pros & cons of a true dual exhaust?
 

i will be putting on a dual setup on my 88GTU and was wondering from the guys that have experience with this kind of setup, what are the pro's and cons of the duals. i will be using RacingBeat headers w/straight piping and stock mufflers for now since i've spent too much on taxes and whatnot. I will be getting the other stuff like presilencer/s and RB mufflers when i save up enough money for it later on this year.



edit: i forgot to mention that i also have another setup i got from a junkyard that has the y-pipe and a presilencer. advice on which i should stay with.


go for the duals or get a flange put on the dual headers and use the presilencer w/the y-pipe?

Price and weight.

well, if i get the piping done around my house from teh same place that did my straight piping before it'll be like $60


if i go with the stuff from racingbeat, its gonna be like around $600

Yep, basically. Weight especially if you end up using the dual silencers, that can make it fairly heavy.

nm, i didn't realize it was a true dual setup. ;)

wow its a good thing u guys pointed that out to me, that hadn't crossed my mind, i don't mind the noise, i have straight piping right now with the stock headers and it doesn't bother me, my friend has headers w/straight piping on his vert and its about teh same as the sound of my car


oh yea i forgot to mention that i took off emmissions and eliminated the 5th & 6th port cylinders so backpressure isn't an issue for me

true duals i have heard flow a bit too much for an n/a, too much flow actually decreases power from the engine. think of exhaust like tuning the fuel, if you have too much flow then power will decrease, if you have too little flow power will also decrease. only a BP and a PP can handle the flow of a true dual setup unless you use smaller diameter piping.

If you don't care about noise, you can do this.

Get the road race header from racing beat with the dual outlets, take whatever mufflers you want, and have an exhaust shop weld piping straight from the header to the mufflers. True duals and only 2 mufflers, no presilencers. It WILL be loud as shit, though. Just fyi.

haha, u simplified what i was trying to say,


that's exactly what i'm gonna get done


dual headers --> straight dual piping --> mufflers

and i thought my T2 was loud, i can't imagine what an n/a would sound like! lol

Probably close to my old setup. Removed exhaust diffusers, streetported intake and slightly larger than streetported exhaust, RB collected header, straight pipe to dual ebay straight through mufflers (basically blown out).

Needless to say I couldn't handle how loud it was and I put in a borla xr-1 midpipe to quiet it down :)

You can make "true duals" in any diameter piping you like, so this is not a factor. Since Mazdatrix states that their "true dual" exhaust is only intended for non-ported engines, and I have never seen a rotary-powered race car with a "true dual" exhaust, I am going to assume that ported engines are better off with a collected exhaust. I just can't see Jim Downing driving a 787 or Kudzu with a short collected exhaust for all these years if a "true dual" were so great for ported engines. ;)

i simply made it a point so that the poster knows that a smaller diameter pipe is necessary for true duals. ;)

what size in diameter would u guys recommend?

Whatever the RB road race header outlet is. I'd just run it the same size pipe all the way back.

I'm currently using 2.25" for my true dual piping.. current setup is as fallows..

RB road race headers>2 22" maganflow presilncers>RB rear mufflers.

Piping is custom, and welded up by me.. bents are mandrel..

Power band seems is 4500-7800.. Pulls nicely till about 8200 but power seems to peak right around 7800.. stock port S5 enegine.


There is a definet differnece over stock..

The only cons I could think is price.. You might add 15 more lbs with the extra persilncer and piping.. but the wider powerband is diffently worth it.. If your going strait pipe.. not going to much of a weight differnce. I would diffently go with true duals.

I been in a few cars with collected system.. power diffently doesn't seem to match to mine.. and seems to fall flat on its face by 7k.

that's exctly what kind of feedback i was looking for. seems u have the same setup i'm shooting for. i can't wait to finish with my car soon, i miss that biatch ;)

Great...That's exactly what I'm planing to do. I already have the RB road race hdr, flanges, gaskets and a couple of fart cans, all I need to get is the magnaflow as a pre-silencer but my question is. Can I still open my ports if I attached the back pressure tube in to the new piping since she's an '86 na?

Any advise will be greatly apreciated.

Great... That's exactly what I'm planning to do, I already have the RB road race hdr, flanges, gaskets and a couple of fart cans all I need is the magnaflow but my question is. Can I still open my ports if I attach the backpressure tube in to the new pipping? since she's an '86.

Any advise will be greatly apreciated.

Has anyone thought about using single-baffle tractor mufflers as presilencers? They're light, dirt cheap, and tractors are run at WOT most of the time, so I don't think heat and reliabillity would be an issue. Any thoughts?

i was going to get a collected header for my n/a but after reading this im not too sure .... ( i have an 87 streetported na)

i want to get the road race header , but i dont want to pay 225 for their presilencer and all that... how much would i be looking to spend to get the road race header ( 200 bux), and get all the other components elsewhere ( presilencer, mufflers, etc)

i would get the collector, but if i can make power above 7k with this system , and wont make it with collected, then why get collected ? ... other plans for me may be getting the s5 intake conversion with vdi , and safc

^ VDI conversion is nice, well worth the effort.

http://www.exhaustproslinc.com/4rore.html

Thats what I used for presilncers.. then been holding up for over a year now.. including a few track days.

Edit: Heres a few vids that show sound and what not.. last one shows some fire balls.

http://www.mirror.wreckedyouth.com/v...unwinmedia.wmv 21.1MB

http://www.mirror.wreckedyouth.com/v...ndowsmedia.wmv 34.7MB

is this n/a or turbo setup because i have a s5 n/a and i was going to switch to 4port street port could i do this with both or is the 6 port better with this dual exaust one more question wats the difference in a car with a collected system to one with out thanx

Well its a N/a.. which is why we use headers.. as for 4 port question it has been my understand 6 port side plates will work better because it will provide nice lowend, if your 5&6th ports are working right... so unless its a big port job and will be track driven I don't see why one would go 4 port on an N/A.