I have a 3rd gen FD wanting to know what the stock motor 13BT and trans will hold hp wise before having to upgrade internals. did some looking but no definite answers.

 

Welcome to forum. That will depend on how many miles and condition of your motor . Your best bet is to rebuild it before it breaks is sooo much cheaper to fix before it dies

 

im rebuilding the stock motor but I want to try to get 400-450hp so I was wanting to know will the stock internals will hold that kind of power or do I need to upgrade the internals

 

It will deppend on the tune, but I would swap apex seals for something else.

 

If you are rebuilding motor best to upgrade the apex seals and corner seals as well

 

Any brands that you would recommend?

 

I have eard good things about Rx7 parts Apex seals and Goopy.
I use super seals, but some people said its very harsh on the rotor housings.

 

I just want to make sure that I’m making 400 to 450 horse power safely. Last thing I wanna do is build something then break it

 

Look into I rotary seals

 

There is a solid difference between making 400-450whp horsepower a couple times, and making that amount continuously and safely. That difference is easily going to run at least $10k-$20k if done right.

What is your budget like for the build? Getting that kind of power reliably isn't as simple as throwing on a turbo and intercooler...

I'm not saying this to be rude, but rather to point out that a build like that isn't achieved by just upgrading the apex seals and cranking up the boost.

 

Check this out for some decent background info: https://www.rx7club.com/3rd-generati...0/#post8003838

Additionally, the tranny itself can have issues at higher hp/tq levels when it's under load at high rpms. Essentially the transmission's main shaft will flex in the middle and cause issues where it meets 3rd gear. This can absolutely chew through trannies and the fix is a rebuild and upgraded main shaft. Liberty Gears can perform this service and their rebuild prices will be different based on what you want done and the condition of the donor unit.

 

are you using the 2mm super seals or 3mm? How much power are you pushing?

 

I am using 2 mm. Power wise is 393 whp at 13 psi on dyno dynimics. Most aftermarkets apex seal can handle double what i am making, including super seals. I am pre mixing a 1.3 ounce per galon. I will use water injection though just for safety. I have a large street port too. I believe if you tuner does a good tune and you have good lube to a good iengine built, it will last a long time, more than 40k miles.

 

3mm seals are an old-school option, there's no good reason to go that route any more. It's a bitch to machine rotors to take 3mm seals and that process usually causes more problems.

With modern aftermarket apex seals people are pushing big power levels (600+) on 2mm seals. Using good seals, a good tune, and water/meth injection is the secret there.

Dale

 

Not sure this whole rotary thing is going to work out for you.

 

The reason to use stock 3mm seals is you gain strength over the 2mm seals, but retain the factory seal hardness that will be kind on the housings so they *could* last 200,000miles if nothing catastrophic happens before then. The old 3mm steel seal rotaries were infact the longest lasting in terms of mileage.

I used factory 3mm seals after trying aftetmarket 3mm and 2mm seals (which destroyed rotor housings in very low mileage.)

From my experience the factory 3mm are strong enough that detonation will crack side housings, dent 9.0:1 rotors, break corner and side seals and wear the engine/apex seals funny from overheating in the combustion chamber area before they break.

The weakness of 3mm seals is you want to keep them under 8,000rpm- which is fine for most turbo set-ups.

Even the producer of i-rotary seals says they are a compromised in regards to long term housing wear in order to be stronger like all the tough aftermarket seals.

If I was looking for a stronger 2mm seal I would try the i-rotary seals though. Endorsed and sold by Mazdamotorsports is good enough for me to try them despite my bad experiences with aftermarket seals in the past.

 

I push 425rwhp with 2mm oem mazda apex seals with n.p. With that said I also premix 1once per every 2 gallons of fuel. I also add 10 onces of 112 octane racing gas per gallon of fuel. The motor is studded, 044 bosch fuel pump, microtech ecu, custom fuel rails and bigger fuel injectors just to name a few mods to support that power level. It gets expensive but once you have a good engine builder and a good tuner it's one hell of a car. I also suggest to use the same engine builder for tuning. Use the ecu that your engine builder feels comfortable with. For me a reliable setup is the best setup. There are many great builds on this forum to help you out including mine

 

could you point out where it says the “I-rotary” apex seals is endorsed by mazdaspeed ?

to my understanding the “I” stands for “Ianneti“...

 

They sell them and gave them a mazda part #.

 

With water injection pretty much solving the high boost detonation problem, the stock seals work fine, imho. I use Goody 2mm seals and am a true believer.