Exhaust system Thread.

[D.J.T.]

(((Any questions on exhaust?? Post here!! & If you find another exhaust thread that already exists please do let me know.)))

Ok so i was searching for Exhaust system options but i only found divorced downpipe threads & such. Decided to make a thread.... Well, I just got a downpipe Megan i believe. 2.25" to 3" & i ordered three 3.15" flanges & a 3" cat so it would all bolt up since the system i have now is all welded & rotting & is basically crap. so i was wondering what muffler to get. Nothing too expensive now. Something stainless steel. Anyone have a thread already let me know & would putting a 2.25 inlet to 3" outlet muffler at the end affect performance? Ive never messed with exhaust systems before Only Engine rebuilds hence the ignorance.

 

[hvyman]

There is a thread around here somewhere on what every exhaust sounds like with youtube videos.

1. ditch the stock elbow and get full dp.
2. do 3in turbo back. Bigger if you have a shit ton of power.

No point in upgrading the exhaust only to have 2.25in anywhere in the exhaust.

 

[D.J.T.]

There is a thread around here somewhere on what every exhaust sounds like with youtube videos.

1. ditch the stock elbow and get full dp.
2. do 3in turbo back. Bigger if you have a shit ton of power.

No point in upgrading the exhaust only to have 2.25in anywhere in the exhaust.

Daing, so that means the 2.25" to 3" pipe is a waste?? & im going to use stock elbow. Main reason is because my OEM DP is torn @ the flexible part & the heat gets inside the interior so its cooking me alive. But i guess if i do go 3" all the way back ill have the system ready for a full 3" since all i would need to change is the DP. well depends if i get a turbo kit & get a differen't DP thats not for CT26 right? Im only 18, by the time im 23 ill have more $$ to spend. Im running Stock, & only reason i would waste money like this is because i really need to fix that problem. & if anybody know the link please post it. so that others like me can also find it. Thank you!

 

[shaeff]

Daing, so that means the 2.25" to 3" pipe is a waste?? & im going to use stock elbow. Main reason is because my OEM DP is torn @ the flexible part & the heat gets inside the interior so its cooking me alive. But i guess if i do go 3" all the way back ill have the system ready for a full 3" since all i would need to change is the DP. well depends if i get a turbo kit & get a differen't DP thats not for CT26 right? Im only 18, by the time im 23 ill have more $$ to spend. Im running Stock, & only reason i would waste money like this is because i really need to fix that problem. & if anybody know the link please post it. so that others like me can also find it. Thank you!

He's implying that having a 3" exhaust doesn't have as much benefit if there's still a 2.25" restriction in it. Get a downpipe with an integrated turbo elbow. That alone will make a huge difference.

 

[D.J.T.]

He's implying that having a 3" exhaust doesn't have as much benefit if there's still a 2.25" restriction in it. Get a downpipe with an integrated turbo elbow. That alone will make a huge difference.

I see so the 2.25" to 3" is a waste. Oh well by the time i get older i will be more knowledgeable & know more about what im doing. Mean time ill be raising money & researching. I can keep stock for 4 years for sure, im in no hurry. What really grinds my gears though are the Haters.... >:/ i guess ill learn to overcome this in time?

 

[Chaingun]

Im only 18, by the time im 23 ill have more $$ to spend.

LOL seconded, at 18 i had a '93 cavalier rs, bought it with a 5speed an in need of some love. I worked that car for 4 years and had it finally ready for paint. Bored, stroked, cammed, and 2.75 in exhaust with a custom manifold. Took me 4 years to get it to that point, but i'm 23 now and i've already got enough parts to do what i want to with my supra in 2 months than i did the first year on the Cavi. Hopefully my supra doesn't end up as a 2 foot square cube like it did.

