Racing exhust system ?
 

Hello all wankelfreaks ;o)

I am just beginning to consider upgrading the power of my FC TII RX 7 and would like some opinions about which mods will do the best ! I will not go "wild" upgrading my motor, but do the basic maybe midway mods (reliability and daily driving !) but for a start, what exhust system will gain me most power for the mony do you think ? I am going for good quality items all the way ! what cold air induction system ? lighter pullyes ? spark plug wires ? spark plugs ? ECU ? if I will put on a full exhust system (downpipe, midpipe, catback exhust) will I have to install a fuel cut defencer and mayby larger injectors then ? where in the upgrading will you recommend to put on upgrading motormangement ? is the power FC a good solution for the FC TII ? and last, where do you think the best place is to get all theese mods if I would like to buy it in the same store ? I know it is a lot of Q, but I hope you guys will try to help me ;o)

Rene
DENMARK

If you are going to do a full exhaust upgrade, you will need to do several things to the fuel system; larger injectors, better pump (walbro), and a fuel controller of some sort. You will also need a FCD, and it would probably be a good idea to port the wastegate to avoid boost creep. Racing Beat has one of the best exhaust systems I have seen. All of their exhaust componenets are very high quality.
As far as intake systems go, they are all going to get pretty similar power gains. I saw a test in some magazine a while back that tested several popular ones, and they all got about the same gains. The difference was in how well they filtered, and the Apex was the best, if I remember correcly.
I see you live in Denmark, so I'm not sure where the best place to get this stuff is. Maybe someone in the area can point you in the right direction.
Edit: Unless you get into some more serious mods, a S-AFC II should work fine as a fuel controller.

So if i got the complete racing beat exhaust system on my 88 na i would have to but those fuel upgrades right? Just trying to clarify.

Turbo will need fuel upgrades, n/a will not, unless you want to get an s-afc and take a bunch away! N/A's can run much leaner than turbos, in fact it's better to run them leaner since it will yield more power.

No, the fuel mods are only neccesary on Turbos. When you open up the exhaust system on a turbo car, the turbo can spool easier so you end up getting more bosst. That why you hav eto get the FCD. When you make more boost, you need more fuel to avoid leaning out and detonating. Also, N/A's generally run rich anyway, so you dont have to worry about leaning out.

The most important thing to note when going with a full 3" exhaust is that it causes issues relating to the wastegate. The increased backpressure will prevent the stock wastegate from properly bleeding off boost and thus creep occurs. While a performance advantage occurs with increased boost, it's dangerous and thus you must take the fuel-related steps. Porting the wastegate is an intelligent step and highly recommended with a full 3" system. Adding an intake will exasterbate the creep issue.

The spark plug, wires, etc. upgrades are not necessary as long as your OEM ones are in good shape. A pully will give you a minor HP increase, but there is not a lot of performance to be had for the money. The main reason for a pully is if you plan to eliminate the air pump.

I recommend calling racing beat and talking to them directly. Just see what they say I trust them.

Or if you race it and your water pump starts cavitating at high RPM's.
The Racing Beat complete exhaust system is $789 and they claim a 32% increase over the stock system at 10-11 lbs of boost.

i'm not quite sure on the power gains on leaning an NA out over the stock fuel map. but not doubting it either. in most forms of motorsports, especially those with high power naturally aspirated engines (i.e. Formula 1), you learn to run lean or you go home. more power and less fuel consumption, why wouldn't you :)
(maybe because your engine may blow up, lol)...

Good point, you're entirely correct. It's not widely known by those on the forum, but the stock cooling system does not perform well enough in roadcourse scenerios. (From the sounds of the post I don't think he's actually going to hit the track in that manner) I've got a big Howe rad for my next time. ;)

There have been at least a few people on the forums that have leaned out the top end and posted before/after dynos. Some of them showed quite noticable power gains. Whether you get better milage or not depends on where you adjust the map. If you lean it out at the top end it wont make much difference, but leaning it out in the mid-low end could help noticably. Anyway, I've gotta get up early so I'll try to locate that thread tomorrow.