Ran into an unexpected snag with the Weapom-R 'S'-Pipe -- the CEL Eliminator wouldn't thread into it. The Eliminator had just come out of the OE 'S'-Pipe with no problems and the threads looked fine (though there was Anti-Seize compound on them). I tried finger turning my 18MMx1.50 tap through the bung and it wouldn't go either. I looked at the threads and saw no obvious problems, just discoloration, but clearly something was wrong -- I'm guessing distortion from the welding. I ran the tap through and it took a fair amount of effort to turn. Afterward, I applied fresh Anti-Seize to the Eliminator and was able to turn it in OK.

 

Ran into a few issues, but it's together, though with at least one exhaust leak -- hoping it's just the "scuba" since I've no gasket for it. I'm not sure yet about the doughnut since it's sized for the Weapon-R collector, and the OE isn't big enough for the 'S'-Pipe and can't be used. I'll find out for sure when the scuba has a gasket.

My first problem was the OE spring bolts aren't long enough to install with the Weapon-R 'S'-Pipe. Simple solution is to use the provided bolts, but they are 10MMX1.50 which doesn't match the 10MMX1.25 OE exhaust manifold and my freshly installed Helicoils. My quick and dirty solution for this was to run a 10MMX1.25 die over the bolts -- however, that's a poor solution and I need to get the right bolts. Which brings up the next complication, the provided bolts are 3.75" and need another 1/4" for comfortable install -- though maybe that's perfect for the Weapon-R header. So, hopefully the last issue is the missing "scuba" gasket. In any case, here are a few photos.






Oh, yeah -- so far, the Helicoils are working great !

 

OK, picked up a 2.5" gasket and the exhaust leak is fixed -- the Weapon-R doughnut gasket appears fine with an OE compatible header. Picked up a couple 100mm (4") bolts and they're fine, but looks like the Weapon-R 3-3/4" bolts would be OK (outside of the thread spec) if washers aren't used at the flange -- looks like a YMMV issue to me. The Helicoil thing is an issue I created myself, but I like the convenience and they're proving themselves reliable through multiple spring bolt tightenings and loosenings. Don't have any driving time to speak of on it yet, but everything is working and tight.

Happened across the OE "scuba" gasket in the driveway, it was broken in half and looking very beat -- I didn't even realize there originally was one! Now I've a new one, it's clear it's been missing ever since I first removed the OE 'S'-Pipe. The OE coupling gives a tighter connection than just bolts and the difference is audible. I'll need some time to conclude whether I've actually gained ground with the 'S'-Pipe change, but I definitely prefer the sound with a gasket at the "scuba" !

 

I'm a little confused about the bolts. The oem bolts are shoulder bolts designed to torque tightly against the header flange while providing the correct spring pre-load to create an air-tight seal between the graphite donut gasket and it's conical mating surface in the S-pipe while still allowing some movement without destroying the donut gasket. In your photo it appears that W-R provided standard bolts with no shoulder for proper seating. How are you supposed to tighten them to the correct spring pre-load and then keep them tight? I suppose you could guesstimate and use loc-tite.

Did you really re-tap 10x1.50 bolts to 10x1.25? If so then you indeed do need new bolts. Bolts with the correct shoulder length, overall length and thread pitch. Good luck with the on-going project.

 

The OEM spring bolts have a stop that limits how far they can screw into the exhaust manifold. Weapon-R provides flat and split ring washers and I guess you tighten the bolts to whatever degree seems appropriate. However, darned if I know what's optimal with the Weapon-R setup, so I tried to leave "enough" inter-coil space to be functional. That is -- I guessed! Frankly, I wouldn't be the least surprised if less spring tension would be appropriate, but I really don't know how to gauge it ! The OE setup is easily more repeatable and specific, and that was why I hoped to use the OE spring bolts, but although I tried, it didn't work out !

Sure did, I needed to use the car and recutting the bolt threads to get me by for a while seemed entirely reasonable. As it is, the recut threads held securely and given I've really no use for 3-3/4" 10MMX1.50 bolts, I can't say I feel too bad about the transgression ! Unfortunately, the replacement 10MMX1.25X100 bolts cost me a little over $7 ! I agree the OE spring bolt arrangement is higher quality and more repeatable, though the Weapon-R replacement is probably serviceable for a' that !.

