BLUE TII

iTrader: (9)

so what does sports car mean now? almost nothing.

Yeah, one of the stories I use to illustrate how "sports car" is an opinion you might have heard before.

Our local car club started in the '50s when timber barons wanted to race their exotic cars with friends up at the local airport/roads.

In the '60s one of our (current) members wanted to join the club but there was much debate as he drove an VW Karmen Ghia.

The Porsche Speedsters or even 912s were just fine, but was a lowly VW Karmen Ghai driver going to be allowed in a "sports car" club?

Later in the '70s the same driver (now admitted to this exclusive club) bought a Porsche 914/6 to race. Well, unlike the regular VW 914 the Porsche 914/6 did have some Porsche parts on it.

Was it a Porsche? Was it a VW? Was it a "sports car"?

His next car? Porsche 928S !

Yeah, he is a character. I think he was thumbing his nose at those Porsche owners by buying Porsches they hated and were faster than the vaunted 911.

j9fd3s

iTrader: (3)

to go right along with that you can't vintage race a Japanese car newer than like 1975 (except the SVRA*), but you can vintage race a 2016 model 911.

*they let you run a GTU ish setup on your Rx2/3 or 1st gen Rx7.

RotaryEvolution

iTrader: (30)

i remember when you couldn't race a truck at the autocross events, i couldn't quite grasp the idea of why not.

BLUE TII

iTrader: (9)

They have a high center of gravity. If you put sticky tires on them they flip.

There is a formula and a list of example vehicles you cannot race in stock category because of this (they assume modified ones will have their safety issues revised and are not explicitly banned).

Lets put it this way, the fast RX-7s corner on 2 wheels... what will a truck do with that much grip.

ZDan

Hard to imagine the RX-8 having lower polar moment vs. FC or FD. It is heavier to begin with, and being on a 106.4" vs. 95.5" means the not-insignificant tire, wheel, brake, suspension, halfshaft, and diff mass contributions to polar moment go up by 24%. More mass, with major portions of it shoved further forward and aft from the c.g. implies a higher polar moment of inertia.

Personal preference, but I generally prefer less caster and less self-centering. To me it feels better, more responsive and communicative. I generally aim for 5.5 - 6 degrees on the FD and S2000. My old street/track 240Z had less than 3 degrees caster! Loved that car....

No arguments regarding RX-8 handling, though, it's pretty stellar!

RotaryEvolution

iTrader: (30)

i suppose that is true for many trucks, but it is also true for many passenger cars as well, even moreso in some cases but they simply draw the line at a "truck" but a Rav 4 could enter? hmmm. on street tires a truck generally just oversteers, SUVs and sedans have an even higher center of gravity. lower a truck to the same height as a car and it generally has a lower center of gravity as the car does.

j9fd3s

iTrader: (3)

i don't know about polar moment, but the Rx8 is not much heavier than an FD, a base 04 with a full tank and no driver is 2950lbs. plus the engine is lower and further back than the FD. plus the fuel tank is in front of the rear wheels, instead of behind.

but yeah the Rx8 is has an amazing chassis, you can just do stupid things behind the wheel, and not only does it not bite, but its still quick.

RotaryEvolution

iTrader: (30)

course on the RX8 club they will argue against doing the swap all day long.

i've had 2 RX8's and always contemplated doing something else with them when the time came to replace the engines.

j9fd3s

iTrader: (3)

the Rx8 club is weird, it seems like those guys go through a set of coils a week, and an engine a year, but my real life Rx8 friends have had near total reliability. i've bought 3 broken Rx8's so i've done more, but still haven't done an engine.

my conclusion is that reading the Rx8 club makes your Rx8 less reliable.

