mikey's2010SR5
New member
Should have bought the 6Runner. That one comes with a 6.2L Supercharge V-8. It is a prerunner but dang it is quick.
I have the Need for More Speed! Suggestions?
- Thread starter Blazer1122
- Start date
DesertCanyons
New member
Dual exhaust for more power
[MENTION=115378]Blazer1122[/MENTION]
You're not getting any help here from the forum. Too bad.
I believe the reason you can't change much is the ECU computer controls and links everything in the T4R. You cant change anything without adversely affecting performance.
One idea I've suggested here before is to rework the exhaust system. Divide the two sides of the exhaust into two separate pipes, possibly making each side a 3" pipe. Cut out the "Y" that's just past the two 2nd cat's. Run the left side back a bit farther, relocate the 2nd cat on the left closer to the manifold (with a heat shield), and cross over under the link from the transmission to the transfer case where there's more room. Turn it backwards on the right, passenger side just past the frame crossbar and run two separate pipes back to a twin entry/exit Magnaflow muffler and run one large, 4.5" tail pipe or dual 3" exhaust pipes. It could be 2.5" pipe and still be a big improvement over the coupled, single 2.5" stock exhaust. Consider a side exit at this point. Make it SS because the labor will cost more than the pipe and you want it to last. Build bolted joints into it so you can access the tranny, trans case and link for service.
After this fix the CAI might make a bigger difference.
Everyone, you're all welcome to steal my idea and build the prototype. Here in So Cal I know a good muffler/speed shop that can do the rebuild for me.
[MENTION=115378]Blazer1122[/MENTION]
You're not getting any help here from the forum. Too bad.
I believe the reason you can't change much is the ECU computer controls and links everything in the T4R. You cant change anything without adversely affecting performance.
One idea I've suggested here before is to rework the exhaust system. Divide the two sides of the exhaust into two separate pipes, possibly making each side a 3" pipe. Cut out the "Y" that's just past the two 2nd cat's. Run the left side back a bit farther, relocate the 2nd cat on the left closer to the manifold (with a heat shield), and cross over under the link from the transmission to the transfer case where there's more room. Turn it backwards on the right, passenger side just past the frame crossbar and run two separate pipes back to a twin entry/exit Magnaflow muffler and run one large, 4.5" tail pipe or dual 3" exhaust pipes. It could be 2.5" pipe and still be a big improvement over the coupled, single 2.5" stock exhaust. Consider a side exit at this point. Make it SS because the labor will cost more than the pipe and you want it to last. Build bolted joints into it so you can access the tranny, trans case and link for service.
After this fix the CAI might make a bigger difference.
Everyone, you're all welcome to steal my idea and build the prototype. Here in So Cal I know a good muffler/speed shop that can do the rebuild for me.
Formidable
New member
http://www.xr-underground.com/forum/showthread.php?t=56915
Contact gadget at URD. He's got some stuff for us.
I am tempted to get the JBA full 304 stainless long tube headers along with his spec U exhaust system including y pipe. Just waiting to see if he will release the spec u headers for our application, (net about 17 hp and 30 torque to the wheels without any tune on a 2012 Tacoma). Albeit different application, (vvti), the most impressive part is that power increased over the entire curve.
Contact gadget at URD. He's got some stuff for us.
I am tempted to get the JBA full 304 stainless long tube headers along with his spec U exhaust system including y pipe. Just waiting to see if he will release the spec u headers for our application, (net about 17 hp and 30 torque to the wheels without any tune on a 2012 Tacoma). Albeit different application, (vvti), the most impressive part is that power increased over the entire curve.
Swarty
New member
Nope
If this subject was an animal we'd have a PETA protest on our hands.
:dammit::director::deadhorse:
Rerouting the one pipe that gets "smooshed" to be constant diameter and go around the transfer case may gain a couple horses, probably not though. The precats and the cats that are in front of that cause way more flow resistance. I would like to reroute the y-pipe but only because it's hanging so low.
Dividing the flow will definitely hurt power across the board.
Here's why: None of the cylinders for the V6 fire together so the pipe only has to handle the flow for one cylinder at any given moment (same with the intake). With that said a 2.5" header should join into a 2.5" y-pipe to allow smoother flow and keep a draw from low pressure caused by the flow at exhausting cylinders. Separating or enlarging only some of the pipes will reduce this draw all RPMs. It basically separates the exhaust into two separate really lumpy 3 cylinder setups.
add to that the precats and the primary cats are before the y-pipe and I'd be shocked if the Y-pipe was losing any reasonable amount of power. Plus good luck getting a 3 cylinder exhaust that is essentially operating at a weird split RPM to not sound like an asthmatic goose. :tsk:
If more HP was this simple the aftermarket would have already put out a large diameter or split exhaust setup for every vehicle in existence. :wof:
You can remove cats or precats. That will probably grab a reasonable amount of horsepower but is not very socially, environmentally, or legally acceptable on road.
Here is a great laymans explanation of exhaust sizing:
Exhaust design
If this subject was an animal we'd have a PETA protest on our hands.
:dammit::director::deadhorse:
You started out nearly correct, on an engine with variable timing on both the exhaust and the intake you have to have ECU control to make more power. That's why no SC from the aftermarket.
Rerouting the one pipe that gets "smooshed" to be constant diameter and go around the transfer case may gain a couple horses, probably not though. The precats and the cats that are in front of that cause way more flow resistance. I would like to reroute the y-pipe but only because it's hanging so low.
Dividing the flow will definitely hurt power across the board.
