RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   New Member RX-7 Technical (https://www.rx7club.com/new-member-rx-7-technical-256/)
-   -   What should I get? (https://www.rx7club.com/new-member-rx-7-technical-256/what-should-i-get-799798/)

daveyg 11-11-08 01:59 PM

What should I get?
 
I'm in the planning stages of a special project, with the only limits being budget, and I have to use a N/A 2 rotor engine. I'm hoping to make about 200-250hp at the flywheel. I have a couple NOOB questions, first, what would be the most cost effectiveand "relatively reliable" powerplant to start with, a:
12A,
13B, or
13B REW
(leaning away from that last one, due to cost, but if it'd be the most cost effective at producing 250hp, since that's pretty much where it is from the factory, then so be it)
Second question, what's the difference in engine mounting locations and rotor case size between the three-transmission included?

daveyg 12-06-08 11:36 AM

Also thinking of going forced induction, but if so, I'd be aiming for closer to the 450-flywheel hp mark... Anybody have any thoughts? Are these goals reasonable/attainable? I've already read about people making up to 600hp with a 2-rotor and big single turbo, but what if I want to keep it twin, so I can have dedicated true dual exhaust? Any thoughts for a rotary newb?

daveyg 12-06-08 11:42 AM

As for the engine mounting, I just wanna know how well I could use an old trashed junkyard 2-rotor engine for mock up purposes, prior to spending money on the real thing, like getting an engine from a Turbo II I've found, and then finding out how messed up it is. Possibly will be using it for the powerplant buildup/ or just using it for the mockup purposes, if it's too messed up. Will it work?

Alldaybored 12-06-08 06:39 PM

question what are you gonna be using for a shell??? any of the 13b motors are a good starting point for a turbo setup. The turbo II motor I think would be good if you can get it cheap.

FirebirdSlayer666 12-06-08 07:00 PM

Off topic but where abouts in Idaho are you located?

daveyg 12-06-08 07:57 PM


Originally Posted by Alldaybored
question what are you gonna be using for a shell???

I will be tig welding up a full tube chassis... Out of aluminum... Again, don't wanna give out too many details until the project gets off the ground...

Originally Posted by FirebirdSlayer666 (Post 8778401)
Off topic but where abouts in Idaho are you located?

Outside Boise currently. Will be attending BSU (machine tool tech program) in Jan, as well as moving to the Boise bench. Why do you ask?

FirebirdSlayer666 12-07-08 01:40 AM

I actually used to live in Boise and am moving back in January. It's always good to find more rotor heads around the area for meets and what not. I'll be on Liberty between Franklin and Emerald.

Aaron Cake 12-07-08 10:26 AM

200HP can be done with the engine remaining relatively manageable. A street port job, good exhaust and a decent tune can get you close to 200HP. 250 HP requires more radical porting such as a bridge. A good bridgeport setup will require a new intake manifold, standalone, etc.

Honestly it's a lot easier to start with the turbo 13B and just turn the boost up until you get your 200HP. This is easily done on the stock turbo while maintaining decent fuel economy (which sounds like it may not be a concern for you) and with a much superior torque curve.

daveyg 12-08-08 01:10 PM


Originally Posted by Aaron Cake (Post 8779421)
200HP can be done with the engine remaining relatively manageable. A street port job, good exhaust and a decent tune can get you close to 200HP. 250 HP requires more radical porting such as a bridge. A good bridgeport setup will require a new intake manifold, standalone, etc.

Honestly it's a lot easier to start with the turbo 13B and just turn the boost up until you get your 200HP. This is easily done on the stock turbo while maintaining decent fuel economy (which sounds like it may not be a concern for you) and with a much superior torque curve.

Well, I'd be thinking more along the lines of the bridgeport and custom intake (Is it possible to use/fab custom ITBs...) Like I said, I'm going into machining, so how exactly is a bridgeport done? Anybody got pictures of their bridgeport? Or dimensions of the ports after porting? Also, torque will not be very necessary... And the exhaust, I plan on custom fabbing true duals, approximately 2 1/2 foot long (from flange, to tip) straight thru, coming off of each exhaust port... I'd like to stay away from turbo, and go N/A if possible. Also, with a bridgeport, and a set of higher compression rotors, what kind of RPM redline would I be looking at, like 15k, or would that be pushing the limits? Thanks a bunch!

daveyg 12-09-08 07:47 PM

So, the Turbo II uses a 13B, right? So I could really get just about any 13B right? And has anybody created ITBs before? I'm going to search now, but if anybody wants to gimme a link... I'd use it.

farberio 12-09-08 08:28 PM

13B's gome in two main flavors, a 6 port and a 4 port.

6 ports are stock n/a's, 4 ports are stock turbos

Most big power street n/a's are done by running the 4 port.

ITB's have been done before, but they are very costly. tweak-it is one supplier.

daveyg 12-10-08 09:40 AM


Originally Posted by farberio (Post 8786320)
13B's gome in two main flavors, a 6 port and a 4 port.

6 ports are stock n/a's, 4 ports are stock turbos

Most big power street n/a's are done by running the 4 port.

ITB's have been done before, but they are very costly. tweak-it is one supplier.

So, you're saying the 4 port is the way to go... And I was thinking of making my own ITBs, to get the most top end possible. I've got pretty much unlimited access to a lathe and milling machine, so I can really make anything I want... Has anybody ever done ITBs straight off the ports, cuz the only things I've found were using some kind of intake, like one for sidedraft weber carbs, with just 2 ITBs on top, I was thinking more like a 4 port, with 4 ITBs, sitting right on the side of the powerplant, Think it's possible? Any support/skepticism?


All times are GMT -5. The time now is 10:43 AM.


© 2024 MH Sub I, LLC dba Internet Brands