Every replaced engine that goes back to Mazda is disassembled and if possible rebuilt. This is what I am referring to. When they pull the engine apart, they'll see if something has been done. Obviously his engine has to be replaced to do this. If he ever blows it up and has it covered under warranty, Mazda will see whatever was done to the inside.

 

yeah but he would be aware of this. I doubt he would send it back under those conditions

 

Here's a clue, do some reasearch: look at some dynos from RX7 Club, look at Ito's dyno, and look at the RX8 dyno. If you take the simple effort to do that and review some of JudgeIto's posts and look at what others said about him and how he loves NA cars and that if you open up the hood it appears stock, and there are really only stock (or formerly stock) parts used....if you can't figure that out on your own, if anybody can't figure that out on their own then they probably lack the intelligence to even know what the modification was if someone directly told them.

 

rotarian do you have some links? like were provided by 86rx7 above? his appear to be all nitrous runs. they also appear to be very similar to ITOs. do you have any links to dyno runs of tertiary port bridgported 6port rotaries for us to examine?

 

not offhand, i just went through rx7club and looked at pics of dynos. Ito has repeated again and again the he did not use NOS.

Well actually the only thing I can get offhand is the dyno of judge's daughter's car which only used "a little nos".

I can't directly post a link to the pic so here is a link to the thread

http://www.nopistons.com/forums/inde...howtopic=47472

 

Since this is an entirely hypothetical thread...

If you were an engine builder and you frigged with your motor and it blew, would you take it back to Mazda to get them to rebuild it, or would you just rebuild it yourself, and improve on it, and put it down to experience??

Cheers,
Hymee.

 

I'd just do it myself but then I wouldn't try to get anything else done under warranty anymore either so there would be no point in keeping secrets.

 

Who Cares!!!!

 

Obviously you don't! That's 1 point for your crowd

 

WOW.

So 10 hypothetical and rather debate"ful" pages later, we have: nothing. By that I mean we have not agreed on one damn thing. I went to the RX-7 forums and am still where I am on this situation. I wish I knew!

Definately a nice curve on his daughters graph.

 

I wouldn't want a virtually flat power curve, with one almight jump, and then it goes backwards.

Perhaps my memory of that curve is wrong. Perhaps you are getting daughters and curves mixed up. J/k!!!! Keep smiling!

Cheers,
Hymee.

 

where we are is that the only 2 things that make sense are a bridgeport of the tertiary ports and/or a shot of nitrous. however the nitrous is ruled out for 2 reasons

1. nitrous use was specifically denied

2. if someone were to open the hood right at the end of the runs you would be able to see the nitrous lines and fittings.

so we are left with the bridgeport.

 

The second pic looks like a large single turbo half bridgeport motor, which isnt even a possiblity.

Btw, a bridgeport isnt going to gain 50+ HP instantly like that, especially an aux bridge which is limited to an open time of ~45 degrees and a fairly small volume.

 

I like the way that zoom described it, there are two options, a port or nos. He has repeatedly denied using nos, and says only stock components were used/modified. That leaves us with porting...

 

As I said waaaaay back when - porting.

The cool thing about all this is that the Renesis can put out 240 WHEEL HP with what is a relatively minimal mod. That is a significant 50 WHP gain. Maybe it's not where we'd all like to see it (across the entire rev band, and especially down low) but it's attainable. Good news, IMHO.

What I'd like to know now, assuming this is indeed what was done, is how it affects the "streetability" of the RX-8. Anyone care to speculate on that?

 

I'm 99% sure that is not the result or porting. If it was, it would have to be either ported 6-ports or something else you could close off/ open at will. Ported 6-ports only wouldnt make that gain i can nearly assure you. If it was porting, it's being openmd way to late, for it to jump like that its obiously making power at lower rpm.


Porting produces graphs with smooth blending curves,.. not large jumps in power. Even with ported 6-ports opening way to late, youll get a kick in power but it will be rounded off, not a sharp rise it torque like the graph.

I'm not sure you understand what porting is,.. It's equivelent to a camshaft with more lift and duration in a piston motor. The Renn is allready effectivly running a 2/3rds race cam on the scale of ported rotaries. (its well beyond the duration a piston motor would have on a full race cam stock) There isnt going to be 50 HP just laying around, and if there was the stock manifolds wouldnt be right at all for making it. Not to mention i doubt Ito went thru all the trouble of pulling the perfectly good motor, cracking it open and porting it,.. it would be time consuming and expencive, and a hassle. Why would you go through all that when other means would do more cheaper and faster, while not having to pull your brand new motor.

The problem is everyone WISHES there was some secret super mod that will make there renn make 240 rwhp with no power adders, so they refuse to accept the blatnetly logical and obvious.

Not to mention Ito said something to the effect of given the durability of the renn in his rx8 hes going to to build a bridged no2 renn for his rx3,.. something to that effect ,.. that thread is gone too..

 

The way the 13B auxillary ports function is in practice no different than those of the 6 port 13B's. They both use rotating sleeves. The Renesis has the advantage of dedicated intake runners to each port. This is the downfall of doing bridge porting on the auxillary ports on in the 13B.

