Check this out...my friend is putting a 350 TPI in his 1987 Mazda RX-7 Turbo II. It's fairly built too!
http://www.geocities.com/grandam4u/Mvc-139f.jpg
http://www.geocities.com/grandam4u/Mvc-138f.jpg

Whadda ya think?

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If you've gotta fix it, fix it better than stock.

[This message has been edited by IROCracer (edited January 10, 2001).]

 

It's GOTTA be better than a Wankel...

He'll have the best Mazda Chevy ever powered up!

------------------
Later,
Vader
------------------
"I cannot take this any more... Saying everything I've said before..."
Adobe Acrobat Reader 4.0

 

Well Vader, If you want to get technical its prolly Not better than a Wankel, But it sure gets a Cool award !

engines at a hell of an angle tho.


------------------
60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Livin' the Stereotype

 

That should be fun, let us know when he's done. I'd be interested in seeing what times he puts down

------------------
91 Formula
305 TPI 5speed
1LE/G92/WS6
K&N, SLP airfoil, ported/polished plenum, March pulleys, TB coolant bypass,Crane AFPR(47psi),Crane Gold 1.6rrs,MSD coil,MSD6AL, Holley 9mm wires,Bosch O2sensor, SLP headers & catback,3:73s w/Auburn posi,160* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.
Street legal with stock throttle body, runners,intake manifold,cam, and heads.

 

I think Wankel's are a FAR superior motor design. It just never became popular. If you rebuild the seals in them, they are way way cool. They can like use a one gear transmission cause they can rev so high..they also have like no drag what so ever. RX-7's are my all time favorite car..IROC's are my all time favorite affordable car. I don't mean to **** anybody off..just sayin my opinion

------------------
-Red '88 IROC 5 Speed 305 TPI w/3.08
-Dual Friction Centerforce Clutch
-Accel 300+ Racing Ignition
-Accel 300+ Pro Sleeve Plug Wires
-Accel U-Groove Plugs
-Flowmaster Force II 3 Chamber Cat Back Exhaust
-Hypertech Chip
-Hypertech Airfoil
-Removed, Then Re-installed (out of fear) MAF Screens
-Gutted Air Box
-Best E/T 14.686, 60' 2.205, 1/8th mile 9.461, 1/4 MPH 93.91
-Best 60' 2.17

 

That looks great! Can he get a trans to fit in there to hold up to the power? What about the rear end?

------------------
Rob
'86 TA 305 TPI

 

With the engine on that much of an angle, I'd be suprised if the tailstock of the tranny doesn't scrape the ground.... I have seen a couple of guys put small block chevys in RX7's...

with the power to weight ratio etc, I'd be suprised if the car is actually any BETTER when your done.... by better I mean handling as well as performance. The twin turbo wankel is fast enough, and you might actually be able to take corners...

 

The engine's at that angle because he doesn't have the back tranny mount in in that pic.

The weight is actually unaffected because he got rid of all that turbo s h i t. The rotary with all the turbo junk is a heavy sonuvabitch.

He's got a T-5 in it with a 4:10 rear (yes, it fits), SLP wrapped headers, a .45/.46 Cam, Roller rockers, forged pistons, ported base, ported plenum, ported heads, you know...all the goodies.

AND...he DID replace the apex seals in it, and that damn engine was still all f u c k e d up. Not worth a f u c k. He spent hella money on that rebuild, but it hardly got him anywhere.

He'll be the first to tell you that wankel engines suck.

 

Yarnboy, Wankles are the worst. Not only are they notorious for every major engine problem, they don't last high miles either. Talk to any 3rd gen RX7 owner..they will tell you they have had MANY problems....

Many rebuild at 50k
Trust me on this one, when I was hunting for a Jap supercar last year...this turned me away from them(RX7s). The supra and the 300 are superior motors. Hell, their drivetrain can take 800+hp..and believe me ..there are some guys on the street running that. How does high 11s sound for intake/exhaust/and 14lbs of boost?



------------------
91 Formula
305 TPI 5speed
1LE/G92/WS6
K&N, SLP airfoil, ported/polished plenum, March pulleys, TB coolant bypass,Crane AFPR(47psi),Crane Gold 1.6rrs,MSD coil,MSD6AL, Holley 9mm wires,Bosch O2sensor, SLP headers & catback,3:73s w/Auburn posi,160* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.
Street legal with stock throttle body, runners,intake manifold,cam, and heads.

