I have never seen a borla system that made the exhaust less efficient... I have, however, seen many MANY exhaust systems and mufflers for other 'ricier' imports that sacrifice efficiency to tune the sound to a certain note. I think everyone knows what I'm talking about. A 5 inch tip on a 2 1/2 exhaust system, with a restrictive resonator after the muffler is definately a downgrade.

While I would agree with you that in most cases this is true, mods like putting a turbo or sc on a car will cause more restriction when cruising, slightly hurting mileage. Most driving IS cruising, so mods that add a certain amount of drag on the engine regardless of throttle position, will, on average, lower mileage.

as crazzyfusy said, this is not true since a turbo and/or a sc WILL reduce your mpg efficiency yet increasing your hp...
don't get me wrong, "your theory" is to be right. never the less this is a new car, a new engine and we don't know with certainty how it will react with certain changes. thats a fact. I know borla is a very reputable company with very high quality (and prices) and would make mods for the better BUT this being a brand new things no one just no one has the experience on it to determine sust conclusions.
And i know you might be right but i rather still be skeptical until proven wrong by phisical proofs from that car itself not just logics and theories and past w/ other cars (i am a big logic person but sometimes..)
heck i might get it to see myself..u never know

I understand your point. We need to think of a test scenario that will be accurate so we can find the answer we are all looking for.

Any ideas of how we can run a scientifically accurate test? In my opinion, it would have to be a comparison between aftermarket and stock exhaust with the same exact route, similar driving conditions, same weight and over the same time period/distance. If you want to get super accurate, RPM's and shift points should probably be kept close as well.

What other variables am I leaving out?

This will be an interesting test. Most of us are normally concerned with power, so this is kind of unique. I can't recall ever reading about an aftermarket exhaust MPG shootout. It's especially appropriate in California these days. We should sell the idea to a magazine!

I think it shows the 'overall' maturity of this forum. Quite different from others Ive visited.

Seems my orginal post was deleted. Maybe an admin fat fingered my post, next time inform me why.

I found the Borla exhuaust for $549.99 at:

http://www.rx-7parts.com/default.php

Shipping is about $25, plug your zip in to get a more accurate price.

You can use your Mazda screw-up AMEX card there too. I asked the owner if they would split up the price over two credit cards since it would be more than $500, no problem.

D-san

i believe it has a lot to do with the fact that vivid racing is a core sponser of this board.

why would they let your thread take away their business?

i think alll in all, since their price isn't that much higher than posted, go buy it from vivid to support the board.

That is a pretty piss poor way of doing business and I don't think Vivid would promote anything like that, I think someone took it upon their self to make that decision. Hmm, who is the mod for this section??? Any guesses? Thanks for the suggestion but I'll save the $25 for gas. Looks like Vivid price matches, so there you have it, saved everyone a bit of money.

OK - installed my Borla last night. There are some Hi-res pictures at the link in the signature, but here are the small versions.

I also took "before" and "after" sound recordings, but they are too big (1 Meg and 1.85 Meg) for the site, so if anyone wants a comparison taken 1 hour apart, in the exact same location, with the recording device (iPaq 3850) at the same location (by the rotary crest), PM me with your email address and I can email them to you promptly.

Pic 1 - the Kit - before installation:

Pic 2 - before:

Pic 3 - after:

Tpryor,
Excellent photos! They really show the difference between the exhausts.

I have a couple of questions for you about the install.

Did you have any problems reinstalling the spring bolts?

Did your kit come with a M6 nut to attach the ground strap to the muffler?

very , very nice pictures...! tell us about any change in mgp IF ANY!!

one question fo r every one.. what if we just do a straight pipe to the back?with a couple of resonators to lower the tone? that will increase the hp lots more, better mpg? and cheaper!! . on time for an inspection, just bolt the factory back on and u set.. would this work?

thats sounds more like it..now we need enouhg peps with the aftermarket one to compare

You know, it's interesting. I had heard on the forum (possibly from you) that the spring bolts were an issue. We actually had the LEAST trouble with those bolts - they went on by hand!

We assembled the system on the ground (all clamps loose), removed the plastic pieces surrounding the exhaust tips, hung the B-pipe hanger first, and the rest went together in 10-15 minutes (adjusting and tightening clamps, etc. and putting the plastic "surrounds" back on). The very last thing we did was reinstall the springs and bolts, and it was no issue.

We did NOT get a nut to attach the ground strap in the kit. On the parts list, it is not listed, so we assumed that they had no intention of including it. Luckily, we had one handy.

