Celica Forums General Discussion Engine and Performance Axle Back Exhaust Question

ok guys i'm planning to buy an exhaust this week but i'm contemplating on which route to take. After jacking up the car and looking underneath and see how the whole exhaust system is made, I've come to the conclusion that I'm going to just do the axle back. My question is...

Would it be better to just buy an axle back system such as hks, apex, etc? Or just buy the apex n/a muffler, mandrel bends, and diy?

I know people will say that brand name is better because you pay for the brand and the time they took to develop the product. It seems very expensive for just an axle back system when I look at the prices.

Will I have significant loss of power if I just diy over buying an axle back from one of the companies or will I just lose minute power? I like the diy because it gives me a fun project to do and i can choose to angle the exhaust the way I want it. And it's way cheaper The companies axle back come with that resonator right at the axle part and doing a diy will eliminate that and just go pipe to muffler. By doing this i'll lose some back pressure, but do I look to hurt the overall performance more than what a companies axle back will do?

thanks

you wont ever have to worry about back pressure on our car its a 4 cylinder so yea. read the exhaust facts and misunderstandings. also i would say go with a axleback system. better gains and sound

i read the exhaust facts and misunderstanding but still didn't find any conclusion. Either way if I diy or buy a name brand it'll be axle back. I guess my main concern is if I go with diy, will I lose more power down low since i won't have that second resonator like the name brand axle back has (ie. hks exhaust)?

you probably won't lose that much HP I heard with the header back kazuma you lose alittle low end but gain a ton of high end power. the only question is can you make a design that will actually give you any kind of gains. the exhausts that are on the market today really do range from 0whp to 6whp or so. so the design of the exhaust does matter as well as the muffler used. I also heard that 2.5" is the best for N/A cars.. BTW where can you get mandrel bends?(I am assuming your going to buy prebent tubing and weld it cause mandrel benders are expencive).. but if you can weld and have access to mandrel bent piping if you wanted to you could do a cat back exhaust. Our cars have almost no low end anyways so high end HP is totally the way I would go. and with a light weight car and a zippy little 4 banger the RPMS get up there pretty damn quick especially if you've got a 6speed. All aftermarket bolton exhausts beside the cat eliminating kazuma are axel backs. I think the trd only has the one muffler. TPR is supposed to give you 10whp or something crazy unbelievably better than all exhausts in existance but they're hard to get, maybe you could pay easy c 50-100 bucks for the design and you could DIY yourself one up. He uses magnaflow or flowmaster or something one of those american exhaust company mufflers.

yep, that's what I was thinking. The worst that could happen is no gain at all. I do have access to mandrel bent pipes and have my own welder so fabing it is not a problem. Ridiculous though down here for 2.5" 180 degree steel at a price of almost $40 when I can get it online shipped here for about $25.

I guess for now i'll just make the axle back and maybe later make a full cat back.

thanks for the reply

just get the name brand, as far as i know the only catback system out there is TRD Kazuma. but its not quite legal

any reason why i should just get the name brand over buying a universal apex n1 and diy?

if you do it yourself, get 2.3-2.4" piping (mandrel bent). this is the best diameter to compensate for mid-though-high rev ranges. if you get the pipes crush bent then you want 2.5" inch (to compensate for the rougher bends).

and the only technology you pay for in name brands is that they use a 2.35" pipe with mandrel bends and a good straight-through muffler (the stock muffler is 'staggered').

so if you can get your hands on a good muffler, a shop to do the mandrel bends, and the correct piping size..then you effectively have every bit of 'technology' as a name brand exhaust.

bottom line: an exhaust is a piece of metal, it's not that complicated. just do it right.

I have a GReddy EvoII "cat-back," but it is really axle-back. Everyday it seems to get louder and the high-end torque seems to be widening. (just as advoed) Love mine!

the kazuma isn't cat back it's header back you toss your cat. with the kazuma you will not pass emissions in most places and you will get pulled over and ticketed for the loudness of our exhaust. but if you don't care about the cops or they don't care and you don't mind switching your exhaust out when you go to get inspected every other year then your all set. also not caring about the greenhouse effect and poluting the world with many harmful polutants and contributing the the destruction of the world and all.

people of the world, unite!! wonder twin powers activate! and form of a tree...the shape of water!

no, it's a cat-back as already noted, NOT a header back.

you can get it to function as a header-back but you'll lose a lot of power because the stock ecu uses the readings from the cat. if you use it as a header-back then you need to replace the stock ecu, which is NOT what it's meant for.

