KnewB

Hi all,

My name is Abe and I'm new to the board. I'm familiar with reciprocating engines but the Wankel often baffles me.

I'm always into trying something different so I'm looking to do a RX motor into a Porsche 914 swap and I would like to know what sort of setup could yield me at least 350 crank HP with some modicum of reliablility. The car won't be a daily driver but should be dependable enough for 500+ mile runs. As with anyone, I want to do this in a cost effective manner with the least amount of tinkering possible.

Anyone have any suggestions for the setup?

Thanks in advance,
Abe.

Greg

60-1

KnewB

OK now how about a real answer that is informative.

Like a base engine to start with. 2 rotor? 3 rotor? Good year? Years to avoid?

Recomended turbo(s): T-4? T-5? Twin turbos? Sequential?

Fuel management: Is there a factory unit that will run with a setup like this? Some sort of piggyback system required/helpful?

Exhaust diameter: 2 1/2"? 3"? Bigger?

Stuff like that will be really helpful to me.

Thanks,
Abe.

CrazyDude

Base engine: S5 13BT (from 1989 - 1992 Turbo II cars); get one from a j-spec dealer and rebuild it (check www.fc3s.org -- great guys!)
Recommended turbo: T04B 60-1
Fuel Management: Haltech E6k (or something like that)
Exhaust Diameter: 3" should do nicely

how's that

HWO

a FD motor with a Haltech E6K controlling it with about 15psi boost with either a better intercooler or water injection would give you 350HP reliably at the flywheel

KnewB

Thanks so much for the help guys!

I looked at the www.fc3s.org site and looks like they have pretty good prices. When I take the plunge I might get a rebuilt from them and save myself some hassle.

Something I wonder about. I know on reciprocating engines we drop the compression when we boost to help avoid preignition. Is this possible/advised/necessary with a wankel? Also I know that apex seals work something like compression rings. Should these be upgraded for the 350HP level? How about porting? Should I have the sideplates ported to help with flow?

Please keep the suggestions coming. I know there are probably a few different ways of going about this and I'd like to see them all .

Thanks again for all your help,
Abe.

relvinnian

Stock twins, mods you mentioned, is more like ~350-370 @ RWHP 15 psi. It's been done multiple times.

350 BHP is stock boost + IC on an FD engine. Absolute cake.

relvinnian

It is of my opinion that if you are going to tear the engine down, you might as well port while you're at it. It is absolutely not necessary to make 350BHP or even 400rwhp if you desire, but it will help with spool and broadened power band.

The stock 2mm apex seals are just fine. These motors run very well with 2mm seals. A stock compression ratio of 9:1 is perfect for general street use. 87-88 T2 rotors are 8.5:1, but are not necessary.

The most important thing is to be very precise in your setup planning, and especially your tuning. Rotaries DO NOT TAKE DETONATION WELL. Therefore things like water injection, rich mixtures (11.2-11.8:1), and precise timing are very important, and will ensure a very happy, reliable engine.

-Brian

HWO

Yes i know that, at 15psi he'd be able to make 350+hp at the flywheel in a SAFE AS HOUSES state of tune. you couldn't get it much more reliable

15psi is the max he'd need to run though, i was being 'pesamistic' with my boost levels

Tim Benton

iTrader: (1)

I agree, get the 13b-rew from and FD, then if you add, and intake, IC, DP, catback, power FC, at or around 12 psi, you should be in the 315 RWHP range, which is around 350 from the crank. As far as mounting it in the 914, that will take some imagination as far as motor mounts, the low hood line of the 914, etc. 350 flywheel HP in that car might make it hard to drive, but then with the PFC you can have 2 boost level settings, one for 10 and one for 12. As far as reliability, I've been making 295 rwhp to the now 334 rwhp for the past 4 years with no problems, just tune for about a 11.5 to 1 a/f ratio and watch the timing.

Tim

KnewB

Thanks again for all the help,

Looks like you guys have prescribed a pretty good setup. Now I'm assured that I can do the 350Hp with little to no trouble and for surprisingly little cash.

Couple of quick stupid newbie questions before I take the leap.
1. Will the stock injectors/throttlebodies handle that type of HP or am I going to have to upgrade?
2. Are there readily available maps for the haltech to get started with or am I going to have to fly by the seat of my pants?
3. I keep hearing the name "FD motor" What year/model/trim level did this come from?

Tim: Mounting the Wankel in the 914 is cake really, kennedy engineering makes an adapter that lets the Wankel bolt right up to the tranaxle. It's just getting the cooling sorted out that is the trouble. As for driveability. I ran some numbers and it looks like I'll have about 1HP for every 5 pounds of car. That little 914 should really move on dry pavement, I'll still have my Saturn for rainy days

Abe.

bcty

you are probally the most informed newbe ive seen! congrats!

KnewB

Thank you BCTY. I am a tech moderator on another board and I hate it when newbies ask questions that are especially ignorant. Example "Can I put on a 1,000HP shot of N2O without having to build my engine"?". So I try to ask at least somewhat informed questions.

