Rotary's wanted!!!!

[cLc]

Originally Posted by Wilson!

i got nothing but love for the rotary. i think the engineering behind them, and the fact that they are different is awesome. i have talked to a couple people that have done the LS conversion, and from talking to them, their cars loose weight when going to a aluminum block LS vs TT rotary. the engine is light, but the turbos and all the piping isn't. the LSx swaps are a double edge sword. yes they are putting them in EVERYTHING now, and getting fairly common, BUT the power you can make for the amount of $$ invested is the reason, that and packaging.

The weight I posted is the fully dressed weight of the rotary with piping and turbos, so I don't get how their cars are getting lighter...lol I will double check my math and everything later, but I am almost completely positive those number are correct. Like I stated before, I'm just not impressed with LS swaps anymore, they are too common. Yes, they do make great power, are fairly cheap and very reliable and good powerplants (for a GM product, I was raised with fords =P.). Now, if someone took a new 5.0 from a mustang and swapped it into one, I'd be impressed with that simply for the uniqueness and going against the grain, even if they are heavier motors, it is just different. Don't get me wrong, I love the LS power plant, I'm just sick of seeing them in EVERYTHING lol.

Originally Posted by Tanro

Most racing organizations double the Displacement of a rotary, and yes, 1 face for each rotor on 13b is ~1300cc. The do have 3 faces though.

The rotary is cool and unique, and I enjoy the one I have, but I would enjoy a lot more if it got respectable gas mileage. Or it had some more power/torque to it.

All Racing organization and series increase the displacement of turbocharged or supercharged cars because they have forced induction, and is not only applied to rotary engines. This is why in the Grand-Am sports car series, rolex series, and the continental tire series, you have STI's in the same class as mustangs, camaros, porsches, etc. Though, you are partially right on the displacement calculation of the rotary, I think you are still slightly confused on the calculations.

If you are worried about gas mileage in a sports car, you probably shouldn't drive or own it, just my opinion.

Here is the full technical explanation of how to calculate rotary engine displacement for those that want to read it, as taken from rx7.com (If someone needs it broken down into simpler terminology or anything, I will be happy to do so to help explain):

The rotary engine is obviously unique. The engine has two rotors shaped roughly like a triangle. This makes for three combustion faces per rotor and a total of six for a standard two-rotor engine. Each face has a “swept volume” or displacement of 40ci(654cc) and there are a total of six faces. With this known, the engine displacement should be 40ci(654cc) times six to equal 240ci(3.9L), right? In a way, yes, but that would not be a comparable displacement to the 4-cycle engine.

The key for comparing the displacement between the 4-cycle engine and the rotary engine is in studying the degrees of rotation for a thermodynamic cycle to occur. For a 4-cycle engine to complete every thermodynamic cycle, the engine must rotate 720° or two complete revolutions of the crankshaft. The rotary engine is different. The engine rotor rotates at 1/3 the speed of the crankshaft. On two rotor engines, front and rear rotors are 180° offset from each other. Each rotation of the engine (360°) will bring two faces through the combustion cycle (the torque input to the eccentric shaft). This said, it takes 1080° or three complete revolutions of the crankshaft to complete the entire thermodynamic cycle. Obviously, we have a disparity. How can we get a relatable number to compare to a 4-stroke engine? The best way is to study 720° of rotation of the two-rotor engine. Every 360° of rotation, two faces of the engine complete a combustion cycle. 720° will have a total of four faces completing their cycle.40ci(654cc) per face times four faces equals 160ci or 2.6L. That’s a well-reasoned number and now gives us something to be able to compare to other engines. In addition, since four faces passed by in the comparison, it’s like a four cylinder engine.

[Tanro]

The N/T rotary is still classed as a 2.6 for most motorsports.

Don't get me wrong, I am not one of the pistonheads that won't own/drive a rotary. But if I keep a car, I have to make it my own. If I can get better MPG, and more torque then I am all for that.

But the rotary is fun for the time being.

[Wilson!]

one swap i found. this car is complete with working p/s, a/c, and abs

1993 touring

Before swap

LF 729 RF 695
LR 705 RR 692

Total--2821lbs

After swap 1999 ls1/t56 trans ac, abs, power steering

LF 748 RF 717
LR 683 RR 700

Total weight 2848lbs

Weight gain only 27lbs

this swap dropped the a/c, p/s, and abs

I weighed both cars over the weekend at our autocross event at giants stadium. Both cars had spare removed. Both had almost full tanks of gas but my car has a reduced capacity tank which holds 5 gallons less (5 gallons at 8 lbs/gallon = 40 lbs). Both had stock 16 x 8 rims but i had 245-45-16's Yok AO32R's and rotary had 265-45-16 Kumho ecsta v700's. My car is missing AC, PS and ABS. My battery is in bin on passenger side whereas stock RX7 has battery in original position up front. Bottom line is mine weighed about 15 lbs more but had a better weight distribution of 50.5/49.5 front to rear and his stock RX7 was 53/47:
--------------LS1 ------- Rotary
Left Front: 684 ------- 718
Right Front: 695 ------- 718
Total Front: 1379 ------- 1436

Left Rear: 705 ------- 660
Right Rear: 645 ------- 618
Total Rear: 1350 ------- 1278
TOTAL: 2729 ------- 2714
% over Front: .505 ------- .53
% over Rear: .495 ------- .47

A stock rx7 places about 55 lbs more over the front tires than my car (which has no AC, PS or ABS and battery moved behind passenger seat) and i find this incredible!

in a stock car with the battery moved to the rear and no p/s, the LS1 will weigh the same, and have better weight distribution.
the silver LS swapped local car has no p/s, but the owner said it's not needed with as little as the car weighs, even with a 19" wheel up front.

[Samir]

Originally Posted by Wilson!

the silver LS swapped local car has no p/s, but the owner said it's not needed with as little as the car weighs, even with a 19" wheel up front.

This one?

[Tanro]

The powersteering doesn't work on my car. The power steering control unit will randomly beep at me, so I just unplugged it until I can get a manual rack in. I have cheap (reads heavy) 17s on a 225.

When I had the PS belt off on the eclipse it was giving me tennis elbow. This car feels normal with no PS on it.

[Wilson!]

Originally Posted by Samir

This one?

that's the one. that is a beautiful car. last i saw, it had working a/c and no p/s. said the car drop so well without it, it wasn't needed.

[Samir]

It is a beautiful car.

[Abrodowski]

hey, I'm still trying to get the rotaries together. so if you're interested, message me or just reply to this thread

[HDP 7]

Reply

[Abrodowski]

okay, well basically I'm just trying to get all of the rotarheads together rx7 and rx8. so if we can get enough people together we should plan a meet, if all goes well....we can make it a monthly thing or something and hopefully the group will grow if you have any info, thoughts or ideas let me know.

[HDP 7]

I'll see if I can get a few others to join HCS. Not sure what things you would be interested in doing, but my friend Mike drag races his FD, and he will probably go to the track tomorrow night. I may go, just depends.

[Abrodowski]

im interested in anything involving rotaries it's been exceptionally difficult for me to find any around here that actually care about their cars.... so is there kind of a rotary club already going? or what

[HDP 7]

So what's the word? Anything planned?

[Abrodowski]

ALRIGHT! all of the rx7 and rx8 people are getting together at providence june 6th from 6-9.... I've already heard from about 10 people and they're in.it should be a glorious day for rotary people

[Samir]

Sweet!! It's going to be a glorious day period. Where's the main communication hub right now? I didn't see much conversation here besides this thread.