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Discussion Starter · #1 ·
All opinions and advice are welcome .
2.5L motor with 4-1 DNA short race headers. Update on exhaust no cats no resonators no muffler. For Low end torque and better off the line power is single or dual exhaust better? I'm asking cuz I've studied and studied single and dual exhaust for better torque and some mechanics and tech guys say single then they say dual and it goes back and forth.lol. that's common in the gear head community. My idea is to custom do my whole exhaust system down pipe back I have literally all I need to do single or dual.
 

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All opinions and advice are welcome .
2.5L motor with 4-1 DNA short race headers. Update on exhaust no cats no resonators no muffler. For Low end torque and better off the line power is single or dual exhaust better? I'm asking cuz I've studied and studied single and dual exhaust for better torque and some mechanics and tech guys say single then they say dual and it goes back and forth.lol. that's common in the gear head community. My idea is to custom do my whole exhaust system down pipe back I have literally all I need to do single or dual.
If you have "studied and studied " and were told conflicting information, which you say is common in the "gear head" community, are you alluding that we are not gear heads...so you will believe, without question, what we say?

I reccomend that you fabricate an exhaust pipe of not less diameter than 3.14 inch, joined with a tail pipe of 2.83 inch. This has been proven to give the best low end torque and massive top end HP gains for the 2.5 engines. As an added bonus, without a muffler or resonators in your system, and with your header, you are now eligible for sponsorship from Rice-A--Roni, as your exhaust noise makes you a full fledged ricer.
 

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Discussion Starter · #5 ·
If you have "studied and studied " and were told conflicting information, which you say is common in the "gear head" community, are you alluding that we are not gear heads...so you will believe, without question, what we say?

I reccomend that you fabricate an exhaust pipe of not less diameter than 3.14 inch, joined with a tail pipe of 2.83 inch. This has been proven to give the best low end torque and massive top end HP gains for the 2.5 engines. As an added bonus, without a muffler or resonators in your system, and with your header, you are now eligible for sponsorship from Rice-A--Roni, as your exhaust noise makes you a full fledged ricer.
Very funny because I'm in contact with a guy that travels from Japan to America on a regular oh by the way he works for Nissan on the nismo line . So everybody here in the states keeps telling me to go 3inch all the way back and he said the qr25de hates 3inch exhaust especially if I'm doing a full motor build which is what I'm doing. Keeping it NA . I've already played around with 2 n a quarter and 2n a half and the perfect set up is 2 inch all the way back and to not lose to much backpressure create my own bends by changing the stock route and placement of the bends. I will be sending the exit out the back behind the passenger tire under the bumper . It blows his mind how people say they love jdm vehicles but don't like the loud Japanese raspy sound of a properly done exhaust on a car that is being made to scream quick n fast.... people really need to understand why the whole Rice jokes were made. It's very offensive to Asian people !!
Unless they was born n raised here then nope probably don't. There is a reason why Japanese cars that are turned into race machines with authentic Japanese mods aka parts tuning etc.. last longer and can bang gears at 9grand and higher and actually last!!! I get on here and actually ask for advice and I get grown folks talking like smart ass children!!! I'm good tho I'll keep chatting with the nissan tech/mechanic from Japan that knows this car inside and out and what he has told me I've tested and it works! So that's who I'm going with. Plus if I've got the money then I'll spend it on what the hell ever I want! Once it's all done I can at least say I have something that's my own creation it's different and I didn't just buy the typical name brand stuff, I can custom fab my own product that works just as good maybe even better and got the desired results.
 

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"All opinions and advice are welcome." Who wrote that?

Since you have a contact with a Nismo tech/mechanic, who offered you advice, why did you want advice from us regular guys and gals?
 

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Discussion Starter · #7 ·
"All opinions and advice are welcome." Who wrote that?

Since you have a contact with a Nismo tech/mechanic, who offered you advice, why did you want advice from us regular guys and gals?
I asked advice b4 I came in contact with Yoshi. But the ricer joke was very unnecessary. I don't do that to others weather they like euro American or Japanese vehicles. Some people like loud raspy exhaust and others don't but we don't have to be rude about it. All opinions and advice is opinions and advice for hp and torque I have already stated I don't care about the loudness as long as I have improvement with these then why would I care when I'm turning this into a street/strip and track car? Same goes for high comp racing cams that can clearly give away that my car is cammed especially from the lopey idle . As long as it's doing the job I want it too then that's the point in making a race machine.
 

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I actually like the sound but hopeless on a car because the legally required exhaust is too long and thus you can call it tuned exhaust all you want but it isn't. There being no such thing as a tuned exhaust that extends beyond the middle of the car. Why you hear rasp, the more throaty part got killed part way back and where your true power is.

