaled 1.3l combined. That's where mazda get's it's numbers from.

Your 1.5 geared 6 idea is a little rediculous because the idea of equivalence is to compare the engines over equivalent speed ranges a diff or reduction gear doesnt do that.

-pete

93 R1

I've said this a few times. If they are they taking the 2jz out of Supras and putting this in, then why not.

Brad

I try not to respond to mindless drivel such as this, but you need to understand a couple things.

Horsepower isn't everything. The value of a motor is not solely dependant on it's ability to make a certain amount of power. Just because a 13B can make 450 bhp as easily as an SR20 does not mean it is just as good of a motor. The question shouldn't be "y the hell would u does this ??? u could easily achieve 450 with a turboed rotary engine" but rather "You could easily achieve 450 bhp with an SR20, have more torque than a rotary, be more reliable than a rotary, not sound any worse than a rotary , and have something that nobody else has...why keep the 13B? You like to smoke crack?"

Or something like that...

rpm_pwr

But in the case of the 3s there is a major weight saving over the 2jz. Since the use a restrictor in GT500, you might as well have the smallest engine that can max out the restrictor throughout the power band.

IIRC, the SR20 is about 10-15kg lighter than the 13b, so that won't make up for the missing 616cc.

BTW good luck with you project tnt, I may not understand it, but that don't think you'll build a good car.

-pete

Decay

Shaun, that idea kicks ***. I give you a lot of props for it, seriously. I too enjoy the FD chassis and design, but I am not a *huge* fan of the rotary necessarily, and the SR20 is choice

And yes a 3S-GTE is tight, but he didnt feel like doing it. I'm sure Shaun knows about it, yet decided on the SR20. It will be powerful and one of a kind. Can't wait to see the results.

Dan

P.S.- You own your own shop?

Nathan Kwok

tnt,
Nice stuff man. Its good to see people trying something new for a change. I personally don't think its worth the effort, but I'm glad that you do because I like variety. Good luck and whatever happens, KEEP POSTING PICS!

rpm_pwr

Prove it. How did you decide that it would make more torque? I'll tell you - you made it up. Oh, and 450hp on pump gas from an SR20 isn't easy eaither, you made that up too. Oh, and how many sr20's making 400HP+ have you seen in your life? so where do you get your reliability numbers from?

Yeah I know it can be done, but I've never met someone who's done an SR20 motor buildup who thinks their motor isn't doing it tough to make big power, and all of those cars felt like slingshots, not a lot of bottom end power. Maybe you know of a stroker kit?

tnt, is doing a project 'for the hell of it' don't make stuff up to help him - he doesnt need it.

-pete

YayeR

k even if you get flamed for putting a piston engine in the rx7, there is no need to talk **** about rotary engines. we know the flaws, we love the car, just because you wanan change it doesn't mean you need to call us dumb because we like it.

Brad

Wow.

Pete, buddy...you need to get out more and relax a little. You are right though, I made it all up...

First off, the wording I chose in that last post was a little misleading. I was just taking the quote from that moron and rewording it. I didn't mean to say that 450 bhp in an SR20 was easy. I meant to say 450 bhp in an SR20 would be as easy as 450 bhp in a 13B. And I never said anything about pump gas.

Anyhow, I don't want to argue about this...it is pointless. I'll just let you all continue with your dilusions on how grand and wonderful the rotary is...

Mazderati

iTrader: (3)

tnt,

If you are consistently dealing with Nissan motors then you are probably familiar with the fact that red top SR20s actually have a better, higher flowing head design than do the black top motors. Later on, the black top motors received the better turbo, hence them making more power from the factory. Thought I'd throw that out there for what it is worth.

As for Toyota's 3S-GTE.... All I can say is yummy. Nothing like 2 liters of displacement capable of putting out over 1000 horsepower.

Thanks.

