has anyone used a straight to muff exhaust on a gslse? i know that some of the ports are operated from the exhaust backpressure so would this still be possible if there were no cats and i had about a 2 inch pipe? i would probably switch to a header if i did this.

It will work, if you make the right pressure line for the 6 ports. It will also be very loud.

it doesnt need much pressure to open, but it will be very loud

Dont do it if its your daily driver/ it'll suck more gas and u'll fell a lag(hesitation) in the mid band RPM range(not all the time).......But its definitelly a gain in HP @about 4-6k RPM range (10)HP) and i think the (engine)runs better(cooler and freely) https://www.nopistons.com/forums/pub...IR#>/smile.png So i guess it is a good mod If you're not in CALIFORNIA!!! https://www.nopistons.com/forums/pub..._DIR#>/sad.png

BTW i 4got to mention that i tryed that with (wired opened secondary ports)

That's how I have mine. Just wired the actuators open. Not that big of a loss in the lower RPM. There was some loss just not that much. As for the gas milage.....mine didn't go down at all.

are there benefits to wiring them open as opposed to actually putting the back pressure line on there? also what size exhaust are you running back to the muff? ive got a pretty good muff on there (flowmaster 40 series i think, not a straight through muff) so i dont think it will be annoyingly loud but i guess well see. this is coming from a guy who drove around for a long time with a chevelle 350 running open headers. <-- man that was loud but it sure sounded good!

also, what are the benefits of removing the airpump?

Eventually that flowmaster muffler will go bad. Rotary's make a lot of heat and I have tried those mufflers and the best one if you want it to last is a dynomax. They work well.

ok but the flowmasters are rather cheap to replace and it doesnt seem like the heat will effect it very much bc the muff is at the very end of the car, now without cats it will get pretty hot. the muff casing is very thick so hopefully that is a sign of the inside quality too.

the flowmaster is about the loudest thing in the world, anything else is better.



you want to have working 6 ports, wiring them open doesnt gain you any more top end, all it does is loose low end power, why do that?

I have 3" pipe back to flowmasters. I realy doubt that the heat will hurt a 2 chamber steel muffler. As for the acuators.....go straight pipe and you lose the back pressure piping. To much to have it custom made and you will NOT lose that much power on the bottom end. Also, when you no longer have the pressure to open them how do you figure that you don't gain on the top end? Once you go with a straight exhaust, like I said you will either lose the pipe to connect the hose to open the actuators or you will pay for a custom job. It just isn't cost effective to pay out any amount of money for a custom job that you can just use a couple of wire ties to do. As I said the effects on the power are not that great.

so could i have the back pressure line with just a straight exhaust? does it just involve having a hold drilled in the new pipe and welding the old line on? if so it doesnt seem like they would charge me much to do that.



also, what kind of top end gains are you talking about? this car is basically a dd so i dont drive in the top end all that much

As far as cost goes...like I said it just isn't that cost effective. You can go straight pipe not even have the two actuators open at all and yo uwould never know it. However, drive around like that for awhile then take 2 wire ties and tie the open....you will see a difference. It won't be anything major but there is a difference. It hurts nothing by wiring them open or just taking them out all together. If it is a daily driver then I doubt you will not notice if they never do open. That statement is more of a metaphore for those who seem to jump at every little thing. I am supprised that as long as you have been on this board and read the things that people have actually done to their cars that you haven't seen anything on this subject.

Kind of like the comment on another thread about the Kia sportage front diff. swap on another thread. Just because some haven't done it doesn't mean that it can't be done. There is plenty of info out there all one must do is to research it and try it. Hell, I had doubts about the 2nd gen direct fire realy working but said WTF, got nothing but time to lose so I did it and it made a heck of a difference. My car is more than just a daily driver so when I wired open the actuators I DID see a difference. It did not hurt my gas milage nor my performance in the least. Contrary to what some may think, it isn't that big of a deal.

thanks for the info, ill let you guys know how it turns out.



now whats involved in wiring the actuators open, or is there something already posted about it?

you can run the actuators off of the air pump, it takes like 5 minutes to do.



is your engine ported? we run a 3" exhaust with the actuators removed in the race car and it makes ok top end power but theres no low end. we have to run stock ports due to the rules, but we do have a haltech, that helped the low end a lot, but its still not as fast as a stock working actuator car

