Rotary Vs. LS1

[SLOWR/T]

Figured Id start a thread shince we were jacking the hell outta Jonflips RX7 thread


That's only true if you use a bare, stripped down V8 install on an all aluminum block and heads. If you strip the extras off the rotary and go single, it is lighter than the V8 can get PLUS the weight is located where it should be - lower down and farther back. This allows the cars handling to be much better balanced. As for reliability, my supercharged, 60K mile Mustang has broken down and cost me a lot more than my 160K+ mile FD ever did.
As for cost - I just sold one of my rotarys to my cousin for $3K - complete with Haltech, HKS boost controller, Turbonetics T-76, 1600cc injectors, FMIC, Aeromotice fuel system, etc. Everything needed for installing it. Engine did 618rwhp @ 28psi in the old chassis. Do you happen to have a full 600rwhp V8 setup for sale around that price that weighs the same?
If you know what you are doing, rotarys are very hard to beat for value.

You know good and well that you gave that away. You couldnt find that build from anyone else for that amount. Haltech and the turbo cost right at 3K (new) then you have the motor which wasnt stock ports, the fuel system, FMIC etc. As far as LS1 weighting more than a rotary, were talking 50-60 lbs. Well worth it for power, aftermarket parts, reliability.


It is cheaper to rebuild a rotary, and pull 350rwhp out of it, than to buy all of the parts necessary to install a V8.


The first time but, what about the next time and the time after?

[Catnip]

My grandfather gave me a car, that doesn't mean it's free for everyone else. He sold it to his cousin for that much.

I know in the 93+ F-bodies, the motor sits very far back and low... hmmm. I don't know how much an all aluminum LS1 can weigh, but it can't be THAT much.

Dead ass stock
http://www.ericohlsen.com/FBODY/CamaroDyno.jpg
that's 300 ft lbs at 2600rpms...
Here's an almost same hp dyno from a rotary
http://www.speedforceracing.com/images/products/mazda/rx8/tubokit/rx8_1_6.jpg
well, LOL at tq.

Amirite?

[Blitanicle99]

I am trying to pick myself up FC in the next few days and I think I will be going the route of an LS1... cant beat the power and reliability.

[87 Turbo II]

I'm a rotary guy myself, but I don't hate on piston guys. I do think it takes what makes a 7 special and makes it into any old generic sports car though.

[1439/2000]

It's whatever. A built up hi revving rotary is fun and with the right parts and tune (very important) they can last a long time. A big cam/heads/exhaust LS car is going to be fun but I'm loving the rotary for now. The sound is awesome too. Sounds like shit and heaven at the same time.

[David88vert]

You know good and well that you gave that away. You couldnt find that build from anyone else for that amount. Haltech and the turbo cost right at 3K (new) then you have the motor which wasnt stock ports, the fuel system, FMIC etc. As far as LS1 weighting more than a rotary, were talking 50-60 lbs. Well worth it for power, aftermarket parts, reliability.

The first time but, what about the next time and the time after?

I bought the entire setup for $3500. I can find deal like that easily. It's not hard if you know where to look. The motor definitely isn't stock. ;)

I've had lots of rotarys - and have only had one of them blow, ever. That was a N/A at the track,a nd was due to overheating, because another driver was driving the car and did not know to click the manual switch for the electric fan. It would have happened on a V8 just as easily. I still drove the car back from Moroso on that motor with no problems - and it was fine for another month after that as well. Could not have done it on a V8.

The LSx does weigh more - and what you usually are comparing is a LS1 with no extras vs a stock setup 13B-REW with all of it's extras like smog, a/c, When you strip down the 13B-REW setup to a single turbo with no accessories, it is a lot lighter.

As for aftermarket parts and power, either will run you about the same if you are buying new parts. You still need fuel, exhaust, etc. The difference is - on the rotary, you don't need forged internals. Yes, I am doing a boosted 408 soon, and it is $5K just for the bottom end, and another $2K on heads, plus another $1K on intake parts, plus another $3K on boost, plus another $1600 on fuel, another $1K on cooling, etc. That will make about 670 hp. Sure, V8 is cheaper... :rolleyes:

[cobalt9123]

I am trying to pick myself up FC in the next few days and I think I will be going the route of an LS1... cant beat the power and reliability.

