Example...

I have an 89 S5 TII, when I had the motor rebuilt the first time, the rear rotor housing was shot.

It was replaced with a S4 NA Housing with the exhaust sleeves pulled.

My question is, after reading up on this subject, it is my understanding that the plug timing is different between my two housings as S4 NA is different than S5 TII housings.

Does this make a difference at all? Or do I have nothing to worry about. I'm running a Haltech E8, and makes me think that the plug timing will play a part somehow...due to the plug firing at a different point on the rotor face.

Any opinions or answers?

 

I have made this mistake before also. My car ran fine though. But when i had an oil leak at the dowel pin, i did open the motor and replaced it with a matching housing.

IMO, you should match the housings up. Even though my car ran fine, just piece of mind for me, and you know how touchy timing is.

 

Right, I agree that timing plays a VERY important role within our motors. Especially when more and more power is added into the equation.

Logically, it makes sense to think that the timing differences between the plug locations would eventually have an impact. Whether that impact is big enough to worry about is beyond me, I'm not an expert.

But thinking about it tells me the charge would be ignited at a different time, thus not being the optimal situation.