2ND generation rx-7 --- v-8 conversion kit.

[Devilbat]

Wow you must be very special. Because no one else has ever made that much reliable horsepower on pump gas out of a 13B.

BTW: The effective displacement of the 1.3l 13B is 2.6L. Don't forget that rotaries use all of their displacement with every rev. 4 cycle piston engines use half of their displacement with every rev.

Originally posted by sr20det2nr


yea my boys both run about 400hp every day on pump gass and over 450+ hp at races ,
yes i agree that rx-7 take alot of $ to hook up but 2 me it is worth it come on having a 400+ daily driven race car..
its worth it... the fact that u can say i beat ur 5.0l+ wit a 1.3L thats enuff satification 4 me.

bty their rx7s are highly reliable

[rogginator]

"yes i agree that rx-7 take alot of $ to hook up but 2 me it is worth it come on having a 400+ daily driven race car.."

but what if you were able to have that horsepower at half the price?

[philly fab]

This place is funny as all hell..SR20 claims his boys have reliable 13bs that are street driven..Lets see, whats teh name of the shop...I used to live in NY and started working at paisley automotive when i was there and im also good friends with Job Spetter of turbo people..I pretty much know of every fast shop there so it seems weird to me that you make this claim..During recent phone calls to NYC to catch up on BS these said cars werent known of..Kinda odd......................BTW puimp gas would be something at every gas station not race gas sold from a pumpWhat track do they drive them to? E town? I talked to the guys at neverlift and wild rides as well as cartec and know one knows of such a rx7?????
At any rate they may run 10s and be street driven but its not a 10 sec street car unless you can run it on the track with just a tire change..Hell I drove my 10.0 LT1/700R4 RX7 from philadelphia to atlanta without any problems...Except for the people at the rest stop harrasing me to look at the car in detail..

[LS1 powered]

I love this forum!

[FC3S]

The idea of V8 in RX-7 is unacceptable by many great mechanics and automakers in the world!!! How can people ever come out with such ideas??? :o

To those who cannot understand rotary can be as reliable and powerful as pistons is just plain ignorant. It is greatly known that pistons are more reliable but not necessarily more powerful just b'coz pistons has less chances of breaking and having higher reliability percentage than rotaries does not prove that rotary cannot be reliable. Plus twin-rotor rotaries are only equivalent to 4-cyl pistons so to be equal, tri-rotor rotary = V8 piston category.

We all rotary players understand it is the matter of cost when it comes to rotary maintainance. But heck, I own a junk-yard(spare parts) shop so I know it is not that expensive to maintain except for the motor, which can cost a bit more than pistons if you have to do a full rebuild. Otherwise, other parts you can just buy used parts, get them reconditioned and it is almost brand new.

I own a 346bhp '90 TII and it has almost 70K mileage on current motor (exact 69+K) and still performs like almost new. Also, my 1st gen motor breaks at 153K mileage in addition to that I bought it at a used car shop with 131K mileage. My '93 R1 ran 114K up to date and still going strong.

Another note is no other can rival the rotary in smoothness(linearic motion) and non-vibration.

[rxsskid]

I love this forum its so full of ignorance. You guys keep saying stuff about rotary enthusiasts and crap like that, give me a break. 80% of the guys dropping V8's used to be rotary guys but wanted real power. Hey, rotaries may be smooth but expensive and a pain to deal with. You say they are just as reliable. HA, I have seen guys run 9 second Big Block 78-81 Chevy Malibus (Flint Michigan) that are street driven every day. And, not quite a V8 but the Grand NAtional guys. Buick 3.8 turbos are probably the greatest power plant EVER and they can run 9-10sec in full street trim. I have NEVER seen a rotary pull a car into the 9's or even deep 10's without having more money put into them than they're worth. It's insane, the turbo upgrades and exhaust (downpipe, manifold) ALONE could break someone who isn't loaded. I don't know about anyone else but if I am gonna put that kind of money into a car I want it to have a great motor making good power that I Can still build on and not have tuned to the hilt. There are people running 8-9 second quarters off of small block chevy's that cost nearly the same to build as 11 second rx-7's, it ludicrous. Not to mention that the car with a small block will have a lot better temperment. SO say what you will and make up all of hte little facts and stories you want but the truth of the matter is that, while rotaries are good motors, they will never compare to a BUILT v8.

[turbo2nr]

well i aint bullshitin the name of the shop is" tnr racing" located on parsons intbetween jamaica and liberty ave, o yea they also have a web site where u can see there e.t's so here u are go and check out www.rx7s.com and see for ur self.

