Scrussanation

How often, if ever, does anyone sell some used downey headers or anything close to it.. Just have a hard time gulping the 500-600 price tag plus shipping.. Ive always wantd one but man thats high.. And some people say they have a hard time with body lifts.. Im curious why is that?

Roark

It took me a solid 3 or so months hounding the classifieds here and locally to find a set of Downey headers..and it still cost me a good bit of cash. I can't speak for the proposed problems concerning body lifts, but I know my install when perfectly and my truck is stock height. Hopefully someone else can chime in on that..

Good luck!

Scrussanation

Curious... Whats the going price for a used set and what to look out for... Biggest problemi have is knowing which headers will work with my 3vze...and does it eliminate the crossover..hate that stupid thing

Roark

Depends on what you get.. I got lucky enough to find the whole kit, including headers and Y pipe new in box. That was about $400 with shipping. Now, if you happen to find just the headers themselves, you can always get an exhaust shop to weld something up that would work, or just make something your self. Check out mandrel-bends.com for a lot of cool metal piping.

Roark

So yes, the headers' main benefit, IMO, is the elimination of the nasty crossover, but being willing to pay for it upfront, unless you have the fab skills yourself or near. Bottom line!

Scrussanation

Damn 400 is a sweet deal.. I do all work on my yota. Cant trust mechanic shops around here. Besides best way to know its done right is do it yourself. But you must must must be mechanically inclined and having some smarts helps too. Just cant be a dumbass or retard that doesnt have a cluewhat hes doingand just trying to save a buck by doing it himself i laughat people for the crap they put their vehicle in the shop for. Ive saved thousands working on my own gummy bears

RSR

Scruss,

IMO -- and if you search through my old posts you'll find a couple posts in full glory -- is as follows (this is the quick an dirty version and where I'm at for planning purposes on a 3vze keep -- since i'm planning a swap, my ideal cat back will be slightly different):
-Remove stock crossover, cut on passenger side if need be to remove
-Use stock crossover, connect drivers side to connect to passengers stock header (rotated to down) as the base downpipe (why? b/c it's already heat shielded) and cut at resonator/expansion chamber; you'll have to likely bend/weld some bend spacers in this setup or can have exhaust shop do
-Block off drivers side crossover intake hole
-Buy the Y crossover, mandrel bent from LC Engineering, ~$200
-Have exhaust shop fab pipe from drivers header to Y crossover and from passenger to Y crossover (unsure how needed passenger is) -- why use crossover but not drivers side downpipe? Drivers side downpipe on mine at least is pretty dang rusty and exposed to far more corroding elements than the crossover is at the back of the engine, plus the previously mentioned exisiting heat shielding.
-Have a 2.25 flange installed on a 2.5 pipe from end of Y to 2.5 inch flange for cat intake (my ideal would be to cut back LC to where the two pipes join and put in a 2.5 pipe from there to cat w/ o2 sensor bung installed for less restriction)
-2.5 hi flow cat in to out, w/ exhaust shop installing a 2.25 flange on your cat's out flange...
-LC engineering 2.25 cat back system, mandrel bent (~$400)

On modern vehicles exhaust goes from larger to smaller as an optimized exhaust keeps consistent flow throughout (while minimizing restriction). Hotter gasses nearer engine require more volume (hence the larger pipe) while cooler gasses near tailpipe need less. And the cat is always point of restriction regardless, so might as well keep the piping larger through there...

Cost will only be about ~$200 less than having it done custom, but (big but) you get mandrel bends with this and the LC piping is stainless steel and heavy gauge. And you save yourself about $500 in headers with this mod and don't burn up your starter, risk setting your fuel lines on fire, and all the other issues with headers... And it's less than 5% (talking 1-2 HP here) loss in performance relative to the headers (still getting 95% of the gains from an optimized exhaust system).

Almost forgot, any of your components if worried about heat and not wanting to pay for very expensive ceramic dipping -- try the high temp ceramic exhaust paint some sell. There's a curing process, but it's only about a $20 expenditure for measurable heat reduction. I'd at least do to where the two down pipes in the Y meet -- that roughly puts you back under factory heat shielding already in place...

Scrussanation

I like but one thing I disagree on is the cat being the biggest restriction. Well Tri truth is I killed the kitty with a pole...so bye bye kitty without it looking like it went bye bye..so with that in mind which pipe sizes would be best. And any way to get everytHing needed to do myself. I hate passing labor cost lol

ddbrock

Headers can be had on the summit site. Must they be downey?

Greg_Canada

LCE headers are very nice. The downey's i got were crap. I had to get the flanges machined flat, grind the weld out of the tube (they were restricting alot of flow) there were HOLES in the welds that i needed to fix, and i needed to get them re-ceramic coated... what a PIA...

Redeyejedi

LCE's are great from what i have heard, but also $800(w/CO...$600w/o CO).

RSR

You also lose your emissions components w/ LCE headers... Same w/ Downey. Thorley is the only one that allows you to keep, but you still have to cut and do some welding I think on your Pair and EGR pipes on the passenger side. Under Texas safety inspections, intact emissions component is a requirement/component, regardless of needing to have the exhaust/smog test...

Somewhere I did all the research/compilation of the numbers on gains by the exhaust, and the primary benefit isn't HP (we're talking less than 5 hp gain if anything) but rather in removing the heat from the engine bay. Cooler engine alone equals better power -- as we've seen elsewhere. And think the flow benefit over stock headers won't be too terribly significant for what's really only 1-3 HP gain once deducting the heat component.

