i'm rebuilding and street porting my s4 turbo motor this winter, and a couple things were going through my mind. i noticed that atkins rotary sells an rx8 eccentric shaft that will fit all 13b's. is the weight savings worth the 200 bucks extra to get one?

On the same topic (i've only had my car since spring, and done know everything yet) will fd rotors fit my s4 setup? i've noticed that are a bit lighter. and do they come with 3mm apex seals? and if they do fit, what can i expect to pay for them?

I will port my wastegate while i have the turbo off, while i'm working on that area, will it be worth it for me to remove the twin scroll flapper on my manifold?

I've noticed that most of the well built 13b's no longer have the huge complicated factory vaccum rack, what do i replace that with?

block off plates are offered for almost everything on my intake manifold, what things should i remove and block off? does the emissions stuff even work? if some of these things are necisary but can be replaced, what should i replace them with?

i'm planning on going with an rtek 2.0, and a new fuel pump.

i've got an exhaust and k&n cone filter, just to let you guys know that i have those couple small things done already.

anything else i should be thinking about besides the obvious replacement of all my hoses and a completely rebuild kit. i'm looking at an atkins master rebuild kit is this a good choice? it seems to have most of the gaskets and seals that i will need. any other recomendations? i'm trying to make a list of things that i want to get or do while it's apart so i will have a good solid car when i'm done.

besides the engine i was thinking about replaceing my suspension bushings with polyurithane bushings. i want to replace my suspension but that will be on my to do list after the car is back together.

thanks for the advice guys, just trying to get as much knowledge as possible. if any of the topics i've mensioned are in previous threads please let me know and i'll search them out.

Thanks, Andy.

 

Don't worry about the e-shaft unless your building a serious engine and a purpose built car. Its nothing you'll notice on the street. ( i didn't)

 

I don't know how much the RX-8 shaft weighs, but if it's more than a pound, I would consider that rather significant. The FD should work, too. It's up to you to decide if the minimal weight difference will be worth the cost.

However, I'd advise against 3mm seals. There's simply no reason to switch to them. They don't work as well as the factory Mazda 2mm seals.

 

I'm running OEM 3mm seals in my FD...i believe its only 1/2 lbs diff between the Renesis shaft and FD's. I couldn't really tell any differance in performance.

With 3mm seals it provides a bit more surviavability to detonation.

 

yeah, thats the weight diference that atkins lists.
any idea on the fd rotors compatibility with my s4 motor?

this evening i tested my compression. i got about 95 psi on each rotor. the body of the car has about 175k on it. the kid i bought the car from didnt know weather the engine has ever been rebuilt or not. judging by the condition the metal oil and vaccuum lines were in, i'd say it hasnt been rebuilt.
since the compression is good should i rebuild it yet?
i had expected worse results.
any ideas?

 

I popped an s4 TII motor that had 180,000km on it. I had compression tested it about 250 km before it blew and i get 95psi on the front rotor and 90psi on the back.

 

alright, thats what i was wondering. thanks, time to start disassembly. haha.

gotta rebuild while everything is still in decent shape!

 

If the car is tuned properly it shouldn't detonate....

Dont use 3mm seals. 2mm work perfectly fine.

 

sounds good to me, but are fd rotors an advantage anyway? and will they work in my s4 motor?

 

Well, they are 9:1 CR so you'd have to account for that. Provided the tuning is spot on, you'll be able to make a bit more power with the slightly higher CR.

As far as them working in an S4, I've never heard any reasons why they wouldn't work. They are basically the same thing (unlike the Renesis rotors which must be machined to use the older apex seals).

 

and answers on the block off plates and emissions removal? or vacuum rack?