Builds DRANGED's GX470 build/ownership thread (11 Viewers)

[MoaByte]

Yeah, it seems super lame.
I had the Toyota dealer (closest one is over 90 miles away) do it. I've got an email out and will follow up with a call today. I'd bet 1 yr 10k mile warranty for factory OEM part... I have the old one so I'm Considering welding that up and reinstalling it, plus new bolts and nuts.

It looks like steel tube given shape and welding but wouldn't it be cast iron, given the way it cracked plus I've never heard of a tube manifold.

View attachment 2857056View attachment 2857057


*Edit*
Lexuspartsnow.com says 12 mo 12k mile
View attachment 2857865

You need to stop using the rev limiter so much

 

[ArBrnSnpr]

I agree that something could be out of alignment, but before the header would crack, I'd suspect the flex in the Y pipe to catback union would eat up whatever stress was being caused.

Also, the manifolds bolt to the Y pipe which feeds into one pipe so wouldn't it stand to reason that the stress would be shared between the manifolds?

To offer another theory, was the previous crack in the same place? If it was, it might be worth looking into what might cause a difference in exhaust gas temps to the exhaust port associated with the cracked area. Possible clogged injector?

That's me just thinking out loud...

Either way, with two cracked OE manifolds, I'd get myself a set of DT headers. Hang the two cracked manifolds on your garage walls as offerings to the Toyota gods and move on.

I have the DT long tubes. You don't get pre-cats with those obviously. You can reuse your factory Y pipe and retain your two downstream cats for emissions.

I originally bought the DT y pipe too, but zero cats provided a pretty gutless bottom end torque curve. I'm getting ready to cut up the DT y pipe and add in two high flow cats. We'll see how that turns out.

I've read the short headers retain the most factory-esque power delivery while offering a steady power bump. If I were to do it again, I think that's the route I'd go.

 

[Rednexus]

I'm running DT Long Tubes. The install is a lot easier than the short tubes as there is no need to slice off the cats and weld them back on, but it's still a PITA to get to all of the fasteners on the heads and it took me several days to get the install done (see my build thread). Obviously, the GX is no longer emissions compliant with LT's. I live in rural Missouri where we have zero smog rules so this isn't an issue here, but in other areas it might be if you have any kind of a visual inspection or sniffer test.

I installed a set of 90-degre O2 sensor spacers with a mini cat (formerly available on Amazon, but no longer - perhaps you can find them on eBay) on the downstream O2 sensors and have yet to throw a code in around 8 months of driving. If you don't do that you'll have constant P0420 and P0430 codes.

The LT's gave the GX a ton more power, but at this point I'm pretty used to it. I retained the stock Y-pipe and rear cats and had zero perceivable loss of low-end torque. The power gains in the midrange (like 3,000+ rpm) were pretty noticeable. I also kept the rest of the factory exhaust intact as I like the GX being quiet.

 

[GrizzlyClint]

I'm running DT Long Tubes. The install is a lot easier than the short tubes as there is no need to slice off the cats and weld them back on, but it's still a PITA to get to all of the fasteners on the heads and it took me several days to get the install done (see my build thread). Obviously, the GX is no longer emissions compliant with LT's. I live in rural Missouri where we have zero smog rules so this isn't an issue here, but in other areas it might be if you have any kind of a visual inspection or sniffer test.

I installed a set of 90-degre O2 sensor spacers with a mini cat (formerly available on Amazon, but no longer - perhaps you can find them on eBay) on the downstream O2 sensors and have yet to throw a code in around 8 months of driving. If you don't do that you'll have constant P0420 and P0430 codes.

The LT's gave the GX a ton more power, but at this point I'm pretty used to it. I retained the stock Y-pipe and rear cats and had zero perceivable loss of low-end torque. The power gains in the midrange (like 3,000+ rpm) were pretty noticeable. I also kept the rest of the factory exhaust intact as I like the GX being quiet.

You should dyno your rig. I’d love to see the numbers after your LTs. I hope one day to get new manifolds for the 460 along with a tune.

 

[Rednexus]

You should dyno your rig. I’d love to see the numbers after your LTs. I hope one day to get new manifolds for the 460 along with a tune.

It would have been interesting to do a before and after dyno! I'm also running a CAI and usually run 87-octane so it's not a true apples-to-apples. I will say that the GX "feels" like it has around 290-300 HP, from the butt dyno (and comparing it to driving similar-weight crossovers with 300-HP V6 engines). It's not fast by any means but lively and has really good passing power (important for our 2-lane roads around here).

