550 injectors won't do anything other than ruin his gas mileage and give him a rich condition.

You add fuel when you add air. He would have to have a good exhaust on maybe porting and intake for him to see any gains from getting bigger injectors.

Turbo guys get injectors because when you up boost(add more air) you need to add more fuel or you chance leaning out and detonating.


Also getting a true dual exhaust system made would be the best on a stock port NA. It will give you better mid range power so I would say.

Save a bit more and get the RB uncollected race header and go with some dual piping. Do a search a couple people have done this and love it.

 

I'm running the MindTrain header with a Bonez cat and would recommend it to anyone. (The Pacesetter design is crap. Unequal length, horrible "collector" and the tubing is WAY too thin.) My midrange and throttle response were very much improved. For power, exhaust mods are the best bang-for-the-buck.
BTW, if you don't plan to switch to a header soon, I have a "race pipe" with presilencer that replaces all 3 cats I'll sell you for $50 +shipping. You'll want to get a double-sheave pulley for your alt and run 2 belts to avoid slippage.

 

My question about a dual exhaust setup on an s4 is back pressure? Is there anyway, say presilencer or some backpressure bung, to open the 5th&6th ports? I would prefer not to slap the air pump back on.

 

Ok well Ive had a Pacesetter header for almost TWO years now, and it is still holding up ok. No holes or rust. If I were to go out and buy a header again though Id get the Racing beat one, mostly because its equal length, and the 02 sensor is after the collector.

 

I have H Rated on my car. Now seriously, how many FCs are going to hit 130 mph. They top out (unmodded) at about 140 mph, so whats wrong with 130 mph rated tires? It's not like they are going to explode at 131 MPH (cuz I have done 135 lol).

 

Yeah I've got H rated as well. I was speaking with the tires guys and they said that it's pretty much a measuremetn for how long they will sustain that speed before the tires fly apart.

So I figured a H tire is balanced enough and some what economical at the same time.

As for the Bpressure you might have problems. I've never done it but I would hope/guess that adding in maybe 1 per pipe or just one RB silencer pipe with pick up bung might work.

Maybe run one on one exhaust pipe and hope the Bpress is enough. If not maybe add one to the other and fab a connector pipe for the bung and hope both pipes create enough pressure(i think it's only 3psi needed to fully open them)

 

the RATING AS FAR AS I UNDERSTAND IT IS THAT THE HIGHER THAT RATING THE BETTER THE CAR HANDELS AT THOSE SPEEDS. WERE IF YOU HAVE A FAST CAR THAT LETS SAY MAKES IT TO 150 MPH AND IT HAS N RATED TIRE . THE TIRE WONT BLOW UP LIKE LOTS THINK ,BUT THE CAR WON'T HAVE GRIP, HANDELING AND WILL MOST LIKELY LOSS CONTROL

 

for christs sake, would you get off the god damn speed rating thing. I said Z rated implying that they would be high traction. I am well aware that his car is not going to hit 149+ mph. The point is, with stickier tires, the car will launch better, handle better, stop faster, and be a better car all around. It has nothing to do with the top speed.

 

Ok stop right there!

Z for one H N V T W Y and all the other SPEED ratings mean just that the speed that the tires are rated to. If you want to talk about grip then talk grip ratings. Yes they have grip ratings. They may be called traction ratins but my H rated tires are AA rated which is the newer rating for the highest grip you can have. With the exception of competition tires. Now your going to say that he should get a Z rated tire for better handling but you can have a slower rated tire with the same or better handling for less money. So please understand what a rating stands for and what the rating is about before you go on recommending stuff. If I don't know about something I try to stay out of it because I will probably mess things up for someone that thinks I know my **** when I don't.

Santiago

 

wow, this is pointless and heading nowhere. If you didn't get what I meant from my first post then fine. You obviously understand what I mean now.

 

Hey, 2 things: I have a RB header on my car I'm going to be selling when I part it out. let me know if you're interested. 2nd: Though the tire rating is for speed, I think the general principal behind it is that the person who is driving faster (Z rated speeds) is probably doing high performance driving of some kind. Mini vans, geos etc never go near that speed and are never used in performance applications. Most companies use a really good gripping rubber compound on their Z rated tires and the compound becomes progressively worse as you work your way back down in rating. This is not proven but what i think seems logical. Anywho, PM me about the header if you're interested.

 

make sure you pass emissions first or that money will be needed to help your car pass.

 

The way I passed emissions before I put on my new exhaust was running over something like a board that kicked up and hit my y-pipe and knocked one of the muffler's pipes off. at that point, you just wedge it so the muffler is only getting about 80% of the flow and you just lowered your emissions 10% :-D

 

Hmm. I don't know about OR, but that WON'T work in Cali. They measure in PPM, so it's really a percentage of the existing flow. (Whatever that happens to be.) Reducing the sample size wouldn't really have any effect on the ratio of pollutants/exhaust volume.

 

same in texas. most likely same all over the nation.