OK - SL01 (not the real name) has converted the files for me to post on the forum (THANKS!), so here goes:

Stock Sound:

Borla Sound:

nice
 

damm this sucks. The good side of me told me "danny dont buy anything for the car yet"But the bad side said "Buy it buy it u know u want to" guess who one im buying next week.:D

zoom zoom

General

Man, is this a great board! Great info, mature "audience," and some real experts. I look forward to reading it almost as much as I do driving my 8! :)

Coupla things: First, John at http://www.socalmotorsports.com says he will do the same price he gave me for the Borla ($560 including shipping) if you mention my name (Paul).

Secondly, question for David Borla or anyone who has put this exhaust on. Looking at that lovely 3" cat-back pipe, I began wondering if I will lose ground clearance as compared to stock. Will I?

Thanks...

What a great growl!!! I was almost expecting to hear "Zhoul" and see my eggs pop out of their container and start cooking themselves on my countertop!! :D

So who are you going to call?!? :p

We actually measured that, as it was a concern for us as well. The pipe bends through the same "hole" as the stock one, and the ground clearance (at it's lowest point) seemed to be very miniscule (less than 1/8"), and the more rearward you went, the ground clearance actually increased slightly.

Not a concern.

Re: nice
 

I have two devils on my shoulders, your lucky to have one side of reason



glad you finally got it tpryor
you waited so long, great pics

So Borla must have bent the cat-back pipe up a bit from the run of the stock pipe, to offset the additional width of the new pipe. Nice!

I'm really torn between borla and mazdaspeed. any advantage of one over the other?

Mazdaspeed offers full warranty still... thats a biggy. It sounds like borla gives a few performance gains, and I think the Mazdaspeed is only offers a richer rotary sounding exhaust note. what are your thoughts?

That puts some water on the fire.

I find it hard to believe that they would void the waranty to the powertrain because you went with a cat-back Borla exhaust.

Would that mean aftermarket mufflers void waranties too? Mineke might be out of business if that is the case.

I seriously doubt they would bring up warranty issues for a Borla catback.

Mr. Borla, what are your thoughts?

-Mr. Wigggles

I have put cat-back systems on all of my cars (even my wife's Volvo) for 20 years, and have NEVER had a warranty issue. The Borla (or any other system) will not affect the warranty coverage.

dealer must prove that aftermarket exhaust is causing whatever the problem may be to void warranty

so could we just do a straigth pipe with a couple of resonators to reduce the noise?

Mr. Borla, are you really the guy that is responsible for Borla, the exhaust?

We have over 150 employees here at Borla performance. It's truly a team effort! However, it's not just a coincidence that my last name is Borla. I do have an ownership interest.

Mr. Borla
I admire your humility:)

Ok, so where does this leave us, from warranty standpoint? Mr Borla, can you elaborate?

I think it's pretty clear. Borla has a warranty on their product, since I'm certain Mazda won't guarantee a product that's not theirs. It is the law that Mazda has to honor their warranty on the rest of the car UNLESS they can prove that the aftermarket parts contributed to any damage. Now that doesn't prevent individual dealerships from being total jerks however. Then you could simply find a lawyer or another dealer. There are some mod-friendly dealerships out there. Some will even install the aftermarket parts for you.

That said, I think as long as you keep the cat, most dealers should still honor your warranty.

And UNO, you can definitely just get a straight pipe with resonators, but I think it would still be very loud. These mufflers are all straight-through design so they don't restrict all that much.

thanks :D i hate it when i am ignored :mad:

As others have already stated, the dealer would have to prove that the aftermarket cat-back caused added stress to the engine or drivetrain. As we have dicussed, the opposite is the case so there's really no issue here regarding the factory warranty. As a matter of fact, there are many Maza dealers that sell the Borla exhaust for the RX8 as well as the Miata. Regarding Borla's warranty; All of our street products are warrantied up to one million miles. I believe that we have the most reputable warranty in the business. If warranty and customer service are a concern, you should really consider Borla exhaust.

I've done more than just consider it, I *bought* a Borla system for my RX-8! :-)

Thanks for the answers...

Borla exhuast
 

Hey guys that sound is awesome , it sounds real angry, really shows that the rotary can scream, if it wants too! I have a question though, why do the aftermarket exhausts pop all the time, can someone expalin it to me, and can it be avoided?



