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stock exhaust and F/I

1K views 22 replies 12 participants last post by  redline814 
#1 ·
will F/I kill my cats on the stock exhaust?
I really don't want to change my exhaust from stock. I'm aware that I won't make as much power as I could if I had the Greddy or HKS exhaust.
 
#2 ·
goldark said:
will F/I kill my cats on the stock exhaust?
I really don't want to change my exhaust from stock. I'm aware that I won't make as much power as I could if I had the Greddy or HKS exhaust.
If you go with an s/c you should be okay. If you go with turbo, you will probably lose at least the first two cats. You'll lose the extra power as you stated, but a hi-flow cat is always an option.
 
#5 ·
DL said:
LOL it snaps, crackles and pops with the L-tuned also! Get a tru straight thru design exhaust at least 2.5" minimum. For maximum gains, get a 3" downpipe w/ no cats, and 3" full cat back exhaust!
No cats? :shame: :shame: :shame: The fines for this are enormous if you get caught. Fines for a shop that does this to your car is even more
 
#6 ·
Yes I know it's against the law, I meant for maximum gains at the track and off road use only. Sorry didn't clarify. You can get a hi-flow cat at the downpipe and that should not take away any power at all. But if this is a track car only then straight thru piping with the least restrictive exhaust you can find.
 
#7 ·
DL said:
LOL it snaps, crackles and pops with the L-tuned also! Get a tru straight thru design exhaust at least 2.5" minimum. For maximum gains, get a 3" downpipe w/ no cats, and 3" full cat back exhaust!
That's a negative. 2.5'' won't even get rid of it. I have the toyomoto catback exhaust which is 2.5'' and it snap crackle and pops all the time. You need 3'' to really get by with it :D
 
#8 ·
lil' IS 300 said:
DL said:
LOL it snaps, crackles and pops with the L-tuned also! Get a tru straight thru design exhaust at least 2.5" minimum. For maximum gains, get a 3" downpipe w/ no cats, and 3" full cat back exhaust!
That's a negative. 2.5'' won't even get rid of it. I have the toyomoto catback exhaust which is 2.5'' and it snap crackle and pops all the time. You need 3'' to really get by with it :D
lil, why is it snapping and popping? I don't have this sound on my HKS Carbon Fiber Ti. Are you sure you are not running a bit rich?
 
#9 ·
Wxman said:
lil' IS 300 said:
DL said:
LOL it snaps, crackles and pops with the L-tuned also! Get a tru straight thru design exhaust at least 2.5" minimum. For maximum gains, get a 3" downpipe w/ no cats, and 3" full cat back exhaust!
That's a negative. 2.5'' won't even get rid of it. I have the toyomoto catback exhaust which is 2.5'' and it snap crackle and pops all the time. You need 3'' to really get by with it :D
lil, why is it snapping and popping? I don't have this sound on my HKS Carbon Fiber Ti. Are you sure you are not running a bit rich?
It's because I go from a 3'' downpipe and mid pipe to a 2.5'' catback exhaust...It's killing my power and restricting the flow. If I hold a gear and give it cagasuse, it'll pop. On the highway at 3k rpms if I get off the gas and then accelerate again it'll pop also.
 
#10 ·
lil' IS 300 said:
Wxman said:
lil' IS 300 said:
DL said:
LOL it snaps, crackles and pops with the L-tuned also! Get a tru straight thru design exhaust at least 2.5" minimum. For maximum gains, get a 3" downpipe w/ no cats, and 3" full cat back exhaust!
That's a negative. 2.5'' won't even get rid of it. I have the toyomoto catback exhaust which is 2.5'' and it snap crackle and pops all the time. You need 3'' to really get by with it :D
lil, why is it snapping and popping? I don't have this sound on my HKS Carbon Fiber Ti. Are you sure you are not running a bit rich?
Do you want to sell your toyomoto exhaust? What is the piping on the toyomoto header? 2.5?

It's because I go from a 3'' downpipe and mid pipe to a 2.5'' catback exhaust...It's killing my power and restricting the flow. If I hold a gear and give it cagasuse, it'll pop. On the highway at 3k rpms if I get off the gas and then accelerate again it'll pop also.

Do you want to sell your toyomoto exhaust? What is the piping on the toyomoto header? 2.5?
 
#11 ·
lil' IS 300 said:
Wxman said:
lil' IS 300 said:
DL said:
LOL it snaps, crackles and pops with the L-tuned also! Get a tru straight thru design exhaust at least 2.5" minimum. For maximum gains, get a 3" downpipe w/ no cats, and 3" full cat back exhaust!
That's a negative. 2.5'' won't even get rid of it. I have the toyomoto catback exhaust which is 2.5'' and it snap crackle and pops all the time. You need 3'' to really get by with it :D
lil, why is it snapping and popping? I don't have this sound on my HKS Carbon Fiber Ti. Are you sure you are not running a bit rich?
It's because I go from a 3'' downpipe and mid pipe to a 2.5'' catback exhaust...It's killing my power and restricting the flow. If I hold a gear and give it cagasuse, it'll pop. On the highway at 3k rpms if I get off the gas and then accelerate again it'll pop also.
lil, I have the same thing. My 3" midpipe and downpipe connect to the stock resinator then the "off the shelf" HKS Carbon Fiber Ti exhaust. So, we have a similar exhaust setup. You must be running rich if you are having popping sounds like that.

On a side note, you can still pull massive hp on the car with a 2.5" exhaust. I am not sure why people think that 3" is a necessity.
 
#12 ·
VVTIS - Yes I am selling the exhaust. Check your PM for details.

