[ash1]

I'm slowly adding extras to my Supra and was curious as to which would be more beneficial. A cat back exhaust or a header. I have eliminated the resonator chamber on the intake and also replaced the airbox with an HKS filter. Thanks for the info.

 

[RaptorRacing]

Most people usually replace their catback first as a general rule. Check out www.rabidchimp.com for a MK2 catback. Good Luck.

 

[WadeT]

A turbo is most beneficial.

 

[Push]

a header is useless, if you have a stock exhaust. I say, go cat-back first, then header. Right now I got a HKS cat back exhaust on my car with no cat. Sounds great, and power in the higher rpm's is crazy! Right now I am looking for a header and a toysport bent intake pipe.

 

[Norbie]

Nonsense. 90% of the performance gains you'll get from an exhaust comes from the first metre or so after the engine. A good cat-back system will help but nowhere near as much as a good header.

If you want performance, get the header.

If you want to make noise, get the cat-back.

Ideally, get both.

 

[Supra_devil]

do the cat back then the header, the header will doits job better with the rest of the system freed up already.

 

[glntom]

If you still have stock exhaust, get it off first, increase to 2.25 inch minimum, with free flow type muffler. Then add the headers.

 

[SupraFiend]

Nonsense. 90% of the performance gains you'll get from an exhaust comes from the first metre or so after the engine. A good cat-back system will help but nowhere near as much as a good header.

If you want performance, get the header.

If you want to make noise, get the cat-back.

Ideally, get both.

I don't know about that Norb. The gas can't flow faster then the biggest restriction in the exhaust, and I think most would agree that the biggest restriction in any oem system is the muffler.

IMHO, do neither. Save for the whole shabang or buy what you can first, but don't install anything till you can afford to do the complete exhaust system. Reason being, if you buy/make just one, then it has to be comprimised to fit to the remaining stock components. Stock piping is what, 2 inchs I believe? If you go with a 2.5 cat back then it has to downsize to 2 inchs at the flange. Even worse, if you get a header that has to bolt to the stock cat back then it has to downsize to the stock catback. Then when you do get the other, both systems are comprimised by the stock systems piping diameter when neither need to be and the flanges where they meet will be your new bottleneck. If you absolutely must, get the catback as its not as hard to elminate the downsized section. Most of the mk2 headers are coated so you don't want to be doing that to the header.

 

[atdsupra]

I believe it is about how it flows, not amount of it ( in a stock car) , headers minimize backpressure from system allowing fluids to go smoother and "freeing" some load to the engine, then, an increased diameter will help to make it flow faster . . .

For me, the header and then the cat back . . .

 

[Zean 82]

probrably better to do it all at once. It'll feel even more like
a dramatic change if you do both together AND It'll be less
work so you don't have to go BACK in and pull stuff out again.

 

[rumptis]

Just run 6 pipes out the Hood it would be really loud and you would have no restriction. You could even get 6 of those Tractor Exhaust Flaps also those would look awesome.

 

[moon]

cat back is the better way/... think.. it can only blo as much as room as there is so puttin hearders then little exhast on after is pretty pointless so cat then headers.. i got pace setters they good gotta grind the p/s pump bracket thou...

 

[badboysupra]

I would go cat back first (2.25"-2.50" piping) then, gut out the cat (press a pipe inside the cat) so its straight through. and install the Headers afterwards, if your not satisfied enough with the cat-back. coz thats what I did =) my set up: HKS hiper muffler (80mm in/ 120mm out), 2.5" straight pipe, gutted cat, pace setter header (non ceramic & it looks ugly after a week of driving).

cat-back = noticeable increase of power from low-mid end
cat-back+gutted cat= more mid end & throttle response (a lot!)
cat-back+gutted cat+headers= more power! hella mid-top end, more throttle response, sucky gas mileage & exhaust smell. but all in all= more POWER!!!

 

[glntom]

I would go cat back first (2.25"-2.50" piping) then, gut out the cat (press a pipe inside the cat) so its straight through. and install the Headers afterwards, if your not satisfied enough with the cat-back. coz thats what I did =) my set up: HKS hiper muffler (80mm in/ 120mm out), 3" straight pipe, gutted cat, pace setter header (non ceramic & it looks ugly after a week of driving).

cat-back = noticeable increase of power from low-mid end
cat-back+gutted cat= more mid end & throttle response (a lot!)
cat-back+gutted cat+headers= more power! hella mid-top end, more throttle response, sucky gas mileage & exhaust smell. but all in all= more POWER!!!

Did you modify the O2 sensor placement to move the sensor into the direct exhaust flow in the 2into1 collector?? If not your ECU is not getting good sensor data to adjust air/fuel, hence the sucky mileage and smell. I am haveing a new 2into1 collector built which will not have the rough fitting and poor weld quality of the pacesetter, it will have a 2.5 inch output.

 

[badboysupra]

I didnt do nothing on the 02 sensor housing, I was reffering of an ugly smell from the HEADERS due to its melting paint. and the smell of a rich mixture from my exhaust (and it was normal to me) because of my AFM and ignition mods. technically, my engine runs fine and well after I did the exhaust mods. with my exhaust set-up and custom KBR spec 3" intake with 115mm HKS super megaflow intake and other engine mods and chassis/body lightening, I got my previous '83 MKII running a best of 13.8 @ 105 mph (Sacramento Raceway), with street slicks tho. anywayz, I'm just saying that I never had any problems whatsoever regarding about the new pacesetter header and its 02 sensor housing & check engine light issue. thanks!

 

[moon]

I would go cat back first (2.25"-2.50" piping) then, gut out the cat (press a pipe inside the cat) so its straight through. and install the Headers afterwards, if your not satisfied enough with the cat-back. coz thats what I did =) my set up: HKS hiper muffler (80mm in/ 120mm out), 3" straight pipe, gutted cat, pace setter header (non ceramic & it looks ugly after a week of driving).

cat-back = noticeable increase of power from low-mid end
cat-back+gutted cat= more mid end & throttle response (a lot!)
cat-back+gutted cat+headers= more power! hella mid-top end, more throttle response, sucky gas mileage & exhaust smell. but all in all= more POWER!!!

Did you modify the O2 sensor placement to move the sensor into the direct exhaust flow in the 2into1 collector?? If not your ECU is not getting good sensor data to adjust air/fuel, hence the sucky mileage and smell. I am haveing a new 2into1 collector built which will not have the rough fitting and poor weld quality of the pacesetter, it will have a 2.5 inch output.

i never did either but im going to cuz there is no way that its gonna git a correct reading way the hell up that pipe..

just cut the top fitting off , with enuff room to weld it bak on and cut at the y weld ,,

 

[WildriceinitialD]

If you really want to help hp, get rid of that freaking cat. Have someone weld you a "test pipe", and you will notice a difference. I noticed no difference with a cat back. Having no cat and a cat back exaust makes you notice a difference. Add the headers to it and its not a huge difference, but it will be more then enough to make you smile when you push on the gas. That and a really good intake would be a pretty good upgrade. Past that there is not really any more low worry mods you could do to make more power.

 

[WildriceinitialD]

A turbo is most beneficial.

hear hear, a turbo is most beneficial. However, if you put a turbo on, I would redo your motor to accomidate that big of an upgrade. I know you may be thinking that "yeah I'll just leave it at stock boost, It'll be enough for me" , you wont. Turbo's feel waaaay too cool at a higher boost to leave them at stock boost. If you leave your motor alone and push the envlope, you will have a huge price tag after a little while. Just some hintfull advice. Enjoy!

Skot