 

[GrizzlyClint]

It would have been interesting to do a before and after dyno! I'm also running a CAI and usually run 87-octane so it's not a true apples-to-apples. I will say that the GX "feels" like it has around 290-300 HP, from the butt dyno (and comparing it to driving similar-weight crossovers with 300-HP V6 engines). It's not fast by any means but lively and has really good passing power (important for our 2-lane roads around here).

~300hp at the crank would be a reasonable number with the intake and exhaust for a 2005+ 470. Now imagine this with a 93 octane tune!

Fast is subjective. To people that only drive compacts and economy vehicles 0-60 in 7 seconds may feel fast to them. Now imagine them driving a Taycan GTS. LOL My stock 470 feels strong off the line but is a bit slow passing someone My 460 is marginally better passing but a bit more sluggish off the line vs the 470. Those extra ~500lbs in the 460 are hard to cover up with 301hp and 329tq and only a 6spd trans.

 

[MoaByte]

Where is the nearest Dyno accessable to us @DRANGED ? I'd like to see if I could dial in the AF's and timing a little more.

 

[DRANGED]

If this is unique to you (meaning others are not reporting the same crack), I’m wondering if the passenger side is stressing/stretching the elbow due to movement of the other sections being further apart from normal.

Torn engine mount came to mind, but was hoping for other brainstorm ideas.

Yup, that's what I was starting to think. Check engine/motor mounts and even body mounts on the failed header side.

Hmm, come to think of it, I did ding my passenger body mont bolt back in Oct, 2019....

that I still need to address. . . .

From That one time getting to rose garden hill on the LocoKoko run ... I still need to write it up.

 

[DRANGED]

Where is the nearest Dyno accessable to us @DRANGED ? I'd like to see if I could dial in the AF's and timing a little more.

2 hours!

I'd assume GJ...
Like everything else.

Maybe Price but dynos seem like for a different market than up there.

 

[DRANGED]

That's sum good discussion!!
Convincing for DTs!

So with shorties you need to weld flanges and tabs to retain fore cats, with long's you lose fore cats and can otherwise bolt up to stock y-pipe and aft cats with power gains and lose emissions (not an issue in rural UT but could be an issue if we move on to civilization some time).

 

[ArBrnSnpr]

Mostly correct with the exception of the flanges on the shorties. Most people are welding the cat directly to the shorty header, then bolting the Y pipe to the flange on the exit side.

There probably isn't enough room to weld a flange to the shorty header and the cat's inlet union.

Basically, the shorty header ends up resembling the factory manifold with the cat fixed to it.

 

[Rednexus]

Correct, you would slice the factory cats off of the OEM manifolds and have them added to the DT ST headers. This really requires TIG welding as it is stainless and you need to use a stainless TIG welding rod although you could probably get by with a skilled MIG welder and normal mild steel wire in a dry climate like UT. Here in MO doing the weld in mild steel would result it in the weld eventually rusting out and a costly/difficult repair with having to pull the header/CAT off again to re-weld it.

The DT instructions say the welding should be done with the header mocked-up on the truck (tacked in place, and then pulled for a full weld), but I don't see why you couldn't build a wood jig for the manifold (to keep the flange at the head and where the Y-pipe bolts up lined up) and do the whole job with the header out of the truck. Either way, this was a major disadvantage for the ST's for me, as I found all of one SS TIG welder in my area and would have had to build the jig (also, as of this spring, ST's were on indefinite backorder and I got the only set of LT's available in the USA at that time - hopefully they've made more sets since then).

Totally understand on emissions controls - had ST's been available in April I probably would have went that route and just dealt with hiring a welder and building a jig. But they weren't and I was tired of the exhaust tick. Although I don't know why anyone would ever want to leave Moab .

 

[DRANGED]

Mostly correct with the exception of the flanges on the shorties. Most people are welding the cat directly to the shorty header, then bolting the Y pipe to the flange on the exit side.

There probably isn't enough room to weld a flange to the shorty header and the cat's inlet union.

Basically, the shorty header ends up resembling the factory manifold with the cat fixed to it.

I like this!
Seems like the best option and I know a guy who TIGs.

 

[DRANGED]

So both you guys run longs?
How long have you had them?
What was your motivation to add headers?
You each have a good string of mods, so clearly each rig was to be purpose-built (mine's still a family generalist), but why headers?

I'm liking this idea though, but with shorts. The instructions seem pretty damned straight forward.
Unbolt motor mounts, unbolt and remove y-pipe, hoist the engine up a couple inches, remove heat shields, dipstick bracket and pull off the manifolds.
Cut off the cats, install headers, tack the cats in, remove then bead it up and reinstall headers fully, button up the Y pipe, mount the engine down and fire it up.