Now can anyone tell me what an "FD" motor came out of? I know it must be from an RX-7 but what year and trim level?


Thanks,
Abe

P.S. IF ANY of you need tech help with your or a family members Saturn I'll be glad to share what I know. Just shoot me an e-mail at abec@cableone.net

setzep

1. The stock injectors won't handle the fuel demands of 350hp, most people upgrade to 1600cc secondary injectors and leave the 550cc primary injectors in place. The throttle body will be fine for your 350bhp goal, some have ported it though to increase throttle responce but some say it won't help out with peak hp.
2. There are many people on this forum that run the E6K Haltech that I'm sure would send you a base map to get your engine running and driving. I'd join the Yahoo Haltech group, there is some very good info there.
3. The FD engine is from the 3rd gen Rx-7 (93 or newer) and it's code name is 13B-REW. This is also the most expensive 13b you can buy. If you can't use the stock twin turbos on this engine and have to use a larger single I'd get either the Cosmo 13B-RE or a T2 engine, either one can reach that 350 goal that you have. It's not worth the extra $ for the FD engine if you end up taking everything off it anyways to make it fit your 914. The 13B-RE is very close to the same thing as a FD engine but can be had for a lot cheeper (check fc3s.org). It has larger intake runners but smaller exhaust ports and also has a little smaller turbos, stock for stock, FD-255hp Cosmo 230hp. The T2 engine can be had for even less than the Cosmo but doesn't have some of the internal/external updates that the 13B-RE and 13B-REW have that make them stronger/more desireable, it had 180 (87-88) and 200 (89-91) hp.

Good luck

Cam

Eggie

Everything I've read says that stock injectors are fine at 350 crank HP. Raising fuel pressure a few pounds could buy some overhead just in case.

See http://www.maxcooper.com/rx7/how-to/...tem/calcs.html and http://www.wvinter.net/~flanham/wlan...l/fuelfaq.html

setzep

I suppose you could use the stock 550/850cc combo if you ran 80% duty cycle and 50psi at the rail but thats a little risky if you ask me.

im4u

aight since u r going with an engine transplant go with a 3rd gen.its a power plant compared to the 13bt.

too be cheaper u can use the stock twins non sequential.
air intakes (hks foam 330 with hardpipes)
downpipe -like 200 bucks
catback -450 bucks
pullies(im surprised no one mentions this) -200 bucks i believe
haltech e6k (not sure but an average of 1500)or u could order from that one australian store.
10 psi
this will easily get u 300 rwhp

u do not need to port ur engine,the bigger ur port the less reliable.but do rebuild it if it is used.use hurley apex 2mm 2 piece seal with some good springs.that is it.this all u need.and some of the things i listed were reliability mods.this is a cheaper form than gettin all this single turbo crap u dont need.u can easily get 330-350 rwhp on ur stock fuel system and turbos.these guys only think big numbers.

stinkfist

The down pipe will fit in his passenger seat but where will he put the cat back?

Mike

KnewB

Looks like the extra injectors are definitely the way for me to go. No way in heck am I going to push injectors to 80% duty cycle. That's playing Russian Roulette. I will kindly ask the members of this board for a base fuel/spark map when the time to start up the engine arrives. I might do a little porting of the throttlebody on my own to make sure it gets a good taper (hence good velocity) to it but I think I'll leave the plate area alone.

I'm thinking I'll leave the 3 rotor late models alone. Those are too rich for my blood and I'm starting to think that with a proper turbo, intercooler and tuning I can easily extract 350Hp from a 2 rotor (Cosmo?).

As for the catback/downpipe. I'm sure that this app. will need a custom downpipe and since a catback made for an RX7 will be hanging about 8 feet behind the rear bumper of a 914 I think I'll pass

Again, Thank you all for your help. I am so glad that this forum is open minded and willing to help someone like me who is not modifying an RX7 but merely using some of it's better parts.

If some of you are curious as to what the car this is being transplanted into looks like here is a link for you http://www.autoatlanta.com/carsearch...dID=96&-search

Abe.

qwck10th

Is that THE 914 the motor is going into?

TriTurboGen3 RX-7

Hi KnewB i was wondering if you could help me out, Could direct me to the site were you found the Rotary transplant kits, Or just tel me if they Make kits, For Dropping a 13b ina 86 or 86 Porsche 944 ?

KnewB

qwck10th:
No that's not the car that the engine is going into, that car is far too nice/original for a "project car".

TriTurboGen3 RX-7:
The site is http://www.kennedyeng.com/vw_por.htm But they can only adapt to a 911 or 914. If it's cheap speed in a 944 package you are looking for you might try http://www.renegadehybrids.com/944.htm . They have kits to drop small block chevies into the 944.

Abe.

TriTurboGen3 RX-7

Well thank you Very much for the help, Looks like i'm gunna hafta to go at this project on my own, its a few years of, but i think its good to plan ahead, I guess going to lil *** Gravette Arkansas schools was good afterall, learned Welding and metal working skills for two school years. i could proboly do the engine mounts, But the all other parts needed will be the big obstacle