Mandrel bends worth it?

[mrdirty]

Anyone have any experience with the power difference between 2 1/2" mandrel bends and 2 1/2" crushed?

Also, will my stock cat work with a 2 1/2"?

[tnord]

click here (http://www.zilvia.net/f/cgi-bin/ikonboard.cgi?act=ST;f=2;t=8048)


or here (http://www.zilvia.net/f/cgi-bin/ikonboard.cgi?act=ST;f=2;t=8211)

there are some good posts in there, and some that are just me yelling at people

[240sBoMex]

yeah, i was hoping someone been through that too... now thought u brought up my post from before, tnord <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'> , can someone back up or fight the idea that =>
Mandrel Bent = better for higher horsepowered cars... power is greater affected due to larger volumes of exhaust gas flow
Crush Bent = just as efficient for NA low HP cars like our 240's... less amount of exhaust gas flow happenin' to really matter?
The muffler shop guy told me on a Drag Hi-performance race car, the substituion of Mandrel Bent piping slice off, at most, -0.1 sec off its 1/4 mile time (IMO doesn't seem extraordinary)
Does this sound rite? &nbsp; <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/cool.gif" border="0" valign="absmiddle" alt=':cool:'>

[guidot]

On a higher hp car the thing is it has so much flow coming from the engine anyways, i don't think it would matter if it was crush or mandrel bent. On a lower hp car you are looking for more flow so you get the mandrel bends, which doesn't create the turbulence of the crush bends...

[tnord]

i'm going to make this real simple;

if you care about going faster: mandrel bends are the only option

if you just want to be loud: drill holes in your muffler, get a replacement muffler, or go the most expensive route and get crush bent cat back

[nrcooled]

It's completely opposite

For lower hp cars it is more important for a mandrel bend because you want to optimize the exaust gas flow much as possible.

Hp gains are from 0-2hp with a crushed bent pipe compared to 5-7hp w/ a mandrel bend. &nbsp;Why just waste 200-300 bucks when you can spend a little more and get exactly what everyone on this forum wants..........MORE HORSEPOWER!!

But don't go run out and get the Apex'i N1 single because you will lose torque

[Jeff240sx]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240sBoMex @ April 24 2002,05:11)</td></tr><tr><td id="QUOTE">can someone back up or fight the idea that =>
Mandrel Bent = better for higher horsepowered cars... power is greater affected due to larger volumes of exhaust gas flow
Crush Bent = just as efficient for NA low HP cars like our 240's... less amount of exhaust gas flow happenin' to really matter?
The muffler shop guy told me on a Drag Hi-performance race car, the substituion of Mandrel Bent piping slice off, at most, -0.1 sec off its 1/4 mile time</td></tr></table><span id='postcolor'>
As for the dragster thing. &nbsp;.1 seconds is a lot. &nbsp;It is the difference of 3.9 second quarter miles, and 3.8 second quarter miles. &nbsp;That is a HUGE difference.
Second, everyone here says mandrel, and you wanna argue. &nbsp;Do it, go get crush bent. &nbsp;Since nobody here can change your closed minded, narrow view on this, stop posting here either. &nbsp;You create a war, and then do your own thing.
Third. &nbsp;(This is to others) &nbsp;The main purpose of a exhaust pipe is more to suck the air out the exhaust. &nbsp;Air is a liquid-like gas. &nbsp;The faster something moves, the lower the pressure of it. &nbsp;Then, the lower the pressure, the more the air moves to fill in that spot. &nbsp;And it moves, and creates a low pressure behind it. &nbsp;A vaccuum, if you will.
If you get the perfect pipe, the exhaust gasses will be sucked out of the cylinder, rather than pushed. &nbsp;This sucking out helps incredibly on torque, since the piston has less work to do.
So, to get the best vaccuum, you have a pipe with an equal sized inner diameter, and very few bends. &nbsp;Keep the bends to less than 30* if you can. &nbsp;
Crush bent just wont do. &nbsp;Air gets spun around after hitting the wrinkles in the walls, causing turbulence for the rest of the airstream. &nbsp;Thus creating a barrier for the new air getting pumped out the cylinder, and more work for the piston, cuz it has to push harder to get the air past the turbulence.
I like tnord's way of explaining better. &nbsp;
Crush bent flows like mandrel bent after I take a dump in it after eating taco-bell.
-Jeff

