HEADER QUESTIONS

I wanted to save some cash and just went from a tundra back down to a tacoma. That being said I am looking to squeeze a little more power out of my taco and am thinking of doing headers to start. I am looking at the dough thorley's or the JBAs and had a few questions.

First can I do the install my self or do I need to lift the motor?

Is there a big enough difference between the two to justify the cost difference?

By deleating the cats and using the o2 simulators are there any issues I should be aware of?

Any input would be greatly appreciated. Thanks!

 

There are a lot of threads about this already. I wouldn't waste time with exaught you don't have enough mods to gain performance and you can actually hurt performance. Find a programmer for it .

 

Not sure what that means.

From the research I've done there aren't any programmers available. How can headers combined with exhaust and intake not create power. The motor breaths better, and a better breathing motor creates more power...

 

Wrong the motor is tuned for 0 overlap so more back pressure cause the valves to seal more efficiently creating more torque. So freeing up exaught will actually hurt performance without cams or retune.

 

Interesting....

Does that same theory apply in just doing a muffler?

 

Muffler you'll be fine because cats and resonator are before it but full headers high flow cats and muffler would hurt torque.

 

Ok, thanks. That's interesting as it's the first time I've heard of mods like that scavaging power. Do you have any suggestions for increasing hp + torque?

 

longtubes, no cats, larger (3") exhaust killed my tq n/a

stick with shorties and keep ur front cats....IDK about the rear cats, I removed those too. YMMV

unless u plan to go forced induction, do not open up the exhaust too much.

 

I wouldn't do nothing if you don't won't to boost or if you do I'd suggest a way to control fuel and ignition and water meth leaner means more torque plus advancing timing water meth would just increase octane and cool the cylinder for an aggressive tune and depress detonation.

 

If its a vvti engine just take it and have a 93 octane tune and have them re map vvti. You can actually hook a switch to vvti solenoid and on advances all the way for torque and off will keep it at base or idle position the factory ecu will constantly adjust cam accordingly but you can have it remapped for a certain degree for a certain rpm range

 

So, who actually does a 93 tune and vvt remap on a 4.0? I haven't heard of anyone doing such a thing. Closest thing is a piggyback controller, but for an 09+ it would require wiring the controller into the ECU harness as no one sells a plugin for the 09+ for anything close to reasonable.

OP, you said you want more power, but did not specify where you want that power. If you plan to stay NA, there are a few HP to be gained, but it totally depends on if you want the power down low, or up high. Gains for 3-4K+ are there, but tend to rob some power down low to enable that gain. If you want power down low, that seems to be harder to gain.

 

They reflash ecu for s/c why can't you reflash with a more aggressive tune? Vvti controllers are available but you can control that during reflash?

 

subed, good thread

 

subd as well. Looking for some of the same answers.

Have a URD Intake and was thinking about shorties and a catback. I will be doing some towing and was wondering whether these mods would help or hurt.

 

subb'd as well!

 

I guess I haven't really thought about that all the way. I guess I'm looking for snappier throttle responce, better passing abilities, etc. I suppose I'm looking for an overall increase. I deff don't want to rob power.

I guess the new question is what is the best way to increase hp + torque? Something like shorties and a cat back system? What are thoughts on that?

I was always of the understanding that open up both ends of the motor and you'll see gains but that doing only one side or the other really didn't do too much. Input?

 

There is only one reflash as far as tuning goes. That is for the TRD s/c. That is it. There are supposedly ways to continue to reflash, but none even to this day have proven themselves over here in the States. If you want any of that done you have to have an aftermarket EMS of some sort.

"Hurt performance" is slightly relative. Where specifically in the lower band are you referring to? Or the whole powerband?

I have posted dyno graphs of the gains to be had with just the headers. One of the graphs is also on www.LCEperformance.com in the 1GR section for headers.

On an N/A setup for these trucks, don't go larger than 2.5" catback. You'll lose to much exhaust velocity thus decreasing the low end scavenging. F/I, 3".

Dyno chart links are in my SIG.

 

You do gain power by letting it breath more but there is a lot more to it than just changing exaught . With newer engines you have almost no cam overlap because you want all the fuel to burn during each cycle. This in theory would create most possible torque. Then when it exits the flow resistance create waves which then create like a siphon effect then when exaught flows to much it takes longer for the waves to travel back causing turbulance until a certain volume of flow is reached. Larger exaught would be to compisate New VE due to cams or boost causing the exaught tune to be at a higher rate. Just to sum it up your factory exaught is special tuned for your stock engine. Without changing VE of the engine your changing in exaught wave length could cause you to lose torque because siphon effect isn't keep high pressure away from valve like designed. The new engines use weaker valve springs to free up rotating assembly so if turbulance is created it could put pressure against valve causing it to leak (lose of power) I meant in previous post velosity not back pressure (I had to reread some exaught tuning book I have to make sure I was telling you correctly

 

Thanks torspd for correcting me that's what made me reread my books. Also I didn't know there was only one flash for them I'm sure someone cout create one though since they are reflashable

 

I'm also assuming his truck is a dd that does city driving, towing, off road, which torque would be more beneficial than hp.