 

[bioskyline]

i got the same downpipe. you will notice a slight increase in performace over stock, but not as much as if you erased the stock elbow.

anways back to your question. now that the exasut is opened up to 3 inch, you must keep it 3 inch all the way. reducing the end down to 2.25 for a muffer just made all the 3 inch pipe useless, finding a muffler with a 3 inch inlet isnt easy, not to many places have one on the shelf.

megan racing makes one, so does hks. best bet is ask the guys at an exaust shop what they have on the shelf. o

 

[hvyman]

Not hating. But seems like a waste to me just to do it over again. Might as well get a 3in in and out muffler since there about the same price.

 

[D.J.T.]

Not hating. But seems like a waste to me just to do it over again. Might as well get a 3in in and out muffler since there about the same price.

I meant haters on the streets.... like seriously they be in their civics revving engines. One even slammed the brakes on me once & then turned around to see my reaction & there was plenty of space i MEAN PLENTY before the redlight... OMFG :: angry :: that just boiled my blood.

& true that. ill just go 3 inch all the way back & some day get the Divorced downpipe. Thank you all much for listening to me. Seriously appreciate it. :bowdown:

---------- Post added at 08:01 AM ---------- Previous post was at 07:59 AM ----------

LOL seconded, at 18 i had a '93 cavalier rs, bought it with a 5speed an in need of some love. I worked that car for 4 years and had it finally ready for paint. Bored, stroked, cammed, and 2.75 in exhaust with a custom manifold. Took me 4 years to get it to that point, but i'm 23 now and i've already got enough parts to do what i want to with my supra in 2 months than i did the first year on the Cavi. Hopefully my supra doesn't end up as a 2 foot square cube like it did.

Well thank you for giving me hope. Lol :icon_bigg

 

[D.J.T.]

I heard something about PRESSURE in the exhaust & a muffler shop told me to keep it 2.5" for pressure? whats this pressure he speaks of? ive used search & it says only use 3" exhaust when about 500 horses!! So would putting a 2.25" at the end help with this "Backpressure" ?? Im running stock & i don't think ill go bigger in the next 2 years lol. im still learning

 

[Chaingun]

The pressure you're thinking of is back pressure on the exhaust and there are quite a few factors as to what affects it. your best bet is honestly to get an exhaust system that is designed and tuned for your overall horsepower goals. Elimination of to much back pressure or making a custom exhaust that's not tuned to what you have or will have can have very negative effects on your motor check out this article on exhaust manifolds and especially the section on scavenging. http://en.wikipedia.org/wiki/Manifold_(automotive)#Exhaust_Scavenging


honestly the best way to learn is to do, find what works and what doesn't by trial and error, knowledgeable friends, the TSRM, and when necessary Wikipedia lol
The internet will be your best friend when restoring and modifying your car, the short time I've been here I've gotten a lot of info from the members here, and i know that I'll be a member as long as i have a supra, but any serious changes to your car should be planned, researched, doublechecked, and researched again to avoid the mistakes we all eventually make.

 

[mecevans]

Get the Driftmotion downpipe, best price around. If you only have money for one part of the exhaust get the dp its the main restriction. I have seen many aftermarket exhaust systems that taper to a smaller size. This is due to the deletion of the cat where the exhaust is alot cooler downstream

 

[hvyman]

Dont worry about back pressure. Its kinda an old skool myth.

Get 3in for turbo cars. Above 5-600hp get 3.5-4in. Turbos like big free flowing exhausts.

 

[Chaingun]

Back pressure is far from a myth, without proper pressure in most engines you'll burn up valves, have poor performance, run hotter, and all around screw up your motor, as the hot gases expand into the exhaust they help draw in a fresh charge of clean air, to much restriction will prevent that, as well as having too large of an exhaust will cause it to slow down and hinder performance. The entire purpose of tuned headers is to use the exhaust gas from the previous firing of a cylinder to speed up the overall movement of exhaust gases, making the charges of gas move in sequence with each other. i honesly don't know that much about turbo motors, but i'll wager that Toyota does, and they put the correct exhaust on the car to match the CT26. i'd agree with removing the Cat in every case (if you can get away with it) but unless the you're running a bigger than stock turbo, why bother with 3" exhaust when the car doesn't need it?