Not as fast? How is that? The actuators have nothing to do with the cars top end. As for the tourque, well....that is a different story, but consider this: the actuators open at 3800 rpm, when I race I leave the line between 4k and 4500 rpm. When the clutch is ingauged and I leave the line don't you think that the actuators would be open at 4500 rpm? If that is the case, why keep them? During a race you wouldn't let the rpm's fall below 4k anyways, so what is the point? From a racing standpoint. As for the street, like I said, not that big of a difference. It comes down to a matter of opinion, you have yours and I have mine, just as most of those on this forum. I have gone both ways and speek from my experience on it. What I have said is from my own experiences from the street as well as the track. Do what you like, but if you are racing and letting the rpm;s go below 3800 then what is it you are racing? I generaly keep mine up and down shift around 5k at the slowest when not on the street.

This all you have to do to get the 6 ports to open up. Cheap and simple. I found all the parts needed at the local Ace hardware store in the plumbing section.





The copper tube is 1/8" line, with a compression fitting attaching it to the tee. The rubber line coming off of the actuator line will slip over the tube, it's very tight though.



I have done this on an S4 and a GSL-SE, works fine on both.



[attachment=28820:attachment]

There you have an alternative. Thank you! Much better than one saying one way is better and another saying it isn't.

yeah ive done both too, i like the actuators working on the street.



our race car (all the 6 port stuff removed) it down on torque compared to a working actuator car, up to about 5000rpms. and actually delaying the actuators opening does help a bit too, depending on your exhaust setup

If you will look jsut above the exhaust toward the back of the motor you will see one of the actuators, the other is toward the front. Hold the little leaver open, run a wire tie through and around it pull it tight.....whola! That's all there is to it. Of course you might also want to try one of the other alternatives.

yeah wire it open, see what you think

since no one is saying that it makes the car faster to have these wired open i think ill just pay the exhaust guy the extra 5 or 10 bucks hes gonna charge to add the bpressure pick up line

ok guys, im getting ready to do the exhaust in a few days and am trying to decide which diameter to use. id like 3", but this is a dd with no other mods right now. should i go smaller?

2 1/2" should be fine, 3" is too big if its N/A.

yeah 2.5 is fine. you dont need any bigger unless you've got a huge port, or a turbo or something

Come on Shane do it right, go 3 into a 5.5 inch muffler with the red leds in the end https://www.nopistons.com/forums/pub...#>/biggrin.png

[quote name='1revnrex' date='Apr 21 2005, 05:07 PM']Come on Shane do it right, go 3 into a 5.5 inch muffler with the red leds in the end https://www.nopistons.com/forums/pub...#>/biggrin.png


[/quote]





dont you mean 1.5 into a 1.5 in/ 5.5 out muff with led tip?



i called the muff shop and the guy is old and has the crappiest hours:

8-5 tues-fri, 8-1 sat. i was gonna try to do it today but i have to work til 1, guess ill try for tues or wed.

Remember that if you use 2 smaller pipes instead of 1 big on you'll have more power as the velocity in the pipes will be much greater, the moving gasses will like suck the gasses that are still in the combustion chamber out..

i went to the place today and apparently its illegal to cut a cat out but he evetually said he would do it for 50 cash and no receipt. he said hed do the whole exhuast from the mani to the muff with 2.25 for 80 so what should i do? should i keep the stock 2in stuff or go with the 2.25? will it make much of a difference to just have it 1/4 inch bigger?



the reason im not gonna do 2.5 is that he says his bender wont do 2.5 well enough to get it around the axle, but he can do 2.25. also, there is/was a presilencer on the exhaust in front of the cat, i say was bc he says its hollowed out and now just acts like a glasspack bc of that. the presilencer is about 4in around in the middle and is about 10 inches long. is there any benefit to having this left on?



another question... the pickup for the actuators is running off of the split air, you guys probably knew that but i was under the impression that it ran off of the exhuast from a split air type line. how do i get this put back on? can he weld the split air pipe onto another spot to have it pick up the backpressure? does this system even run off of bp or does it run from pressure from the air pump? i just need to know how to keep the actuators working the easiest way (without wiring them open)

well i was hoping to have an answer or some opinions by now but i guess ill have to wait longer.



i need opinions on the size (whether to go to 2.25 or stay at 2) and what to do about the actuator pick up line.

ok, does anyone have a pic of their actuator pickup line? how about an opinion on keeping in the old presilencer? basically its a hollowed out 4 inch X10inch section of pipe





i can make a decision on my own for the other stuff but i really need to know what will work for the actuator line.