Exhaust Manifold replacement/upgrade

Currently looking into addressing the exhaust manifold leaks on the 340k+ Tundy.

Originally my thought was to swap for new OEM manifolds/gaskets but recently I’ve been looking into upgrading to some jba headers and possibly upgrading to a cat-back muffler system as well. Main priority is making it reliable for the future, but getting some extra horseys would be cool.


Ive been browsing JEGS for some JBA shorty headers I read recommended on another forum.

https://www.jegs.com/i/JBA/578/2010S/10002/-1#reviewTab

Would adding a Cat-back duel system add or take away from overall performance and reliablity? Thanks.

 

I would contact @dirtydeeds, has lots of experience with headers and exhausts for tundras

 

I installed jba shorties in 2009, not a single problem with them. They will discolor if you don't get a coated option, I can't say how well the coated options stand up because I went with raw.

I've also had a custom cat back since 2009, no problems there either. If you want a little sound just get a good muffler and swap the big stock muffler for what you like, keep as much of the stock pipe as you can since it is well made. Some mufflers will drone pretty bad in these trucks. If you have the stock resonator you might want to keep it there to prevent drone at low speed.

 

Thinking about wrapping the jbas in fiberglass header wrap if anything

Looking into some Borla, Magnaflow and Jba options for muffler/tailpipe. All I’m really looking to replace unless my Cat goes bad

Also seeing lots of flowmaster and Gibson options

 

I ran a Flowmaster and it had a lot of drone but admittedly it was dumped before the rear axle. Whatever you run you want to have the piping run all the way out from under the truck.

I replaced that with a Spintech Pro Street and haven't heard a better muffler yet on these trucks. They're a little bit loud outside but inside the truck it's quiet. I don't even have a resonator anymore, just shorties, stock cats, y pipe, a little muffler and stock piping.

 

Is that where or why they drone? Is it the reverb back and forth between the under-bed and the road?

 

It usually makes things worse. If the exhaust is dumped under the truck the sound waves will be emanating under the truck rather than away from the truck. With the sound hitting the ground and reflecting there is a stronger chance of resonance getting amplified, kind of like when you drive into a tunnel and your exhaust gets louder. That can hit your cab and cause a lot of headache.

Two things that will help avoid drone are to have the exit out from under the truck, and keep the stock intake airbox. Intake gets super loud on these trucks with a cone filter. The sound frequency of the intake can match the frequency of the exhaust and cause a weird sound wave. If you ever see somebody tune a guitar by ear, plucking a note on one string and hitting the same note on the other to balance the sound, its the same concept.

All that said, my truck has the section of pipe where it bends to go behind the rear wheel cut off. The exhaust still escapes my truck once I'm driving.

 

Thanks for the explanation.
I had originally wanted my exhaust dumped out of the rear fender pre tire, but that presented it self to be to difficult so I’m dumped down and back past the axle, maybe one day I’ll get back under and see how or where else I could route/extend the tubing to

 

So ideally exiting just below the rear bumper instead of bending out & exiting just past the passenger side rear wheel?

 

Either would be good, as long as the pipe can carry the exhaust out from under the truck.

 

Did someone already say shorty headers do nothing for added HP, but long tube headers do. Duel exhaust is good and running straight off headers is best. Someone did mention Borla or Corsa muffler system. Those two have good sound with personality to me, and not the boring red neck loud mufflers that all others are. Slow moving stock vehicles with loud mufflers are plain stupid. I have no idea if the 4.7 has enough oomph to create the sound those are known for. Both Borla and Corsa have 0 drone. You'll get nominal/insignificant hp with headers and dual mufflers, and it stays the same with aftermarket cold air intake added to them on any stock run of the mill engine. The OEM TRD muffler system is quite but puts out a good tone when stepping on it. These motors don't have aftermarket cams that add horse power nor have I heard of someone doing a dyno tune. Those are two items to look for for if around and can be done. They marry well with dual exhaust, aftermarket intake and long tube headers. Throw the correct torque converter in there with limited slip and your done with the around town daily driver fun stuff. To me the gearing is already right for all around driving.

 

If I could add. Is this still true.
I remember reading that one problem is you would not be able to replace one of the 02 sensors if you changed to headers and had the need in the future.

 

Isn't @empty_lord the one to ask, pretty sure he's done it and general consensus is you can throw all the upgrades in the world you want at the engine shy of forcing induction (FI/SC) and you'll be lucky to net a 30-40HP gain?

 

Cams are $2,000, and should only be done if boosted IMO. Dyno tuning ATM can only be done with a standalone or piggyback like the MAP-ECU on mine, at least until VF tuners gets to our ecu(they just added support for 4runners with vvti 2uzfes)

 

Shorties will add something (anything’s better than the god awful factory manifold design.) but long tubes will be the most potent. Past that proper exhaust design will dictate if you will gain or lose power. It’s an art to extract the most power out of a exhaust on N/a engines.

 

Keith told me that wrapping the headers will promote them rusting. I have a set about to be installed

 

K&N barks. I loved using mine to scare pedestrians.

 

Yea header wrap is notorious for rotting out manifolds. Coated headers help with heat and d protection

 

$2000 for cams! Is that the current inflation price or what they'll be by the end of next week. That price is crazy. I looked for cams and found none.
Who makes them? Are they for the Tundras before the VVTi came out? Would like to look into that.

 

the price for 4 billet cams is usually in the 2-3k range. has been for years. regrinds are cheaper. but billets are far superior

XAT racing sells the cams. vvti and non vvti i believe. high lift and a less aggressive. the high lift requires pocketing of the head.

 

I was a bit off, $1700. Suprastore sells them, XAT makes them (https://www.suprastore.com/xatrasucubiu.html) and I wouldn't bother if you're not boosted.

 

high lift for sure. the mid lift likely would end up with a respectable gain. but you'd want to be spinning a little more RPMs with a proper tune


wish someone would post a dyno graph of these suckers.

 

Thanks guys. Add it all up with necessary parts for cams to work and I see why people say this is the way to go. https://www.youtube.com/watch?v=iE3VqpfVBTM

I heard it's about the same cost. But don't ya miss the cam lobes sound! Like someone said, and agree with, 'I listen to this to go to sleep,' Lol. https://www.youtube.com/watch?v=-1z...8hgQKF3Et29A&start_radio=1&rv=-1zH32Pu7Xk&t=0

 

Great videos! I love how the Turbo Tundra has the gas light on during the "Freeway Fun" portion of the vid - very relatable!

 

Even with the shorties?

just swapped all my O-2s , looking to pass emissions

 

Just received some JBA shortys

Thinking about getting some OEM gaskets for the swap

Is getting a y-pipe recommended?

 

While the factory Y pipe looks really restrictive, from what I've heard an aftermarket doesn't yield any performance gains.