 

An engine that uses the axis of a rotor to connect to a driveline is very cool in my opinion..you don't have pistons going up an down against the forces of gravity and drag. Wankle engines have problems because they were never accepted with open arms and were only really extensively used in the RX-7, the worlds finest sports car. They make rebuild kits that are fairly inexpensive in comparison to the car that they suggest all 3rd gen owners buy. This solves most seal problems..the engine is a marvel of design..just because it only has been used in like 5 cars does not in anyway mean it sucks. Supra's are awesome but they have an extremley bad habit of shooting pistons out the top of the engine. The tranny in Supras are extreme strong but the steel driveshafts are not. There is a guy here that owns a speed shop that has a Mark III that runs mid 9's. I still get that standing next to a Ferrari feeling when I am around 93-95 RX-7's..They are the ultimate car in my mind. A 1.6 litre engine that does 13.8 stock and looks badder than any other non exotic. I dont really wanna talk about this cause It is pointless to argue over this..I am very bias to this car Ok the end..I like IROC's..anybody else?

------------------
-Red '88 IROC 5 Speed 305 TPI w/3.08
-Dual Friction Centerforce Clutch
-Accel 300+ Racing Ignition
-Accel 300+ Pro Sleeve Plug Wires
-Accel U-Groove Plugs
-Flowmaster Force II 3 Chamber Cat Back Exhaust
-Hypertech Chip
-Hypertech Airfoil
-Removed, Then Re-installed (out of fear) MAF Screens
-Gutted Air Box
-Best E/T 14.686, 60' 2.205, 1/8th mile 9.461, 1/4 MPH 93.91
-Best 60' 2.17

 

Gravity plays a VERY little role in the piston engine. Try the forces of inertia and momentum....those are what have to be overcome, but with a crank that rotates the other bank of pistons with the downstroke of some on one side, this isn't a huge problem (obviously....cars run don't they?). Tell ya what...go spend 5 grand on a rotary (or any other jap engine for that matter) and I'll spend 5 Gs on my 5.7 IROC.....what do ya think will happen?

Kelly

------------------
If you've gotta fix it, fix it better than stock.

 

Plus rotary's spew huge emissions (that is why they quit building them) and the gas milage they return is a joke. A 300 hp twin turbo rotary is the "ultimate" engine? I don't think so. Its dead. I'll take a 385 hp ZO6, and laugh past the gas stations with 30+ mpg

BTW - ever actually weigh a rotary engine? I have. They aren't light. Pretty much the same as an aluminum headed SBC.

------------------
'83 Trans Am. 400 CID, 224/234 crane cam, Summit aluminum roller rockers, hand ported intake, home bored 2.09" (53mm) throttle bodies, MSD 454 injectors(75 lb/hr), Holley 255LPH fuel pump, custum modded FPR w/Vacuum port added, Edelbrock TES headers, empty cat, SLP 3" stainless steel cat back, stock ECM & chip. Borg/Warner T-5 World Class, 12" Corvette rotors and clipers, GTA 16" wheels, South Side Machine subframe connectors, 1LE sway bars, 3.45 ring and pinion, Alpine sound.
Best E.T. 13.532
Best MPH 102.24

[This message has been edited by Tom 400 CFI (edited January 12, 2001).]

 

I hear ya there 400, those things are heavy bastards, especially with all that turbo crap.

It's gonna be wild.

KElly

 

dont dismiss the rotary idea because its not normal, or you dont like it. no, they dont have great emmisions, no, they dont get GREAT gas mileage, but they are fair (15-20, and no, im not making this up). They can rev to insane rpm levels(the race engine redlines at 15k) and make great power for their displacement. now... before i get crucified, i will say yes, i'd rather own a camaro over any car on earth, period, i dont care if a ferrari is faster, i simply LIKE camaros more. end of argument. BUT, that doesnt mean i dont respect other engines/cars. wankel engines have been around for a damn long time, and the guy (wankel) who started them didnt exactly get support in making the design better. Yes, they are expensive, but holy moly are they fast! anyone looked at the stats of a thirdgen (90's body style) Rx-7? their very very quick, and dont even think about messing with a turbo model--they'll hand you your *** before you can even think about catching them. THEFORMULA, high miles? my friends 87 model has 165k and is running great, he's having trouble elsewhere on car.. but the engine is just loving life. and yea, he drives it quite hard. another tid-bit of info-- in a rotary engine, fuel combusts 3 times each revolution of the crank, and in a piston engine fuel combusts 1 time every two revolutions... yea, impressive isnt it?