/thread.

[87 Turbo II]

I don't know, I just prefer the way the rest of the car was engineered around the rotary, and it's what makes the car what it is.

[OneSlow5pt0]

id like to have a 20B 3rd gen camaro and a LS2 FC

[redrumracer]

...Welcome to the home of the V-8 powered Mazda RX-7, where we've designed, built and raced muscle cars powered by both piston and rotary engines for over 35 years. Since our 1st RX-7 / V-8 conversion kit sale back in 1995, we have sold over 3500 kits worldwide, with customers in Argentina, Australia, Brazil, Canada, Dutch Carribean, Fiji, Germany, Greece, Guatemala, New Zealand, Pakistan, Puerto Rico, Trinidad, Virgin Islands, and thousands right here in the USA.

...This is a very easy engine swap. Although our instructions may seem a bit long, don't be intimidated- the swap is actually quite straightforward. Most people would agree that installing a V-8 is probably easier than re-installing the rotary engine. Most hotrodder types are able to complete the mechanical part of this swap with little or no direction at all.

...The RX-7's layout and structure is well suited to engine conversions. The rotary engine's eccentric shaft centerline is way up in the center of the rotary engine, dictating a much higher transmission location than that of a piston engine. The net result is that Mazda designed the RX-7 with a HUGE transmission tunnel, big enough to fit even the monster T-56 6 spd manual transmission which was used in the Viper and Corvette. The rotary engine's low torque output required Mazda to use a very heavy flywheel and a high rear gear ratio, a combination of factors that combined induce large amounts of stress on the RX-7's rear axles and hubs. Mazda planned accordingly, and designed plenty of strength into the RX-7's rear differential/axles/and hubs. Experience has shown that the stock NA RX-7 components are strong enough to withstand low 10sec 1/4mi passes, a feat that requires around 500hp.

About 1/2 way down this page you will find links to pages containing specific info, on-line instructions, and parts lists / pricing.
Be sure to check out our RX-7 Conversion Index, a page of 40 or so links to pictures of various RX-7 conversion projects. Please e-mail us if you have one you would like to add.

...Think the v-8 will forever ruin your handling? The August 2005 issue of Grassroots Motorsports Magazine will features quite a few V-8 powered RX-7s that entered their $2005 Challenge event in Florida. The premise of the event is to build the best handling, best appearing, and quickest car possible for a total budget of $2005., including the price of the car and all components. You will be surprised at the wide variety of entrants and how creative they are. Check out the August issue for a feature on this year's challenge winner, a FORD POWERED 2nd gen RX-7!!! For a free copy of the magazine or to check out this year's $2005 challenge results, go to the Grassroots Motorsports website.
In the 2004 event, of a total of 76 cars that participated, a total of 9 RX-7s took part in the event, 5 V-8 powered and 4 rotary powered. In the drag race portion, all the V-8 RX-7s finished ahead of the rotary powered cars. No surprise here. The quickest V-8 RX-7 recorded a 12.636 ET, the quickest rotary's ET was a 14.323. What DID suprise a lot of sports car people is the results of the autocross competition. The quickest RX-7, a V-8, finished nearly 4 seconds ahead of the quickest rotary version. Among the 9 RX-7s present in the autocross, V-8 power captured 4 of the top 5 spots. Don't listen to those who tell you that a big V-8 will ruin your handling!!!
Daryl Evans's ZZ4 powered RX-7 solo car was last years local, regional and Canadian Western Champion in E Mod.

thats all

[David88vert]

thats all

Have you ever done the swap, or even driven one? I have done one, and have driven several - including all 3 gens. The only FD had a stock LSx in it, and didn't impress me.
One install did impress me though - that was a 2nd gen vert, with a stock 302. Simple, with lots of torque. The convertibles are heavy enought to benefit from the swap. Plus they were only available N/A.
Let me put it this way. If you had a N/A FC, and you wanted to do the swap, I can see it being worth it - if you were doing it yourself. Otherwise, keeping it a turbo 13B is much more cost effective and is reliable if you know what you are doing. FBs are easy to swap to TII setups, and putting a V8 in them definitely hurts their handling.
By the time you have gone through the cost of putting a LSx motor in a FD, you could have bought a Vette, and would be better off.

