We (Granny's Speed Shop and I) developed a custom subframe which is lighter than the OEM cradle...





There's plenty of room in there. The late model LT1 is very compact.

 

Well, the 3rd gen. is very common around here. I don't think a day goes by when I don't see at least one, usually MBM or VR. Then again, on a nice day around here, you can't hardly step into the street without stepping on a Modena or F355.

And as for the Corvette... I'm trying to track down an '02 Z06 as we speak.

 

No idea on quarter times until we tune the engine on the dyno and see what it actually makes. We'll have calculated estimates once the heads and intake have been finished and we have concrete flow numbers, but until then I can only speculate. 650+ horsepower isn't unreasonable, and ~600 ft. lbs. of torque, over a very broad band. The motor is stroked to 396 cubic inches.

Horsepower may be higher... hard to say, since no one has ever built a motor like mine before, not even in the F-body/Y-body camp. Not to this extreme, anyway, and not with this combination of parts. The engine will have an imposed 8,000 rpm redline, but could easily spin higher, if I weren't concerned with making the car relatively streetable. Everything is light weight (titanium valves, ultra light 38 lb. crankshaft, ultra light 505 gram rods, etc.) and most of it is not off the shelf.

The bushings are on their last production run... I have a couple sets left that I'll be auctioning off, probably, but that's it. All the rest have been spoken for from this last run. Details are here...

http://home.earthlink.net/~jimlab

 

My predictions are 1/4 mile in the 9s if the re holds up. Good luck with all that low end torque.

Ken

 

just a question...is that legal for street use? if u runnin 9's it cant be... i like the FD because hardly anyone has them, they are great for handling and if u keep them stock, maybe cb and dp, im sure they wont die on you too fast... i dont know, as long as u dont actually buy a v8 car i dont care at all, just dont pop ur hood around to many "rotary enthusiats" hehe just tell them u have a turbo u could sitck ur head in =) LOL, man i crack myself up, oh well have fun.

 

Damn!!! I really can't believe how closed minded some people are. I myself am really looking forward to doing this conversion. After some of the problems I've had with mine, I think an LT1 would better suit my needs. More torque and more power. please don't give me **** about getting a camaro. I think the looks of an FD and an NSX is the best any company has offered for there price. I love the looks of my FD and would love to have a 10 sec streetable car, or at least an 11 sec. I can easily sell my engine, tranny, clutch, flywheel, DP, intake, power FC, and other samll parts for $3000. Mine won't be as nice or as fast as jimlab's but my goal is to be in the 10's and I don't think it'll be that hard

 

You'll probably need 450rwhp to get into the 10s. 60' times should be awesome. My brother's FC V8 Chev with only 350bhp does that in 1.7 on street tires. The RX7.com guys I hear use NOS at the start and they get about 1.55 60' times. I bet JIMLAB with slicks could be lower than 1.4 in the 60' time. Probably break something trying.

 

" your installation looks very clean." Nice work on your crossmember but I was wondering if you moved the rack altering the suspention geometry.

 

No, they didn't - see Granny's website
http://www.grannysspeedshop.com/

Jim, please tell theirweb guy to PLEASE stop using frames so I can give direct link.:p

 

It wouldn't be legal for street use if it ran 15s... no catalytic converters and no air bags. "But they don't gots to know that..."

 

No, that was one of the prime reasons why I wouldn't put a 20B in the car without finding a better solution to the steering rack issue. I'm a lot more concerned about the handling of my car than everyone gives me credit for, even if I am a drag racer at heart.

An OEM engine subframe (mine) was used to make a welding jig, and from that the subframe was fabricated. It bolts to all the stock points on the frame, the steering rack bolts right up (as you can see), and nothing has been relocated and no cutting or welding is required.

 

hi jim,

I don't want this comment to generate into a international war - but something I've never understood is this ;

In Australia the Rotary is *not* considered to be unreliable. At least , not from the automotive crowds that I hang out with.

Whilst most people would agree that the rotary is more fragile than a good quality piston motor, whether it be a v8 or a 2jz-gte, the general consensus is that they are a good strong little motor that copes well with lots of hard use i.e. high revving etc.

On the other hand, in these forums I see nothing but comments on how 13b's blow up all the time, how if you start getting good power from a rotary that you should have some money left aside for a new motor/rebuild and all sorts of things like that. You stated this yourself in one of your messages.

