TeamRX8

iTrader: (2)

it does because otherwise I'd be wondering why you aren't opening them later, but your reply makes that obvious so thank you.

ultimatejay

iTrader: (1)

This is where it's at- adjustable runners like on the 787.

http://www.youtube.com/watch?v=GWeIIRqvgco

GtoRx7.

iTrader: (12)

Yeah I've seen that video before looks like a cool race car. I have some variable length trumpets in the works, but not sure if it will work from a power standpoint. Earlier testing I did showed impressive gains across the rpm band, but that was before the latest methods of gaining power. These new methods might not like variable length. But we will see!

fidelity101

iTrader: (11)

I saw your site and this is slightly off topic but, will your 13b header clear the camden intake manifold for s/c application?

GtoRx7.

iTrader: (12)

Yeah it should. It clears the 6-port intake

Starfox07

This isn't entirely germane to this particular conversation, but what do you think a Renesis can do with a proper intake manifold and exhaust system? It seems like a lot of the gains you guys are getting are purely from intake and exahust geometry, IE; maximizing flow of air through the engine. If a streetport 13b-re can do 230whp, why can't a renesis put up good numbers with careful exhaust and intake tuning?

TeamRX8

iTrader: (2)

they can do that and have with a Renesis

however, you have several things working against you to get them up to the NA output/displacement of this thread

the exhaust ports can't be opened up much before hitting the water jacket, you can convert to GSL rotor housings or aftermarket derivatives to have peripheral exhaust ports, but can you still call it a Renesis?

I believe the mechanical actuating mechanism for the APV ports on the factory LIM is in the way for fitting a semi-PP, so you might need an entire custom intake system when it's all said and done

and then there is the inevitable side seal issue for engines that see long duration WOT use (might not be an issue if you convert to peripheral exhaust port housings and effectively block off the side ports, but again it's not really a Renesis anymore so why bother?)

if you have the dough, would love to see someone try ...

Starfox07

Well I was just thinking how much a box stock internal renesis (aka no porting at all) could do with a perfectly matched intake/header combo.

GtoRx7.

iTrader: (12)

A renesis has a hard time making 230rwhp like our 13b-re. The methods to achieve the same power is pretty different. I willl do my best to explain-

Basically a very low overlap engine is more tolerant to poor intake and exhaust combos. Low overlap engines are any stock port 13b made. The best header vs. the worst on this type of engine may result in only 10hp.

Now as you build a much nastier engine (large ports, more rpm) overlap is vastly increased. But for a high overlap engine to work properly, the intake cannot get dilluted. So these engines can see a 40hp difference from a poor vs excellent header/intake. This is why you see many bridge ports and even full p-port n/a engines making the same or only a little more than our 230rwhp streetport.

The Rx-8 engine purposely was made to have VERY small overlap for low emissions. With almost no overlap the intake and exhaust length tuning has MUCH less effect on power output. These engines respond best to very optimal intakes. But there is a limit, and it will hit a wall without the help of overlap.

TeamRX8

iTrader: (2)

270 - 275 @ flywheel is about as good as it gets

I kind of hate to discuss whp because there can be so much variation on chassis dynos

porting might get you another 10 - 15 hp if you are lucky, probably less based on what I've heard or seen. All my direct experience is non-ported

anway, probably should start another thread if necessary than continue to dilute this one