Any ideas as to what my base timing should be for a 91 turbo motor with a Pineapple Racing Medium Streetport?

 

OR.... you could use the original pulley and hub from the engine (don't mismatch them, otherwise get a new pulley from Mazda), where the timing marks are made from the factory by a precise machine. Follow the CAS installation procedure in the FSM, and verify the timing with a timing light. Then adjust the ignition advance at particular boost levels with an aftermarket ECU.

There is no substitute for accurate OEM timing marks IMO, only "good enough" solutions which I feel are inappropriate on turbo cars.

 

Thank you for your posts. I guess you miss understood me and I probably worded it weird. When I built the motor I installed the cas exactly how the fsm states BUT I am curious if I should be looking to adjust the cas in the retarded or advanced direction for better power. It still has the stock turbo and boost.

 

You're driving a turbo car. #1 priority is don't blow the ****** up. You're better off keeping it installed in the stock way. Then get the Rtek chip for the s5 cars and you will have safer timing for higher boost levels.

 

My thoughts exactly. Playing with the CAS is a great way to blow it up.

 

So keep the CAS dead center of the adjustment range?

 

Keep it stock.

 

There is no center. Adjustment requires removal of the CAS and lining up the marks on the gear and body.

 

To the OP: this thread (http://forum.teamfc3s.org/showthread.php?t=41915) will be helpful in getting an understanding of tuning ignition timing. It looks like some of the well-known turners prefer to retard timing on ported engines. And that's not by playing with the CAS; it's done with a standalone EMS.

I hardly know where to begin. I hope you're trolling, because everything you just said is B.S... The spacer only sets shaft endplay. It has nothing to do with how the CAS gear meshes with the gear on the e-shaft. If it did, the CAS would no longer give the ECU proper timing information & the engine would blow due to spark occurring randomly in the stroke.

The O2 sensor measures percentage of oxygen in the EXHAUST. Sticking it in the intake path would be telling the ECU that the engine is running insanely lean because INTAKE air is 21% oxygen! This could make the ECU dump MORE fuel in whenever it switches into closed loop (cruising) to try to achieve a 14.7:1 ratio. Your fuel economy will get WORSE, and that's if the sensor even works at those low temps. If it doesn't work, economy still gets worse due to no functional O2 feedback. Do you think the O2 sensor is actually used under load conditions? It's not. And that crap about allowing the AFM to not "work as hard" is ridiculous. The AFMs use a door or a cone w/ a spring. How can they "work hard"? Engine vacuum does all the work.

Then we have the idea that switching around four injectors of the EXACT SAME SIZE will have some effect on fuel. Do you really believe this? It won't do a damn thing to smooth out the lean spot before the 3800 RPM transition. And even if you do add more fuel there (by tuning), it's done to make the AFRs safer, which actually means slightly LESS power. More fuel does not equal instant nitrous. That's probably the dumbest thing I've read on here in a long time.

Lastly, rotating the CAS to advance timing 2-4* under every condition on a turbo engine is NOT a good idea. 4* of advance on the stock map, with stock fuel will blow the engine. You can get away with some advance on an NA, but a turbo will not react well. The stock turbo timing map is already on the aggressive side.

 

this is what I mean by center...



Where should this adjustment be set at then?

oh and the O2 sensor idea is one of the dumbest things I have ever heard.

 

That nut is mainly there to lock the CAS in place. Aligning it properly requires removing it and restabbing with the gear and front pulley aligned properly. This thread might help: https://www.rx7club.com/showthread.p...t=stabbing+CAS. There will also be info in the FSM or a haynes manual.

 

I understand that, but after I stab it I should NOT rotate the CAS for fine adjustment then? That is all I am trying to get at.

Thank you all for taking your time and replying, it is helping me out tremendously.

 

NO, NO NO, NO, NO, NO and NO!

Set the location of the CAS as per the instructions in the FSM. Stab it, place it in the middle, then start and warm up the engine. With it idling under 1000 RPM and the initial set coupler jumped, hook up a timing light to one of the leading wires and then adjust the position of the CAS until the LEADING MARK on the pully lines up with the pointer. Lock it down.

Any further timing adjustments get done in the ECU.

I am deleting the posts from blackrotary23 because they are wrong, don't make any sense, and are dangerous.

 

I've gotten dumber reading blackrotary23 post.

 

This thread is amazing, lol.

 

Thank you! this is exactly what I was looking for.

 

From the factory, the pulley and the hub for the eshaft were meant to be matched together or the timing marks will not be correct. So don't use a pulley from one engine and a hub from the other. I ended up buying a new OEM pulley/hub combo from Ray Crowe at Malloy Mazda for about $190. For a high horsepower turbo build, I just needed the peace of mind.