But the problem is - I just don't see it happening over here. Is there a difference with the familiarities of rotaries in australian rotary workshops compared to american rotary workshops? Rotaries are very popular down here for drag racing, you can go to the drags each wednesday night at eastern creek raceway in sydney and usually see many rotaries running in the 8's to low 11's. These are a mix of RX7's & older rotaries like RX3's.

Perhaps it is something to do with the fact that there are some fantastic ECU's produced locally in Australia such as Motec/Haltech.

I'm not doubting that if you pump 600hp through a 13b that you'll eventually have to rebuild it - but it's the sheer frequency of rebuilds/new motors that you listen to in this forum that is the surprising thing.

I know quite a few people with 3rd Gen's, here is my experiences with the life of the motor.

* My own one - motor overheated at 106,000 km's due to first catalytic convertor getting blocked. Car was purchased in 1992, motor overheated in 1999.

* A friend of a friend - single turbo conversion on the car when it was 12,000 km's old. Running approximately 450hp at the motor with a haltech e6k. Car is now on 110,000km's and was purchased in 1995. Still original motor and feels fresh.

* A friend - 1992 model, made 126,000km's on stock motor before the car overheated due to a problem with the coolant system at a track day in very hot weather last november.

* Another friend - 1996 model, has done 168,000 km's (not a typo) and is still on original motor.

* Last but not least, a 1995 "RX7 SP" (factory modified limited edition), 77,000 km's and just recently had a compression test in preperation for selling and was flawless.

I hope you see my confusion now - on this board I hear talk of people putting their 3rd/4th motor in - but we just don't see that down here - at least not in the circles that I frequent.

cheers

Gav

 

Alot of it probably has to due with the lack of knowledge for the rotary. Most people is the US only know it exist and know nothing about the motor. I bet within 500 miles of me there are only a few shops that really know how to work on a 3rd Gen and REALLY know what its all about.

What type of maintenance schedule do you guys use. How ofter do you change things like oil, coolant, fuel filters, ect.... what brand/type oil do you use? Do you guys add a pre mix in the fuel? Maybe there are some differences. One thing is I dont think yours has the pre cat like ours does and that is one of the major probs with the car, it causes a ton of heat.

What is the conversion from KM's to Miles

Thanks,

 

My first engine failure wasn't caused by previous abuse (I bought my '95 PEP new in April of '97, one of the last two '95s imported, apparently), improper maintenance, or improper tuning. Not sure what caused the second...

The car had the pre-cat, along with everything else removed a few months after purchase when I went full non-sequential (without ever having had a problem with the sequential system) and full mods.



At that time, the availability of computer mods were limited, and after trying a PFS "Gold" computer, I went with one of the first Mostly Mazda (now M2 Performance) reprogrammed ECUs, after talking with Brian Richards about my setup.

My first engine failure wasn't due to my tuning maps, but due to a configuration blunder and the stock clutch. The Crane HI-6 had not been set with a rev limiter, since we assumed that the rev limiter in the stock ECU was intact. In fact, it had been removed, and one nice day when the stock clutch decided to let go at 90 mph, I found that indeed, a rotary motor will turn to far, far over 10k rpm. I think I waited several seconds (seemed that long, anyway) for the needle to drop back below 9k rpm.

Needless to say, after finding out that the car ran fine, idled fine, and didn't seem to have been harmed by the experience, I had a Racing Beat flywheel and clutch installed. No one had pointed out that I should replace the clutch after adding all the mods I had, and being new to heavily modified car ownership at the time, I didn't think to ask. It wasn't a matter of having the money to do it, it was simply that no one advised me to, and I didn't know that it was necessary.

The car ran fine for another couple months and then while cruising in traffic at 70 mph, just completely died. All warning lights came on, the engine died, and I had trouble restarting it. While I was still rolling at 60 mph, I got it restarted and it felt all right, except that when we reached stop-and-go traffic, the car idled badly and shuddered horribly. I immediately got it to Trev's house and in trying to find out what was wrong (after checking the MAP sensor and replacing the 02 sensor) he blew it up completely while test driving it. We limped it back to his house and that was that.