Thanks

That popping sounds to me like a backfire, and I think it was audible in the stock soundclip too... not very good. Maybe something is wrong with that 8? :eek:

Based on my experience with RX-7 rotaries, I believe the popping/backfire sound is normal, and a function of the rotary engine's design.

I test drove a new Volvo S60R ($54,000 300HP Inline 5 engine AWD) and it also popped in the exhaust. Dealer proudly stated that he can even get a little flame/spark at times. I am no expert but I think it is just part of having a more free flowing exhaust that is more concerned with performance than quietness.

Borla exhuast
 

I wouldn't really call that a backfire, I had a 1980 rx-7 for about 4 yrs , it was my first car and the start of my love for rotaries, but I can undoubtly say that that car used to back fire when cold , in fact my friends used to tease me about it, they said it sounded like a gun going off!! Anyway , Mr Borla can you please comment on why aftermarket exhuasts have that popping sound, Im very interested in knowing why.




Thanks...

The stock exhaust also pops if you let up on the throttle quickly but because the exhaust is so quiet it doesn't really catch your attention. Where as the Borla exhaust is noticeable louder and so is the resulting pop. So I think the pop is inherent with the Renesis.

FYI - If you don't like the pop then just ease off a little slower on the throttle and it never happens. ;)

BTW...people are calling it a back fire. I could be wrong....but I always thought "backfire" was when (in carburated engines mostly) combustion occurred in the intake manifold. Causing that Whoooosh pop inder the hood. Scares the christ out of anyone near the engine bay.

It is not backfiring, it's "burbling". This occurs when you lift off throttle. When the throttle body closes, you lose pressure in the exhaust, forming low pressure bubbles. These bubbles are what cause the burble when they "pop". An aftermarket exhaust that is freer-flowing than stock will accentuate this behavior. For even more burbling fun, remove the cat.

congrats ryan on the mod

Awesome posts to all. My 8 is only 2 days old and I am raring (or should that be rotoring?) to go for the Borla exhaust.

An open question to the folks who have converted to the Borla exhaust. Are you getting the same amount spluge residue as the stock pipes or has it decreased with the high flow exhaust?

Dynojet offers corrected hp. What that essentially means is that two cars on either side of the country can jump on the same model dynojet and their numbers can be compared. Dynojets correct for altitude, temp and barometric pressure (anything else?). So theoretically, if the input parameters for the correction factor are not fudged, the numers are "precise" in relation to one and other. Meaning, if one car records 180hp and one records 190, the 190hp car really is stronger.

Things such as dyno maintenance come into play as does the operator. it is possible to fudge the numbers through correction factors.

Dynojets correct their readings for differences in pressures and temperatures, but the engine itself will make more or less power at different altitudes and temperatures. Plus the fact that a rotary engine builds up deposits that actually affect it's powerband, so the way a car is broken in will actually affect the power curve of the engine (to an extent). The important thing in this situation is that this was the same car on the same dynojet, at near the same atmospheric conditions, so it is an accurate portrail of the HP gain offered by the only changing variable, the exhaust. Even though it may be a different absolute value, the relative change is what is important here.

Put on my Borla this evening :D The 8 has a little attitude now! As has been said -- it sounds a little deeper -- a little meaner. Just as I hoped it doesn't sound like a Civic fart can -- definitely sounds more mature and refined. At idle it rumbles a little more than stock --- during hard acceleration you can really hear the difference -- cruising at speed I really couldn't tell any difference from stock.

Installation -- this took me about 4 hours! Most of the time was spent trying to remove the dang rubber hangers - estimate 3 hours. I was going to just cut them off as tpryor suggested but I went to two auto parts stores and could only locate 1 replacement hanger! (Need 5 total) So I decided to remove them instead of cutting them off -- wow what a pain! I did end up cutting one off and using the one replacement I found -- not sure that was any easier -- the new hanger was so stiff I couldn't quite get it all the way on. If there is some secret to this -- I don't want to know at this point :( Everything else was as expected (except I broke another clip off of the exhaust cover plate -- broke one off when I put the exhaust finishers on). The spring bolts were actually the easiest part of the process. Well I managed to break a screwdriver and gash up my hands pretty good on those exhaust hangers -- still have one that I don't think is totally on right (the one closest to the spring bolts) -- just can't get it to stretch far enough.

Fired her up and went for a quick spin (1 am) -- sounds great and seems to rev a little more quickly. Didn't want to wake up all the neighbors so I will have to play with it more tomorrow.

Are you guys using liquid soap on those rubber hangers? It makes them slide on and off much easier.

jds