At this point, I'm especially noting the difference made by installation of a new 'S'-Pipe to "scuba" gasket -- a very worthwhile move coming from none ! I've yet no clear sense whether my 'S'-Pipe "upgrade" really accomplished much, though it's still a little early to tell. I've come to realize the difference in ID between my header collector and the Weapon-R plus the OE 'S'-Pipe and the Weapon-R is only perhaps .2", though it increases to about .7" at the 'S'-Pipe half way point. IMO -- that doesn't really speak for much of a performance boost! My suspicion is the multiple header paint coats and 'S'-Pipe wrap are my best bets for any realized improvement.

Got to see how it goes, I guess, but I'm not yet jumping to recommend the Weapon-R 'S'-Pipe as a performance upgrade for our cars. Interesting to play with though !

 

Thought a lot about the darned spring bolt setup and decided to revisit it. One thing is I believe it's a mistake to install a washer at the flange end of the spring -- the space is too tight and it binds against the bolt, restricting the very motion it's intended to permit. I'm suspecting the only reason Weapon-R includes a washer at each end of the bolt springs is to make sure the spring stays in place before install and I simply erred in installing both. (Plus, 3-3/4" bolts are definitely fine if you don't install washers at the flange.)

In any case, I've dropped back to a single washer per bolt, with the split ring washer between it and the bolt head. I've also switched to the OE springs since the wire gauge appears the same, but the OE are a smidgen longer and have a more open wind. I screwed in both bolts finger tight to start them, and then used a ratchet to add 10 quarter turns of spring tension per bolt. The connection seems stable to me and the OE springs have plenty of remaining travel. If needed, I can easily add matched bolt rotations to increase the spring pressure.



With the threaded lower header flange, I'm thinking the combination of split ring, washer, and spring tension provide enough stability that it's not necessary to add Loc-Tite. I suppose I could install jam nuts on the bolt ends, but I don't think they're needed. However, if the bolts were held by nuts instead, then either Loc-Tite or another split ring washer would probably be a good idea to prevent loosening.

Just an observation, the scuba connection to the OE 'S'-Pipe has a very positive pipe alignment because of the bolting arrangement, this is lost with the Weapon-R 'S'-Pipe, so it's necessary to very carefully align the pipes for optimal exhaust gas flow. Also, I think I'm getting spoiled by the OE 1.25 thread pitch -- it makes it easier to get a tight connection, plus it's less likely to loosen than with a 1.50 pitch.

 

Fired it up, slowly passed my hand around the doughnut coupling, and no sign or sound of any exhaust leaking. Took a look down at the coupling and it appeared to be flexing easily with the engine movement. So, seems to me finger tight plus 2-1/2 bolt rotations works fine with the Weapon-R doughnut and OE springs.

Took it out for awhile and the exhaust rumble seems lower than ever (installing a gasket at the "scuba" helped a lot). I tried giving it throttle up the nearby hill in fourth at about 40 mph and there was actually some push against my back, not lots, but enough to notice. Also, more of the accelerator travel seemed to be useful than before. So, perhaps cylinder scavenging has indeed increased and I'm getting a little more torque -- it always accelerated, but not so that I could feel it at all. So, I'm currently thinking I've gained a little ground, but if so, it sure wasn't cheap and it involved some work.

 

Since I'm thinking this mod actually accomplished something, I'm looking at extending it a little, but since the viewers of this thread apparently have no particular interest, I guess it's time to take my efforts off line. Cheers !

 

quick question did you have any clearence problems with the o2 sensor? i tried to install my weapons r s pipe this weekend with out the 90 degree cel eliminator and the o2 sensor hit the cv shaft

 

I'm actually interested. I just come in to read. It's interesting to see other people's results.
I haven't done any type of exhaust work on my xB yet. I have the TRD eBay replica on it's way. I'll have to look at everything more carefully, like you have. I may eventually get the Weapon-R header/s-pipe, but then I'll have to add a catalytic converter. Not a huge deal, but I'm sure I'll need to do a bit more work to tame the exhaust note.

 

I never tried that since I needed the CEL Eliminator for the header. I can say that with the Eliminator, the Weapon-R allows more open install/removal access to the O2 Sensor than does the OE pipe. If I need to swap the OE manifold back in, I just leave the Eliminator installed, doesn't hurt anything.




Just like me, you lose the pre-cat when you install a header, but unless you specifically choose to delete the "scuba", you'll still have your main cat.

