maxcooper

That is an interesting idea. So far, everyone (including me) have seemed to give up on a factory turbo because the cats wouldn't heat up fast enough from the exhaust at start up. However, perhaps there is something "outside the box" that could be done to overcome this problem.

Bypass the turbo for start up and send all the exhaust through a pre-cat until the main cat is hot enough to work on its own. Then switch it back to running the exhaust through the turbo. You don't want boost during warm-up anyway, so this could also serve the function of the double throttle system on the FD.

Electrically-heated pre-cat?

Some kind of mixture or ignition adjustment to quickly heat the pre-cat during warm-up?

-Max

50tooslow

I have heard that GM is working on or probably has a prototype of a self-heating converter. I have a friend who works for GM.

rotorbrain

so are the 6th ports operated electronically? someone posted that they arent using the old stuff. i would hope they are electronically operated. those old actuators made me sick just looking at them

paul

fdracer

what's w/ the weird shaped port edges?

Wargasm

My guess is that the machining tools/process that they use to make that port opening can't make perfectly shaped ports. In other words, it's easier to drill a hole here, cut a rectangle there... another circle here... and end up with something that looks pretty good. Perhaps they are too cheap to buy a machine capable of cutting things "just right".... I dunno.

rotarygod

iTrader: (1)

Not sure how exactly the 6 port actuators work now. I've heard that they are electronically controlled based on load and rpm but I can't find any definite proof. I can only tell that they are still there and there are no actuator rods so they must be turned from above somehow.

I wondered about that port shape thing myself. I don't know why they wouln't be able to do a nice smooth shape like the old ones. They've been doing it for 30+ years. How are they going to not be able to do it now? They must have found some performance advantage by doing this since it would take more effort to do than a smooth port.

setzep

Maybe the second throttle body is for those ports? If that was the case you woulden't need any actuators.

drago86

The seals look 2 pice to mee, and on the turbo charging thing, the wrx ran into the same problem, so they put a cat before the turbo, the only problem is this causes massive lag, but it will get you through CARB. also keep in mind that the renissi will not generate very much heat in the exaust as opposed to our 13b's because the exaust opens WAY late, current 13b's open the ports while the mixture is still combusting, hence out high exaust temps, renisis will be much lower. Also that engine looks hand ported kinda to me, look at the slopy edges, and if you look at the top part of the exaust port it looks like somethign was welded, and the exaust port sleves look welded aswell

drago86

Ok, looking at the pic again, it looks like the port edges are not uneven, but they both have a "tab" sticking out into the port a little, this i believe is to support something to it doesnt fall into the port, maybe the third oil ring or soemthing?, or its exactly on the path of the corner seal so it doesnt fall in? also notice that the oil controll rings are thinner, and moved inward farther, alowing the ports to be cut farther inward twards the e-shaft. also the apex seals appear alot thinner to me, like maybe 1.5mm?

HEVNSNT

iTrader: (3)

Nice observations drago. Keep them coming.

drago86

hmm, the rotors arnt interchangable from front to rear anymore, one edge, either leading or trailing has the corner where the side, and the rotor face meat ground out, kinda like the rotor on the pineapple racing website, also look at the corner seals, no more lil rubber plug, insted its made of some sort of shiney metal, possibly aluminum, and if you look real close you'll notice theres rectangular cut out in the plug, that wouldnt alow for the apex seals to fit, so either this plug was placed there for the photos, or it does have a recess, it is just caped off at the end for better sealing maybe? also the side exaust ports greatly restrict the water jacket around the exahust, so if you used earlyer 13bhousings, the periphreal exahust ports might get too hot,... but that motor would be sweet,.. 3 times the exahust area, also is the plating on the housings still chrome? , it doesnt look shiney at all, its kinda a dull grey, the rotors have a much finer finish on them than ours, the face, excluding the dish looks almost mirror polished