I immediately started on having Hayes Rotary build me a 3mm ceramic apex seal motor, because that was supposed to be the solve-all solution... ceramic apex seals. Knowing what I know now, I would advise anyone thinking that there is a magical seal that will save an engine to give it up and just spend all their money on proper fuel management and stick with the stock seals. But at the time, I had been convinced by Francesco Ianetti (who of course wanted to sell his seals) and by Trev (who was enamored with anything really rare and horribly expensive, especially when he wasn't paying for it) and went that route.

While I was having my motor built by Hayes, we pulled the one in my car and found one damaged rotor (rear), one damaged housing, and the rear turbo had taken a beating, pretty standard for the course. The engine had about 5,000 miles on it, and I had bought another core at the time, thinking we'd just rebuild mine with a good rotor and housing, but ended up trading them both in for core charge ($250 each) on the motor at Hayes.

In the meantime, we put a junkyard salvage motor in the car, and I ran it that way for the rest of the time it moved under its own power. That motor leaked oil from the beginning, and after a wild adventure caused by a junkyard oil cooler hose that had been damaged (and not replaced with my low mileage hoses as I'd asked Trev to do), we skated our way to a gas station on a 5 qt. oil slick and almost stuffed the car. So my 6,000 mile car was coated in oil at this time (hood liner, all the underhood area, entire underbody of the car). Niiice.

So we tried reconnecting the oil system (as all good adventures, this one took place at about 1:30am) while I ran over to Safeway and bought what motor oil they had in stock. We dumped it in, started it up, and blew another 5 quarts of oil all over the place. So at that point, we walked the 7 kilometers (measured with the odometer in my Canadian Grand Am rental car that I had at the time on the trip back) to Trev's dad's house, got my new oil hose and drove back with even more oil, and then fixed the car and drove it back to his dad's house and parked it. At about 4:30am.

So after doing my best to degrease the car and scrapping the hood liner as a complete loss, I drove the car with the junkyard motor for awhile and it let go not long afterward, maybe a month. My engine from Hayes wasn't ready yet, and so I just hammered the motor in the car. 2 or 3 months later, I took it to the RROW dyno day event and put down 238 RWHP with a stock intercooler, stock cat-back, and 10 psi with a motor that had bad compression on 2 faces of EACH rotor. Not bad. That motor actually ran reasonably well for another 5 months until I pulled the last running motor from the car in May of '98. I haven't driven the car since.

The Hayes motor took months to finish, and I had to dog them most of the way. Then we found out after another motor they'd built at the same time seized up and died that they'd substituted a lot of shoddy parts, wrong year parts, done a horrible and incomplete job of porting, and hadn't machined the rotors for my 3mm seals at all, but substituted 3mm rotors, which was the cause of death with the first motor. The seals bound up, cracked, and it lost two out of the rear rotor.

At that point, I'd already decided that I was going with a 20B, and I'd actually sold the motor mentioned above to Trev's dad. On finding out that there was probably something extremely wrong with "our" motor (it still hadn't been run or installed in his dad's car), Trev disassembled it and found all the problems I listed above, coupled with the fact that the intermediate plates had been lapped so many times that there wasn't sufficient groove left for the water jacket O-rings. They'd split immediately when the motor was torqued down and had spooled out of the "grooves". It would have overheated or at least consumed coolant at an alarming rate immediately on running. Here's a picture... looked good on the outside, at least...



So Hayes promised to rebuild the motor if Trev would keep quiet about it (he didn't obviously, but we did until after they'd already rebuilt it) but would not allow him to be present when it was assembled. I assume it was assembled correctly though, since it got them to California for a road course event at Buttonwillow and back, and I drove the car while the motor was in it afterwards at 160+ mph. After the wreck of that car, in which Trev died, the motor (which was unharmed by the wreck) was sold to a buyer who agreed to take Trev's R1 off his family's hands.

So at that point I had a 20B (shown below) and still planned on putting a rotary in my car. It wasn't until I had unpleasant experiences with vendors in regards to that project and could not resolve the problem of relocating the steering rack easily that I chose to sell the 20B and think about it some more.