 

I know this'll sound crazy, but with the latest mods, my xB2 is reminding me a little of my modded turbo Eclipse (my experience with which factored into these xB2 mods). There's a nice touch of eagerness showing up that requires I ease back on the throttle to behave. In the Eclipse, I interpret it as earlier-than-OE spool that I have to moderate by backing off a little. I've ordered some more wrap for the lower portion of the header (where the four pipes run together) and am hoping it will further the car in that direction. Unfortunately, Amazon seems to be doing their level best to make me wait as long as possible ! Took me awhile to start experimenting with the pre-"scuba" exhaust, but it's appearing complementary to my smooth bore TBS that preceded it.

 

Huh? Typo I presume?

Glad to hear that the s-pipe wasn't a waste of money. If you haven't already you should consider a CAI for your next mod. Import Tuner got the biggest hp/tq gains from adding a AEM CAI. More than the Strup header.

BTW, back to the spring bolts... it shouldn't be hard to duplicate the oem desgined spring tension without the proper length shank on the bolts. Just measure the oem compressed spring length and tighten the bolts to the same. It only has to be close. Personally I'd prefer loc-tite to split washers since the bolts will be 'loose' without a shank but it may work just as well with the spring tension and split washers.

 

Perhaps a mis-communication of some sort? I never had a reason to use the Weapon-R 'S'-Pipe without the CEL Eliminator since my first step was to install a header. As soon as a header replaces the OE exhaust manifold, the Eliminator becomes mandatory. So yes, I meant what I said, no typo.

Frankly, I'm finding that one a little hard to evaluate, though it's probably best to just ignore the cost . I'm clear I've gained some ground, however, that could be entirely due to being able to wrap the Weapon-R 'S'-Pipe (corrosion safe SS), though the slight dimension increase may also factor in. I'm taking a gamble in wrapping the lower header pipes in that I'm guessing any moisture will be able to escape from within the pipe bundle -- that is, it won't be sealed within the wrap. I think it'll be beneficial since air passing through the radiator normally cools that portion of the header. Wrapping should reduce that cooling.

Actually, I'm happy with my home brew CAI. I like that I have easy access to the high flow air filter and since I'm not pursuing max horsepower, any losses due to the presence of the OE air box (I see Descendent keeps it too) isn't a serious issue to me.

The spring bolt question is interesting. The OE design has the tension on both bolts defined by the built in bolt stops. My approach with the after market 'S'-Pipe is to take up the bolt slack by hand, and then increase the tension by a set number of bolt revolutions. Fact is, the contact area between the Weapon-R 'S'-Pipe bell and doughnut gasket is different from OE -- it's greater. So, the spring tension required could well be different despite using the OE springs. My approach was to go light and see from use if I needed to increase it. So far, the addition of 2-1/2 bolt rotations appears adequate (1.25 pitch), though to be sure, it's possible less would also do the job.

 

I was tired and skimmed the post to which you were replying. It sounded as though you were saying that you needed the CEL eliminator for the header, as in you installed it there. Clear now.

I'm assuming that the biggest benefit you've felt was the s-pipe and not the wrap. Typically the little things like header wrap don't produce noticeable results although they do add up.

From the test results I've seen high-flow air filters add nothing vs paper unless the filter surface area is under-sized, which is not the case with our engine, IMO. I was referring more to the turbulence and airflow reduction caused by the accordian intake pipe that World Racing eliminates. I doubt the airbox or the paper filter present much restriction.


Whatever works... it's certainly not rocket science.

 

Well, the Weapon-R is officially 2.5", but turns out that's outside dimension, not inside (I was imagining it to be ID). So, the real difference in ID for the first half of the pipe is about .2", and around .5" (EDITED from .7" to .5" on 5/24) for the last half where the OE pipe is smaller. That makes for a very small increase in volume and a very small decrease in flow velocity, which gives me a little more of a pre-"scuba" reservoir effect for power, but works a little against me for scavenging. Looking at the OE pipe, I don't see any serious flow issues in the bends, worst concern being the modest ID reduction at the halfway point, but the reduced Weapon-R resistance should provide some flow velocity increase. What's the net effect? I'll guess some reservoir and near unchanged flow velocity.

On the other hand, the increase in average gas temperature in the pipe should be significant going from bare metal to wrapped. So, I'm inclined to think velocity is having at least as much and likely greater effect here than volume and flow. 'Course, I've no proofs one way or the other -- just me trying to apply theory as best I can . If I'm wrong, then wrapping the lower portion of the header is going to be pretty much a waste of money and time.

Can't say I know if there's a difference in restriction between the two filters on mine. I know people have claimed to notice a difference with a high flow in the absence of the snorkel, but I never seriously tried to evaluate it myself.

