Exhaust Review by mach1review
 

http://www.mach1review.com/CATBackEx...emsReview.html

even though they said magnaflow won, it was only by 4 rwhp difference against slp. slp made more tq than magnaflow or bassani. hey, not bad for a straight resonator design that was supposed to make you loose tq :), and cheaper than magnaflow,

loudmouth should be the winner here, best price, better average power, best sound. what else do you want :)

what do you guys think???

also, i'm installing an mrt h pipe next week, i was going to buy the jlt cai, but after seen all the little issues, i decided to play safe and get a mid pipe. i went with a catted h because of the sound. i would receive the pipe on july 6 (thanks yellowshaker) :CHEERS:

what do you guys think my car would gain with an mrt h pipe.????
loudmouth already installed :THUMBSUP:

I got my Magnaflow shipped to my door for $330. What did the SLP cost? The best sound is subjective. I had Magnapacks on my 01 GT and thought they were too loud. I've heard the SLP's on a dyno and they are obnoxiously loud. But, you can't go wrong with anyone of the catbacks reviewed.

did you notice the "what else do you want :)"
you can't go wrong with any catback at all, is just a matter of opinions. i said that as a joke, but is up to you to take it or no ;)

Awesome!! I have always been a believer in Magnaflow and I have always recommended the regular system to anyone who asks my opinion. Great review! I wish more companies would have stepped-up and submitted their systems for the review, but still a nice job. Confirms my bias! :THUMBSUP:

i wish the borla crew would have allowed for the testing of their cat back.

:agree: The borla is one of the systems Iam considering. Glad to see the others were close, Its probably going to come down to looks and sound for me.

The results point out exactly what my results concluded. Compared to stock with just the cat back mod, you will lose HP and TQ below 4K. You will gain HP and TQ over 4K. If can make up for the low end loss, then it is the thing to do because the top end gains are nice.

I think you missed what they were saying. It was the combination of CAI and cat-back that made it so lean and robbed the low end power. Seems like a dyno tune of some sort is in order with both of those mods.

Oh I got that. I just wanted to point out they also mentioned the cat back alone would cause a lower rpm loss. That was my point, but I guess I did not state it well. Sorry about that.

My A/F was pretty much 12.5 after 2300 rpm and hit a low of 11.9 at one point before holding at 12.5. Since this does not indicate a lean condition, I have to attribute the loss solely to the cat back flow design since it did not lean out the engine. I guess only the combo would do that, or would a CAI alone do that?

My question to you and everyone is: What is the best way to get the low end power back w/o going back to the stock cat back? I am new to EFI and computer controlled engines, so I need some suggestions.

Thanks

An intake spacer from PHP did it for me.

I was considering that (just as another mod), but did not want to do it until I heard the results. Thanks.

In August I am going with the MRT h-pipe and mag cat back not magpacks and there will be no losses only good sounds and good gains :HOPPY:

So, are you saying the MRT h-pipe will offset the losses from the cat backs alone because even the "Flows" will have low end loss just like the "Packs" do. How will the MRT h-pipe prevent the low end loss?

Huh...?
 

Dude, an H-pipe w/o cats, are you kidding? That alone will give you 15-20 hp...Isn't that more than enough to offset any low-end loss from the catback....?

Matter of Opinion
 

I really like the sound of the Magnaflows, as well as the power gains. I also had to take in to consideration the noise level (need to keep it quiet). I even went so far as to purchase and install the Bassani baffles in the tips (helps just a little bit). For the power, looks, noise level, and price it seemed like the best buy for me.

Robert

Re: Huh...?
 

Right, but I would not go catless. :D Unless I have missed something, cats are still required in Oklahoma.

I guess the MRT H-pipe referred to 40MACH1 are catless, right? If that is correct, I understand what you are talking about now.

I have the Magnaflow X/cats and Magnaflow catback. It's not overly loud at cruising RPM's, the 2 were designed by Magnaflow to work together, and I noticed no low RPM power loss. But my tune is good.


While I appreciate tach9 and crew's hard work testing the catbacks, I don't think it proved much by adding different catbacks to a car with CAI and not tuning for each. It did prove, to me anyway, that all the catbacks are similar in the power they make, and your decision should be based on factors other than reported power gains or losses. I believe Tach9 has said the same thing.

Ralph,

Thanks for the info.

Can you explain what you mean by "but my tune is good"? How do you know it is good. That may be the area I need to look into.

Again, thanks.

My A/F are in the 12.5 to 13-1 WOT range all the way.

I think you guys are making way to much over any potential low RPM power loss from bigger pipes. Even if it's there, and on my car I don't think it is, it's not very diffucult to be in the power range when necessary.

I also don't think there is anything wrong with just adding aftermarket H or X of choice, and weld in some straight thru muffs. I think you make about same HP a little quieter....and maybe a little lower in RPM curve.

