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-   -   How much power can you make out a NA Rotary? (https://www.rx7club.com/2nd-gen-general-discussion-323/how-much-power-can-you-make-out-na-rotary-1117217/)

Qahu FC3S 08-01-17 07:17 AM

How much power can you make out a NA Rotary?
 
So this has been on my mind lately, but relativity how much power can you make out a S5 NA 13B tell me your experience on how you did or what problems you had, cause I kinda wanna build a nice NA just to "daily". If I should post this in build thread please let me know!:nod:

FührerTüner 08-01-17 07:56 AM

Not much. 200hp with a lot of money.

Qahu FC3S 08-01-17 08:33 AM


Originally Posted by Fuhnortoner (Post 12204857)
Not much. 200hp with a lot of money.


How much money we talking and what would you need to do? I'm guessing full Bridgeport to start off right?

FührerTüner 08-01-17 11:23 AM

Bridgeport, Standalone, Straight pipe probably get you around 250 with a fresh engine.

Qahu FC3S 08-01-17 11:36 AM


Originally Posted by Fuhnortoner (Post 12204901)
Bridgeport, Standalone, Straight pipe probably get you around 250 with a fresh engine.


That's not bad, I've seen some crazy NA builds from Australia and those cars boogie down the street

FührerTüner 08-01-17 11:59 AM

TII will cost you about the same price with the same power, with way more potential.

Qahu FC3S 08-01-17 12:37 PM


Originally Posted by Fuhnortoner (Post 12204908)
TII will cost you about the same price with the same power, with way more potential.

That's true... But it's hard to find TII engine's nowadays especially in my area (NJ), that's why I was curious to see if a NA could make decent power, even if I were to do a TII swap I wasn't gonna make stupid power, just nice comfortable 300ish HP, not to mention I need a TII rear-end, driveshaft, trans etc. to make sure everything works in order unless there's other alternatives for a rear-end, most TII's come with a trans anyway and I can get an aftermarket driveshaft, but it's the rear-end that'll kill me.

FührerTüner 08-01-17 01:03 PM

Dont do a TII swap. Its a lot of money.

Dak 08-01-17 01:04 PM


Originally Posted by Fuhnortoner (Post 12204901)
Bridgeport, Standalone, Straight pipe probably get you around 250 with a fresh engine.

Also add in a different intake manifold setup. ITB's are a common option in the n/a world it seems. According to most over in the n/a section the S5 intakes are only good for about 200whp. So without changing the intake one won't see the full potential of the Bridgeport.

Spend some time looking around here:
https://www.rx7club.com/naturally-as...nce-forum-220/

Dak 08-01-17 01:18 PM


Originally Posted by Qahu FC3S (Post 12204911)
I can get an aftermarket driveshaft, but it's the rear-end that'll kill me.

Yep. Mazdatrix sells one to mate a TII transmission to a n/a rear end. Besides if you have a GTUs like your sig. you'll want to keep that 4.3 rear end. Or at least I would so unless you break the rear end it shouldn't kill you.

SingleTurboRx7 08-01-17 02:03 PM

converting an NA to TII is way more trouble then its worth, what is your goal for this build? have you thought about maybe pulling some weight out of the car?

Qahu FC3S 08-01-17 03:36 PM


Originally Posted by Dak (Post 12204924)
Yep. Mazdatrix sells one to mate a TII transmission to a n/a rear end. Besides if you have a GTUs like your sig. you'll want to keep that 4.3 rear end. Or at least I would so unless you break the rear end it shouldn't kill you.

I'm pretty sure it's have a GXL, I just forget to change it cause the previous owner said it was a GTUs, but I'm convienced it's a GXL cause its has everything and I know GXL's were "fully loaded"

Qahu FC3S 08-01-17 03:45 PM


Originally Posted by SingleTurboRx7 (Post 12204938)
converting an NA to TII is way more trouble then its worth, what is your goal for this build? have you thought about maybe pulling some weight out of the car?

My original plan was to do a TII swap but like I said before NA's are much easier to come by thesedays and I live in a area that isn't very import friendly (Pine Barrens of NJ). Basically my goal for the TII was a just gonna be a simple setup nothing crazy, 300hp range, decent size turbo, small brigde, standalone ecu, etc, but I wasn't having any luck finding TII engines so I was gonna scrap the idea and build a decent NA that wouldn't be a slouch on the streets, and I don't think there's much weight to pull out also I don't think the GF would like idea of being in a gutted FC lmao, I would like to keep a full interior.

Dak 08-01-17 11:41 PM


Originally Posted by Qahu FC3S (Post 12204964)
I'm pretty sure it's have a GXL, I just forget to change it cause the previous owner said it was a GTUs, but I'm convienced it's a GXL cause its has everything and I know GXL's were "fully loaded"

In that case not sure what to do as the 1990 GXL didn't have LSD no reason to keep that rear end.


Originally Posted by Qahu FC3S (Post 12204972)
My original plan was to do a TII swap but like I said before NA's are much easier to come by thesedays and I live in a area that isn't very import friendly (Pine Barrens of NJ). Basically my goal for the TII was a just gonna be a simple setup nothing crazy, 300hp range, decent size turbo, small brigde, standalone ecu, etc, but I wasn't having any luck finding TII engines so I was gonna scrap the idea and build a decent NA that wouldn't be a slouch on the streets, and I don't think there's much weight to pull out also I don't think the GF would like idea of being in a gutted FC lmao, I would like to keep a full interior.

