well mainly FMIC to V mount setup, new ecu, aem smart coils instead of stock with fc1000 amp and FFE trigger kit and dual oil coolers instead of stock one.

 

dat 3 rotor

sweet jesus

 

updates marco?

 

I'm going to start porting it next week. I'm doing a custom monster streetport on it . Finally decided on the port timing I want.

Little teaser of the primary port... I might end up rounding the bottom part, haven't decided.



thewird

 

Looking good..... Can't wait to see it on the track, should be lots of fast RX7's this year . Good luck with the build.

 

Thanks Jim, you better keep up old man or I'm going to get bored

thewird

 

Not enough torque to keep up with that engine .....soooo you better kick my *** , fun will be had..... with that said it's not me you should be focusing on

 

Mr. Kimi and Sasha are too serious to have fun with. I just need to beat their times, not have fun with them LOL. Maybe you could lend me your wing one day

thewird

 

Can't wait. Still will be sporting my stock FC unless Marco buys be an EMS for Christmas. Lol

 

This isn't meant as a criticism, but why are you porting down? It doesn't net you any port timing/duration, and only increases the bowl volume which will only slow the charge down even more than it already is, right before entering the chamber.

It's not like it's the limiting factor, since it's larger than the runner stock. I believe you'd net more torque without it.

 

Because we're not talking about static ports, the intake port shape changes throughout the intake cycle. By having it pulled down further allows for more intake volume when the port opens and by the time its fully open, that bottom part starts (or is already) closing. Trying to optimize flow in the short period the port is fully open wouldn't be ideal in my opinion. I think given a set amount of port timing, having it pulled down wouldn't have any negative effects, only positives. If I get bored enough I'll make a video of the intake cycle with the port. Of course this is theory and I'm sure everyone has their own opinions. If I ever get a dyno, I will probably test different port designs on a test car to turn theory into fact.

But some side notes... the cosmo intake runners are pulled down a lot more and are fed by a much larger intake tube then any other motor. Also, I've decided my goal with this motor is for top-end which is why I decided to do radical porting. Too much torque would just make me spin tires coming out of corners which is wasting time. Also, don't use that picture as reference as that is an REW iron, the cosmo stock port is even smaller.

thewird

 

Ok, but how long is the port ~3/4 or greater open for vs the short amount of time that it is just opening though? I think it's the opposite, trying to optimize the short period of port opening wouldn't be ideal.


The best testing for port design is on N/A's, because everything is applicable to turbo engines, but without the aid of FI to change torque figures. The highest-powered streetport 13B that I've seen on here was Defined's, using 13B-RE irons. His design did not port anything down, I would have to say that that agrees with my thought on it. Remember the Venturi effect, when cross-sectional area increases, flow speed decreases. It's your engine, I'm just trying to be helpful, tell me if I'm out of line.

I hear you, but I really don't see un-necessarily increasing the surface area of the port giving you any top end, let alone any benefit. Like I said, the restriction for the charge is not the port face, it's the runner, no matter which runner it is. Lynn Hanover has many posts on the topic over on the n0pistons forum.

Man, for all out you should totally go semi-pp. I've always dreamed of doing a semi-pp turbo 20B, but the block I picked up from Joe Ferguson is already bridged in the thick iron, and I'm torn now. I swear there would be no better sound in a turbo engine...

 

I don't mind it but I think a discussion over port designs wouldn't lead to anything productive without actually testing with an identical setup on the same dyno to compare torque curves. I've always found Defined's dyno's to be on the high-end. The 500 rwhp GT35R @ 16 PSi on pump gas comes to mind. Not to say its wrong, some dyno's read high and some read low. So without comparing apples to apples, your never really getting the true story.

I see that area as useful space so I will use it but maybe I will curve it instead. Will really come down to when I actually do it and see how the runner leads up to it. I'll post pics for those that are interested.

I thought about Semi-pp but I don't think its right for me. Besides I can always do it later when I get a tranny. You know most of the semi-pp drag cars have bridge + semi-pp right. I would still do it if you want it that bad

thewird

 

Nice work Marco!! cant wait to see/hear the sound and motor run! love this build thread! Keep up the awesome work

JDK Hopefully my fc is fast for next season 400+whp should be alright i guess O,o!! to keep up with some higher horse power cars!!! for sure i cant keep up with you guys on the straight but maybe in the turns i mght have some luck!

Best regards Pat

 

lol, I haven't done anything particularly awesome yet but thanks hehe. I just wanna get this thing making some noise.

thewird

 

Heh!..Hey Marco!
This thread is getting more movement than the actual engine!!
My dream Christmas present is Twins.
Not turbos..2 blonds!

 

Ok, so I finally scribed my timing onto my 20b irons. However I can't decide to curve the bottom part or not. I included the difference in the picture, open to suggestions/opinions haha. Now for the secondary port, pretty much finalized, however I'm debating an extra mm of opening timing. I then moved to the exhaust ports and then pretty much said **** this because I still haven't decided if I'm going to do square or curved ports.

Building something for yourself is so much more complicated because you get so picky, jesus LOL.




thewird

 

Hey, do you have a cut open rotor to scribe the side seal tracks? What I did for my last streetport porting template was to scribe the leading and trailing tracks of the side seal onto the template itself, and then ported as far open as possible leaving 1mm or less for the leading edge of the side seal to ride on for both primary and secondary. The trailing sideseal edge just drops in to the port regardless, and as long as you have a bevel and/or a steep enough angle on the closing face of the port to allow the side seal to "scissor" back onto the iron, you're good to go.

Now, when it comes to streetports, you really can't open them too early IMO. Earlier opening really doesn't affect drivability much/at all, and you actually gain torque, or at the very least lose none in the whole RPM range. The closing edge has more effect on drivability and the shape of the power curve in general.

You already know how I feel about the bottom of the port. lol

 

I have a template that is made all the way to the side seal track. That is why I say I can go another mm which means more intake/exhaust overlap. Drivability/idle is not a concern with this engine. It needs to work 5k-8.5k, the rest I do not care about. I do believe that more opening reduces torque though which is why I'm debating just how much mid I want to sacrifice for more top.

thewird

 

Very well thought of design and mods, looking forward to hearing about the completed project.... Best of luck.

 

I say, leave a mm of meat on those ports for now. And don't take too much off the bottom either. Because, once it's gone, it's gone for ever.

Once the 20B is put together and you run it hard for a while, it will eventually need a re-build. Then you will have an opportunity to re-size the ports.

Don't over do it (all at once).

 

^^^^Sounds like a wise idea but im no engine builder/tuner

 

Mr. Trots*88TII-AE*, what do you think about this... Rough cut with a shitty picture LOL. I think I might try this since I never did before. I freehand ported it down to the runner.



thewird

 

those are my pineapple racing templates, they have it sloped more to the bottom inner corner like you were planning.
the pics are of my s5 ports but i did the same on my fd.
ran 11.42@122mph with thoe ports and a S5 hybrid turbo

 

The pineapple medium port timing is targeted more for the midrange. They don't add a lot of closing timing. I'm targetting my powerband 5-8.5k which is why I went aggressive on the closing side. The bottom part of the port is just more volume and Trots has me second guessing myself on that part LOL.

thewird