gorockrx

Does anyone have a 87 or 88 Turbo with the dual scroll actuator removed? I think the 89 to 91's don't even have one so I don't see the need for it with my mods. I just son't want to run into a problem if I remove it. I may just get an 89 to 91 turbo and manifold instead, but does anyone have experience with this? Thanks,
Greg

Keith

Well, Foo-ey on you! I love my FC!
Seriously, the valve redirects exhaust gasses at low velocity (low rpm) to achieve quicker spool-up of the turbo. The reason this was not included on '89 or later models of the FC was because the turbo was connected directly to the exhaust outlet of 1 rotor, instead of the combination of the exhaust of both rotors, making the turbo more responsive.

OK, if you want to try to see how everything will work without this valve, simply disconnect the electrical connector going to the twin-scroll turbocharger solenoid valve (1st solenoid toward radiator, the connector is green, I think). You will then run with the valve always off. Have fun!

Irv, Keith's dad

Turbo FB.

Ok here we go the 87'-88' dual scroll is located in the manifold. 89'-91' symilar system is built into the turbo.
I myself like the system it works well in my girls car, as far as my car goes I have removed it due to a 12lb flywheel Its no longer needed.
If you want to remove it well its a pain well more time consuming than anything, and its not worth that much HP. and youll increase
Turbo Lag and buy simply disconecting it all youll have is a big chung of meteal abstructing exuast flo youll need to grind it out to be of any performance gain.

HN

this is how to remove it. you pull the turbo off the car take and unbolt the scroll. the little door that is left in the manifold is the flapper they are talking about. take some vise grips and bend the door back and forth till you break it out. go get the little hole welded at some muffler shop or wherever. Now for me i did not notice any difference at all. At that time i had a single n1, straight pipe, dp and fcd. i noticed more gain once i ported the turbo runners. i was kind of doing my own R&D testing one mod at a time. if you are going to do that mod might as well port the turbo runners. go to www.k2rd.com if you need to see what i mean. later.

gorockrx

Thanks for the replies. Believe me, after 8 RX7's I fully understand how it operates and why , but since I have my car already torn down to the block, I started to do some mods and so far this is the only solenoid that I have left that is still being used.
I have never removed this actuator before, but I have seen the mod on a web page somewhere, but I can't find it and now I am ready to reinstall my manifold, but I am wondering if this will be beneficial or not. I figure that if I port the 87 turbo manifold and the exhaust manifold to match and remove the arm and flapper that I will increase the turbo lag, but my powerband should move a bit higher up. That is what I am trying to do. I know the low end will suffer due to the low velocity of the exhaughst gasses at low rpm. The Mazda engineers designed it that way, but if I am going to get max power from my setup without buying another turbo then I figure this may get me a few horses.
By the way, the actuator is kinda slow and may be ready to quit on me and that is another reason I want to do the mod, but I would like to hear from someone who has actually done the mod to their car.
Is there anyone out there who has done this mod? Give me some more pro's and con's.

Maybe I should leave it as is? Let me know. Thanks,
Greg

HN

ive done it. get rid of it. and port that turbo. i did not notice any difference with either in the lag department.

gorockrx

How much difference after porting the runners? I can port them today if it's worth it. I know how to port them, but will it make the lag really bad, especially from a stop? This may put me out of ASP cateragory in autox too, so I want to know if there are any others out there who have this mod.

I am also match-porting the intake runners and doing the TB mod and coolant bypass and maybe an electric fan...Lots of work to do! Thanks for the reply HN.

Anybody else done the mod?

gorockrx

Well,
I have decided to go with a better turbo. SO.....Nevermind....