Exhaust - Toyota Nation Forum : Toyota Car and Truck Forums

TheOtherCarolla · 09-17-2006, 10:14 PM

Do you guys think a full exhaust would be worth it on a geo prizm 4afe. I put an intake on there and noticed it was a little quicker. Do you think getting some more air out would help enough to make this car more fun?

I plan on doing a header, downpipe, and mandrel bent 2.5" exhaust.

I have the money to do it, Im just wondering if its money well spent.

89yotarollagts · 09-17-2006, 10:59 PM

you wont make that much more power with a stock car.... you just think you got more power therfore you might be satisfied ; )

Flashmn · 09-18-2006, 09:00 AM

Why dont you first decide if you really want that turbo or not, because it seems like you're going back and forth with that.
2nd, naah, it wont make much difference as the head is the real restriction.

trexbob · 09-18-2006, 04:19 PM

I've been asking myself that same question since finding my cat is shot and the pipe behind it is too, not to mention the front downpipe is rusted to the cat. My only thought is that I believe your 2.5" might be too big for such a small (output) engine. Too big and the exhaust velocity gets low and you lose power (especially low end torque). So they say... First hand experience: when I did a cat-back exhaust change on a 1.8l volkswagen from 2" to 2.25" it made a noticeable difference, so I'm thinking that might be a better size. Ebay headers are cheap, and so are universal fit cats.
Or maybe I'll just sell this rusty POS I've got and get something rear wheel drive!

89yotarollagts · 09-18-2006, 04:27 PM

well whether you turbo or not a cat back will be a nice upgrade
as far as ebay headers well you get whatcha pay for i currently have an OBX from Ebay & had a bit of fitment issues but its great upgrade as it will get rid of that rusty d/p you talken about..

freakinbox · 09-18-2006, 06:58 PM

exhaust makes more of a difference on a higher output engine. If you do a bunch to the engine then make the exhaust conform to what you have done to it then you will find you get more from it than just shoving it on a stock car.

TheOtherCarolla · 09-18-2006, 07:16 PM

I decided not to turbo. Although the idea is appealing, I just dont have the time or money to do it right. I don't want to do it half assed.

The head has been reworked. I took it to the machine shop and had the runners P&P'ed and the head was milled. It moves pretty good for a stock 1.6.

Kr0n1k · 09-18-2006, 07:45 PM

I got an exhaust on my 93 Prizm, 2.5" of eBay (I'm assuming that's the one you're looking at) and for the $235(shipped) I paid for mine, I think it was worth it, just to get rid of the nasty, hole ridden, stock exhaust I had on it. Its not too bad on noise, maybe a little loud for some, but cops don't mess with me, although in NC, I don't think you'd have that problem anyways. Its decent quality, the welds look damn nice for the price, although I'm going to warn you, it has a spot for an 02 sensor that the 93 does not have, so you'll need to plug it with something ( I don't remember quite what I got, but it was in the plumbing section of Home Depot and cost me less than $.50 ). I can't comment on any header, seems as though I haven't bought one yet, but all in all, the exhaust is pretty good, and does leave some room for a GZE if you decided to go that route. Cheaper and more reliable than a turbo kit, and allow for a (safe) turbo upgrade later on.

TheOtherCarolla · 09-19-2006, 08:52 PM

What other mods can I do to really take advantage of a full intake and exhaust? I drive the car every day, so I can't really rip the head off since that will take a while.

89yotarollagts · 09-20-2006, 12:17 AM

well then there aint much you can do if your not willing to tear into it.. i was gunna mention some beefier cams... basically you wont gain much power/ nor take full advantage of all bolt ons without building the motor for more power..

Flashmn · 09-20-2006, 09:09 AM

if you keep the head stock, you're shit out of luck powerwise, since you decided not to turbo.

Beemik · 09-21-2006, 10:50 AM

these are the parts i bought from ebay
header+flexpipe
obx high flow cat(look in one end and see out the other, no honeycomb, catalyist is on walls)
greedy style n1 catback(tsudo exhaust)

Like was said in prev post the catback has place for other sensor i used the plug from the header to plug the hole in the catback!! perfect fit.
the obx cat shown is for a acura i think but it is very similar to the one you can purchase and the one i did purchace.
i had no fitment issues with any of the parts except the catback seems to sit a little low. there are no brackets to pull it up so im thinkin on putin a bracket on to bring it up some

notice how i didnt burn in the header properly. a very spotty uneven burn looks like shiiit. but is fixable if you want to get out the metal polish, then wash then idle the car for about 20min or until fan kicks on. then get on the highway and do 120km/h or about 70mph in third for about 2min. you will then get a nice even blue, purple and gold burn in. I work in a machine shop and had one of the metelergests look at the steel he said it is a high grade stainless.

yull hav to pardon the pics they were taken with a v710 camera phone
this is the obx highflow cat. i notice i get some deep vibrations at around the 2800rpm mark if i try to gas it. it sound as though its comming from the cat and resonator area but could be the lack of support on the catback im not sure.

this is where the catback sits a little low

the cap in the pipe comes with the catback. the large hole in the end is standard. i had to put the cap in the drill press and drill the smaller holes because it wouldnt run with just the one hole in the centre. i had no power. put the gas to the floor and it wanted to stall. sit at a light and it wanted to stall. i took the cap off and it sounded like shiiiit. its a high flow muffler so its straight through without the cap there is not much muffling goin on. there is a pipe from the large hole in the centre of the cap that goes back into the muffler i also cut this short and drilled some holes in it.

The full exhaust does sound a little airy when at idle or low rpm but when you hit the 3400rpm mark and higher i think it sound pretty good. you will notice that the car does idle a little lower but that is due to losing alot of back pressure. after i put this full system on the car i went and picked up my girlfriend and i punched it at the same set of lights i alwas punch it as when pickin her up. i reved to the same 6000-6200rmp redline i always do and she said " why does the car seem so much faster " she made me smile and say " its suppose too "

just thought this might help u decide.

Beemik · 09-21-2006, 10:56 AM

oh forgot did the install myself. had to cut off the old exhaust but all together it went pretty well and took only a few short hours.
good luck!!

TheOtherCarolla · 09-23-2006, 11:26 PM

Dang man, thats not bad. You did this all without a lift?

I love how that header looks. I think Ill buy them when I get my paycheck.

The only thing I will do different is leave the stock cat. In out county its "illeagal" to replace it or some crap, but I dont think it will hold me back too bad.

Beemik · 09-26-2006, 01:25 AM

yeah without a lift. i made some crude wood ramps to get one end off the ground at a time about 6inches. i think its illegal here in Canada too. im gonna get an emission test done before i have to redo my government emissions test and see if i have to put on a stock cat for the test