[Omega]

Only 2 ways to go mandrel bent or pre made cat back, all depends on what u want and how much cash u got

if you are going to get crush then why even do it? our car has crush stock, if u are going to upgrade then dont do it with the same shit

[mrdirty]

Well my mind is made up to go mandrel already; I'm really just looking for what to expect; like are we talking 6 Hp or 12 or what?

[240sxspeedracer1]

well, NRcooled said 5-7 so I guess we can go for that.
I have no idea what the feeling would be between uping up HP 5 and upping it 7, so you can just tell your friends you now have 7 more hp(well, after you do the exhaust job)

[Broadwayblues]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">On a higher hp car the thing is it has so much flow coming from the engine anyways, i don't think it would matter if it was crush or mandrel bent. On a lower hp car you are looking for more flow so you get the mandrel bends, which doesn't create the turbulence of the crush bends...
</td></tr></table><span id='postcolor'>
It's the opposite.Just like NRCOOLED said. I am going to school to be a pilot and hence aerodynamics. As the speed of the air increases past a point, like a crush bend that causes the air rushing past to be disturbed, the drag increases exponentially. Ok in English, as flow from the engine encounters the crush bends, the flow tumbles. Just making up numbers say 100 HP causes a loss of 5 hp. So 200 should lose 10 HP. But since it's exppmemtially, it's actually like 25 HP lost.
So as you can see, it's a matter of your plans I guess. On higher horsepower cars, it's very benifical. On my car for instance, I would go with the crush bends. Don't have a lot of money and the universal muffler I got from PDM $150 prob won't get a huge increase from my car. Later on when I can afford one, I'll get a cat-back pre-fab from someone. Right now I think that the money I would spend on mandrel bends, I can see myself getting a $140 K&N intake, where I think that I would see a bigger increase in power.

[vududoc]

I have to agree with that last reply. i really havent seen a reason for mandrel unless running a t3/t4. i run crush with an econo can and opened it up to 2.5" on the piping. Check the place out before you go that way you dont end up with a serious hack job. im lucky and live next to 3 race tracks so the guys here are savvy bout the installs and run theyre own racers. do your research and you should make out. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'> &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'>

[tnord]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (vududoc @ April 26 2002,10:55)</td></tr><tr><td id="QUOTE">I have to agree with that last reply. i really havent seen a reason for mandrel unless running a t3/t4. i run crush with an econo can and opened it up to 2.5" on the piping. Check the place out before you go that way you dont end up with a serious hack job. im lucky and live next to 3 race tracks so the guys here are savvy bout the installs and run theyre own racers. do your research and you should make out. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'> <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'></td></tr></table><span id='postcolor'>
what about any other turbo, like a T25, are they not good enough for mandrel bends, what exactly in your mind justifies such a rediculous expense? what about NA race cars? no turbo there, i spose it's just a waste of money to put good piping on them. and oh yes......i forgot, you live next to 3 race tracks, so none of the shops are trying to make a quick buck, they don't want to take your money, they only want to give you the best equipment for your money. give me a break. may i ask how many of these tracks require right turns, if turns at all?

do it.......all of you.....get crush bends please, then i can be faster than everyone and you guys will think it's because i'm such a great driver

from now on i'm implementing a "no comment" policy on all exhaust threads because no matter how much information or proof you give these nimrods they just don't want to believe you.