[philly fab]

and one year in bandcamp....................Websites are nice..

Since your so cool with them ask them to bring it to atco during the pan american nationals..Havent seen either car there and i didnt miss an event last year or the year before..If they are daily driven im sure they wouldnt mind proving to all us V8 Rx7 owners how stupid we are for saveing wads of cash and having a proven reliable drivetrain..We could go for a cruise through south jersey NMRA true street style and then make some passes....

[turbo2nr]

Since your so cool with them ask them to bring it to atco during the pan american

we'll i could do that if i was cool with u and all but scine you are trying to make me look like a lttle bitch, and i gave you proof of my claims i do not owe you anything else ....
... if you want to race them call up the shop and ask to talk to tony and\or romeo and set up a race date or something! i am not there agent i cannot tell them to go race someone all the way in alanta and also they have a shop to run! there shop is open monday through saturday so they are very busy but if u really want to race them give them a call and work something out.
their phone number is on there web site!

1

[Chris V]

Typical rotary "purist" ignorance being shown here.

An RX7 is a CAR, not a religious shrine. It isn't rare or particularly valuable. Even a NICE 2nd gen can be had for around 2 grand, because they are so common. Dead ones can be had free.

People call the cars crap if they don't have the rotary, meaning you people who like the RX7 even feel that other than the engine, the car ITSELF is crap! As if without the engine, it loses it's superior suspension design, it's superior build quality, it's superior ergonomics, and it's outstanding styling. If I wanted another Mustang, i would have BUILT another mustang. If I wanted another 145 hp stock RX7 engine I would have SPENT the $2000 on doing that.

Here's the FACTS:

My '86 RX7 Sport had no AC, stock, no sunroof, and no power steering. But it had all teh suspension from teh Turbo. I added Tokiko sport springs and Tokiko HP struts, Yokohama A008 RSII autocross tires, and raced it for a year, winning the BSCC season's championship in it's class. At the end of that year (1993), the stock 145 hp rotary died. It was going to cost, at that time $2500 to build a new, stock 145 hp rotary. Or considerably more to install a stock 200 hp turbo rotary (or a Cartech turbo upgrade to a stock N/A rotary). Once the horsepower goes up, especialy in the early '90s, rotaries simply DO NOT LAST. For a grand, I bought a nearly 400 hp Ford 5.0 that had just been built for a friends drag car (but he decided not to go small black). I spent less than a grand doing the rest of the conversion (starting with $20 in materials to make the mounts). there was NO WAY to match the hp/torque per doller of the conversion by using a rotary.

Because of the engine setback (the V8, like the rotary, sits nearly completely behind the front axle centerline) the added weight of the V8 (420 lbs vs 330 lbs) was spread between the front and rear axles. Moving the batter y to the rear balanced that out, and WITHOUT GUTTING THE INTERIOR the weight balance ended up at 49/51! The total car weighed 2720 lbs, and 1300 lbs of that was on the nose. The pivot point is the wheels when judging mass. That's why corner scales are used, and not just one big one in the center of the car. Using corner scales, the pivot point is at the wheels. Since the weight is behind the wheels it pushes down not only on the front pivot point, but on the whole car to the rear of that pivot point, thus weight/mass is carried by the rear pivot point as well. Since both pivot points carry the mass, they split the total weight. That's the whole POINT of a mid engine car.

This a recorded, repeatable, fact. If you say the cars become nose heavy, you are WRONG. Get over it. If your theory doesn't fit with demonstrable fact, change the theory to match the facts.





A stock RX7 Turbo weighs 2880lbs. So even if I took my conversion, and changed it to a cast iron Chevy, thus adding at least another 100 lbs overall, the total weight is still not going to be heavier than a stock RX7 Turbo as a complete car (under 2900 lbs), and the weight balance will not be much different than my car, even though the total is up, for the reasons outlined in my description about weight pushing on a the pivot points. My car pulled over 1 G laterally, and even with teh RX7 rear end and gearing limited speed AND road race suspension setup (with short autocross tires) ran low 12s in the quarter. All for a $2000 total investment in the conversion.

Since a turbo RX7 is not considered a nose heavy pig, then obviously a car with the same weight and overall weight balance cannot be so considered, either. And that's the part we try to convey. What's funny is that people complain about the V8 being nose heavy and expensive, then offer up the 20B Turbo as a more appropriate option, even though it costs VASTLY more and actually ends up with much worse weight balance than even a stock RX7 turbo, due to the added forward length and the fact that the 20B with turbos and intercooler weigh more than the small block V8...