You don't need a bridge to get 300hp with a turbo. Streetport and the right turbo setup would do it. With standalone and other supporting mods of course. Actually I think people do it on stock ports quiet often. Check out this thread:
https://www.rx7club.com/2nd-generati...300hp-1075262/

For 300hp you can drive comfortably on the street a turbo is the way to go. If you can be fine with 200 or so n/a may be for you. At least to make that power on a n/a you need a standalone so if you decide to one day go turbo you'll have that base covered.

As for cost. Start pricing standalones. Then exhaust pieces and the exhaust will have to be custom as you'll have to do some tuning to the collection point of the primaries. No off the shelf exhaust will get you to 200whp. The Defined Autoworks header is a good start but it's $820 and you've still got to finish it out with mufflers, etc. You can buy Racing Beat stuff and cut and weld it into what you need but unless you can weld you'll have to pay someone to do it and then go to the dyno and repeat the process till you find what make the best power. Luckily some good starting points are out there if you search the forum for them. You'll need to start pricing intakes, ITB's, and injectors as well. Seems 2xID1000 injectors in the primary locations is what people are recommending at the moment. Good luck.

Qahu FC3S 08-02-17 10:36 AM


Originally Posted by Dak (Post 12205077)
In that case not sure what to do as the 1990 GXL didn't have LSD no reason to keep that rear end.



You don't need a bridge to get 300hp with a turbo. Streetport and the right turbo setup would do it. With standalone and other supporting mods of course. Actually I think people do it on stock ports quiet often. Check out this thread:
https://www.rx7club.com/2nd-generati...300hp-1075262/

For 300hp you can drive comfortably on the street a turbo is the way to go. If you can be fine with 200 or so n/a may be for you. At least to make that power on a n/a you need a standalone so if you decide to one day go turbo you'll have that base covered.

As for cost. Start pricing standalones. Then exhaust pieces and the exhaust will have to be custom as you'll have to do some tuning to the collection point of the primaries. No off the shelf exhaust will get you to 200whp. The Defined Autoworks header is a good start but it's $820 and you've still got to finish it out with mufflers, etc. You can buy Racing Beat stuff and cut and weld it into what you need but unless you can weld you'll have to pay someone to do it and then go to the dyno and repeat the process till you find what make the best power. Luckily some good starting points are out there if you search the forum for them. You'll need to start pricing intakes, ITB's, and injectors as well. Seems 2xID1000 injectors in the primary locations is what people are recommending at the moment. Good luck.


Well after all that, I'm probably gonna stick with going turbo, and I'm still saving my pennies for the TII, but like I stated previously... I live in a very non import friendly area and just finding a TII that is isn't trash will be hard enough. (being 19 and a full time student... It's not easy). Also as for what you're saying about the rear-end, so basically what you're saying is that I can use a GTUs rear-end and it should work just fine correct?

Dak 08-02-17 01:22 PM


Originally Posted by Qahu FC3S (Post 12205155)
Also as for what you're saying about the rear-end, so basically what you're saying is that I can use a GTUs rear-end and it should work just fine correct?

It depends on what car you are starting with and what you are doing to it. If you are doing a turbo conversion on a your current n/a car it would work just fine with the driveshaft Mazdatrix sells( as would your current rear end). That is if you could find one as there weren't that many GTUs' made. Something like 1000 in '89 and around 100 in '90 IIRC. It would probably be easier to find a complete rear TII sub-frame and swap it in( as the half shafts are also different). If you were starting with a GTUs it might be worthwhile to keep it for the 4.3 gearing vs. the normal 4.1 if you're not planning on crazy HP numbers. If it's a '90 GXL with no LSD then go with the TII setup if at all possible to get an LSD rear end in there.

If you're starting with a turbo car the GTUs rear won't fit without swapping a bunch of parts. If you want a 4.3 rear it'd be better to shell out the cash( $757) for the gear set from Mazdatrix.

To be honest the only thing the GTUs rear has going for it over say a 86-88 LSD car is the gearing. The Viscous type LSD isn't know to be the best. The 86-88 clutch type with a fresh clutch pack or a torsen unit from a Miata (n/a rear) or FD(TII rear) would be better.

Qahu FC3S 08-03-17 07:42 AM


Originally Posted by Dak (Post 12205206)
It depends on what car you are starting with and what you are doing to it. If you are doing a turbo conversion on a your current n/a car it would work just fine with the driveshaft Mazdatrix sells( as would your current rear end). That is if you could find one as there weren't that many GTUs' made. Something like 1000 in '89 and around 100 in '90 IIRC. It would probably be easier to find a complete rear TII sub-frame and swap it in( as the half shafts are also different). If you were starting with a GTUs it might be worthwhile to keep it for the 4.3 gearing vs. the normal 4.1 if you're not planning on crazy HP numbers. If it's a '90 GXL with no LSD then go with the TII setup if at all possible to get an LSD rear end in there.

If you're starting with a turbo car the GTUs rear won't fit without swapping a bunch of parts. If you want a 4.3 rear it'd be better to shell out the cash( $757) for the gear set from Mazdatrix.

To be honest the only thing the GTUs rear has going for it over say a 86-88 LSD car is the gearing. The Viscous type LSD isn't know to be the best. The 86-88 clutch type with a fresh clutch pack or a torsen unit from a Miata (n/a rear) or FD(TII rear) would be better.

Okay thanks for the info! very much appreciated it :)

Jager 08-10-17 07:13 PM

You could buy my Cartech turbo kit and bolt on power?

Honestly, I've noticed the best builds are usually based around porting, good exhaust, and a good running car. Icemark was doing 173 through a factory exhaust manifold.


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