I have personal experience on hi-perf engines of all types, BIG American V-8 and up to over 1500 hp. pro stock drag racing and lots of Japanese 2 stroke and 4 stroke hyperbike racing too.

There is no such thing as necessary backpressure once your pipe gets anywhere over 30 inches long, after that you do everything you can to kill backpressure as it kills power. And, any thing that is classified as a 'shorty; header will pretty much be junk as it cannot work tuned because it is too short. If you want to talk about backpressure I will talk about a backpressure 'spike' but only momentary and timed to do a specific thing and most people do not have a clue. Talking about backpressure signifies someone like that, that stuff died in the '40s and lost science dead and deserved.

You can also get rid of most of the cam lope of the biggest cams to fool people if you know how to do it.

When you are working with a full length exhaust system on car you have to recognize there WILL be lost power, you can recover part of it but not all as the system is too long and never will be 'tuned' true wave tuning cannot work in that length.

I don't care if person saying the opposite comes from Japan or Russia, that is wrong.
 

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It will bore you to death but it tells the tale.
 

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Discussion Starter · #10 ·
I actually like the sound but hopeless on a car because the legally required exhaust is too long and thus you can call it tuned exhaust all you want but it isn't. There being no such thing as a tuned exhaust that extends beyond the middle of the car. Why you hear rasp, the more throaty part got killed part way back and where your true power is.

I have personal experience on hi-perf engines of all types, BIG American V-8 and up to over 1500 hp. pro stock drag racing and lots of Japanese 2 stroke and 4 stroke hyperbike racing too.

There is no such thing as necessary backpressure once your pipe gets anywhere over 30 inches long, after that you do everything you can to kill backpressure as it kills power. And, any thing that is classified as a 'shorty; header will pretty much be junk as it cannot work tuned because it is too short. If you want to talk about backpressure I will talk about a backpressure 'spike' but only momentary and timed to do a specific thing and most people do not have a clue. Talking about backpressure signifies someone like that, that stuff died in the '40s and lost science dead and deserved.

You can also get rid of most of the cam lope of the biggest cams to fool people if you know how to do it.

When you are working with a full length exhaust system on car you have to recognize there WILL be lost power, you can recover part of it but not all as the system is too long and never will be 'tuned' true wave tuning cannot work in that length.

I don't care if person saying the opposite comes from Japan or Russia, that is wrong.
Very well put thanks for the input I understood it.
 

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All opinions and advice are welcome .
2.5L motor with 4-1 DNA short race headers. Update on exhaust no cats no resonators no muffler. For Low end torque and better off the line power is single or dual exhaust better? I'm asking cuz I've studied and studied single and dual exhaust for better torque and some mechanics and tech guys say single then they say dual and it goes back and forth.lol. that's common in the gear head community. My idea is to custom do my whole exhaust system down pipe back I have literally all I need to do single or dual.
The more air you run through the engine the faster it will go! Many cars can also require a certain amount of back pressure as well or the emissions system goes 🤪 If you want to go fast Ricky Bobby then hit it with a dose of NOS or a turbo! Keep driving with the fear!! 😂 🤙
 

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All opinions and advice are welcome .
2.5L motor with 4-1 DNA short race headers. Update on exhaust no cats no resonators no muffler. For Low end torque and better off the line power is single or dual exhaust better? I'm asking cuz I've studied and studied single and dual exhaust for better torque and some mechanics and tech guys say single then they say dual and it goes back and forth.lol. that's common in the gear head community. My idea is to custom do my whole exhaust system down pipe back I have literally all I need to do single or dual.
OK, if you have to do something with the exhaust do this! You say you have a header so under the drivers seat area where the exhaust runs cut it and put a Y in it. Attach a throttle butterfly from an old style carb (Holly 650 double pumper works well) in the open end of the Y, use the rest to put the exhaust back together. Then run a choke cable mounted by the shifter to the butterfly. When you want to have exhaust (no cops around) and your about to run it. Pull the choke cable and just run it open dumping the exhaust right under your ass! That is the best I can give you Ricky!
 

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To minimize cam overlap lope you can lean out to get part of it but the biggest part is a super hot multispark ignition, it works because the lope is caused by exhaust gas dilution at overlap to make patchy single spark ignition. Thus the lope as part of the mixture misfires or doesn't burn at all. Multispark greatly lowers that by sparking as many as 30 times at idle speeds. It's why we were able to lower idle speeds on 700 cubic inch race engines that formerly had to idle at up to 2000+, with multispark the lope dropped way off and the engine then idles down around 900 rpm or so. With 4 inch cans on end of headers it sounded then like individual sticks of dynamite going off in the pipes.

On post #13.............we used to run simple short straight through pass header mufflers of the Thrush type with 2.5" cores. On one heavy cammed 304 AMC engine the difference in that very short setup to lower BP as low as possible the setup was worth a solid 50 hp compared to the best turbo muffler setup going past the rear wheels.

