12a Rotary 200rwhp?  

84300zx
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Post #1 post 27th November 2007 - 03:29 AM
hey just askin some advice from the rotary expertise people on here
!

Im thinkin of gettin an fb but as i know very close to nothin on rotaries, heres my question.

Say with the standard 12a and you got a mild port, intake,carbs and free flowing exhaust would 200 rwhp be possible?

If not what would make it possible keeping it N/A

any help would be helpful!!!
IEATU
Post #2

very unlikely, but im sure you can find a dyno that will say u make 200rwhp. either way it will be quick with the above mods listed. Quick enough for a P plater

Mr-RX
Post #3

Agreed with reece.

200hp is a strech for a 12A unless it was a very serious bridgeport or peripheral port.

However 1st gen RX7's only just nudge above 1000kgs and handle very well, So a mild port 12A will give you lots of fun.

Just remember, The bigger the port the higher you need to rev them. The higher you rev them the more issues they give you.

Keep it simple, fun and most of all reliable!


At the end of the day, If you want to keep a rotor N/A your not going to get anywhere fast, Unless as i said above you go a very serious port with some N2O.

RX4_guy
Post #4

Agree with the above forget 200rwhp.

wat'r
Post #5

If you have to make 90dB to be legal exhaust wise ( pre '88 I think ) you can hope for about 130hp with a great intake set-up and good porting.

If you go pre 1988, a better breathing exhaust at 96dB ( legal limit ) I recon 140-150hp is on the cards.

150hp in any little / light car is way fast enough to kill yourself real fast if you stuff up smile.gif

Mr-RX
Post #6

Leigh, The exhaust rules are actually a tiny bit off tongue.gif

Post 84 is 96db
Pre 83 is 90db

Rule of thumb is Series 3 RX7's are the cut off. Unless your REALLY lucky and own an 83 built S3.

ron180
Post #7

I used to have a S1 Rx7 with a bridge port 12A with extractors and a 2.5 inch system. Had a modded original 4 barrell. Was very noisy but i loved it. Think it used to make 120-130 hp at the wheels. I would go with an aftermarket ecu with a webber style throttle body if I was to go a rotary. I hear Phil Laird makes a hardcore quad throttle setup for the IPRA boys.

metalhead
Post #8

QUOTE(Mr-RX @ Nov 28 2007, 08:23 AM) [snapback]1281668484[/snapback]

Leigh, The exhaust rules are actually a tiny bit off tongue.gif

Post 84 is 96db
Pre 83 is 90db

Rule of thumb is Series 3 RX7's are the cut off. Unless your REALLY lucky and own an 83 built S3.


I think you mean vice versa.

Regardless, I think with a good setup you should see around 150hpatw with a largish extend port and a reasonable exhaust level, with a good exhaust, weber or modded niki, and a well built and tuned motor. 200hp is not likely to happen though. Still, it ought to be plenty of fun. The cars are not heavy and handle pretty well. You'll still keep up with most cars with this level of power.

I had a series 3 rx7 12a in a 323, stock carb, ports cleaned up but not much more, and a very loud (well above legal) exhaust, though it wasn't the best design for an n/a rotary. It made 116hpatw, and was very fun and quite quick in a 323, although they weigh around 200kgs less than a first gen rx7.

IEATU
Post #9

^^^^ thats correct <83 is 96db 84> is 90db, the older the better biggrin.gif

TwinCam16
Post #10

200hp is piss easy for a 12a non turbo.

Leave it in 1st gear on the dyno smile.gif

floydy
Post #11

as stated 200rwhp is not very likely without a full race build!
(not worth the money on na)

Good bridgey, 48ida, free flowing exhaust etc should easy put you over the 150 to 160 mark

plenty to have fun with

hope this helps

wat'r
Post #12

'83 /84 is it hey smile.gif

I wa not sure and it was late. Makes sense though.... they were well on the way to tighten things up be '88.

Mr-RX
Post #13

Whoops, Sorry guys, Well i knew what i ment.

Injected N/A is only a good idea if your very serious about having a flawless powerband.

The missus has a 13B Bridgeport that is injected. When it had a 48MM webber (carby) it made 198rwhp. With the injection setup, which has 55mm throttle bodies and 4x 550cc injectors, it makes 196rwhp but drives completely differnt, sounds very very different and it uses more fuel biggrin.gif

The only reason why you would spend the money going to injection (which by the way was above the 3k mark) would be because you really really like the look of the injection manifold (which i do tongue.gif) or because you want a bit more low end torque.

84300zx
Post #14

thanks for the advice, does nayone know how much roughly a mild porting costs? i know i could search etc. but i want someones opinion whos already had it and how big was the difference in fuel consumption before and after the porting?

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