And so eventually I just got tired of looking at the car, and decided to do something a little unorthodox after reading an article in Vette magazine on a 409 cid LT1 (late model) built by TPIS which made some very, very impressive numbers. The end result, after doing a lot of research, was that I partnered with Granny's to develop a V8 conversion kit for my car which they would then market, and which started all this controversy over V8 swaps into 3rd gen. cars.

Can you tune a rotary engine properly? Most certainly. Can the turbo engines last a long time? With careful maintenance and some luck, and with reasonable use and a cautious eye on temperatures and pressures, sure. But there are a lot of engine deaths that I've read about or heard about over the years that aren't attributable to maintenance or tuning. Sometimes they just let go. A Mandeville-tuned full Motec (including the Motec dash) car at 10 psi died, even with the ceramic apex seals. Most of the people I know who have made over 350 RWHP have had an engine (or two) die on them. Their components and programming range from PFS boxes to Pettit ECUs to Mostly Mazda ECUs to even a Wolf 3D. There's no single "right" answer to why the engines die, they're just delicate (in my opinion, when compared to a piston engine) and have to be treated as such.

I went my own way just to do something a little different, and not because I hate the rotary or can't tune (or afford to have one tuned) properly. I did it because for the power I wanted to make and the use of my car (mostly street, with a bit of drag racing) it made sense to me. Obviously it doesn't make sense for everyone, and especially considering my car's history, the expenditure on different mods and engines, and the latest expenses related to my V8 swap, my car can't even remotely be called typical or average, so it can't be used as a case study into "why rotary engines blow up" (in the United States and not eslewhere) or a case study for much of anything else, including "what's the average cost of a V8 swap?".

I don't have the answers. I just know that the number of engine deaths (and the wide variety of conditions, configurations from stock to wild, and climates) indicates that the rotary engine isn't as robust as some people would like to believe, although the fact that they do produce extremely impressive power and can be tuned properly and can live long lives can't be denied. However, it's become common enough to see people with problems that are engine related that the car has received an extremely bad reputation. Perhaps the high initial sale price is to blame. People especially don't want to believe that they bought a "lemon", or that they paid so much money for something that is (in some instances) unreliable. They want to drive their cars. Those initial people, who probably didn't have much understanding of their car's inner workings (coupled with dealerships that didn't know how to work on them properly, and never did learn, in most cases) are probably to blame for the initial bad image the 3rd gen. got in the United States, and for the (initial) number of 2nd engine used FDs on the market. Not to mention the failing sales long before the high dollar Japanese sports cars were discontinued in other model lines.

Just a few thoughts... think I'll take a break.

 

I'm going to have to agree with this one. In all of my personal experience with RX-7's and rotary's (over 200,000 miles) in general, I have never once had a problem (other than my FC flooding once on a Christmas night at 15 degrees, since then it's never happened again) with a rotary engine. I'm not talking just stock either. My R1 is highly modified and hits 8,000 rpm and speeds of 160+ mph when ever weather permits. My FC is mildly modified and hits redline everyday. There's nothing I like better than hearing the REV Buzzer go off. I have no idea why people go through so many engine problems and engines. I tend do just to normal maintenance on both of my current 7's and have never had any engine related problems. Mind you, that doesn't mean I don't have any problems. My FC has the famous electrical gremlins and a few other problems. I change my oil at 3,000 and 2,000 miles respectfully. I change my fuel filters and coolant every two years. I have most of the reliability mods on my FD which help, but I still can't imagine everyone just go through engines. In fact I wish that my engines would go. Then I could go single turbo with street ports for the both of my engines. No matter how hard I beat on them, they keep coming back for more. These engines can take it. If you make careless mistakes or get a shity rebuilt motor then you can't blame the engine. I had a first gen Talon and I won't even go in to detail what a nightmare that car was.

 

1km is 1.6 miles from memory.

Most people I know change oil every 5000km's. I didnt use premix myself but i know some people who are.

We did get the pre-cat, however i believe that in the 1996 update this was removed but am not positive.

 

Jim,

We don't deserve such an excellent explanation. Obviously your decision to swap a V8 was well thought out, with pure performance motives everyone here can relate to. Without putting my head too far up your ***, let me thank you for your time and creativity. I have an automatic FD and was thinking of swapping in a 5-speed, but now I have a lot more options to consider. Thanks again.

 

Hmmm (strokes chin hair), I wonder if the ZO6 Corvette engine/tranny will fit in there....