 

[bioskyline]

yes, lack of back pressure is one way to achevice the flamethrower exaust, or at the very least the "pop pop pop" when you lay off the gas, but seems to be more a N/A thing, which is why all those hondas with there fart can blue blue smoke, as they cooked the valves. but at the same time to much backpressue in a turbo application seems to kill perfomance, since its a compound effect. all that compressed air going in, has to get out, and so you need to keep the turbine out free, ther is a reason here but i cant think at the minute, but it has something to do with the pressure slowing down the turbine itsself. ill look into this and get more info.

in my experiance, atleast with the megan dp, there seemed to be enough pressure pre-turbo to keep the motor happy, but i was over the 300hp mark so maybe i was lucky and got away with it, since i never had an issure with blowing blue, blowing black yes, but not blue.

obviously age and engine wear may have something to do, since most of the honda's with the fart can, rev the living shit out of there cars all day long, which im sure the abuse is one of the main casues for valve burning, wouldnt surprise me there even hitting valve float at those 9 grand shifts.

 

[mecevans]

You want the greatest pressure in the manifold and the lowest in the dp. Its like heat it always flows from high to low. The greater the pressure difference the faster it will spool. I Would only go 3in after the dp if the cat is deleted. You want 1-2 psi of exhaust pressure at wot. Laguna seca is practicly my back yard and I have seen many high powered turbo cars such as the HPF M3. They all taper down to a smaller size by the time they the reach the tailpipe. I haven't had any dyno time with.the supra but when my teacher was doing a demonstration on a saab turbo with differnt exhausts sizes on the dyno it was the one with.the most hp and torque.

 

[D.J.T.]

yes, lack of back pressure is one way to achevice the flamethrower exaust, or at the very least the "pop pop pop" when you lay off the gas, but seems to be more a N/A thing, which is why all those hondas with there fart can blue blue smoke, as they cooked the valves. but at the same time to much backpressue in a turbo application seems to kill perfomance, since its a compound effect. all that compressed air going in, has to get out, and so you need to keep the turbine out free, ther is a reason here but i cant think at the minute, but it has something to do with the pressure slowing down the turbine itsself. ill look into this and get more info.

in my experiance, atleast with the megan dp, there seemed to be enough pressure pre-turbo to keep the motor happy, but i was over the 300hp mark so maybe i was lucky and got away with it, since i never had an issure with blowing blue, blowing black yes, but not blue.

obviously age and engine wear may have something to do, since most of the honda's with the fart can, rev the living shit out of there cars all day long, which im sure the abuse is one of the main casues for valve burning, wouldnt surprise me there even hitting valve float at those 9 grand shifts.

Wow. thank you for teaching me this... im thinking about a Magnaflow 14806. I have no idea how it will sound like.

 

[Chaingun]

^^ seconded, like i said i know little about turbo cars, with this being my first. after researching a bit more it does seem like the less back pressure after the turbo the better, due to the expansion of the gas across the turbine being what turns it. that should produce a fairly constant stream of exhaust after that point but with a stock motor 3" seems a bit much. perhaps not though. The sound of your exhaust is the reason fart cans were made lol, anyone know of good mufflers that would be good for this application?

 

[D.J.T.]

^^ seconded, like i said i know little about turbo cars, with this being my first. after researching a bit more it does seem like the less back pressure after the turbo the better, due to the expansion of the gas across the turbine being what turns it. that should produce a fairly constant stream of exhaust after that point but with a stock motor 3" seems a bit much. perhaps not though. The sound of your exhaust is the reason fart cans were made lol, anyone know of good mufflers that would be good for this application?

LOL i was also thinking about a Magnaflow 14835. OVAL.. or to keep the back pressure a 14825, just a round muffler with a long tip. I want to avoid the fart cannon sound at all costs.

 

[radiod]

The inline 6 engine won't typically produce the "fart cannon" sound, so you should be pretty safe with whatever you go with.