The shorter you can get pipes the closer the system comes to working truly as a tuned one. A correct sized and length pipe will run best with a short exit to air (atmospheric) which is ZERO back pressure, kinda blows all that back pressure theory into the weeds.
 

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To minimize cam overlap lope you can lean out to get part of it but the biggest part is a super hot multispark ignition, it works because the lope is caused by exhaust gas dilution at overlap to make patchy single spark ignition. Thus the lope as part of the mixture misfires or doesn't burn at all. Multispark greatly lowers that by sparking as many as 30 times at idle speeds. It's why we were able to lower idle speeds on 700 cubic inch race engines that formerly had to idle at up to 2000+, with multispark the lope dropped way off and the engine then idles down around 900 rpm or so. With 4 inch cans on end of headers it sounded then like individual sticks of dynamite going off in the pipes.

On post #13.............we used to run simple short straight through pass header mufflers of the Thrush type with 2.5" cores. On one heavy cammed 304 AMC engine the difference in that very short setup to lower BP as low as possible the setup was worth a solid 50 hp compared to the best turbo muffler setup going past the rear wheels.

The shorter you can get pipes the closer the system comes to working truly as a tuned one. A correct sized and length pipe will run best with a short exit to air (atmospheric) which is ZERO back pressure, kinda blows all that back pressure theory into the weeds.
I like you! Probably because I know your old like me to be spouting that lingo! 😂 I agree told him to dump it with a Y but I have seen several new models that just stall with no back pressure, the computer won't let you turn the idle screw to 2000 rpm's lmao
 

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Discussion Starter · #16 ·
OK, if you have to do something with the exhaust do this! You say you have a header so under the drivers seat area where the exhaust runs cut it and put a Y in it. Attach a throttle butterfly from an old style carb (Holly 650 double pumper works well) in the open end of the Y, use the rest to put the exhaust back together. Then run a choke cable mounted by the shifter to the butterfly. When you want to have exhaust (no cops around) and your about to run it. Pull the choke cable and just run it open dumping the exhaust right under your ass! That is the best I can give you Ricky!
Noice!!!
 

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Discussion Starter · #17 ·
The more air you run through the engine the faster it will go! Many cars can also require a certain amount of back pressure as well or the emissions system goes 🤪 If you want to go fast Ricky Bobby then hit it with a dose of NOS or a turbo! Keep driving with the fear!! 😂 🤙
After I do the na build I wanna get the supercharger kit they make for it that's my end goal.
 

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Noise lol that's why I told him to put a butterfly on the Y with a choke cable, just dump it under the drivers seat when the coast is clear lol hell they even have the butterflies with electric coils so you can run a switch to them now lol i did that to a 68 GTO. Sitting at the light, guy next to you starts RPMing so you slowly start pulling the choke cables until all anybody can hear is your headers dumping on the ground, light changes and for miles everybody knows i was hitting it roflmfao! originally I told him to just hit it with NOS or put a turbo on it lol Ricky just wants to be first and drive with the fear!!
 

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people really need to understand why the whole Rice jokes were made. It's very offensive to Asian people !!
The phrase “ricer car” is common in the street racing and high-performance tuning community. However, it’s usually a derogatory term towards the owner and their car. In most cases, the person saying the phrase will use it in a mocking tone, as Throckmorton did in this case.

Some people like loud raspy exhaust and others don't but we don't have to be rude about it.
The others who don't like the illegal, loud, raspy exhaust include your neighbors, local and State Police, and Traffic Court judges. Don't believe me? Drive you loud ass grocery getter, with the lighter racing tires in the front, and an alleged 225 HP to a local Police or Sheriff's station, rev it to about 5 grand, and ask the officer's opinion about the street legality of your non muffled "race" car. You will in short order be meeting a Traffic Court judge, hopefully none of people you meet there will be rude to you.

As long as it's doing the job I want it too then that's the point in making a race machine.
Here I go again, saying something that will upset you.

You are using this 2005 Nissan Altima 4dr Sedan as the basis for what you perceive as a "Race" car, wanting to Supercharge it, but you have neither the tools, experience, or knowledge to remove a broken bolt from the exhaust manifold. This is you from September 29, 2022..." I have the 4-1 DNA motoring full race header not installed yet because i don't have the proper tools yet, so i took it to him and he got four of the bolts off of my exhaust manifold but one he claims gave him so much trouble that he cut it off!!! very sloppy for having a shop by the way.."

You picked the wrong car. Neither the transmission, engine or chassis were designed for "High Performance, strip/track" use.

Thomas Tusser is credited with this saying: “A fool and his money are soon parted

You will understand that phrase much better as you buy tools and high-performance parts for your 18-year-old car or pay someone to modify it.
 
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