RotaryEvolution

iTrader: (30)

there is plenty validity to those claims on that website, i have a box full of RX8 coils and alot of them i tested and were in fact dead.

the plugs don't even last what the recommended replacement interval is before they begin showing signs of misfiring.

the engines i tore apart with ~100k miles had 250k miles of wear if you had an n/a FC comparably speaking, or in other words they had 150k miles of wear that a 12A would produce with its 3mm rotor housing eating heavy seals. some had sheets of chrome missing, rendering them completely useless even for resurfacing.

i diagnosed numerous engines with sub 75psi figures with a totally calibrated digital compression tester, verifying their hot start issues.

the one RX8 i gave to my ex that was just severely flooded at 82k miles now has 96k on it and ~70psi on one rotor but still runs reliably, but i told her it may just not start one day and to be prepared. the other i owned had a spun rotor bearing and half a trashed engine, i dropped in a new engine and sold the car about a year ago.


spending $300 on an ignition every 30k miles, a new engine every 100k and getting only 20 or so mpg highway to me didn't offset the fun factor of the car. the manual transmission is also weak and unreliable for any sort of fun driving. the car is just a sporty tourer sedan, not something i would expect to live long at the track in their current configuration. put in a small block V8 with a T56 meant to haul around a 4k lb car and you have something completely different.

one customer locked his engine on the track at sevenstock a few years back, i tore apart the engine and the seals were such a mess that they froze the engine up which is rather rare so even high revs will chunk an MSP and liberate it of its seals. both rotors no less. there was metal half way up the intake tract to the throttle body... rather surprised it didn't shear the e-shaft.


when people complain about the reliability of an FC or even an FD i just have to laugh to myself. it was very rare i saw an early engine(pre 21st century) last less than 10 years or 100k miles, yet quite common with the early MSP.

but arguing common sense issues with the RX8 community is a waste of breath, they still for the most part don't even believe that premixing has any real benefit.

i have seen RX8 shells for as little as $1k with complete interior but no engine or tranny, they kinda just scream "engine swap". while the 2nd gen RXs catch up in value, the turbo models have already surpassed the S1 RX8 in resale value for a decently clean one.

ZDan

Call it +150 lb. over the FD, maybe +250 over non-turbo FC?.

Maybe further back relative to the front wheels, but that's not what's important. What is important is where it is relative to the c.g. Given the much more generous "+2" rear seats of the RX-8, it's possible that the engine sits further forward of the car's c.g. than in either the FD or FC, which would add to polar moment.

But I would bet that the engine didn't move much relative to vehicle c.g., that basically the RX-8's front and rear axles moved fore and aft respectively, giving the *appearance* that the engine moved aft.

Yeah, that would make a difference especially if we're talking full-tank vs. full-tank. I wasn't considering that and that is a big move of a ~150 lb. (full tank) mass. But then again the tire/wheel/brake/suspension/diff/halfshaft masses that all moved ~5" further from the center of the car in the RX-8 probably total close to 350 lb.

I test drove one and would have bought if not for the fuel mileage. Handling is indeed sublime

j9fd3s

iTrader: (3)

that depends, my 87 GXL, with ABS and steel hood was 2880lbs with a full tank, no driver. from previous experience, putting the AL hood on, and swapping cat backs is an 80lbs weight savings!

RotaryEvolution

iTrader: (30)

yep, the 2nd gen dual stock catback is a brick, not that the FD single exit exhaust was much lighter but still. the FC isn't very difficult to shed weight.

j9fd3s

iTrader: (3)

i know, that is my point. my real life Rx8 friends have had nearly trouble free experiences, yet somehow everyone on the Rx8 club has constant problems.

ergo, reading the Rx8 club makes your car break

frijolee

iTrader: (1)

Just read most of this on my lunch hour. Synopsis if you're just joining:

-Detailed description by one dude weighing the pros and cons... Nicely written and well thought through.

-Lots of arguing over the exact but small amount of weight a swap typically adds. More arguing over what constitutes apples to apples comparisons when supporting mods are factored in. I think exact apples to apples are hard since the setups are different but +50 lbs or so is pretty typical for an LS vs. rotary all in. Iron block LS engines are ~112 lbs heavier their alum counterparts (saw this in GM literature one time).