 

and another thing... they do weigh 1/2 to 3/4 of the weight of a V8. also, the first time they raced in the Le Man's 24 hour race, they absolutely obliterated the field---27km ahead of the next guy.. so yea, dont feel bad if you need to tuck tail and run

 

first off, I like what he did to the car. I always wanted to do that to a 83 I had. I to like the rotory. It would wind up all day long. I don't think I ever shifted under 8000. It had 180k when I sold it and still ran strong, for a little motor. These cars were not made to go straight only. On autocross days a guy runs a new body style(not sure of yr) and spanks almost everything, including vettes. Don't get me wrong I love my car, but give credit where credit is due. I will shut up now.

Jeremy

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92 Z conv
5-spd B&M shifter
home-made ram air, air foil, headers, no cat, TB bypass, kevlar pads, slotted rotors, BMR panhard, alston SFC, 3.42's
when it warms up Edelbrock STB maybe springs

 

I have yet to see a rotary powered car that didn't need work every other f u c k i n g day. The one in the pics was the one that required the least amount of work out of all that I've known, but it had it's problems. There's another one in town just like it that breaks down, gets fixed, then breaks something else. Don't get me wrong, the IROC needs work alot, but I don't have to order plugs from GM when I need them. I've also known two first gen Rexes that were cratered in races just from revving them to 8 gs, so don't gimme that 15grand crap. I've gotten my IROC to 8 grand twice and it hasn't given me problems since. I realize you said race engine, but have ya ever looked at what they rev some of the V-8 powered racers to? It may not be 15, but I guarantee its close to 12. Basically, ask the guy, he wouldn't be doin the swap if he didn't think it was worth it would he?

------------------
If you've gotta fix it, fix it better than stock.

 

I've seen all the "pros and cons" regarding the Rotary engine, and I agree with the majority of them. Seals have always seemed to be a problem with the Rotary, especially in the early years, but Mazda has come a long way in solving that problem. Emissions and gas mileage still are not great, but you have to consider the performance you get. No argument, the rotary engine does produce a lot of power for its displacement.

The biggest problem I've ALWAYS had with a rotary engine is the sound. Sorry, but an old baseball card stuck in the spokes of a child's bicycle sounds better. THAT alone is why I've never was impressed. Mazda seems to come a long way in fixing many of the problems of the rotary engine, except the sound.

Guess that is why I have always seen (heard) loud stereos in those cars; even the owners can't stand the sound.

 

A wankel combusts 3 times per revolution while my 350 combusts 4 times per rev.....hehehe....I win

 

I want to see that rx7 with a big roots blower sticking through it's hood, that would be one hell of a sight!

 

Vortec,

Actually, the combustion sequence is three times per revolution, per rotor. The output shaft rotates about 1-1/2 times for every rotor revolution. Torque is very poor at low engine RPM, but gearing and RPM range compensate for that. A two-rotor engine has essentially the same power pulse per shaft revolution as a four cylinder four stroke piston engine.

It's not a bad design, just not as evolved as it could be, and certainly not as evolved as the piston engines of today compared to those of 120 years ago. The simplicity of the design mandates some pretty high performance materials to make if functional. Fuel delivery and control are very critical, and the tendency to afterfire in the exhaust is a constant due to the necesary port designs.

Also, there is very little room to modify a Wankel engine once it is designed and built. No valve timing to experimant with. Very little exhaust change. Not much to change in the induction system that will have a lot of effect short of a boost. In essence, not very fun to own, since your car is the same "cookie-cutter" model as everyone else's Wankel, and there's very little you can do to change that.

I prefer the term "Wankel" since the engine really is NOT a true "rotary" engine. It's more of a hybrid recipro-rotating design. Rotary engines are made by Garrett, Pratt & Whitney, Allison, And General Electric. Mazda makes "Wankels". Now THERE is some RPM for you to play with.

------------------
Later,
Vader
------------------
"I cannot take this any more... Saying everything I've said before..."
Adobe Acrobat Reader 4.0
KaleCo Auto Parts

 

alright guy sorry gotta step in here
yes early rotary motor sucked *** . those pesky 12a and 13b motors from 85 and early were horrible. there seals were known for breaking though if you took care of them they could last for about 150-200k miles now if you did not take care of them maint wise they could break within 50k. now lets go the the third gen. 92-95 . cause they are running about 10psi with only a 2 mil seal they will last ya around 100-120k miles. but when you start tweaking the boost as anyone else would( I am sure you guys with TTA do the same :-) and dont adjust fuel mix or go up to a 3 mil seal you can see breakage after a while. but still if you have the R1 package that is able to out turn a z06 vette and run 5.2 0-60 times stock who is complaining.
as for the 2nd gens if you are running an N/A motor I have seen them get in excess of 300k . have a friend right now getting 320k.
mine right now is pulling 165k autocrossed on a weekly basis, also I do a lot of street drags. I am able to run with a v6 camaro,rustang, and other little imports. not bad for a motor that is only 80ci about the same size a metro motor.
now dont get me wrong I like and respect your cars. one of my best friends owns a camaro and I even owned one. just dont let one car ruin your impression of them all.
just give them some respect for what they can do. heck your beloved GM was even thinking about putting out a 4 rotar vette :-)

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Got rotary?

