Rx7Forums.com

[email protected] · 01-12-2011, 07:22 AM

So what happens if I take all the emissions and exhaust system off except the large manifold that actually is attached to the engine. Then replace the carb w/ a regular one w/o any electrics and then put a regular exhaust attached to the manifold? Gas, Air, Compression, Spark, Boom. I've seen aircraft rotary engines that do not have any of the stuff ours do so what gives? It seems like all the extra stuff is for emission control. Any thoughts? I once took the FI off an Audi Quattro and put a Weber on the manifold top sealing off the throttle body opening. It ran really well. Thanks Doug 1980 RX7 in Cottage Grove Oregon.

**BoostedFC** · 01-13-2011, 04:50 AM

So basically you want to do a full emissions delete? There are a few options as far as carb upgrades for you out there Check out Racing Beat. I'm a little confused to what is a regular exhaust? Are we talking an open exhaust no cats? If you are looking to make more power, clean things up under the hood & not worry about emissions, then paying attention to the induction & exhaust is a good start. What exactly are you trying to do with this car?

**black rocket** · 01-13-2011, 06:38 AM

Ohhh, classic Weber runner! Love them Webers. Contact Atkins Rotary located in WA and Dan can order you a mani you need!

You know you'll need bit of back pressure for N/A engines, right? And as to EGR crap, you won't have to worry about inop solenoid issue and as long as your county is smog free or track use its all worth it.

[email protected] · 01-24-2011, 07:58 AM

Thank You guys. The reason for wanting to do this stuff is that the air pump for one has got to take power to run. And all the electrics on the carb are for what? As for the exhaust my word, what a mess. I just got done taking the tranny out cause I thought I had a leak in a freeze plug (turned out to be in the intake mani) and of course in doing so had to remove a bunch of the exhaust sys. Seems like a lot of heavy garbage. I've replaced my clutch a couple of years ago and thought the same thing then but I didn't know this engine requires back pressure such as a two cycle dirt bike engine. So the only real advantage there would be weight. How bout this downpipe I keep hearing about? I guess the thing is that most of the vehicles built in the early eighties/late seventies suffered from US government intrusion, ie. more gas in less power out. It's not like the car really needs more power although it could be fun if the mileage is there also. I would like to iimprove mpg. I believe in simplifying things so... but hey a nice old AFB sitting on the mani would be cool, although I noticed that the intake ports on the block and mani are pretty small and seperated for the primary and seconds. OK OK I'll get to the point, I hate smog control crap of this era. A guy has a hard time beating a 327 289 265 250 or any other of the mid sixties American engines for simplicity and ease of backyard mechanics. And as my old auto shop pro said "When they tell me how you can put more gas in and get less power out then I'll believe in smog control" Thanks for the time any more comments or suggestions are very welcome... Doug Horvath 1980 stocker

**black rocket** · 01-25-2011, 12:41 AM

Does your county require smog cert? It's all depend upon smog ck issue. If you are not restricted I'd remove them nasty CAT.

Also, you might want to look into EMS that can be fine tuned to get optimum results to suit your needs (both economizing or performance). Another factor is RX needs to run bit richer so you can only do so much to improve that aspect.

Good luck and let us know your progress!

[email protected] · 01-26-2011, 07:31 AM

OK so what's EMS? No we don't have any smog cks here. So I don't have to worry about that. The cat is empty already. I usually take them off and drill them out w/ a large auger bit so all the material is removed and the only thing left is the empty pipe so as not to have a new piece made to fit. One thing I have noticed is that the engine seems to really pull until it can't get enough intake and then it kinda flattens out. You really notice it in 2 and 3, a little in 4th as it gets around 6500-7000. I've been told these dudes will run 10,500. ouch, what about clutch disks etc. I notice the flywheel is very thick so... Anyway thanks for all the input. These cars are almost scary fun. dj

**BoostedFC** · 01-26-2011, 06:43 PM

"EMS" = Engine Management System. If you were asking about clutches I personally like Exedy & Clutch Masters. You could use a lightened flywheel, but you will need the rear counter weight from an automatic.

**black rocket** · 01-26-2011, 06:43 PM

EMS (Engine Management System), Haltech, Microtech, etc. Some are easy to install and plug & play type, some are programmable to your liking.

**BoostedFC** · 01-26-2011, 10:35 PM

Basically you have a few options where EMS is involved. A piggy back system in which the aftermarket unit is hooked in with the factory ECU with the ability to adjust Fuel & Ignition maps. There is the full stand alone in which the new unit replaces the factory ECU for control. They have chipped factory ECU's which are generally set to predetermined adjustments according to mods. There are units where all they really do is trick the factory ECU to add more fuel to compensate. You would have to find out what type of system would benefit your needs. The more feature & complex the system the more you will spend.

**black rocket** · 01-26-2011, 11:14 PM

Originally Posted by [email protected]

...These cars are almost scary fun. dj

Yes, it is. Especially when you look at the tiny engine and think it can produce 700 bhp (lacks torque) and listening a fine whine and just want to push on RPM to shift.

These cars are so addictive.