I think the Y crossover that LC sells is as or more important than the actual headers themselves... Some of the DIY crossover delete piping looks pretty awful for optimal flow.

With my recommendation, I think you can get by w/o any labor if you can weld by my recommedation above -- just buy the reducer/expander pipes and do some cutting and welding rather than paying someone (I assume that exhaust shops have the ability to compress/expand pipe without using new, but don't know for certain). Or stick w/ the whole LC system and get some silicone before you clamp and you should be good to go.

I would do 2.5 as close to the collector as possible through the cat, or at least to the cat, and then you can do 2.25 out if you're going mandrel. If going to crush bend your own, then definitely keep it 2.5 throughout, possibly 2.75 from cat back due to those fairly tight bends over the rear axle...

For the cat, if your cat isn't clogged, and hasn't ever melted or otherwise become clogged, I think it only has about a 25% of the max gains you can get on the exhuast by replacing. About 25% on the headers to cat. And then 50% on the catback. Just replacing the catback alone, folks report 20% increases in MPGs and 10% increases in power...

On all of the premade systems, they are made to service both our 3vze and the 22re interchangeably w/ the 3vze having 20% more displacement, so a 22re setup will restrict. IT's better than stock, but not the best. Fortunately it's most straight pipe from collector back so easy to replace and use premade 2.25 where there's bends...

Not cat back is referring to from the cat exit, but not including the cat. Think that might be the disconnect after re-reading.

RSR

Essentially, with the setup I"m thinking, you have one downpipe from your header instead of 3, making it much easier to heat shield and keep other stuff from overheating with your now non-factory setup... With the fuel and brake lines, and starter all where they are on the passenger side, our trucks don't have a lot of extra room. And why the floor boards on the passenger side have also been known to burn from headers... If going headers, the thorley ceramic look like the best bet, but at $600 for less than 5 HP I'm passing. YMMV.

Greg_Canada

The only way catback will net you 20% better MPG and 10% better power, is if your stock cat is clogged.

RSR

Most systems sold as cat back exhaust systems don't actually include replacing the cat and are not referring to cats in regards to performance gains... Or at least that's been my experience.

Several folks w/ or w/o replacing factory cat cite the 20% gain in MPG by replacing exhaust from cat exit to exhaust tip (20% is only a couple add'l MPG, but still...)
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http://www.toyotanation.com/forum/80...ml#post2870800

*In his signature:
https://www.yotatech.com/members/108469.html

Not saying you're wrong, but a replacing a plugged cat should be even further gains. Also bear in mind that just like the timing on our engines being set to 10 due to emissions reasons (when somewhere between 12 and 15* btdc is best performance on stock), the stock emissions system was also designed to reduce emissions as much as possible, not to maximize power/performance. The cat we have is really good at cleaning but not optimized for flow. So by going w/ a high flow cat, there'll be gains there, but probably gains only amounting to 1/2 of what you see from a mandrel bent and high flow muffler cat back (again, I generally see the cat back as from cat exit to exhaust tip, excluding cat, but maybe I'm wrong...) and probably equivalent to the gain you get from spending $600 on headers... Well, until recently with the EPA mandated MPG requirements and that entire fleets have to meet certain MPG #s (e.g., they need to maximize fuel efficiency from all vehicles to meet required #s and be able to continue to sell the less fuel efficient high HP vehicles that the American consumer actually wants...), auto manufacturers tended to skimp on exhaust and leave a lot of power on the table. They don't anymore so much, but for our trucks they did.

RSR

For instance, Borla cat-backs aren't sold w/ cats: http://www.borla.com/products/4runne...t__140379.html

Greg_Canada

Gotcha, but if you think about it, if toyota could have easily increased mpg from 20 to 24, don't you think they would have done it originally? Typical catbacks give a 5% power improvement. I did a full downpipe back exhaust with highflow cat and turbo muffler, and the only difference i noticed was a bit more low end torque... And way more noise. I did not see any mpg increase with a different exhaust. The largest variable for mpg's is weather and driving style. He could have done 20 mpg in the winter then 24 in the summer.

In my 3vz manual, my best ever mileage was 19mpg. In the 5vz auto i hit 24. That was cruise at 68mph for a whole tank on flat ground, a/c off windows open. Ormal driving i could never achieve that. 20 mpg normal driving, no problem. Always remember there are many facts that people leave out when they are trying to justify a purpose.

To me, you buy an exhaust for sound. Power increases are minimal unless you do headers, intake and a tune as well.

RSR

In short, no. They were already the segment leader in MPG and high flow cat backs are also noisier (as you mentioned) -- which turns off a lot of folks when what they were marketing this truck as was a prudent/pragmatic/responsible alternative to the much less fuel efficient American competitors.

In short, engineering decisions are driven as much by marketing as performance. A mandrel bent high flow exhuast, even from factory, is also more expensive (nearly 2 times as expensive), so you can't ignore the almighty dollar either.

Not getting into the whole systems discussion, but generally speaking there are a few basic things that can be done to significantly increase flow on the front end, and a decent exhaust is accordingly needed on the back end to fully realize those gains. Ultimately, a lot of Toyota engineering decisions in regards to the 3vze, including exhaust, were due to emissions restrictions, not performance...