When rebuilding a 13B from an FD what are the best mods to do for a daily street driven/weekend raced FD motor?
(drag/track/autoX/freeway blasts/canyon carving)

Street port?
Intake/Exhaust port and polish?
Dowling the block?
Port coolant passages?
2mm ( ) apex seals but what material?
Any rotor mods?
Oil passage mods?

Thanks for any input.
Personal experiance would be phenominal and any information about bad mods would be amazing as well.

SF

 

- Definitely get a street port. You make so much more power at 7000+ RPM it feels great.

- Port-match the UIM/LIM/block.

- Dowel pins are said to only be needed for really big power, but I wish I had pinned my motor anyway. Even if you aren't going for big power, this might be worth doing if you can get it done well for a reasonable amount of money

- Get your exhaust manifolding, LIM and UIM ceramic-coated to reduce heat transfer to the engine bay and intake air.

- Get the cooling passages modified (they cut grooves into the walls of the water jacket to increase surface area).

- Stock, 3-piece, 2mm apex seals.

- Get the rotors lightened (and the assembly balanced) if you have a money tree in your yard.

- I don't know what they do to the oil passages, but it sounds like a good idea if your engine builder offers it.

-Max

 

eeeeerrrrr.......
LIM and UIM?

Thanks for the input.

SF

 

LIM = Lower Intake Manifold
UIM = Upper Intake Manifold

-Max

 

And the obvious:

hose job
test solinoids
test injectors & fuel pressure regulator
all new coolant lines/hoses

 

I agree with almost everything but the dowel pins..and the oil passages..
1) Not even close to needing dowel pins (hp)
2) Oil passages are well done by madza from the factory especially for the power you will make with the twins.
3) Coolant grooves can help if you road race the car..The wall is actually thinner in this area from mazda..They improved this over the years.

 

Who said anything about stock twins?


Depending on funding I may be adding a GT35/40 turbo kit at the same time as the rebuild.

SF

 

i got the water passage port, and if i could do it again i would get a wilder street port. My car isn't going to pass smog anyways. when i finally get the money for a single turbo, im going to get my upper and lower intake manifold extruded hone.

-andrew-

 

If your new to your car, i would not recommend going single so fast, the stock car has enough power as it is. I would learn how to drive it before doing all that stuff at once. But if you've had your car and your just new to the forum, i would like to say welcome first of all. Secondly All the things stated above sound good, but if your gonig with a single and all of that i would think about doing a lot of things while the engine is out. A lot of parts are easier to install while the engine is out.

 

Scrub -
I WILL be new to the RX-7 and going single right-off-the-bat is a concern but I figure I can just start at like 6psi and gradually increase boost as I tune the car. IF I go single I will also add a standalone managment.

My tentetive plan is to grab a car cheap with a blown motor and have it rebuilt. This way I can get all the engine mods and have a known engine condition rather than be continually guessing if it will pop on the next hard drive. Basically if the stock twins are shot and I need turbos i will skip out and grab a single kit.

Can the stock computer handle a ported engine ?

SF

 

one thing to also think about, since you have autox listed, is what mods will put you into what class. not sure how important that is to you, but i thought i'd mention it.

 

I would install a thermal pellet to get rid of the oil thermostat. Do a search in general rotory tech with thermal pellet to show you how to replace or bypass the oil thermostat. If you can't find it I will post a link later. Jeff

 

I would not recommend the stock ECU for a ported engine. Either get a reprogramed one ex. M2 or a stand alone. I would do stand alone. That is a good idea to generally increase the boost, and start off low.

 

Heh, there is no way in hell you will keep the boost down to 6psi for longer then a week when you know you have 385rwhp on tap at 15psi. Temptation is the devil!!

 

Thermal pellet is a good tip. You can also use an older eccentric shaft (much cheaper and no pellet if you need a new one anyway). I don't see any problem with going single as long as you have the supporting engine management bits (programmable ECU, fuel pump, injectors). No sense running 6 psi. Get a wastegate with a 12 psi spring and start there.

-Max

 

Will it still pass CA smog with porting?

Patrick

 

Dosen't matter.
I have the "hook-up" on SMOG testing. Besides I bet if I run a high flow cat and tune well enough I could pass the dyno test, its the visual that I could not get through.


Thanks so much for all the input on this subject. I have picked up a few things do do that I did not find in my own searches.
Lastly, does anyone have any particular links or threads that they feel are relevant to this?

SF

 

Shane racing says they have a epa friendly port. At least thats what he said in sport compact car.My friend pass ca smog inspection with a pretty big street port on a na fc and the engine wasnt even broken in. So its possible.

 

Porting/nonporting is really up to you... ever gonna stock the car out and sell it? Might not wanna port if so... but its NICE.

Oil/coolant passage porting isn't a bad idea either.

Definately do the thermal pellet.

The big thing nobody's mentioned... blow the 80 bucks and get the upgraded water o-rings.... Mazda SHOULD have made them OE.

 

hey
i want some of those but never have the time or the memory to find out about them. help me out with the upgraded teflon water seal thingies: where can i get 'em
thanks

 

You're gonna do all this stuff to your car right when you get it? Have you been autoxing for a while or something? If you have, that's cool and go for it, but if you're just thinking about doing this to have the fastest car on the street, its deffinitely a no-no. Just read all the stuff that Max puts up. He's the racer to listen to. The only other thing I could think of was get a set of pulleys and remembering the cooling stuff- radiator and extra oil cooling capacities. Just remember that you can't use any of that power unless you have the suspension and drivetrain to handle it.