1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

to turbo or not to turbo

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Old Apr 21, 2006 | 07:55 PM
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i play with my wankel
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to turbo or not to turbo

well i got an 85 gsl-se 13b 6 port Fuel Injected...and i want to turbo it but after searching ive found people say "turboing a 6 port is a waste blah blah blah" and other people saying its not....now im confused on what to do??? also i have a good idea of what i need: turbo, piping, turbo timer, exhaust and intake manifold, intercooler, injecter upgrade and pump upgrade, and FM system
i dont think i forgot anything but if i did plz correct me. i have a couple other questions like what size turbo should i use?? what size injecters should i get?? and where can i get a piggy back or SAFMS?? im looking for a good amount of boost w/o blowing an apex seal or somthin.. any help besides saying search more would be great thx

Last edited by rolfs_7; Apr 21, 2006 at 08:00 PM.
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Old Apr 21, 2006 | 09:38 PM
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My understanding is that the fuel injection on these is junk. Simply changing to a good carb set-up as much as 30-50hp. I bought a GSL-SE a couple a months ago planning the same thing. After meeting Robert at the Rotary Shack I decided to go with a TII swap.

You can boost the motor you have but it probably won't last long with lots of boost.

Best route- change to a carb set-up with a S5 turbo. It the cheaper route to go. Robert is great at all this.

Good Luck
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Old Apr 22, 2006 | 01:10 AM
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The GSL-SE EFI is about making usable torque.No other N/A rotary has as low and as long a torque curve as the SE.That means tractable power and no waiting for the power to arrive.Its not the best system to turbocharge since its tuned for N/A airflow,but you can turbo it.However,the more direct TII intake manifold and simpler,4 port engine are designed for forced induction and would make a better candidate for hign boost,high HP usage.
The SE engine does have 3MM apex seals which are more resiliant to detonation damage,but if your gonna be boosting above 10-11psi,you really should be looking at a TII based engine with lower compresion rotors and stronger irons,such as the S5 engine.
For factory boost levels(5-8psi) the SE engine with a S4 or S5 turbo is completely do able.Thats around 200hp.You just need to adress the weak points of the SE.Inadequte fuel pump,only 2 fuel injectors,restrictive AFM,ECU tuned for N/A operation only,ect.Its not as simple as speed density fuel injection,the mass air EFI used on rotaries is made to work a certain way and boosting changes the entire personality of the engine.You can compensate to a degree with additional injectors and fuel controllers,but it can get frustrating trying to tune around what the factory input/ouput devices are try to tell the stock ECU.
By far,the easiest way to turbo a rotary is a TII swap.Everything is designed to be conducive with forced induction and there is plenty of room to raise boost into the 12-13psi range while retaining the stock controls.Im currently around 300 crank HP on my S5 system,at 14psi,which I believe to be about the limit.Any more power and a stanalone and tuning will be required.
Also,the staged,4 injector EFI of the S4/S5 engines is much more matched to the Jekyl/Hyde personallity of a turbo rotary.
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Old Apr 22, 2006 | 01:27 AM
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ditto
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Old Apr 22, 2006 | 10:45 PM
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i play with my wankel
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i really wanna keep the engine i have....around here (midwest...northern Indiana)
TII's are hard to find.....whats an alternative to have enough power to put down the local mustangs and camaros???
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Old Apr 22, 2006 | 10:51 PM
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TURBO. Just the sound of mine spooling makes me hard and the car still hasn't seen the street...
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Old Apr 22, 2006 | 11:38 PM
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You have a good weight advantage over the domestics,so 200HP ought to be plenty to dispatch a stock or mild ponycar.
Like I said,its totally possible to turbo an otherwise stock GSL-SE engine/control system.But its much harder to tune and proof things to the point where you are confident that your not going to blow it up.If you dont have any experience with turbocharged engines,this is not a great way to start.One bad tuning session or run through the gears with a lean condition, can cost you the engine.
A bone stock TII engine comes pretuned and ready to run 100K or more,already making 200HP.
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Old Apr 23, 2006 | 12:10 PM
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so how can i make enough horses to put them down
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Old Apr 23, 2006 | 02:21 PM
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If you don't go turbo, you can get your engine rebuilt with a port done. I don't know about the 6-ports much, but you should be able to port it quite a bit to make more power. If you do go turbo, then I suggest searching for a place to order an engine from and getting a TII engine like Steve is preaching.