I guess the only way I can find out for certain whether that short length of 3" flex hose is having much impact would be to try something else (the flex hose inner ribs are very shallow). In my case, that would also replace the flexible inlet hose (more shallow ribs). However, max intake airflow is only needed at high rpm. My usage is very much midrange and below -- I never get even remotely near redline. Also, exhaust gas volume is hugely expanded over equivalent intake gas volume, whereas that's a 3" intake Vs 2.5" pre-"scuba" exhaust. I don't know, my logic is telling me I don't stand to gain much, if anything, by upgrading the intake pipes (and recognizing the intake manifold has a decent sized plenum plus there are two resonance chambers that smooth air demand from the piping). I think the gain on that side of the engine with N/A comes from ditching the snorkel and smoothing the constrictions (the TB approaches 2-1/4" at its widest following the plate, is a fair amount less than that at the plate, and I understand the WOT spec is only about 62% open) (EDIT -- My understanding was wrong on this -- Fred is correct with 80% being the spec 5/24). I'm just not seeing the 3" flex piping as a problem.

What I think I am seeing is the problem of getting the exhaust gases out of the cylinders. As I make improvements to the engine's ability to accomplish that, the intake side doesn't appear to have a problem delivering fresh charge -- I run out of throttle response long before I run out of pedal travel (despite the modest throttle plate size and restrictive spec). Sure, there's a computer between them, but I doubt it's leaving that much dead pedal travel in its plate control. I really think my best attack is exhaust velocity, and the lever available to me for that is temperature control.

 

Theory aside for the moment, here is a dyno sheet comparing the AEM CAI to the stock airbox:

http://www.importtuner.com/powerpage...rs5/index.html




Dyno 2
AEM Cold-Air Induction System
Peak HP: 134.4 / Peak TQ: 138.6

Horsepower Gain
* 4,000 to 5,500 HP range: 5.5 to 10.8
* 5,500 to redline HP range: 6.9 to 12.0

Torque Gain
* 4,000 to 5,500 TQ range: 4.3 to 14.8
* 5,500 to redline TQ range: 5.7 to 11.2

So much for the resonance chambers or should I say intake sound dampers? Also where did you hear that the "WOT spec" is only 62%? I've never seen or heard anything like that.



From the Scion TC performance parts testing roundup:

https://www.scionlife.com/forums/viewtopic.php?t=92108

"Second up Stock Air Box with Drop In K&N filter. We left the charcoal thing in as well
This one was an absolute bummer IMO. It lost HP but the air fuel was good."

Now I don't believe that the drop-in K&N actually lost hp or tq but I find it easy to believe that it made no difference or the gain was so minimal that it falls within typical dyno test variance.

Anyway, good luck and have fun with the theoretical experiments. I'd guess you've added a respectable 10whp and 10lbs tq with all your mods while essentially maintaining the oem tq and hp curves. If you ever have any actual data to show I'll be very interested to see it.

 

Stock includes the 2" looped snorkel, how certain are you that isn't a factor in that dyno run? Also, only one of the two resonance chambers is oriented towards sound (adjacent the MAF), per Toyota, the other is aimed specifically at mid-range torque (within the intake manifold). Both of them have the effect of smoothing mid-range air demand. The WOT spec came from a Toyota "Master" Mechanic, I'm presuming he knows what he's talking about (EDIT -- my information on this was incorrect 5/24).

Perhaps, I'm not trying to argue that one way or the other. That mod was essentially day one for me and I presumed TRD was offering a genuine enhancement -- if it was just bull____, the boom falls on Toyota/TRD, not me. One comment though, the intended air flow for the stock filter was via the stock 2" snorkel, and that flows far less air than my shorter 3" CAI setup. How certain are you the TRD high-flow isn't a better choice?

Thanks Fred, but please understand, I'm not meaning to be persnikity with this stuff, I'm just trying to interpret and apply as best I can. In absence of a dyno test, comparison between car behavior stock and car behavior now is, I think, closer to 20 per category than 10, and probably with more emphasis on torque than power, but that remains speculation. I can say flatly that simply removing the snorkel made a huge difference, and I'm betting that AEM dyno run keeps it in for the airbox run -- do you seriously disagree?

In any case, I'm expecting the wrap to arrive late week (finally shipped Friday) and I'm hoping there'll be a further improvement in mid-range performance. Attempted application of theory is the only protection I have against taking broad shotgun blasts, and it's clear that approach is expensive (as evidenced by the Weapon-R 'S'-Pipe). The tack I'm taking seems expensive enough !