Here's why: None of the cylinders for the V6 fire together so the pipe only has to handle the flow for one cylinder at any given moment (same with the intake). With that said a 2.5" header should join into a 2.5" y-pipe to allow smoother flow and keep a draw from low pressure caused by the flow at exhausting cylinders. Separating or enlarging only some of the pipes will reduce this draw all RPMs. It basically separates the exhaust into two separate really lumpy 3 cylinder setups.
add to that the precats and the primary cats are before the y-pipe and I'd be shocked if the Y-pipe was losing any reasonable amount of power. Plus good luck getting a 3 cylinder exhaust that is essentially operating at a weird split RPM to not sound like an asthmatic goose. :tsk:
If more HP was this simple the aftermarket would have already put out a large diameter or split exhaust setup for every vehicle in existence. :wof:
No, again the intake is only feeding one cylinder at a time. The correct diameter causes a small "ram air effect" from the flow velocity at the RPM range the system is tuned for. At different diameters you only move this point to a different RPM range.
You can remove cats or precats. That will probably grab a reasonable amount of horsepower but is not very socially, environmentally, or legally acceptable on road.
Here is a great laymans explanation of exhaust sizing:
Exhaust design
Swarty
New member
Early 5th gens...
You'd have to get rid of the smog pump first... But for those of us without it:
5th gen 4runner (no smog pump) U-spec header
You'd have to get rid of the smog pump first... But for those of us without it:
5th gen 4runner (no smog pump) U-spec header
Jetboy
New member
Does anyone actually know what the dual vvti system will do if you had say 3psi of boost? Would it recognize it as an error?
Possibly a low boost turbo system could actually be a viable option. I don't know enough about the system to even guess about what level of boost the 5th gen could take without any modification. If we could add 50ft lbs of torque from say 1500-3500rpms I'd think that would be a significant difference in normal daily driving. This could be possible to test with the right fan in a controlled shop setting to see how the system reacts to pressurizing the intake.
Possibly a low boost turbo system could actually be a viable option. I don't know enough about the system to even guess about what level of boost the 5th gen could take without any modification. If we could add 50ft lbs of torque from say 1500-3500rpms I'd think that would be a significant difference in normal daily driving. This could be possible to test with the right fan in a controlled shop setting to see how the system reacts to pressurizing the intake.
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DesertCanyons
New member
Swarty
New member
It's a sad tale but tis true...
Just so you know I'm not trying to be an ass but it kills me how much marketing is selling people on "get power quick" schemes. Currently it takes hard work and knowledge to make a car faster. Oh man, I sound like my dad...
Nope because you have to have the entire exhaust flow the same! not just the back end. You have to start with the most restrictive part to get good flow, which are the cats. Then you have to re-tune the engine... Which we can't so far or we would have a SC from Gadget already.:moping:
Exactly! Removing cats is the only place in the exhaust where you can add meaningful horsepower which is why it is the only aftermarket exhaust product with dyno numbers showing a difference above what could be achieved with a change in temp or humidity.
Just so you know I'm not trying to be an ass but it kills me how much marketing is selling people on "get power quick" schemes. Currently it takes hard work and knowledge to make a car faster. Oh man, I sound like my dad...
Nope to both points, the Y-pipe crosses over the transfer case and is where it gets skinny and low. It is also definitely not as flow restrictive as even one of the 4 cats that come before it.
Exactly, which will mess up flow and back pressure the most. It becomes a separate exhaust for each of the 3 cylinders and you haven't made it any less restrictive because the cats are what's causing the flow restriction. The flow is what helps suck some of the exhaust out of the cylinder improving HP and efficiency. You've removed the consistent flow while keeping the restriction. Not a good plan.
Nope because you have to have the entire exhaust flow the same! not just the back end. You have to start with the most restrictive part to get good flow, which are the cats. Then you have to re-tune the engine... Which we can't so far or we would have a SC from Gadget already.:moping:
Exactly! Removing cats is the only place in the exhaust where you can add meaningful horsepower which is why it is the only aftermarket exhaust product with dyno numbers showing a difference above what could be achieved with a change in temp or humidity.
Hellamatic
New member
Going to a big dual exhaust will all but eliminate any scavenging effect. Not good. Remember, our engines are just little bitty ones that don't need a ridiculously large exhaust system.
Besides, didn't you guys hear that the TRD supercharger is coming out tomorrow? All forum members get a 75% discount.
Besides, didn't you guys hear that the TRD supercharger is coming out tomorrow? All forum members get a 75% discount.
LandCruiser
New member
I'll be the first to say the 4Runner could use more horsepower, but Toyota doesn't agree with me.
I'd rather have an underpowered 4Runner than any of its competition, tho.
With that said, I'd like a 400hp/400torque V8 version.
I'd rather have an underpowered 4Runner than any of its competition, tho.
With that said, I'd like a 400hp/400torque V8 version.
DesertCanyons
New member
Thanks Swarty,
And BTW, you are a dad. I'm a granddad and so I could sound like your dad if I tried. But I won't.
:jump:
Maybe I'm calling the Y by the wrong name. I'm referring to the part where the two sides come together. From what I can tell it's just in front of the frame cross bar, above that same bar. It's the driver's side cross-over pipe below the 1st cat that is so low. The 2nd cats are tucked in pretty close to each other just before the junction, or "Y" as I've been calling it.
Thanks again. After bringing this idea up, you're the first person to answer my questions about whether it would increase power.
I get up to Bend, Oregon and Sun River once in while. Usually at Christmas time for some snow shoeing and family gathering. Nice country.
Dave