I'll gi looking for this unobtanium and see if there are ANY to he found. I think I was out $1400 all told last year, so hell if I'm doing that again! I got the exhaust goop for a temp fix, hopefully this doesn't fall into the pattern of temporary-permanent fixes , but for a more solid solution with a bonus power gain - headers seem a no-brainer!
Sounds kinda too good...


What about noise?
@Rednexus , you'be got a full system right, upsized pipes, cat-back and muffler?

How about yours @ArBrnSnpr ?

Do you gain any throat, or under hood growl with a header alone and all else stock?
In my Subaru (and 20 years ago) I was into a note change, kept it mellow but got a bit better tone with upsized pipe, substituting a cherry bomb as the inline resonator downstream of the cat, and going through a magnaflow.... It sounded great for a four-banger...
But we love how quiet the GX is and I'd like to keep that. I've considered hacking the tailpipe resonator, but I think it would up the decibels in a little bit of exhaust note that would probably not go over well with the wife and kids

 

[ArBrnSnpr]

When I installed my headers, I installed a magnaflow cat back exhaust system, DT Y pipe and the DT long tube headers. I installed long tube headers because I was running 34" tires and hadn't regeared yet. I was hoping the increase in power would offset some of the issues associated with running such a large tire with 3.73 gears.
I quickly found that setup was WAY too loud for my tastes and had a pretty significant bottom end power loss.

I ended up putting the factory Y pipe and cats back in and kept the magnaflow exhaust system. It's louder than I'd like right now and I think an OEM cat back would have been perfect. Mine was pretty crushed though so that was part of the motivation to swap systems. My OE manifolds were in great shape though.

Over Christmas break, I'm going to install a set of magnaflow cats in the DT Y pipe and put that back in, then replace the straight through magnaflow muffler with a chambered design.

I'm hoping to tackle an exhaust leak and tame the noise at the same time.

I originally opted for the long tubes as I was chasing power. In addition to the tires, I was lugging around bumpers, fridge, sliders, drawers, RTT, ect I was so I was trying to gain back everything I could. Now I'm running 4.56 gears and 35's and it feels like a stock GX power wise.

Doing it all over and availability not being an issue, I would do the shorty's and a catless Y pipe and stick with the factory cat back.

 

[Rednexus]

I went with headers because 1) I could not stand the exhaust tick any longer and 2) as ArBrnSnpr mentioned, more power. I kept the rest of the exhaust system after the headers 100% stock including the Y pipe and secondary cats, muffler, resonator, etc. It is maybe 5% louder than stock and not really noticeable. Most of the engine noise on my GX is from the aFe cold air intake, the actual exhaust is pretty silent. I personally like that setup as my GX is also used to haul our kids around. It's luxury-quiet at part throttle/cruising, but sounds mean on hard acceleration (all induction noise), which my kids actually like (not so much for my wife ).

I would also do the ST's again if they were available, for environmental reasons. I don't lose any sleep over running only half my cats, but in a perfect world I would be polluting less. Tailpipe emissions are a bit stinkier than stock under cold start conditions, but it's not really noticeable once the GX is warmed up.

 

[DRANGED]

Doug Thorely Toyota 4Runner / Lexus GX470 4.7L Short Tube He

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Seem to be in stock there, others are out....

 

[ArBrnSnpr]

$799 is a good deal if they are in stock!



I found that having a variety of wobble socket adapters and extensions made the job much easier.



I regret not swapping my motor mounts while they were unbolted too.



I did install a 240 amp alternator while I was down there though. I recall having that out of the way making a few bolts on the front of the engine a bit easier to work with.



Just a suggestion, but I'd recommend ordering new exhaust manifold studs and nuts too. Several of mine were seized up pretty good and pulled the stud out with them. I did start a daily application of PB blaster about a week before the install but with all the heat that cycles through there, even that wasn't enough.

 

[DRANGED]

No guarantee in availability. I could call tomorrow and ask for an estimate, or just pull the trigger @$800 and call it late Xmas, whenever it gets fulfilled.

$800 seems like trigger-pulling price for a pair of DT shorties.

 

[MoaByte]

No guarantee in availability. I could call tomorrow and ask for an estimate, or just pull the trigger @$800 and call it late Xmas, whenever it gets fulfilled.

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$800 seems like trigger-pulling price for a pair of DT shorties.

Seems reasonable after what my 2F header cost. I hope you are as happy afterwards as I am.