OK.... first thankyou in advance.

I have a 1994 Rx7 with a single turbo conversion.

I went to go FINALLY have my RX7 tuned and the tuner told me that my motor had a S6 housing on the front and a S4 housing on the rear. He told me that my motor is UNtunable, because there is a timing variance between the spark plug position of a S4 vs. a S6. (apprx 8 degrees)

Is this true?

Am I going to have the tear out my whole install to rebiuld my motor with two S6 housings??

The setup I have is able to push 500Hp+, we were going to tune it to approx 440hp.

Thank you,

Please verify this and please send me your comments.

fulblown@gmail.com

 

he is right, they have different positions for the spark plugs that causes a difference in timing.

 

what about between S5 and S6?

 

I'm not sure if I buy it or not. The 3rd gen chassis requires the mounting members be on the rear iron housing. Those mounting positions are only on the 13BREW. Unless that 13BT (FC) rear iron housing was setup to run rear motor mounts (they are setup on the center/intermediate plate, instead), then I don't buy it.

Can you take a couple of snapshots of the driver's side of the engine and post them?

B

 

*Rotor*housing Brian...

 

That was awfully polite kevin, I was gonna do this instead:

 

I have seen the differences in plug position first-hand. Having rotor housings with two different plug positions does seem like it would make tuning pretty poor unless you had separate settings for each leading plug.

-Max

 

I must be a complete idiot! I didn't even notice it was about that. Is there an "I'm a moron" icon anywhere? :p

B

 

Hi Max,

Now that I'm on the right page here, I don't believe it's as detrimental as people say. I ran a mix of S4 and S5 housings on my old street-race motor several years ago unwittingly. I had no idea they had different, physical placements for the spark plugs. But, sure enough, as I later no ticed, they did. Problem was, at the time, I had already dyno'd over 420rwhp so it was pretty much a moot point. I believe the change was made between 88 and 89.

B