[redrumracer]

Have you ever done the swap, or even driven one? I have done one, and have driven several - including all 3 gens. The only FD had a stock LSx in it, and didn't impress me.
One install did impress me though - that was a 2nd gen vert, with a stock 302. Simple, with lots of torque. The convertibles are heavy enought to benefit from the swap. Plus they were only available N/A.
Let me put it this way. If you had a N/A FC, and you wanted to do the swap, I can see it being worth it - if you were doing it yourself. Otherwise, keeping it a turbo 13B is much more cost effective and is reliable if you know what you are doing. FBs are easy to swap to TII setups, and putting a V8 in them definitely hurts their handling.
By the time you have gone through the cost of putting a LSx motor in a FD, you could have bought a Vette, and would be better off.
actually i do have an fc that im performing(slowly) a 383 lt1 swap in, and a rotary motor will never be as reliable as a SBC at the same power levels and amount of mods. arguing that is a losing battle. and as far as the 302 goes :tongue1: im not a fan of ford. and its not just convertibles that can benefit from it, the coupes or hatchbacks(depending on how you look at it) can also easily benefit from it.

[Whiteboy572]

I am trying to pick myself up FC in the next few days and I think I will be going the route of an LS1... cant beat the power and reliability.

It would be a lot cheaper to do a 302 5.0l mustang motor. You could have t fully built and would probly be as much as a stock ls1 and its carbed so not much wiring :goodjob: Ive looked into it already the stock swapped 5.0l in a fc will do 13.6's in the 1/4. thats not a bad starting point.

[1.8t]

I have a good friend that races his FC ITA RX-7 and he will be the first to tell you he doesn't like the rotary engine when it comes to durability. BTW, he is probably one of the biggest RX-7 enthusiest you will ever meet.

[87 Turbo II]

I have a good friend that races his FC ITA RX-7 and he will be the first to tell you he doesn't like the rotary engine when it comes to durability. BTW, he is probably one of the biggest RX-7 enthusiest you will ever meet.
Mine is durable, so your friend's comment doesn't apply to me.

[Boosted FC]

I have a good friend that races his FC ITA RX-7 and he will be the first to tell you he doesn't like the rotary engine when it comes to durability. BTW, he is probably one of the biggest RX-7 enthusiest you will ever meet.

He is one of the biggest RX7 enthusiast you will ever meet, but does not like the Rotary due to reliability issues...:rly:

[dazn]

I have a good friend that races his FC ITA RX-7 and he will be the first to tell you he doesn't like the rotary engine when it comes to durability. BTW, he is probably one of the biggest RX-7 enthusiest you will ever meet.

who's building his engines? Ive taken care of multiple ITA and IT7 1st and 2nd gen 7s that never had motor problems, it was always a subcomponent failure that may contribute to engine failure if not found and resolved. and those cars raced on 87 octane with premix. Ive worked on several street 3rd gens. Ive also had my hands in a few 3 and 4 rotor LMPs and a 3 rotor rx-8 that saw their fair share of races. lets not forget about the Formula and Star Mazda's too. people wouldnt race it if it wasnt reliable.

as far as putting a v8 in a rx-7.....well i wont get started on that. why buy a rx-7 just to remove the whole reason it was built. its like buying a supra and taking the 2j out to put in a rb26 or vice versa.
maybe I should start a trend, buy a vette and put in a 3 rotor. and immediately toss the leaf springs for an inverted coil setup.