You can't feel 10 HP on the street one way or another, and 5-10 HP doesn't make a performance difference on the street either. No matter what the butt o meter says.

lol on the butt o meter part. :CHEERS:

I don't disagree with you either. After 2200rmp my A/F was a flat 12.5 with one short dip to 11.9 so I think the tune is probably ok. Would like to see a flat 13.0, but that might be difficult to get.

I understand about getting into the power band. I went up against a C5 on the expressway and found out in a hurry about what gear to downshift to at 70mph with the new cat back. Going to 4th was a joke. The C5 showed me his tailend. Going to 3rd at 70mph got me above 4K and I could stay with the C5 and even pulled him a bit.

On the dyno we tested the shift level. Shifting at 6K the rpms stayed at or above 4400rmp so we were in the power band. I will learn to live there if I can not get back the lower end rpm. I may just go to the MRT cated H-pipe. ;)

this is a retarded review........ were are the chamber type mufflers, i.e flowmaster, mac flowpath. Arent the borla and magnaflow the same "straght thru" type muffler.

If you'd be so kind as to provide those systems, the M1R would gladly review them....as it was, those MFG's wished not to participate...don't blame the review, we're just a messenger :ANGEL:

Just wanted to say I found the reveiw interesting, even though not everybody wanted to send an exhaust to you. I would have liked to see the Borla Stinger but it appears that there isn't much difference between exhausts power-wise. Thanks

Curious how the borla catback would compare?
 

Thats what I'm lookin to get. Not sure what to do with the midpipe situation yet. Anyone here know any good midpipes to use with the borla? Does it matter or change the sound alot? Thanks

tach9
Sorry, did not mean to come across so harsh......I'll have to say those MFG's are retarded for not participating.

Frank, no worries...I too wish we could have gotten more MFG's to participate, but well Borla and Flowmaster etc...didn't feel that they needed an independent review, nor could they see the value apparently :SMASH: But the MFG's that did participate...I take my hat off to them!!! They understand the value and they respect what is happening online in all the car forums, enthusiasts are getting smarter and are not buying into their marketing hype. Magazine reviews are skewed, the Mach 1 Review is independent and unbiased....thus we just report the facts...Oh we may ad our "Subjective" comments, but they are always listed in the "Subjective Comment" title so that there will be no mistaking them for anything but their intended notes.

Looks like we'll be doing a full Predator Review and a X and H Pipe review next ....:ANGEL:

That sounds great! I'd love to hear some sold facts about the predator, I have been kind of skeptical about that thing.

M1R has already done some preliminary testing, and so far we have found the Predator is everything that the MFG says it is...it is easy to use, gives you control over some important functions and corrects some basic performance limitations. More to come in an official review soon...

Why do you lose?
 

If you improved the intake, and the exhaust, how could you possibly lose HP or TQ?
I would think you would stand to gain in both areas?

Re: Why do you lose?
 

The Mach motor as programmed from the factory MCU is rich (safe)...adding a CAI tends to lean it out..thus you gain a bit of HP/T...but by adding further a CAT Back..it leans it out further..so depending on how rich your system was in the first place..the lean condition created by adding the CAT Back may put you in a power loss situation until you can restore a better A/F ratio....YMMV..

So does the computer adjust?
 

So having changed this, wouldn't the computer adjust accordingly over time?

Do you have to tune, or get a chip to compensate?

Re: So does the computer adjust?
 

While the stock MCU is prety good about "learning" it has it's limitations. Tuning is the best way to get a better A/F ratio..and thus increasing performance. Chip or Predator....For most I think the Predator is the easiest and the least expensive route. Those that want the "Best" should look at custom chip flashing...YMMV

Definately an interesting and much appreciated review. Right now my mach 1 is stock except for 2 1/2 inch Vortech mufflers welded in w/3 inch chrome tips. The Vortech's are less expensive, and supposedly flow better than and sound the same as flowmasters. Everybody that has heard them so far says they do. My car is somewhat quiet, but has a mean exhaust note. I'm considering right now leaving the mufflers and rear end exhaust plumbing stock, and hooking it up to shorty headers mated up to an MRT catted H-pipe. Then I would add electronic exhaust cut=outs directly after the cats. That way I could be somewhat quiet when I wanted, keep the backpressure, and then go absurdly loud when I wanted to also. Anybody have any feedback on this particular setup I'm thinking about??/

-Thanks
-Dan:CHEERS:

Hey Dan, the Electric cut outs would definately make things louder..AV8tor on this list has them..IIRC..they cost about $300.00 and that doesn't include installation...for that kind of money. you could get a CAT Back from SLP, MagnaFlow or Flowmaster...if you shop around a bit...YMMV....FYI

Tach 9,

Thanks for the feedback. I know I could get a mean exhaust note with a good catback. I'm just thinking it would be cool if I had both a quiet exhaust and loud on the car. If I get a loud catback its always loud. But if I leave my vortechs on, it stays somewhat quiet when I want it to, then screams when the cutouts are open.