 

So then with a CAI installed you still have the performance enhancing resonance chamber in the intake manifold and lose nothing but a sound damper. I'm not saying that removing the airbox snorkel doesn't add power, just that I do not believe that it adds as much as a smooth-bore CAI or even a SRI. Assuming that the oem paper filter is too restrictive for a mildly modified 2AZ-FE (we really don't know), a K&N drop-in could also add a little.

As for the "WOT spec" being 62%, I'm not sure what that means but the throttle plate opens to ~80%. Maybe he said 82% or misspoke?


Not at all, I can't be without any test data. Which is pretty much what we're talking about. Without any flow or dyno testing we can speculate back and forth all day about whether your home-brew airbox works as well as a aftermarket CAI or whether your TBS actually adds mid-range torque or wrapping your s-pipe negates the restrictive effect of retaining the scuba with it's small inlet and outlet pipe sizes. I find your theories and unconventional experiments interesting but am also a bit frustrated that all we have for proof is the subjective impressions of a unavoidably biased reviewer. No offense but if you didn't believe in what you're doing you wouldn't do it. I don't see how you could possibly remain totally unbiased and impartial.



I'm sure that Import Tuner left the snorkel intact for the stock baseline dyno run. I'm also fairly certain that removing it doesn't add as much hp/tq as the AEM CAI does. Again we come down to the lack of test data. You say 20, I say 10... I guess we'll never know.

BTW, I removed my airbox snorkel and felt that it added some power too but I also installed a CAI and felt that it added more. However I have no data to support this speculation.

Good luck with it and please, if you ever have an extra $100 to spend, get a few dyno runs. I'd love to see how your theories actually work.

 

My point was just that the 10HP didn't come from simply replacing the air box, it replaced the snorkel as well, and that in itself would easily account for most of that improvement. I don't question that smooth bore piping allows greater max flow than does ribbed, and hence a higher max power possibility (whether or not actually realized by the rest of the engine systems). However, my emphasis is on mid-range performance, which not only requires lower average pipe air flow (including pulse peaks), but also benefits most from resonator flow smoothing (further reducing the peaks). Consequently, I really doubt it's a concern to me, just as I doubt the "scuba" presents a mid-range constriction.

Assuming 62% is the actual spec, I'd hope it's the minimum "acceptable" plate opening -- there's no question there'll be vehicle to vehicle variation. I was very disappointed with that number, since I'm used to hard pedal linkage where a properly adjusted WOT is truly 100%. However, he reiterated 62%. I'm presuming your 80% is measured? If so, that wouldn't necessarily be a contradiction, just a production sample -- hopefully typical (62% is depressing ). (EDIT -- as already mentioned, 62% is actually not the spec, it's 80% as Fred said. 5/24)

My point here is just that the OE filter flow area is only required to support the 2" snorkel. So, even if it's true that replacing it with a high-flow with no other change would have little effect, if the snorkel is removed, it's a very different landscape. Also, since Toyota's intended intake enhancement is the TRD which includes its own filter and fully replaces the air box/snorkel, it's not clear the OE filter was planned to accommodate more than the snorkel (though to be sure, it could've been).

The thing to remember is I'm not targeting power per se'. I'm not talking high rpm, I'm focused on mid-range performance. I'm not saying what I'm trying is a way to achieve a fast N/A track car. Some or maybe even all aspects may help, but by themselves, they're clearly insufficient (your intake and "scuba" concerns being examples).

As for the things I choose to try, my interpretation of theory leads me to believe they provide my best shots at mid-range performance enhancement. Yep, I'm hopeful each item will benefit me (otherwise I wouldn't spend the money), but I'm not flatly assuming it up front -- I want a little driving behavior corroboration before concluding it worked. Problem there, of course, is objective measures are hard to come by. I end up looking at things like (for example) how hard it was to keep up with quick traffic from a standing stop going up a hill to a light -- then Vs now.

As I said above, I don't doubt smooth bore piping has a flow advantage over ribbed piping. I added 10 primarily due to your apparent dismissal of my air box based CAI in comparison to the AEM (meaning you were leaving off somewhere around 10). I'm quite certain they're nowhere near 10HP apart, hence my pointing out the snorkel. In any case, I don't even know what the OE WHP is, I'm thinking the published 158 number is measured at the flywheel.

Man, I don't even know where I'd take it for a competent dyno test. If I ever get finished with it though, I admit it would be interesting to give it a try .