 

I think its funny that people argue about cars so much. Cars are cool. Fast cars are cooler. It doesnt matter who makes them, where, or what design they are.

 

I agree I just dont like it when ppl start rippin on my rx7's so I defend them
but hey all ppl have there own interest for there own needs
there are a whole bunch of fast cars why not give each of them thre own respect and dont laugh at the others just b/c you think yours is better

 

I'll stand by what I said. The Wankel was never fully developed, and probably solely for economic reasons. Mazda isn't wallowing in a pit of cash, for sure. It makes an interesting engine with lots of horsepower at higher RPMS, but was condemned for use by the masses due to production complexities and costs.

Yes, GM had several running examples. Piston engine technology was so much more developed and commonplace that the sheer economy of producing it killed the project at GM. There were peculiar problems that could be worked out (obviously, Mazda could get a small rotary to behave well) but GM Powertrain was just too comfortable with the big V-8s producing whatever power they needed with reasonable reliability and efficiency.

Some Mazdas can be surprizingly quick, but you probably won't black out from launching one. Sub-five second 0-60s are great, but I'll be a whole lot more impressed when a 4,500 HP rotary does a five second quarter like so many big blocks do on a daily basis.

Your RX7 is a nice little ride. Take care of it and you should be able to rely on it. I guess I'm just spoiled by the 735 inch Brodix blocks that turn 14,000 RPM, just like the little rotaries.

------------------
Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Please explain how my friend has a car that was used as a pizza delivery vehicle and then a newspaper delivery vehicle for almost all its life, and lasted 290,000 miles before the TRANNY puked, never even had the seals replaced. Its an 84 btw.

Some people just cant maintain a car properly IMO. Those cars are designed to and do use lots of oil, most people dont keep up on that and ruin it that way.

Personally, I like the rotary... or wankel for those who are picking on technicalities. The rpm range is much wider than any stock SBC I have been in. Most of them are not speed demons, but I dont think that was ever the original intent anyway.

 

What's it matter? He's tossing it for an SBC...

 

Wankel's suck, the sound sucks and torque is crap. American/Canadian Power is what you need! V8 muscle power baby!

 

Why does it always seem that the threads here that have 25+ post's on them, don't really relate to the F-body?

 

What are you on? I hope you were using that term loosly. "Worlds finest sports car" Jeez..

 

Ever seen what Piston engined race cars can rev to like F-1 cars? 17k no problem.

 

I agree that SBC is a damn nice motor has more torque then my little wankle has but does not seem to be as reliable. though yes if you dont like to take care of your car then a SBC will outlast a rotary anyday. but if you know how to do normal maint then they last forever. as for being underdeveloped I would not say that. the new little wankle comming out has 250 hp a 10k red line and is still the same 1.3LT
has the same emissions as a boinger. gets about 25-30 miles to the gallon prob.

just quit saying the rotary sux unless you have owned one and know how to take care of them.
they are so simple to rebuild. really reliable. for there size they put out lots of power though again you guys still have torque on me :-).
please though dont get me wrong I love you cars and if I was to ever buy another car it would either be a 93 RX7 R1, 70-71 camaro or this 91 Camaro z-28.
I love your piston motors they work and have lots of power and hella torque just dont suit me like a rex does

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Got rotary?

 

Here is a little bit of engineering on a piston and a rotary engine.
A piston engine has several problems. The first one is trying to turn vertical force into rotational. This is the function of the connecting rod and from an engineering standpoint it does a horrible job. As a force is applied to the crankshaft it starts out of the top pushing straight down. This wastes a huge amount of your force. As the engine continues to rotate over half way down you start getting almost perfect energy transfer. At the very bottom of the stroke the piston is now hardly capable of pushing on the crankshaft because of the crappy angle. It is almost as bad as the top. The upside of the piston engine is superior cumbustion chamber seal.
With a rotary you only have pure rotational energy. There is no energy lost in converting from vertical to rotational thus in concept the rotary is the far supperior engine. This is how mazda got 150 hp from an engine that only sucks in 1.3L every rotation. The down side of the rotary is poor cumbustion chamber sealing. Trying to get the center triangle to seal to the case is something rotary engineers have been trying to due for the past 90 years. If anyone makes that engine seal it will be the best gasoline engine.