WXman - I know it isn't a neccessity but you gotta keep in mind that you're being robbed of power if you're only 2.5''. I would expect to get around 30crank hp with the 3'' upgrade. Not to mention it'll help spool the turbo up quicker...there are many benefits to it.

And with the amount of power you have, you would benefit the MOST out of it!
 
#13 ·
lil' IS 300 said:
VVTIS - Yes I am selling the exhaust. Check your PM for details.

WXman - I know it isn't a neccessity but you gotta keep in mind that you're being robbed of power if you're only 2.5''. I would expect to get around 30crank hp with the 3'' upgrade. Not to mention it'll help spool the turbo up quicker...there are many benefits to it.

And with the amount of power you have, you would benefit the MOST out of it!
Alex, you will find out the hard way that power is not what it is about with this car. It is about traction. These guys are getting traction at the track, however we all know that is different. Getting traction on the street is a whole different story. Anything over 400 rwhp is almost impossible to get to the ground in 1st or early 2nd gear without very wide tires. So, even if I gained 40 rwhp... who cares????[/b]
 
#14 ·
Wxman said:
lil' IS 300 said:
VVTIS - Yes I am selling the exhaust. Check your PM for details.

WXman - I know it isn't a neccessity but you gotta keep in mind that you're being robbed of power if you're only 2.5''. I would expect to get around 30crank hp with the 3'' upgrade. Not to mention it'll help spool the turbo up quicker...there are many benefits to it.

And with the amount of power you have, you would benefit the MOST out of it!
Alex, you will find out the hard way that power is not what it is about with this car. It is about traction. These guys are getting traction at the track, however we all know that is different. Getting traction on the street is a whole different story. Anything over 400 rwhp is almost impossible to get to the ground in 1st or early 2nd gear without very wide tires. So, even if I gained 40 rwhp... who cares????[/b]
I guess for you it's easy to say who cares about 40rwhp when you have so much to spare :p

But it's all personal preference. I don't live my life a quarter mile at a time so I don't care too much about quarter mile times. In fact, I have NEVER gotten in a race from a stop with the IS on the street. Every single one was rolling, so traction isn't as important, it's the horsepower you're putting out. So that's why it counts for me.

Plus, 40rwhp is nice...people will spend thousands on N/A upgrades wishing they could reach that number. Stop being greedy! :lol: :chill:
 
#15 ·
Wxman said:
lil' IS 300 said:
VVTIS - Yes I am selling the exhaust. Check your PM for details.

WXman - I know it isn't a neccessity but you gotta keep in mind that you're being robbed of power if you're only 2.5''. I would expect to get around 30crank hp with the 3'' upgrade. Not to mention it'll help spool the turbo up quicker...there are many benefits to it.

And with the amount of power you have, you would benefit the MOST out of it!
Alex, you will find out the hard way that power is not what it is about with this car. It is about traction. These guys are getting traction at the track, however we all know that is different. Getting traction on the street is a whole different story. Anything over 400 rwhp is almost impossible to get to the ground in 1st or early 2nd gear without very wide tires. So, even if I gained 40 rwhp... who cares????[/b]
good point..... :wink:
 
#16 ·
This is why the Supra and most of the other big turbo cars don't get much respect from the V8 crowd. Many of the turbo guys just want to race from a roll. That is like saying that the other guy is faster overall, but I want to race from a roll because that is where my car is faster. People will always laugh those cars off. There is a 750 rwhp around here that will NOT race from a stand still. People laugh him off and honestly, I don't blame them. Don't take this the wrong way, I am just stating my opinion.
 
#18 ·
Wxman said:
This is why the Supra and most of the other big turbo cars don't get much respect from the V8 crowd. Many of the turbo guys just want to race from a roll. That is like saying that the other guy is faster overall, but I want to race from a roll because that is where my car is faster. People will always laugh those cars off. There is a 750 rwhp around here that will NOT race from a stand still. People laugh him off and honestly, I don't blame them. Don't take this the wrong way, I am just stating my opinion.
nah don't worry about it. No arguments here, just talking :)

It's just that I only get peoiple who race my from rolls...I don't expect someone to get to the same light as me when stopped and we'll go from there. The chances are so slim of that happening. Usually highway races are where people challenge me and get eaten alive :D

My races all occur rolling whether I want to or not, so in the end it benefits me :D
 
#20 ·
quick question...what does f/I stand for???


I really don't want to laugh, because I didn't know at one time either! BUT........... :lol: :lol: :lol: :lol: :lol: :lol:


F/I stands for Forced Induction, by the way, like a turbocharger or a supercharger. N/A stands for naturally aspirated, meaning it's NOT F/I.
 
#21 ·
Goldark, I would say if you were boosting at 7-9psi or lower, then the stock exhaust should be fine, you'll lose like 10 rwhp only. If you're planning on going 1 bar and above then start to look at upgrading the exhaust system on the car IMO.

Like Wxman stated, traction is the key once you start upping power. I used to have 235's in the rear and let me tell you traction sucked @ss big time. With 255's now it's a whole new world but I'm still spinning in 1st and a little in 2nd at 15psi. Listen to Wxman, save your money for wheels and tires 1st then look to upgrade the exhaust system later. And I hope your car came equipped with LSD!

BTW, Gabe where are you, has my TRD LSD shipped yet?
 
#23 ·
When I added the SRT Stage 2 turbo, I kept my L-Tuned exhaust. If I were to base my dyno on other Stage 2 kits running a full 3", the restrictive exhaust cost me about 25rwhp.

The nice thing is I could sneak up on a grasshopper in a field.
 
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