[DVSRX-7]

idk im sticking to rotaries 4ever so fawk piss ons

[DVSRX-7]

[/QUOTE] maybe I should start a trend, buy a vette and put in a 3 rotor.[/QUOTE]

do sum research my fellow car nerd.... there were rotaries in vettes already... there was a 4 rotor built by GM and put into the vette concept but never made it to production because of the gas prices going up back in the day.. but yea vette owners, dont talk shit about rotaries cuz u wuld of had them in urs if it werent for the gas prices going up in the 70's :D

[Elbow]

I have a good friend that races his FC ITA RX-7 and he will be the first to tell you he doesn't like the rotary engine when it comes to durability. BTW, he is probably one of the biggest RX-7 enthusiest you will ever meet.

Who is it?

And I have many other SCCA racers that LOVE RX-7 reliability lol.

[Elbow]

...and as Dazn said..I think anyone saying a rotary is a unreliable engine needs to get out more, look at Star Mazda....how often do you see those blow up? I knew a guy with a older one ran it two seasons with NO form of rebuild, just basic maint. NEVER missed a beat. Lots of people do it.

Rotary > ANY V8 for me personally.

[David88vert]

Ever hear of the 24 Hrs of Daytona? Ever hear of IMSA? Ever hear of Jim Downing? He is local, and has won many races with rotarys. Rotarys have been consistent in racing for a long time. I've had Chevy V8's also - and they have never been as reliable of put out as much power for the same money as a rotary.

[cobalt9123]

=driftjunior]
maybe I should start a trend, buy a vette and put in a 3 rotor.

do sum research my fellow car nerd.... there were rotaries in vettes already... there was a 4 rotor built by GM and put into the vette concept but never made it to production because of the gas prices going up back in the day.. but yea vette owners, dont talk shit about rotaries cuz u wuld of had them in urs if it werent for the gas prices going up in the 70's :D
That makes no fucking sense what so ever.

[Catnip]

Ever hear of the 24 Hrs of Daytona? Ever hear of IMSA? Ever hear of Jim Downing? He is local, and has won many races with rotarys. Rotarys have been consistent in racing for a long time. I've had Chevy V8's also - and they have never been as reliable of put out as much power for the same money as a rotary.

Don't rotary motors last longer if held at higher RPMs?

[Elbow]

Yeah

[OneSlow5pt0]

u baby a rotary carbon will build up

and yes GM built a rotary vette,and lot of the styling went into the 3rd gen fbody

[David88vert]

Don't rotary motors last longer if held at higher RPMs?

They need to be revved a lot to keep the carbon from building up. They were designed to run at higher rpms. That's why they are used in some of the mini helicopters - they are extremely reliable and can hold high rpms for a long time.

[ueyedgr8tness]

I say 2jz>ls2>rotary

[DVSRX-7]

That makes no fucking sense what so ever.

im not stupid i kno my history buddy, and maybe if u could fucking read you would understand what i was saying... Ask HypnoToad.. he gets my point..thanks HypnoToad :D

[DVSRX-7]

oh and by the way if rotaries are such wack engines wen compared to piston engines, then why do even bring it up? if u dont like rotaries go suck a dick, rotaries can be put thru any fucking test and still be better than a dam LS1.. anyday everyday!! i seen so many dam LS1 being built, and not one will be as good and reliable as a rotary motor... but then again i want some one to prove me wrong... please for real do so... :cheers: ill be waiting :D

[HillClimbGuy]

i love my FC but you know which is better.............. which ever one you like :D
if every one had rotaries then mine would not be as Special:crazy:

[Atlblkz06]

When comparing dyno charts - stop looking at JUST peak numbers. You dont drive at the peak HP RPM all the time...

The area under the curve is hugely important and in that respect the rotary suffers a fatal loss.

[David88vert]

When comparing dyno charts - stop looking at JUST peak numbers. You dont drive at the peak HP RPM all the time...

The area under the curve is hugely important and in that respect the rotary suffers a fatal loss.