V8 RX7s are a cheap way to have a balanced handling car with superior style, ergonomics, and build quality, with the high power and high torque, and reliability of a low cost understressed domestic V8.

[TOUGHGUY]

Cbass, me thinks your idea about the Porsche transaxle may be undermined by the available gearing. When doing a V8 swap, the rear end gearing is a concern because V8s produce their power and torque lower in the rev range than rotaries do. You are swaping in a motor that will only need about 2500 RPM to EFFORTLESSLY propel a car with the aerodynamic properties of the RX7 at 100mph but you require the gearing to do so. Typical RX7 gearing is in the 3.90-4.10 to 1 range with a rotary that can turn 7000rpm with more revs in reserve (at the cost of worn apex seals) so when you swap in a SB ford that makes all its HP below 4500 rpm and can (on average) safely spin to about 5500 rpm before doing bad things, the final drive gearing becomes an issue. With a SB V8, your motor will be turning in the neighborhood of 4000 rpm at 70 mph! While this may be great for autocross, you will find that it won't be very good on the road. Find out what your ratios are and do the math to see if you will end up with something streetable or with something that will need 5000 rpm to maintain 80mph on the highway! Now, while it is easily possible to build a SB Ford that can spin to 7000 rpm, it is NOT cheap and it certainly won't be very civilised on the street.

My '82 will be getting a SB Ford sometime in the next couple of years so I have done quite a bit of reasearch on this. For all you die-hard rotary guys, I think it's sad that you do not see the merit in an engine swap of this nature. You are absolutely correct that per displacement, the Wankel rotary is a tough design to beat when it comes to making horespower. The problem is that I want a car that can last a long time before needing a rebuild all the while giving me the power to be able to hang with 'vettes and vipers. To each his own.

Toughguy

P.S. I turned every bolt on this car and I'll be damned if ANYBODY is gonna tell me what I can and can't do with it! If you don't like the color, close your eyes.

[LS1 powered]

Good info ya got there, but........

Those of us who use the T56 (6 speed) come out perfect. My car, on the Interstate at 75mph, turns 2400rpm. That's not to bad!

By the way, I'm running 4.10's in back...

[Devilbat]

Dude, your car is a work of art. You did a fantastic job.

Originally posted by Chris V
Typical rotary "purist" ignorance being shown here.

An RX7 is a CAR, not a religious shrine. It isn't rare or particularly valuable. Even a NICE 2nd gen can be had for around 2 grand, because they are so common. Dead ones can be had free.
d reliability of a low cost understressed domestic V8.

[Kaneto]

Originally posted by Chris V
Typical rotary "purist" ignorance being shown here.

An RX7 is a CAR, not a religious shrine. It isn't rare or particularly valuable. Even a NICE 2nd gen can be had for around 2 grand, because they are so common. Dead ones can be had free.

To some people, a car almost is a religious shrine.

People love different cars for different reason, and it's not always something that you can just boil down to numbers. Heritage and history have a lot to do with it.

Yes, you can put a V8 in a RX-7 and make more power than most rotaries out there. Sure, you can make it handle about the same. If that's the way you want to go, then by all means go for it.

Understand, though, that to a rotary "purist", the rotary is part of the car. Taking the rotary out of the RX-7 is like taking someone's heart out. It can be replaced with something else... but to some people, it's just not the same.

It's not ignorance, it's love. Love for the car as it was built, and the history that the line has. If you refuse to accept that some people can hold such reverance for a car's design, then it is you who is ignorant.

[Cbass]

Toughguy, the transmission I am using is a transaxle for a front engined, rear transmission Porsche 924 Turbo. There is a traditional bellhousing, and a driveshaft that goes to the transmission, in the rear. Actually, there is an outer shell containing bearings, and an inner 1.25" solid driveshaft, this arrangement is called the torque tube. The differential is contained inside the transaxle, so the gearing should be perfect. At 5000 rpm, I should be doing 160mph.

Kaneto, I understand exactly what you mean. There is a certain mystique and feeling about rotary engines, and if I had the money, I would have a FD parked in my driveway right now, powered by a 400hp 13B.

A common misconception is that rotaries are unreliable, and this is a half truth. An engine is only as reliable as you make it, and if you abuse any engine, it will fail. Some engines have more tolerance for this than others, but that doesn't make them more or less reliable, that makes them more tolerant to abuse. A rotary that is well cared for will last a very long time, just the same as a smallblock. A smallblock that never gets it's oil changed, is overheated, and then flogged daily will break down fairly quickly.

We all love RX7s, why should we quibble about which engine powers the car?