I am working on a 88 13B 6-port motor to run nitrous.. looking for some advice
want to be able to hit a 125 IF its safe on a street port for the 6-port motor. Staying with the stock fuel setup if I can and get a pump and fpr.

Need some advice on going direct port into the mid intake manifold or if there is a better spot.

Anyone running a shot this big on a street port?

Already have energy suspension bushings, stage 3 clutch, pretty much ready to go. I'm rebuilding a 13b right now for nitrous, dont want to miss anything before I put it together.

 

Be sure to use the most quality internal parts for that big of a shot. FD corner seals, RA apex seals, OEM apex springs. As for the nitrous direct shot into manifold, I know a lot of people do methanol / water injection into their manifolds, search up on that for info.

 

I'm gonna jump out on a limb and say that a 125 shot equals BOOM ...of course I am jumping out on a limb

Seriously though, that is too much for the motor. A v8 on the other will love you for it.

 

Yeah, i think thats a little too big of a shot. If nothing else, youll prob blow the tranny.

 

Did you just recommend RA apex seals for the best quality internal parts??


For the love of anything....
No. Use mazda OEM.

 

I seem to remember reading somewhere that RA seals resist detonation better that OEM seals. Somehting about how they just bend and dont shatter.

 

The branch broke. You fell.

Not too much at all. If anything, not enough.

 

They do.

But if you detonate on nitrous, it doesn't matter what apex seals you run... you're going to take out the iron/corner seal/side seal anyway. Best bet is to tune properly and avoid detonation completely.

The Mazda seals are the best apex seals for street use. They are hard enough not to wear out too quickly (electron beam hardening on the contact edge) and soft enough not to chew out the rotor seal grooves.
RA seals cannot say this. They chew up rotor housing and rotor grooves.

 

I have seen discussions about this and the general concensus(sp) I'd seen was that 75-100 was the most you should run. Now, if you build the motor up with high quality parts like you would for a high boost engine, it can take a larger shot. You would most likely need to get a T-II tranny if you plan on using that large of a shot much at all. Nitrous adds a sudden increase in power that jars the tranny, and the NA tranny can't take many sudden jolts from high torque engines.

 

I thought that was due to faulty RA springs. Or was that something else?

 

I thought there was a batch made too hard, that ate housings, as well as grooves, and that they don't wear the housings like they used to.

 

Alright. Here's advice straight from someone who has actually run nitrous shots that high... and higher. Ignore everyone else who has no experience.

Let's start with the block. All stock internals is great for nitrous. Run all of the mazda seals, including apex. Don't bother with the aftermarket seals, they'll only give you problems.
Porting: Don't touch the intake timing. Leave it at the stock 32 degrees. Close as late as you want.
Intake: Remove the auxilary port actuators and the sleeves. Weld the holes closed and grind smooth.
Oiling: TII oil pump and FD oil pump regulator. You'll want the extra oil pressure.
Fuelling: At least an aftermarket FPR and a high volume fuel pump. I would also add a fuel pressure gauge, at least for initial system testing.
Nitrous system: You can get away with a single fogger... but you're better off with direct port. Put the foggers in the straightest run of manifold possible.... the intermediate manifold is a great location for this. For direct port... you only really need two foggers. One in each secondary runner will be fine.
Timing: stock ECU should be running 5 degrees retarded off optimum at WOT already... conveniently, you need 5 degrees of retard at a 125hp shot. But, for safeties sake... retard 2 more degrees with your initial setting. You won't notice any change under normal driving conditions. If you're running an aftermarket ECU... even better.
Plugs/ wires: stock is fine.
Tuning: Aim for 12:1 AFR's. EGT's depend on where the sensor is.
Engage above 4000, shut off BEFORE THE REV LIMITER.
Nitrous system: I use NX and NOS brands pretty much exclusively. Run a bottle heater and a nitrous pressure gauge... you'll need them to tune. Purge valve would also be a good idea.
Hope you've got traction... or this is going to be a 4th-gear only setup.


You'll like it.

 

Engine, all stock, will support hundreds of horsepower. What exactly do you think there is to upgrade? 300+ shots aren't out of the question... its merely a matter of what you bolt onto the block.

 

I think maybe he read that the most you could run was 75-100 without additional timing retardation. that possible?

 

https://www.rx7club.com/rotary-car-performance-77/rotary-aviation-apex-seal-report-397712/

Nope.

 

I must give props to Scathcart. There is nothing worse that a bunch of opinions that haven't done it.Some people around here seem to think that hearsay is the same as fact. Thanks for informantion based on TRUE LIFE exsperices, It is a nice change to hear FACTS instead of opinions!!! Anyone else actually done this themself? A+ for bringing the true out. IMO people should never begin a post with " I thought" WTF kind of help is that?!

 

So some racing beat block off plates for egr, acv, and csv pull the valves, street port, and direct port injection, a summit racing rpm activated switch (for activating nitrous) and a boost timing master at -2 or -3 degrees, with a racing beat street/race from the manifold back (the one thats still a y pipe)

 

you have to retard timing on both leading and trailing coils. if you plan to run more than 75 shot.

 

Do I need 2 in this case, one for each rotor?

 

since im pulling the valves, I could grind the 2 ports on the manifold to rotor housing (Both sides) and on the rotor housing, grind off the space between the valve intake and regular intake rotor housing myself? leaving a giant port.

 

Why don't you just DO IT and stop whining about everyone else?
At the same time, why don't you just suck scathcart's...


-Ted