-Dan

good review:THUMBSUP:

exhaust
 

Does anyone know which exhaust mods., if any, will not jeapordize the warranty on the '04 Mach?

Re: exhaust
 

Most dealers will not say anything about a cat-back exhaust and it is emissions legal since you are not modding anything emissions related. Now noise emission on the other hand....it depends on how strict law enforcement is.

To all inquires,
I thought the exhaust review was great for all manufactures involved, However i must say i thought the subjectives notes inregaurds to SLP's loudness was highly exagerated. The SLP loudmouth cat back system, in my opinion was not too loud and i disagree that you could be heard from 10 blocks away. Maybe 2 or 3 blocks, but not 10. The installation was like what they said. I have the SLP loudmouth cat back system on my Mach1 and the installation took me 45 minutes on a hoist. It might take as much as a 1 1/2 for others but the installation was a piece of cake and probably the easiest exhaust cat back system i have ever installed and everything fit perfectly. At this point i wouldnt hesitate to recomend them to anyone that want an awsome sound. SLP has a tone all their own and thats what sets them apart from all other exhaust systems. Also note, i would go a little louder by getting rid of the cats and use a offroad H-pipe or X-pipe in place of cats. Dont waste your time with the catted pipes doods and you'll save yourself some money too. And though you many void your emission warranty at least you wont have cats to plug up your exhaust system or rob your engine of the power it truely makes. Its your choice. Thats my 2 cents.

Great review....I just wish you had sound clips.


Those SLP's look prety good. :THUMBSUP:

Great review....I just wish you had sound clips.


Those SLP's look pretty good. :THUMBSUP:

Cat-back exhaust
 

DanK, thanks for the prompt reply. What is exactly is a cat-back exhaust? As I read the Mach 1 review of the three exhaust types tested, they looked like much more than a muffler. Which system do you like for power w/o too much noise?

A cat back system generaly is everything from the catalyst toward the rear of the car. Which include mufflers, tailpipes, and tips. Some systems have the mufflers welded onto the rest of the tail pipes making it a two piece system. SLP makes their system in 3 pieces which makes installation a piece of cake. Some systems have mid inlet pipes, mufflers, talipipes, and tips. Depends on what system you want to use. This gerneraly is how a cat back system is defined.

Re: Cat-back exhaust
 

Orange Whip answered part of your question. If you look under your car you will see where the "cat-back" bolts to the stock H-pipe. As far as what exhaust I like....as far as power...we're only talking a couple of hp difference between exhaust brands. My suggestion is to pick by sound, fitment, durability, and weight. I went with the Borla Stinger cat-back from Performance Peddlers back in March. They had the absolute best price around as many others here will attest to...$405 shipped to your door if you tell them you are with the Mach 1 Registry. I had a lift I rented and removed stock exhaust and put on Stinger cat-back in an hour and twenty minutes. Everything fit perfectly and the system was really light. The tips are already in place so you don't have to worry about putting them on unlike some brands. Just alighn the tips in the center of the bumper exhaust cutouts and tighten all clamps. That is the hardest part of it all right there.

The exhuast sounds like the car is running under water when brand new but don't be alarmed. The exhaust will sound better (sweet) after a few hundred miles of break-in time. The sound is awesome but not overpowering with the stock H-pipe. Good luck with whatever you choose. :THUMBSUP:

Nice link
 

The testers remarked that the tone quality was very pleasant and gave the Mach 1 an authoritative note without an ear shattering loudness.

Everyone who's heard my car with the 'Flows on likes them. A couple of buddies who really aren't too high on the Mach loved the sound of the Flows. They aren't enough for a lot of people, but they are plenty loud for me.

That write up claiming a 12rwhp/8rwt gain from the Flows is consistent with my seat of the pants assesement. The car just seems to run a little stronger. The change in the A/F ratio's may explain why it seemed to run better with the Flows after I disconnected the battery to reset the computer.

cat-back
 

Thanks for the detailed info. One more question. Why not just get a muffler, why change out so much of the piping under the car? Isn't the muffler what makes all the difference? :gears:

Re: cat-back
 

YOu can do that too. tach9 tried that also(do a search) and found that at stock or near stock hp levels changing out the muffs was within a couple of hp of doing a whole cat-back. The larger piping will give a little deeper sound too. If I had my way.... I would want a mandrel bent 2 1/4" cat-back but they don't make one. Try it out and verify tach9's results. I went ahead with the exhaust I got so there is plenty of flow for mods done down the road. 2 1/4" would be perfect.

Magnaflw
 

I also had the Magnaflow X/cats and catback installed. The power gain was noticable the second I put my foot to the floor. I couldn't be happier. It was $950.00 well spent.