 

Will the Z06 drivetrain fit? Nope, and for several reasons.

1) The LS6 is the same size, dimensionally, as the LS1, which means that it's about 1.5 inches wider than the LT1, and another inch taller. The throttle body of the LT1 comes within hairs of the hood (except on my car, and you don't want to know how I'm getting around that without modifying my hood) and the LS1 will definitely not fit without hood modification, or modification to the cradle to drop the engine lower in the car, which would A) decrease ground clearance, B) screw up drivetrain geometry, and C) cause you to have to move the steering rack, negating one of the things we strived to keep stock.

2) The C5 (and Z06) are transaxle cars, of course. You would not be able to use the torque tube and bellhousing from a Corvette in the RX-7 without huge modification of the rear of the car. Yes, you could use a late model Camaro hydraulic T-56 6-speed, but they are quite a bit more expensive than the pull-type LT1 T56.

3) The LS6, as nasty as it is (405 horsepower, 400 ft. lbs. of torque in the '02 Z06) is only nasty in a car with a warranty on it. Half the lure of having the LS6 was that it was such a bad-*** motor in a car that came from the factory that way. You can build an LS1 or LT1 to make that much power with a cam and head swap, and in fact, 450 horsepower from an LT1 is so simple and cheap to make, you'd be nuts trying to buy an LS6 (since they're rare as rare right now) and trying to fit it into the car.

 

Ohhh, I see now. Also answers my question as to why you did not use the LS1. After digging around abit, I know now that the LS6 is a modded LS1, correct?

I DO want to now how you got more hood clearance - this way I don't have to think about selling my CF hood, hehe.

 

Just thought I'd add the current status of my upcoming LT1 powered FD is (hell I may even get it done before Jim does). Currently the engine is at Lingenfelter having their 383 LT1 job done to it...should be good for 440rwhp/430ftlbs (it even comes with a 2 year warranty). I'll be mating this with the borg warner t56 6 speed transmission once it's finished. Incidentally, the engine is 50 state legal - the law regarding engine swaps states that as long as the emissions parts required for the donor vehicle are present (main cat only for a '96 Z28), then you're fine.

Big thanks to both Jim and especially Bill Hagan for their assistance thus far.

And as Jim mentioned somewhere earlier, performance is my goal. If it involves me putting a Chevy engine inplace of the 'unique' rotary then so be it. I've been about as much of a rotary enthusiast as I could have been over the years, but the constant maintenance and reliability issues (3 motors in 4 years says it all) has pushed me over the edge. And before anyone starts screaming about tuning, yes everything was tuned correctly, all reliability issues taken care of, blah blah. And as for gas mileage...I'd be better off having a gas tanker follow me around Hollywood seeing as I end up at a gas station every 100 miles or so off a 15 gallon tank...awesome.

And PLEASE PLEASE these fools who spout nonsense regarding weight balance and how the car will never handle as well ever again, just be quiet. Please? Myself and Jim several times have mentioned the fact that a) the car weighs roughly that of stock (Jims even weighs less than a stock FD), b) the weight balance is *shock horror* still 50/50!

 

This is a very informative thread, whether you like V8's in FD's or not. I know I have learned alot. I am not considering doing much to my car. I have had it for 4 years almost and haven't had an engine blow up. Of course mine is pretty much stock. This thread should definitely be archived for reference.



Petros

 

At the rate my engine is coming together, it might be done in December, so chances are good that even someone starting right now will beat me to having a running car.

I almost fell off the NA truck today, but the 90 lb. weight gain and umpteen customizations required to mount the supercharger I was considering changed my mind. Guess I'll have to settle for around 700 horsepower.

For anyone interested, here's the 421 cid supercharged LT1 under construction by the owner of the shop building my engine... it'll be pushing nearly 4-figure horsepower.

http://www.c-zone.net/markm/blown421/

 

What is the total cost of the engine you are building? If it works out to less than $15k I'm gonna be pissed...

 

It probably could have been done for $15k, if I'd made some different decisions. However, I spent a lot of money on parts to ensure durability, high rpm stability (and capability), and to reduce rotating assembly weight wherever possible. Not only will it spin to 8k (easily), but it'll get there very quickly, and it weighs substantially less than a stock LT1 now.