------------------
84 Z28 383
Stripped w/Cage back halved w/ladder bars and coil overs and 9 inch
700R-4 3.73

 

hey I like my wankel

 

Talk about searching for an old post. Good job RX.

 

and I will be the first to tell you that he prolly doesn't tune the car that great.

I take it he did some mods to it like a exhuast and filter and maybe a few other things

but it wouldn't surprise me if he forgot to put a better fuel pump in there and higher flow injectors... little fuel lots of air = detonation..... that can kill any motor... so it wouldn't be the fault of the wankel

and why is it I hear a lot of stories of ppl running these motors for a while and not having any problems it is those ppl that do not understand it and do not tune it right that have problems and then complain about it

 

can be done on a wankel also

I am pulling almost 180k on mine
there is a turbo guy pulling 146k
most all of our turbo guys are abovce 100k miles

we have a few that are running 12's and most are 13-14 if turbo but again abovce 100k miles


as for a thirdgen it is not the motor that is the cause of the problem. the problem comes with the ****ty ECU. if you mod the car at all the ECU doesn't adapt well to it and you tend to run lean... lean again equals detonation which will cause any motor to go boom


so it is not hte motor fault but fault of the tuner

 

hehe oh yeah every engine problem around.... not a whole lot that can go wrong with them

and forgot to mention there is another guy 210k on his car and another friend of mine wiht 246k


all still running strong

 

I don't have to buy plugs from mazda

get my NGK from shucks.

I don't work on it everyday and most the problems I do have are not related to the car but rather to bad installs lack of maint stuff like that...or again lack of tuning

with my N/A the only problem I ever really had was a broken driveline that took out the tranny


but when you dump at 6000 rpms and have a 170k on the car I expected that. other then that it is just the basic old car stuff. plugs need changed, plug wires, exhuast leak from bad install (stripped a stud) anything you guys go through and I bet I have done less work on my car then you have done to yours

 

just like to point out that I also have 175k on my car I hit 8000 ALL THE TIME with no problems. not once or twice like you said you have done...
I have pegged the tach a few times

I downshifted from 5th to second once on the freeway at about 80mph
that prolly put me close to 10k-11k rpms my motor is still kicking


maybe they can't take 12k stock but they can rev a lot higher a lot longer without as many problems as a piston motor could as long as things are doing ok and the cooling/oil system is working again just like any other car

 

I l;ove the sound of my rotary


and gas milage is ok
30-35 hwy and about 20-22 city

 

I agree

 

output shaft rotates 3 times for every rotor revolution
low end torque is not the greatest but it does ok. I drive around town in 5th at 1500. just can't step on the gas... but as you said gearing does help a lot... that so far is my biggest complaint with the rotary little low end... enough but... not enough



I agree...
though the afterfire is not all port design also look at the exhuast temps of a rotary. 1800* is normal at wot and any fuel unburnt will easily burn in the exhuast. though on second though I guess part of the reason the exhuast is so hot is b/c of the port.


there is quite a bit of room to modify a wankel....
you can change the port timing on the car. might not have valve to change but port timing yes can be changed by quite a bit. exhuast headers are very common, you can run true duals, cat,backs, 2 into one headers, port the exhuast port, change the exhuast port timing, get rid of the stupid silencer thing in the exhuast.
there are different intakes that can be had. some cars had it setup so when you hit 3800rpms you have more intake duration as well as more area in the port to allow more air in, again porting the intake manifold or intake ports, they have a VDI setup that is almost like variable intake runners and helps increase pressure in the intake without using a turbo.
then you can add turbos and quite a few thigs, N2O is useds on some cars, for the most part you can do anything that you can do on a piston motor just with less steps and less parts except for stroking and boring.. at that point you just add more rotors


those aren't rotarys but radials

different motor there

 

so we are not at 4.5 yet but we are in the sixes and getting faster

 

damn you mark at it again


leave me alone ok I am not going to sleep with you

but I saw a guy in this post https://www.thirdgen.org/techbb2/sho...&highlight=rx7 talk about it by the name of IROCracer so I took a look

 

and what is it you have?

 

nope not for 1/4 like most ameri cars


but for road racing

 

thirdgen rx7 is only 1.3L

 

spend 5 grand on my car and I should be hitting least 11 if not 10s

 

I get 30-35 hwy miles
and 20-24 cty

300hp stock but with a turbo easily modded

not uncommon at all seeing 500+hp out of a rotary with only 1.3L and yet they can still get about 25mpg with that much power

weight of a rotary is about 300lbs with all fluids in it and full intake exhuast
370 or so for a turbo