 

you can get a ps header for 150 shipped, all you have to do to it, is drill the bung for the o2 sensor. This header will bolt up to your main cat, then if you want, you can gut your main cat. Check to see if your mufflers are straight through, if so, you're gonna want to open you're 5/6 ports with your airpump, so take the small hose that goes to the pipe heading down to the cat and drill a hole in your airpumps exhaust pipe and epoxy the little hose in there, now your 5/6 ports will function.

So now you have full exhaust that you spent 150 plus 9$ for gaskets.

Its winter so if you have a/c you can remove that belt and you can also remove your p/s belt if you have one, this will just give you a little increase.

Build a cold air box, by searching, you can get a really good design for 5 bucks. Go on e-bay and get a 3" maf adaptor for $9 shipped, then order a 3" apex filter for $70.

Now you have full intake and exhaust, from here you can do the tb mod, remove all emissions, and build a better intake tube.

 

Do a search on Pacesetter and see what people are saying about them. I was gonna buy one until I heard all the horror stories. I was looking at a RB header until I found a sweet deal on a lightly used MindTrain header, Bonez cat and Corksport single for $400. The fit on the header was perfect! The system bolted right up. Only problem I had with it was that with the CorkSport I measured 122db at 10' at WOT in neutral. Now I'm running a TII CB and it's 94db and sounds great! Fairly subdued with a nice growl and an awesome midrange! I don't know how much you'd pay for a new MindTrain header, but you can get a RB for $175 at racingbeat.com.
I dunno about driving off the air pump. The Series4 ports are designed to open by exhaust backpressure. Have you obtained reliable port actuation with this method?
If your AC is working, keep that belt on. The pump may well seize up if it doesn't get spun regularly. Also remember that turning on the AC helps defrost the glass faster, since AC dries the air.
If the AC DOESN'T work, you might consider just removing it entirely. I did , and haven't regretted it. Saved a bunch of weight and made getting to the spark plugs a ton easier.
I would never consider taking the PS belt off. Either leave that system working, strip it down and put a looped line on the rack or put in a manual rack. The resistance of moving all that fluid through the plumbing and dead pump WILL get you in trouble at the worst possible moment.I picked up one of those "cheapie" MAF adapters and they are NOT worth it. Unless you get a cast pice that matches the opening of the MAF and has a SMOOTH inner contour you are costing yourself HP. Have a look at those cheapies that are just a chunk of tube welded to a chunk of plate so that the incoming air can slam into the flat spots where they connect and see if you can visualize the turbulence. Then go and spend $25 for an HKS adapter.
Poorly done mods will always cost more in the end when you have to replace them and/or they break something else. Do it right and do it once. You'll ssave a ton of money in the long run and be a lot happier with your car.

 

Can you elaborate on these pacesetter horror stories? I wanna know what people are saying, links would be nice.

 

Best mod for $300 = FULL TUNE UP. All filters, fluids, plugs, wires, timing, TPS adjustment, etc. Now take the remaining money, and go buy a cone filter and make a cold air box. Save up another $400, then upgrade the exhaust. After that, grab an S-AFC and lean out the sucker about 10%. Aside from some little things, you need to go into the engine to get more...

 

I'm a cheap bastard. I love this thread.

I second the full tune-up recommendation. It makes a huge difference, although if you do it yourself it will be much less than the $300, just do some searches about the best places to get the parts.

After Christmas is over, my stock NA is going to slowly be turned into a monster...

 

I also agree with the tune up comment. I also condone learning how to work on your own car so you save as much as possible and learn something in the process. I'm not saying that anyone here doesn't work on their own cars. It is just much cheaper if you do. I will disagree with the S-AFC though. For half that price you can build a Megasquirt and have it work infinitely better. I don't believe in any computer mod that requires that you keep the air flow meter. They are just a tuneable bandaid. It is true that not everyone is capable of building their own Megasquirt but almost everyone knows someone who can.

 

this is some great info for all us new guys. thanks.

 

Aside from the S-AFC bit, I totally agree w/Aaroncake. (Sorry, but the stock ECU kinda sucks to begin with. Why lie to the poor thing?) You wouldn't believe the difference that a good (thorough) tuneup makes. I swear I picked up at least a 30% power increase just by making all the STOCK parts work right. Out of everything I did before the header, setting the TPS and variable resister had the biggest effect on overall drivability. (Really smoothed it out) The header and K&N made a huge difference in midrange and throttle response, but I dont't think they would have done anything useful if the baseline settings weren't tight.

 

For most people who are beginners, tuning an S-AFC is a lot easier then a Megasquirt. It also doesn't require a rewire of the engine and an ignition solution (whether that means leaving the stock ECU, dizzy, etc.).

 

True, that. I guess I just prefer more complete solutions. It seems to me that by the time you've bought and wired up an S-AFC, you might as well have kept saving, done a little more studying and gone the full standalone route. I think that most of the people who go that far would really be better served working with a proper ECU, rather than than modifying signal to the stock POS.
Besides, I think an engine rewire is a good thing on these cars. I know MY engine wiring harness is crunchy.