-A few traditional barbs over "ya shoulda bought a vette" (too big for my taste, thanks), as well as the hypocrisy of weight not being discussed by rotary folks when evaluating 3 or more rotor engines. Verdict: power to weight matters. Power delivery also matters (matters more in certain applications).

-General agreement that the LS is a cost effective approach to equivalent power in the 400 hp or so range. Counterpoint made that rotaries can be cost effective as well if you have the tools and knowledge to do everything yourself (in which case more power to ya).

-Agreement that rotaries tend to be unforgiving with forced induction and gutless with 2 rotor NA's, so you damn well better know what you're doing (or figure it out fast).

-Agreement that v8's aren't 100% bulletproof either (oiling seems to be the LS weakness IMHO).

-Limited discussion regarding gas mileage improvements with the V8, which I think is a big deal if you want to live with a vehicle on the street. I'm going to assume there was so little discussion because this benefit is simply factual vs. anything turbo'd rotary making similar power. When I swapped, I tripled my HP, quadrupled the displacement and gas miles went up notably. Strange but true. Almost all LS engines live happy on 91 octane. Not all rotaries do.

-Finally some off the wall discussion about other swap candidates. (Ronin is working with an RX8 development mule by the way).



My conclusion:

-On paper, the LS wins for more folks, but not everyone. Your personal biases, emotional ties, wrenching history, and values will all affect how each person's pro/con list pencils out. The fact that few (if any) swappers go back, is likely the simplest argument as to most folks' happiness with swaps. This logic is noted to include some folks who were hardcore rotary before, like the OP.

-In practice, I can say that I'm not good enough to appreciate any subtle differences in handling and/or weight. I can say that the power (and power delivery) have made my car into a completely different class of vehicle than I started with. It did take a variety of supporting mods to balance that out (tires, brakes, etc).

-If you're on the fence, getting a ride or driving one may make up your mind. My favorite quote from a passenger (hardcore rotary prior): "that was awesome but you've ruined me!"

-Your experiences and decisions may vary. A fast car with good attention to detail and build quality will always have my respect. Good luck with whatever you do.


Joel Payne
(of Ronin Speedworks)

RotaryEvolution

iTrader: (30)

if the argument is going to weigh heavily on why V8 swapped RX7s have not been converted back, well that answer lies in the fact the car has to be modified to accept the swap. those who blow up an LS and opt out of the car would simply sell it blown, in pieces, part it out or drop in another engine and sell it.

once you chop a car for a swap, it's kinda tainted to be what it is at that point.

of all the V8 swapped RX7 owners i personally know, i know exactly that same amount who sold their V8 powered RX7.

of the half dozen or so people who asked me about swapping their cars, 0 actually went through with it, and honestly i didn't try to talk them out of it at all. most wound up doing it themselves or simply knew it wasn't as small of a job as they thought after i started rambling off all the things that needed to be done with prices in the $10-15k range. people start to quickly second guess their decisions when you give them a price and they look up the value of their car after doing the work, you have to be dedicated to your decision and not just get tired of it as soon as it rolls out of your driveway under it's own power.

The reason i went on a side trip of what car is a better candidate for a swap is, well you'll lose more by swapping an FD due to their rarity being a rather large part of their value. they are the best RX7 in many other areas but selling a swapped FD for $18-20k+ isn't going to be easy. An FC holds much less initial value, so they generally sell for $8-10k with a swap. An RX8 is cheap, has good characteristics for a swap and would probably sell for somewhere between an FC and FD once done, also giving it better value retention since it is a newer car with nicer amenities than both the FC and FD, which also includes suspension regardless of the CoG talk above.

Wompa164

iTrader: (4)

For whatever it's worth, I was a rotary purist for almost 10 years. My first car as a teenager was a '79 SA, second car '88 TII FC, third car '94 FD (in my sig). I lived and breathed rotary for all those years, and after a few years the FD gave me engine trouble - about $15k worth of engine trouble to be precise, after 2 rebuilds and a turbo rebuild that I was never able to attribute a root cause..

I will never look back. The LS/LT engine is a modern engineering marvel, and if our cars had those engines from the factory, they would be just as valuable now (or moreso) as Supras.