it's meant to be cut at the cat, therefore making use of the stock ecu to make improved gains.

yea i think im going a diff route with my new exhuast plan as before i was going to get the rs*r exhaust but now after reading this i think im going to go with a apexi n1 titanium muffler and get a shop to fab something with 2.5inch piping hopefully i can figure something out im not to worried about gains so and i want this exhaust to be angled im just wondering would my car fit on the lift with my buddyclub2 kit and a 2inch drop all around

^^ it could fit on some ramps..but its doubtful many places would risk it. a lot of shops around here decline to do cars with a body kit (even without a drop) for risk of cracking a bumper and having to replace it. sucks, but i have to agree with them...$15 bucks isnt worth replacing an expensive bumper.

and as long as the exhaust isn't a strait pipe and the muffler resides in the stock location...an angled exhaust will generally have better gains than one that has to bend to be flush with the back bumper. this is only a rule of thumb and of course depends on a number of things..but given 2 identical (except for the final angle/bend)..the angled one will do better.

yea i going to go and see if they can do it

garble i can only get the mandrel's in 2.25 and 2.5 inch pipe. Almost all shops down here crush bend and I've only heard of 1 mandrel bender on this island but idk who has it. So I guess custom fabing it is the way to go. Now the hard part is to find a cheap flange that one cost me and arm and a leg at the machine shop.

well what type of driving do you do? if your interested in a higher peak gain but don't mind losing a little bit down low, then go with the 2.5" mandrel.

if you're more interested in daily driving and every now and then you take it out for a race, then get the 2.25" mandrel.

it's mostly daily driving, but when i was looking at the piping, it looks like 2.5" until the axle. So wouldn't i just go with 2.5" since that's stock?

2.5" isn't stock. i forget what the stock diameter is but it's no more than 2".

but yes you would be correct..it's best to have the same size piping length the whole entire way, granted it's not a restrictive or overly wide pipe.

o wow i must've been hella tired wen i saw that. It looked like my 2.5" pipe. Either that or he had a cat back and only changed the axle back back to stock. It looked odd becaues the axle back (stock) part looked like regular steer. The pipe from the axle to the cat was blackish like it was powdercoated like catbacks do. hmm...

WhiteCeli, if you go down the DIY route please post some pics before it goes on the car, as I'm thinking of doing this myself in the UK as to get a system imported this side is around $1000!!
Or if you could email them to samfinch1@aol.com that would be great.
Good luck.

i should be doing it by next if i can just figure out what muffler to get. Gonna get just a ebay one for now since this is my test project and don't want to mess up the real good one in case this turns out to be a disaster.

I'll take tons of pics and do a write up or something of how to make an axle back and which/how many mandrel bends it takes.

an axle back should only have two primary bends. one from the flange to the muffler and another from the muffler to the exit pipe at the rear.

if you're going to do it DIY though, why not get a strait peformance muffler (apexi offers a few of these) and go almost straight from the flange to the rear exit?

flange > pipe > muffler > exit pipe. this should work with minimal bends.

if you use the stock location for the muffler you will need 2 primary mandrel bends, as i said earlier.

flange > mandrel bend to muffler > muffler > mandrel bend to exit

yea i was looking at it but wasn't too sure because it needs to go under the rear axle and not be in the way of the rear lower control arm. Also, I was gonna angle the exhaust. Do you know if i need only 2 90 degrees or 2 180 degrees. I'm so drunk right now so idk

lol well you definately don't need to 180 degree bends...that'll just put you back where you started.

on the stock setup (and most axle-back exhaust systems for the celica) it's 1 90 degree run to the muffler and then another 90 degree run to the rear. if you want to angle your exhaust though then you could probably do somewhere around a 60 degree bend to the rear instead of the 90.

thank you very much. Imma just go for now with crush bent since i already have straight pipe and my bro in law's shop will do the bends for free. This is gonna be on a generic muffler anyway so it's kinda like a mock up. thanks for the info and i'll take pics and such

if you crush bend, go with 2.5" or 2.6" pipe. that way it'll compensate for the more restrictive flow

if you're not really worried about it then thats fine. but that would be the best thing to do

yep i got 2.5" pipe. Long ago I was going to make a 2.5" downpipe and exhaust for my turbo civic so I have about 10ft of 2.5" piping left over. Hopefully it'll go smoothly. By looking under the car, even with eibach springs I'm going to need a small exhaust like a n/a n1 size since the ground clearance is close