Kyle

domokunSPL

the prob with the 3s-gte is the intake manifold. it flows the air unevenly so the number 3 cyl. runs lean. #1 cause of blown engines. you would have to buy a $700 manifold to fix this. or get a standalone that can control each injector ind. the engine seems over rated here honestly.....The 3s-gte community isn't doing to well ether here in the states. they are all preaching about the stock turbo so no one upgrades and then complains about being behind the dsm community. STUPID i would love to build a 500hp TRD widebody mr2 for road race/ highway battle. but the front end would have to be LOADED with spliters to keep it planted.....i'm rambling

sullycrx

HEY JACKNUTS!!! (AKA SHAUN) you gonna write me or what you funking honkey!!! shoot me an email, im going to japan ths week so i might not get it before i leave. yah thats right im going to japan, sucker!!!! later scott

MikeC

Its not ridiculous at all. This 1.5 times gearing is part of the rotary's design, no difference at all to if you just stuck a gearing on the back of the engine. By placing the gearing on the piston engine you are evening things up and only then making a valid comparison. If you have a look at the graphic you posted it doesn't match any piston motor on this earth, except, strangly, it matches my geared up 6 cylinder piston motor exactly.

If you have to use the 'per rev' method of calculating capacity then how would you rate a 2 litre piston engine where the drive was taken off the camshaft. The engine sucks 4 litres in 2 output shaft revs so must be a 4 litre, right?

johnchabin

iTrader: (2)

You could change the badge to read "PX-7" (for "P"iston). Just knock the leg off the "R".

Or, if you get tired of this project, how about this...

http://sdsefi.com/features/apr00stool.htm

I don't understand why people get upset with this kind of stuff. It's your car. I'd say "do what you want", but it's clear that you already are.

Good luck.

paw140

I've been following your argument because I think it's interesting, but you've completely lost me. An internal combustion engine is essentially an airpump. If one were comparing one engine to another, I would think that the volume of air pumped per crankshaft revolution would be a valid method. Since rotary and piston engines operate at essentially the same RPM ranges, this seems valid to me.

If you removed the camshaft drive on a piston engine, half of the chambers would not even pump any air, so I fail to see the logic of this comparison?

DRAG0NEER

good job! I'd rather have your motor in a 7 than some V8 anyday! I don't understand why people give you **** for this while others get praised for swapping an V8??

rpm_pwr

OK so maybe I was a little rash for calling it rediculous!

You can't use the 1.5 idea because of operating ranges. Your 1.5:1 3.9L 6 is comparable to 13b except the fundamental internal designs are too different. The rotors themselves do displace 3.9l but they operate from 300-3000rpm whereas a decent 3.9 6 should operate from say 700-6500 but, thanks to your 1.5:1 gear you now get 1050 - 9750 which gives it an unfair potential gearing ratio advantage.

It just so happens that a the 3:1 ratio inside the 13b makes up for the lower operating speeds of the rotors.

To use your logic, we could gear up a 13b with a 1.5:1 and call it a 1.7 that could rev to 12750rpm! A little unfair dont you think?

The mechanical multiplication of the e-shaft evens things out. But I guess you could say there is no fair comparason, the 2.6 is just the best.

Mazda won in 1991 at lemans by competing in the fuel consumtion equivalence category NOT the displacement category, this is a common misconception. In reality fuel consumption is as fair as it gets. Fuel + air = power no matter how you do it.


-pete

MikeC

I'm not suggesting that the drive be removed from the camshaft, I'm suggesting that the output shaft of the motor would be attached to the camshaft. If, as you say, engines are just airpumps and you can take the capacity as the amount of air sucked in 2 revs then this motor that is a 2 litre actually sucks 4 litres of air per 2 revs. So it must have changed from being a 2 litre to a 4 litre just by moving the point from which the drive is taken, right?

Boost Junkie

Hey tnt...
I admire you for you're courage to do something different...And in my eyes the Sr20 motor is the perfect swap into an FD cuz well 1- It can make about the same power (generally, seeing that 90% of the single-turbo guys arent making much more than 450 rwhp) 2- The Sr20 motor is prolly very close (in weight) to the 13b-rew and 3- You dont have to deal with all the headaches that the rew motor offers..

[flame suit]
On another note....Yes the 13b is what makes rx7's, rx7's...And altho to me the main reason to have an Rx7 is cuz of the rotory motor, i would not swap any 13b into another car So that is an explanation in itself.

Plus im sure after a while (Not in all cases of course) it gets tiring to deal with all the BS that the 13b gives...
[/flame suit]

cheers
-Boost Junkie (aka Mike)