Airwolf RX7

Are there any options to have the tranmission shift like an Rx7? I heard the t56 and t6060 transmission options are pretty notchy?

Viable solution would be: t56 magnum or a 370Z tranmission swap?

ZDan

I just got a T56 Magnum and it feels FANTASTIC. Seriously a WAY bigger improvement over my old F-body T56. It makes the shifter in my S2000 (w/ 210k miles...) feel notchy! Really slick, direct, very snick-snick-snick and no balkiness.

I'll post up my T56 Magnum/McLeod clutch review from norotors in another thread here:
https://www.rx7club.com/v-8-powered-.../#post12000164

LargeOrangeFont

iTrader: (7)

A fresh, quality rebuilt T56 is not that much different than a TR6060/T56 Magnum. I have had both. They are all notchy, but smooth. It should feel like a bolt action rifle, that's just how they are. If everything is dialed in it will always go into gear. A light flywheel helps shifting quickness. Also keep in mind a donor T56 typically came out of a car for a reason.

A 370z trans will require an 8.8 conversion. The gearing is totally wrong.

ZDan

The new T56 Magnum definitely feels significantly smooover than the T56 in my old stock/never-tracked '95 Z28 convertible. That trans did have a somewhat notchy "bolt-action" feel, but I thought it was totally fine. Definitely a lot more CHUNK-CHUNK than snick-snick on gearchanges, but fine (unlike the one that just came out of the FD).

Based on the value of my used servicable-but-really-in-need-of-rebuild F-bod T56, the price of a rebuild (big $$$$, particularly with greater than stock 450 lb-ft capability), and the price of a brand new T56 Magnum, it was a no-brainer for me to go that route and sell the T56 over getting the it rebuilt.

LargeOrangeFont

iTrader: (7)

That makes complete sense. The only "new" 0 mile T56 I have had was in my 04 Cobra. The feel was notchy, but very positive. I missed 2 shifts in that car in 40k+ miles, and that was due to the clutch adjustment. I've driven a couple lower mile T56 Camaros and Vettes that felt very similar. I have never had any problems with them not going into gear if the trans was in good shape.

The T56 is not the best trans by any stretch, but if it is in good condition, and the clutch is set up correctly, they work well if not abused and you are within the power that the trans can handle.

In my 09 CTS-V the TR6060 trans was smoother in and out of gears but still had a very positive feel. but it also had an external shifter, vs the T65 Magnum's direct shifter. Id be interested to see if there is a difference between the 2.

I have thought about making the switch myself, mainly because the T56 Magnum has the .83 5th gear I want, while keeping the "Fbody" 1-4 ratios. The problem I have is that the rear mount is different than the F body trans, as is the shifter position and I don't really want to reconfigure the car.

Tremec has said they are going to release a "drop in" Fbody specific T56 Magnum, but that was over a year ago. If that comes to market for $3k, I will be first in line. Right now my only "drop in" option is a $4k converted Fbody T56 with all Magnum guts. I could still probably get $2k for my built T56, but I will hold out and see if I can save $1k with a Tremec drop in offering.

ZDan

Rear mount to the Samberg crossmember is the same (99% sure of this, though I didn't do the install). Shifter position is different. IMO, best way to go is to modify the shift rod coming out of the trans, basically cut the top off of it and weld in an extension like reply #4 this thread: http://www.norotors.com/index.php?to...0812#msg280812


Crude but effective! zero slop, no linkage to wear, no wasted motion.

Driveshaft mod is also required, needs to be shortened and a different yoke welded on. Not a huge deal for a competent shop.

That would make the switch easier... I couldn't wait, my T56 was popping out of 3rd gear sometimes at the track, and downshifting took too much effort and concentration away from braking/turn-in. Not fun!

Littleguy

iTrader: (5)

Great minds, lol

LargeOrangeFont

iTrader: (7)

Yep that seems to be the solution I see most for the shifter.

I had heard the rear mount was in a different spot than the F body, I'll have to investigate that further.