bart_heemskerk

I plan to make a complete new exhaust system for my car. (stock port 12a) Thinking to do 2 borla proXS in line. So 1 acting as pre silencer and 1 as muffler. Using thick wall 2' pipe all the way.
Any comments on sound, loudness???
Thanks, Bart

kgray

With 2" piping, it will be fairly quiet.

mikewoodkozar

What the hell kind of car is that in your sig? Oh and search, this exact question has been beaten to death!

LokiRx7.1

iTrader: (1)

Is this a mid engine rotary conversion?? Mad props to you, you have some serious skills!

Just so you all know this is a Matra Murena, it is a mid-engine car that came with either a 1.6 or 2.2 four cylinder. Both of which were OHV and not all that muscular, I think it is a lovely car and entirely appropriate for a rotary conversion considering they were made in the eighties. It is a three seater, and a car made by the french.

Thats about all I know about them, if any of that is incorrect I apoligize. But this swap is very impressive! I would like to see more videos of your "Maztra"!

mikewoodkozar

Whoa! That is cool as hell, more pics please!

spankle my wankle

That website needs english version so i can understand the badness of the conversion...

LokiRx7.1

iTrader: (1)

I would say dual Borlas would be a good idea, anything you can fit underneath of your car to make it less obnoxious will be worth it. I dont know how long your exhaust is, so I am assuming you already know that two borlas will fit. Just make sure you go with a chambered muffler and not a straight through or glass pack. You will want at least one chambered.

Oh, and i hope you dont mid me posting a few of these pics, this is impressive!

dj55b

iTrader: (2)

bad *** car indeed and need a write up in another thread for everyone to view. 2 borla will be good, if you want a bit more fun in the higher rev do a 2.5"

Jeff20B

iTrader: (13)

Do you still have the Nikki? I remember you were complaining that the engine didn't have as much power as you thought it should have. One way to get more power out of Nikkis is to mod them a little. It is something you can do yourself. Search the forum to learn about the accel pump, mechanical secondary and choke simplification. Also up the primary jets to at least 95 (stock is 92) to work better with your stock ports. You could also try 100 (1.0mm) which I've tried on my '74 spec ported 12A with great results. I may try 105 on mine next but it might be too large for you.

Two borla pro XS and 2" thickwall pipe will work very well for you. The volume level should be acceptible.

Jeff20B

iTrader: (13)

Oops. Do you have a megasquirt? I just noticed the sticker pictured above. I assumed you kept the Nikki because you left the air cleaner lid sitting in your car.

bart_heemskerk

Search borla: 500 returns.. ... The posts i've read are all about borla as pre-silencer with an other brand muffler, or as muffler with (or without) an other brand pre-silencer. Not about dual borla setup.

The nikki will be replaced by megasquirt efi. I am now (still and slowly) in preparing stage. Collecting efi parts, throttle body, modifie intake.... When i install the efi, i want to have the new exhaust system ready.

Thanks for the input

Jeff20B

iTrader: (13)

Those borla posts are all mainly by 2nd and 3rd gen guys. I've searched too. I think you will be ok with two 2" borla pr XS in series. It is what I plan to use in my '81 S model. Well, I'll use 2.5" thickwall and 2.5" borlas because it will have an NA 20B but that's beside the point. If I had my red REPU's exhaust to do over again, I'd have gone with two Borla pro XS 2" instead of the rotary engineering glasspacks because the interior gets a little loud when you open the throttle. Hmm, there is enough room after the rearend that I could probably fit one borla under the bed back there if I wanted to...

So go ahead and get two borla pro XS 2" mufflers and thickwall .120" pipe. It is up to you to determine whether you need centered/centered, centered/offset or offset/offset. Whatever fits.

The reason I suggested modding your nikki now is because it is a worthwile thing to do. That nice 12A I put back in PercentSevenC's white '83 GSL really came alive after I swapped in some 100 jets. It already has the simplified choke, increased accel pump shot and mechanical secondary mod. The exhaust system consists of a stock manifold (not great for flow), straight thickwall pipe to a stock '83-'85 muffler. It sounds funny but it really moves!

PercentSevenC

It does, that thing has some kick.

Don't bother with chambered crap. Go straight through with Borlas, or a combination of Borla and Magnaflow like MosesX605 did. He has a sound clip of his car on here somewhere, sounds very low and mellow.

Box_Man

You could probably mount them one on top of the other (or would that be side to side?) like the Durocco has in the back.

Just imagine another one in the same position in front or behind the other.

(yes that's a Scirocco with two enignes)
http://forums.vwvortex.com/zerothread?id=2095097

LokiRx7.1

iTrader: (1)

IMO straight throughs sound terrible on rotaries. If his exhaust is anything like my MR2's which it looks about the same length, two straight throughs will sound like a straight pipe. I had glasspacks on a 4age, and it might as well have been an open manifold. Using a chambered muffler as a presilencer will be about the only way to get it anywhere near tolerable with such a short exhaust.

But then again, my idea of tolerable and good sounding may be different from yours. So go on your instincts, do what you want.

bart_heemskerk

My website is now translated in very bad englisch.
http://www.maztra.nl

Rx Seven

iTrader: (12)

I enjoyed the build up of your maztra on your web page that was great. I cant wait to see how the exhaust is goingto look when you finish.