gear_grinder

iTrader: (4)

I was wondering if you could swap the front cover from a 13bREW on to a 13bt engine so that i could use the REW crank sensor system rather than the 13bt. i'm sure that it is more accurate and less prone to user error seeing that you dont need to "time" the sensor.

EB Turbo

iTrader: (1)

Both options have the same trigger pattern. When installing a standalone you should always confirm the ignition timing. With the FD the offset will have to happen with the ECU. With the S4/S5 CAS you can move the CAS or offset with the ECU. Unless you are worried about the CAS moving, Which it wont unless it is user error, there is no benefit to using the CAS over the wheel and sensors of the REW. Depending on your ECU you may take advantage of upgrading to a higher resolution wheel with the option of going to a hall effect sensor. You can do this while retaining the S4/S5 front cover.

EB Turbo

gear_grinder

iTrader: (4)

more to the point i'm trying to make is that you wont have to trust the accuracy of the timing marks of the stock crank pulley on the s4/5 to time the sensor correctly.

EB Turbo

iTrader: (1)

You are still gonna have to trust the timing marks on the FD wheel...

EB Turbo

gear_grinder

iTrader: (4)

do you mean the accuracy of the inductance ring?

EB Turbo

iTrader: (1)

The accuracy of the timing mark. The mark on the FD wheel is -20 ATDC. On both FC and FD there is a little bit of slop in the wheel. You will have the same timing concerns with the FD wheel as you have with the FC CAS. The FC cas is probably easier to work with.

What engine management are you running?

EB Turbo

John Huijben

iTrader: (1)

I found that the FD timing mark isn't always perfect, it can be off by a few degrees. Most people use it though, because finding TDC with a rotary is tricky. I found a way to do it though, I machined a bushing that screws into one of the sparkplug holes that has a nipple attached to it where a 6mm transparant tube fits onto. You can probably also take an old sparkplug, knock the center out of there and use that, the point is connecting an transparant tube to one of the sparkplug holes of the #1 rotor. When you've got that move the e-shaft around untill the marking holes line up, this doesn't need to be accurate, it's just to get the rotor near TDC. Then take a small funnel and pour 2-stroke oil in the transparant tube, this may take a while but it should go in, rotating the e-shaft back and forth helps. After a while the combustion chamber should be filled with oil, and there should be some oil visible in the transparant tube. Now take a big socket wrench, put it on the front bolt, rotate the e-shaft counter-clockwise untill the oil level in the tube has dropped a bit, then turn the e-shaft clockwise very slowly, and stop when the oil level in the tube stops rising and starts falling. Add marks to the triggerwheel, and check the mark a couple of times. When your confident that the mark is OK remove the tube and plug, and manually rotate the e-shaft a few times with one of the sparkplugs removed to clear all the oil out. This is important! You don't want the engine to hydrolock at the first startup.

This method of finding TDC works very well for me, although it takes a while to get most of the air out of the combustion chamber to get a good reading. When you have an accurate TDC mark the rest is easy, start up the car, fix the timing at 0 degrees advance and check the timing using a simple timing light. The engine won't like running with 0 degrees advance so it will bog down a bit, but it should run if you use a little bit of throttle. Don't use one of those complicated timing lights that let you set advance degrees, they don't work well with rotaries. Oh, and check if the ignition timing is stable by revving the car while looking at the TDC marks with the timing light after you've set the base timing.