Kouta

Okay so I am looking at upgrading my exhaust system but I have a few questions.

1) If i want to keep my 5/6 port actuated I have to purchase a racing beat header thats made for 6port N/A engines?
1b) Whats the difference between the MT and the AT versions of these (other than the AT being cheaper)
2) If I decide to just get a presilencer and cat replacement and keep the stock exhaust manifold, I have to find another means to have my ports open and close (via solenoids/etc) if i dont want to wire them open/keep them closed. Correct?
3) with a stock port engine, will replacing the items before/at the cat help me that much or will a catback do just fine?
3b) Will doing a catback still give me enough back pressure or will I have to find another means? (my cats are already gutted but my ports still open at 3800rpm)

ddub

1) You will need to have something (either presilencer or stock main cat with air tube) after the header that will still have the split air pipe hooked to it with the aux port nipple on that to get back pressure to open them. OR you can use the airpump to actuate the aux ports.
1b) I don't think there is any difference besides the fact that the auto and manual are different shapes/sizes so a different configuration of the header is needed to fit it in properly.
2) No, if you get the presilencer replacement pipe from racing beat, get the one that has an air feed for the split air pipe still. If you get this one you can leave the split air pipe hooked up to the presilencer to get backpressure and actuate the aux ports. Or, again, you can use the airpump to actuate them.
3) Of course it'll help, the stock exhaust manifold is a box basically, not the best flow, and the catalytic converter/s (pre and main) choke the exhaust a lot. The biggest change will be in getting rid of the main and pre cats.
3b) Just a catback will still give you enough backpressure, yes, even with gutted main cat. If for some reason it doesn't you can always hook it up via the airpump or some other method. There is a how-to in the archive I believe for aux port actuation without using backpressure.


EDIT:
Forgot to mention, some of your exhaust ideas (keeping some stock pieces while changing others) WILL require some customizations to the exhaust. For example, the racing beat presilencer cat replacement pipe is not the same length as the stock main cat. The stock main cat is 17.5" while the RB unit is 20". Also, the RB header is not the same length as the stock exhaust manifold/downpipe. Keep these in mind too.

My Junx

the header is not what opens the ports, that would be the presilencer. you can keep the manifold and just get a down pipe and s4 presilencer if you want to still open the ports for cheap. or get the header and s4 presilencer together. The header will make the car pretty loud but the presilence rhelps keep it down a tiny bit. I can tell you my s5 na with header presilencer and corksport cat back is very loud at WOT but is reasonable at idle. You will loose torque down low with a cat back or with a header and with both you will loose even more. But the power gains up high make up for that if you like to keep the revs up there.

Is your car an AT or MT? Or is it a conversion? Mine is a conversion, AT chassis with an MT installed, I have an MT header and presilencer and it works, so the difference in the two must be just that the AT header swings out a little farther to clear the big fat AT body I guess. Correct me if I'm wrong guys.

(I see dDub beat me to it, oh well)

Kouta

Thanks, i read it wrong for some reason i thought the tube for back pressure was on the header not the down pipe.
Here is my ideas.
1) Replacing everything header-back
2) Replacing everything behind the exhaust manifold
3) Just going a catback.

On racing beat's site it says (http://racingbeat.com/resultset.asp?PartNumber=16208)

"The 1986-92 13B 6-port engines, in stock form with the factory fuel injection, produces similar power gains with either our Header/Presilencer combo or our Cat Replacement Pipe/Presilencer combination. If you have no intentions of installing our Holley intake System (or any other aftermarket carb set-up), we recommend the use of the Cat Replacement pipe/Presilencer combo since it offers a slightly quieter exhaust note, is easier to install and less costly. If you are intending to upgrade the intake or fuel injection system, the Header/Presilencer combo offers the greatest performance potential."

From that i gather that you can replace the cats and keep the stock manifold then connect up the cat replacement/presilencer. Furthermore from this I have gathered that if i want to go to a header I will need to ditch the cat replacement for the header. So if thats the case it might just be more effective to buy the header back and if they have something to actuate my ports on the presilencer that would be awesome.

Yes its still an auto, yes i know i wont gain much by replacing the exhaust with my setup. I am just toying around with ideas for now, I have my reasons for wanting both AT and MT.

My Junx

Yeah that item you linked to is what I would go with if I where you. Just bolts to the manifold and back to the Y. Keeping the stock manifold will keep the noise down, but not get as much power out of it, but since it's an Auto you are dealing with tranny limits first of all. That setup will keep it a nice low and quieter tone but still let you drop some nice flames too

bdrx-7

i have RB header to a 2.5 striaght pipe 2 a apexi turbo muffler and i have enough pressure 2 open them bitches up so u should b cool

therotaryrocket

tranny limits?

TOOSHORT_88

iTrader: (15)

hey bro i got RB HEADER 2.5 CUSTOM Y PIPE.DUAL MAGNAFLOWS AND MY SHITT IS WIRED OPEN IDLES JUST FINE , I SEE A HUGE AMOUNT OF POWER INCREASE IN HIGHT RPMS . PLUS IT SOUNDS SO UNIQE, NEVER HEARD A 7 LIKE MINE..

My Junx

Yeah the auto tranny sucks all your power right out of the car. Modding the exhaust on an auto 7 is pretty much just a sound upgrade, not much in terms of real performance numbers. The tranny limits how well the power gets to the road.
Add more power (or take away less power actually in this case) and you still have to go through a power robbing auto. But it will sound better none the less.

Kouta

Yeah i know the AT sucks. I just looking at it for now for sound reasons/my cats are rusting out and making exhuast come up through the engine bay.

88rxn/a

iTrader: (6)

thats funny! i called rb the other day and they said that the header presilencer combo will bolt right to the y after cat. so your saying that they wont because the lenght is diff.? just curious cause im about to order them both next week.

ddub

The RB header AND presilencer will yes because they are a matched combo made to mate up to the stock catback. BUT just the header and the stock cat wont work, or the header and a bonez high flow cat wont work, or a test pipe the lenght of the stock cat wont work, etc., with the stock length/location catback. The presilencer is 20" long and the stock cat is 17.5" long, so when only using the header or presilencer by themselves you have to do some custom work.

88rxn/a

iTrader: (6)

GREAT! thanks for the info! they also told me that id get 18 hp at flywheel. is this true! thats alot!i also heard that they give you a acv block off plate,true? i plan to use the stock y pipe and use rb mufflers later anyone know how it will sound? what will it sound like without a catback and just header presilencer?

ramses666

iTrader: (1)

Yo! I just installed a complete RB Road Race Exhaust from header to muffler. It is F@#$% awesome!! It was truly a piece of art just to look at on the garage floor! It was really easy to install. After an hour or so of prep work - bolting the pre-silencer to the Y pipe - & reading the directions it took only 2 hours to remove the old junk & install the new system. It totally suprised me when I cranked the motor!! It just PUURRREEEDD like a kitten then jumped to life with a throaty growl then a scream like some kinda death machine muted scrream. It was much quieter than I expected & all my friends & neighbors are now happy that that damn noise has been fixed. I also did a K&N intake kit at the same time - other than that I have a Bone stock 88 SE. The car is now alot of fun to drive... just got to fix the stuck actuators or ports now.....

Anyway good luck

Ramses666

Molotovman

iTrader: (49)

haha, I have the Exact same thing, and a huge exhuast leak. I also closed up my ports.