That's where you are missing it. ANY motor/chassis combination can be tuned to place it's power whereever it is needed. Rotarys usually are put in lightweight vehicles that don't need gobs of torque. Lots of torque in these same vehicles would simply blow the tires off.

[Catnip]

They need to be revved a lot to keep the carbon from building up. They were designed to run at higher rpms. That's why they are used in some of the mini helicopters - they are extremely reliable and can hold high rpms for a long time.

So is one of the secrets to keeping a rotary running correctly to drive around at like 4500(?) rpms? I've never talked to anyone with knowledge of rotary motors.

[1439/2000]

So is one of the secrets to keeping a rotary running correctly to drive around at like 4500(?) rpms? I've never talked to anyone with knowledge of rotary motors.


The secret to have them run correctly is a really good tune. You dont have to drive around at 4500 rpm. If you go WOT every once in a while to clean off carbon build up, you'll be fine. Even more important if you premix.

[NoRotor]

Lots of torque in these same vehicles would simply blow the tires off.

Yeah, I HATE it when that happens :lmfao:! Who needs torque???

[Elbow]

torque's gay

[OneSlow5pt0]

torque's gay

x2

[David88vert]

You dont have to drive around at 4500 rpm. If you go WOT every once in a while to clean off carbon build up, you'll be fine. Even more important if you premix.

Correct.

[David88vert]

Yeah, I HATE it when that happens :lmfao:! Who needs torque???

Torque is great, but the chassis and tire combo has to be able to get it planted to the ground. Most swaps that I see don't address it. For straight line power, yes, you need as much torque as you can plant. For road racing, the right balance of torque and handling is necessary for each track. If hurt your handling for more power or torque, you won't necessarily do any better lap times.

[Catnip]

Torque FTW. The only reason I drive a Honda.




Wait...

[87 Turbo II]

So is one of the secrets to keeping a rotary running correctly to drive around at like 4500(?) rpms? I've never talked to anyone with knowledge of rotary motors.
They are very rev happy. I've cruised at 4500 RPM before when I was relatively new to the car cause the engine just plain didn't feel like it was straining, the sound and a little"shift up" fuel economy light were the only signs I was revving too high. No crazy vibrations or asthmatic throttle responses. Most piston engines wouldn't of taken so kindly to driving that high in the rev range as if the engine was only a hair above idle.

[Atlblkz06]

Well if the requirements are up in the air, then its hrd to decide on what you want.

Its a lot of fun driving a torque-less revv happy engine, but it can also be taxing.

EVERYTHING depends on what the driver is looking for, so I guess the discussion is pointless if the purpose of the car isnt known.

[Elbow]

^Entirely agree

[sidewayz13b]

the only rx7's that should get the LS1 should be the fc's. the fd's should keep the rotary. just my personal opinion. i just sold my fc yesterday.

[Blitanicle99]

I think I already posted in this thread but...


LS1 all day long. I love my Rotary, never had one before and find them fascinating. However the reliable, cheap, monstrous power you can get out of a basic LS1 with Tuning, cams, intake exhaust, and headers is un real. The weight distribution is messed with yes, but my car is completely stripped, even the sound deadning is grinded out. So my car doesn't have the weight distribution like it should and I love the way it drives.
Further, if anything breaks on my LS1 I can go to napa and probably fix it in the parking lot with a simple set of tools and some elbow grease.
When I start the vehicle with some nice open pipes and a low lsa cam it scares children and is a distinctive powerful tone.
No apex seals, no torque problems, no funny parts from Japan, and no arguements across the tuner world. Anyone who is anyone would agree that an LS1 is a better build than putting lots of work into a turbo Rotary. If you still want your turbo, LSX turbos are great. If you don't like turbos, LS1 and all LS series motors respond very well to Nitrous and as much as you want to bash Nitrous, I have personally seen LS4 (4.8 and 5.3) motors with 100,000 miles of Nitrous abuse and no huge signs of wear in tear that a normal 250k V8 gasoline motor wouldn't have.

My 2 cents.