I'm going to nearly entirely disagree with what 86rx7 just said. I have no idea what you meant when you said for it to jump like that it has to be making more power at a lower rpm. This is right around the point where the auxillary ports open. Have you ever seen a VTEC dyno? They do the same thing when VTEC kicks in. There is a sudden jump.

It is entirely possible that it could jump like this if only the auxillary ports were worked on. If the auxillary ports were bridgeported, the small amount of port overlap with the exhaust would actually let the exhaust scavenge the intake which is something it can not do in stock form. At this rpm, there will be little to no exhaust gas recirculation at this point. This would cause the efficiency to go way up at this spot and probably over 100% by several points. The stock Renesis only gets near the 100% volumetric efficiency point one time and even then only for a short period. It typically sits much lower. What it the efficiency jumped to say 104% here? That's a big jump. GM had a large 4 cylinder engine in the 80's which reached over 100% vol. eff. for over a 2000 rpm range. Imagine what our engines would do with this! What do you think brideporting does at higher rpm's?

As long as there is no port overlap, there aren't going to many gains without taking the motor apart. Once it is ported, we will see an entriely different animal emerge. The problem isn't that everyone only wishes for a super secret mod that can give us 240 hp without power adders. The problem is that many people don't understand how things work well enough to know how to do it. Anyone who has even studied Renesis port pictures should see alot of potential in this little engine. There is some power to be had from the intake ports but the real gains are going to be had porting the exhaust ports. If you have ever seen a 13B taken apart, look at the size of the stock primary ports. Since they are all similar in size just pick a random engine to look at. The Renesis exhaust ports are about this size stock. Those are some small exhaust ports. Study the pictures of the housings. They can go about as big as a T-II street port intake template. That is a huge gain in size and flow. There are going to be some wonderful things happening to these little engines in the next year or so when people start pulling them apart.

 

Yes but I had to add the link of where to get it...

 

Don Marvel of Marvelspeed said the exact same thing about the exhaust ports on all rotaries. He said that the exhaust side of the rotary engine is so constricted from the manufacturer, that there's almost no way for it to reach volumetric efficiency as it just cannot flow the exhaust out fast enough.

 

What i was saying was that if the power jumps like that and it was from porting the auxes, the auxes should be opened earlier because they are obiously going to be making power at a lower rpm if the graph jumps that much. You would want to open them where the dyno without them and the dyno with them crossed,.. a nice smooth curve.

Im going to have to disagree with you on the size of the exhaust ports as well. I believe mazda stated a 50% increase in exhaust port size over the 13b. They are definatly much larger then a primary port. They actually look a little bigger then a T2 secondary to me. There is not going to be much to gain from porting, except maybe a PP or a full bridge. The intake ports are allready effectivly streetported,.. youd drop seals if you went bigger. The exhaust ports could use alot mroe timming but there is going to be a limit before you star to drop seals.

Have you, Rotarygod ever ported a motor?

Thats besides the fact that a ported aux dyno graph wouldnt look like that, the graph goes almost instantly vertical, which wouldnt happen. The gasses in the intake would need to gain momentum, and before they did so the bride/ aux would tend to revert for a bit which would round off the power gained to a nice smooth curve,.. not verticle.

 

Maybe the aux. ports should be opened earlier but it doesn't mean he did open them earlier. That's simple to explain.

The total area of the ports is 50% greater than the 13B ports in area. Have you ever actually looked at the size of a 13B exhaust port and then compared it's size to a 13B intake port? That exhaust port is not that big. It wouldn't take much to have more area. You need to stare at your own picture a little better. Take a streetport template and turn it upside down on a 13B plate where an exhaust port would go. Trace it and then compare it to the size of the one in that picture. Heck just trace a stock sized port onto that part of the plate and compare them. The opening side (closing on an intake) isn't even in the same area code. I don't suggest anyone try to open a Renesis intake port any larger. I am fully aware of where the corner seals ride. Just because I say port them doesn't mean I suggest touching this part of them. There is far more to porting an engine thanjsut making the hole larger. That by itself doesn't do a whole lot. It's how you blend it in that makes all the difference. You can get a big gain out of a stock sized port by paying attention to this area. If you bridge the Renesis, you still won't have a whole lot of port overlap so it won't really idle bad. Just cut a little bridge in. Power will go up. Then enlarge the exhaust ports by about twice their area. There's room.

Have I ever ported a motor? I drive one every day that I built. I currently am driving a streetported 6 port engine in my GSL-SE. My 4 port engine on my engine stand that is waiting for a new home is also a streetport but it is much larger. The exhaust sleeves were replaced with custom machined ones that keep the cross sectional area the same unlike Mazda's terrible flowing design that everyone else on the planet uses. I have a custom built intake manifold that I built out of aluminum for that engine. One of my friend's drives a 3rd gen that has an engine ported by me and another one of my friends has a streetported 2nd gen T-II that I built. I am currently building a set of peripheral port housings. These are only the things that are currently running and does not mention past efforts. Have I ever ported a motor? Have you?

 

Hell If you going to post this:


I just have to post something too: Those would be 4 finger exhaust ports smooth as hell too.

 

PoLaK, is that a 13BT, or REW, or some other Mazda rotary?

 

It looks like an REW. The picture is dark.

Eugene turn your phone on! I just tried calling you!

 

so you guys call each other all the time but still havent met?