You've already got the best model of the first gen, and either way its going to be at least a couple thousand dollars if you do it yourself. Why not do it the best you can? You can buy a TII from rotaryshack for 1,200 dollars if I recall correctly, and just by doing that you're looking at an engine better suited for boosted power.

Edit: This was my 300th post.
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Old Apr 23, 2006 | 03:41 PM
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You're gonna need more than 200 hp to run with the big boys.....

Kev (11.79 @ 114 mph with a relatively small/mild 350 (5.7) SBC)
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Old Apr 23, 2006 | 03:45 PM
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Porting an SE is kinda iffy.The 6 ports dont have a lot of extra port material to work with and since there are 6 ports already,there is lots of port volume in factory guise.Yes, its been done.......no,none have ever come close to making turbo-like torque.

You can increase topend power a bit with bolt ons and a streetport,but itll be at the expense of lowend torque,which is the SE's specialty.
Add to that,the fact that your wanting to race and defeat V-8 powered cars that make almost nothing but lowend torque and thats a good arguement to go turbo.Catching them at the end it cool,but getting royaly spanked off the line can be embarrassing.
Youll have to excuse me for being biased,but it comes from 5 continuous years of driving my turbo FB.......after 5 years of trying to make more power from N/A engines!

Novaboy,whats your car's weight?
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Old Apr 23, 2006 | 03:57 PM
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3360 lbs. No back seat, battery relocated to trunk, heavy pontiac wheels, sound system and 95% of interior intact. It's in transition from daily driver/drag car to strictly weekend warrior.

Kev
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Old Apr 23, 2006 | 06:26 PM
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Originally Posted by novaboy009
You're gonna need more than 200 hp to run with the big boys.....

Kev (11.79 @ 114 mph with a relatively small/mild 350 (5.7) SBC)
There is a dude in Jersy over on www.nopistons.com that ran a 11.5 with a bridgeported 13b that only put 230 to the wheels. that was with slicks though. and it was a street car full interior not his race car.
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Old Apr 23, 2006 | 08:38 PM
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I've put maybe 3 or 4 grand into the whole car. It's been a highschool/college budget driver/racer. I doubt you can get that kind of performance out of a rex with that kinda money.

Kev
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Old Apr 23, 2006 | 09:58 PM
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so if i get a fm system off ebay and upgrade the injecters and pump and do some tuning will it be alright
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Old Apr 23, 2006 | 10:07 PM
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You'll need that 200 HP to the wheels and then some to stay ahead of those V-8s.

Last edited by RacerX7fb; Apr 23, 2006 at 10:09 PM.
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Old Apr 24, 2006 | 06:31 AM
  #17  
rolfs_7's Avatar
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well im pretty sure im going to turbo that 6port how much hp will i be getting with an 8-10 psi turbo?? and if i do some weight reductions how will i stand??
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Old Apr 24, 2006 | 08:46 AM
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I was thinking about how I would go about turbocharging my RX7 (GSL-SE), if I ever got around to it. I have an older GReddy EManage piggy-back fuel computer that I used in my turbocharged Festiva. It has the ability to either retard or advance timing based on manifold pressure and engine speed (RPM). It also has the ability to run two additional injectors based on the same inputs. My idea was that I would use the computer to retard timing once the engine goes into boost. I would also use a FC upper intake manifold (if it bolts to the -SE lower intake manifold) and then install the two additional fuel injectors in their respective location in the UIM, then use the fuel computer to switch these on once the engine goes into boost. This is of course after supporting modifications had been taken care of, such as a higher flowing fuel pump, and two MSD boxes to increase the strength of the ignition system. Another idea I had was to run the auxillary actuators off manifold pressure, that way the engine would be relatively good on fuel when it was out of boost, and once it went into boost the aux ports open increasing the VE of the engine and ultimate power output.
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Old Apr 24, 2006 | 09:18 AM
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whoa. people are seriously over doing it. search around. alot of people have turbocharged the hell out of everything. there really isnt a lot in the way of "new" ideas. you do need to know what your doing in sense to properly turbocharge a N/A but its really not that bad. just use common sense.
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