[AceInHole]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (tnord @ April 25 2002,01:18)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (vududoc @ April 26 2002,10:55)</td></tr><tr><td id="QUOTE">I have to agree with that last reply. i really havent seen a reason for mandrel unless running a t3/t4. i run crush with an econo can and opened it up to 2.5" on the piping. Check the place out before you go that way you dont end up with a serious hack job. im lucky and live next to 3 race tracks so the guys here are savvy bout the installs and run theyre own racers. do your research and you should make out. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'> <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'></td></tr></table><span id='postcolor'>
what about any other turbo, like a T25, are they not good enough for mandrel bends, what exactly in your mind justifies such a rediculous expense? what about NA race cars? no turbo there, i spose it's just a waste of money to put good piping on them. and oh yes......i forgot, you live next to 3 race tracks, so none of the shops are trying to make a quick buck, they don't want to take your money, they only want to give you the best equipment for your money. give me a break. may i ask how many of these tracks require right turns, if turns at all?

do it.......all of you.....get crush bends please, then i can be faster than everyone and you guys will think it's because i'm such a great driver

from now on i'm implementing a "no comment" policy on all exhaust threads because no matter how much information or proof you give these nimrods they just don't want to believe you.</td></tr></table><span id='postcolor'>
can't we just leave it that heavy crush bends WILL NOT produce a laminar flow and therefore will negate any piping size calculation, thus defeating the purpose of a catback??? &nbsp;or are people still stuck in the muscle car mentality of "backpressure"<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>

Mandrel bending is also not as expensive as everyone makes it out to be.... compact mandrel benders don't cost the multiple tens of thousands of dollars people seem to think they do....... &nbsp;I had mandrel bent piping (2.25") done for my S13 for $100 + the price of the muffler.... ($220 at the time total).

[240sBoMex]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Second, everyone here says mandrel, and you wanna argue. Do it, go get crush bent. Since nobody here can change your closed minded, narrow view on this, stop posting here either. You create a war, and then do your own thing.</td></tr></table><span id='postcolor'>
Ouch, that hurt,
when i said 'fight' i meant that i was probably wrong and for people to say how come.
Yeah, mandrel bent isnt that expensive at all, but i was talking in the context of having a dual exhaust setup, which nearly doubles the price of a single cat-back system.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">rom now on i'm implementing a "no comment" policy on all exhaust threads because no matter how much information or proof you give these nimrods they just don't want to believe you.</td></tr></table><span id='postcolor'>
Sometimes you can be Real Mean and your insults kinda hurt sometimes, but i like your straightforwardness. &nbsp;Keep postin', just ease off a little on cutting ppl up maybe?. thats what i say...

Btw, im getting mandrel bent

[Broadwayblues]

well i got my muffler put on and since i live in a small town, nobody does mandrel bends anyway! Turns out I didn't have a choice. I got a unversal from Don and the removable tip is great, my wife will not drive the car with the muffler wide-open.

[rotaryknight]

Bottom line is what do you want to be? &nbsp;RICER or Racer. &nbsp;There are so many kids out there that have no idea what the hell to do and all they do is look at magazines and try to cheaply copy it.

YES there are some modifications where a name brand or expensive will not make a difference but read and use common sense. &nbsp;If you really can't afford it.....DON"T DO IT.

Again my point that modifications compliment each other on the car still stands. &nbsp;At this time maybe you are not going to get much HP out of just an exhaust...but believe me later as you mod your car more a crappy exhaust will come back to bite you in the ass.

Remember you bought a N/A 240 sx

[rotaryknight]

Damnn got cut off.

Anyways you bought a 240sx which is a 2.4l 4 banger....simple mods do not increase HP any mind blowing way. &nbsp;On turbo cars like FD you free up the entire exhaust motor back you are looking at a 40+ hp gain, mustangs you do the same and gain 15-25. &nbsp;When you start with a higher base HP comes a lot easier.

Going back to the mandrel bends imagine a straw and bend it to 90 degrees...that's crush bent.