turbo elbow a little small?

[mjjstang]

So I put my dp, turbo elbow, and test pipe togather for a test fit today and knew the elbow was smaller diameter but didnt know it was so damn small in comparison, I got the ss one that has the two runners or what ever they are called, not the greddy hks like ones that are just one outlet, why is it so fing small, isnt that quite a bottle neck, so whats the point of a 3 inch exhaust if that outlet is like 2.5 or even smaller. I know some of you guys must have the elbow that im talking about. whats the deal.

[mjjstang]

so nobodys got this and wondered why its so small.

[sr240mike]

Are you talking about getting that ebay one with the seperate pipe for the wastegate? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2481047867&category=33742&sspagename=WDVW I was looking at getting one of those.

[mjjstang]

yes that is the one, HKS style I guess, it seems nice but why is it so damn small, its like the opening sizeof a golf ball, maybe since it is so close to the start of the exhaust that it doesnt matter that it is smaller but I thought that it would be a bottleneck.

[s14srpilot]

I got the greddy one from phase2. It has a dividing wall inside. They said it added 16 rear whp on one of their cars they dynoed. It definately pulls much stronger now and is more willing to rev past 7000 rpm. Visually it is much wider than the stock elbow so I can see how it would flow more efficiently. Perhaps the 2 separate runners flow better than a larger single one. you'll never know until you try it.

[mjjstang]

well i guarentee you your not getting 16rwhp from it, but aside from that, yes overall mine is wider becaues of the second tube, but that tube goes back in to the main one and comes out to a golfball sized hole, now for a hundred bucks I better have improved hp, the stock pipe itself is wider than the outlet of this one, im just wondering does it really help that the wastegate has a separate outlet, I only bought this becuase the stock one was rusted to fuck and the bolts for elbow - downpipe were rusted on. but I sure as hell dont want to go down in power.

[sr240mike]

By having a seperate outlet the wastegate gases will not interfere with the exhaust gases as much. This is good because it reduces the backpressure behind the turbo = better spooling. What is the inner diameter of the pipe at the outlet?

[mjjstang]

I.D is 2 inches, terrible. so in escence (sp) would I even see a difference in power if i went a 3 inch or 2 inch exhaust, not that I would ever go 2 inch, but my bottle neck is at 2 inches dont see what the advantage of a 3 inch exhaust is, im sure somebody knows how this shit works.

[s14srpilot]

well i guarentee you your not getting 16rwhp from it, but aside from that, yes overall mine is wider becaues of the second tube, but that tube goes back in to the main one and comes out to a golfball sized hole, now for a hundred bucks I better have improved hp, the stock pipe itself is wider than the outlet of this one, im just wondering does it really help that the wastegate has a separate outlet, I only bought this becuase the stock one was rusted to fuck and the bolts for elbow - downpipe were rusted on. but I sure as hell dont want to go down in power.

Just curious, how can you guarantee that it didn't add 16whp? I can't guarantee that it did but now that you mentioned it I'm gonna try to get the dyno chart. I also have a 3" downpipe and 3" exhaust but I still have the 2nd (fake) cat which restricts the flow b/c it's smaller in diameter.

[sr240mike]

You would see a difference in power with a 3". Anything you can do to reduce backpressure allows the turbo to spool faster. The 2" may still be an improvement, what is the i.d. of the stock one?

[mjjstang]

s14: Im not knocking you in any way, its just a common fact that you will never get even half of the power that somebody advertises. Someone please back me up on this, usually they are straight out lieing or they find an insanely boosted massively powered car wehre it may give that much.

sr240: that is the thing, the stock one looks much bigger. I dont know, im just confused why I would have payed 100 bucks for crappy performance, I Know that even if it did decrease performance a lil, its not the end of the world, but its like Im taking a step backwards here and thats not good. so the guys that have the greddy one, what is the inner diameter of the side that goes to the downpipe, not the turbo side.

[DuffMan]

16whp might be possible as a gain, but not at stock boost.

2 inch inner diameter seems small, but the turbine housing opening is only 43mm on a stock T25 or T28 (excluding a gti-r turbo).

[mjjstang]

so im just wondering the advantage of having a 3 inch exhaust if the smallest area is 2, I guess that it would be better because the exhaust only has to get past that small area and then it is freed up a little bit. oh well. well see.

[ryan hagen]

heat wrap it, the farther down steam exhaust gets and it starts to cool the exahust expands, thats what i was told, the hotter u can keep the inside of the pipe like with heat wrap the smaller exahust u could use, i notice alot of double wall exhaust on stuff now. so it would be at its hottest point right through and out of the turbo and expands the whole way back.......some one correct me if i m wrong

[mjjstang]

heat expands though, wouldnt you want it cooler, either way I plan on going 3 inch, its just weird to me why I would "upgrade" to a 2 inch outlet.

[ryan hagen]

heat expands though, wouldnt you want it cooler, either way I plan on going 3 inch, its just weird to me why I would "upgrade" to a 2 inch outlet.

go fill a bottle up with water and put it in the freezer, or put a soda in the freezer see what happens

[mjjstang]

ever put a ballon in a freezer and see it shrink, or over the stove (obviously not on the stove) and watch it expand, also how bout hot air balloons, but yah it is learned that heat expands in like 6 grade, heat molecules are bouncing all over the place while cold molecules are tightly bonded together. but that frozen shit has always made me wonder how in school you are taught one thing but it can go the other way also. so maybe your right and maybe ive been brainwashed by my teachers I donno just gonna go ahead and put this shti on and if it works it works. not tryin to be an ass or anything, just very confused.

[sr240mike]

It doesnt seem like its a good upgrade. SS autochrome is known for some cheap ass stuff but it looks nice so people buy it. I got their ss manifold but havent put it on yet. You do want the gases before the turbo to be hot as possible because it does expand and will help it to spool faster.

[s14srpilot]

s14: Im not knocking you in any way, its just a common fact that you will never get even half of the power that somebody advertises. Someone please back me up on this, usually they are straight out lieing or they find an insanely boosted massively powered car wehre it may give that much.

sr240: that is the thing, the stock one looks much bigger. I dont know, im just confused why I would have payed 100 bucks for crappy performance, I Know that even if it did decrease performance a lil, its not the end of the world, but its like Im taking a step backwards here and thats not good. so the guys that have the greddy one, what is the inner diameter of the side that goes to the downpipe, not the turbo side.

I'm running stock boost so you are probably right but I did feel a noticeable enough difference to not regret doing the mod though.

[ryan hagen]

i used a bad example, i was hung over at the time. heat effect liquids, gases , and stuff differnt, i didnt like 6 th grade, the hotter your exhaust gas though the less resistance it has going out your pipe, it travels faster, it wants to get out. the less disturbance in the exhaust flow the easier it is to pull its self out the wastegate tube helps, that why the best would be a divorced wastegate that emptys to the atmosphere.

[uiuc240]

ever put a ballon in a freezer and see it shrink, or over the stove (obviously not on the stove) and watch it expand, also how bout hot air balloons, but yah it is learned that heat expands in like 6 grade, heat molecules are bouncing all over the place while cold molecules are tightly bonded together. but that frozen shit has always made me wonder how in school you are taught one thing but it can go the other way also. so maybe your right and maybe ive been brainwashed by my teachers I donno just gonna go ahead and put this shti on and if it works it works. not tryin to be an ass or anything, just very confused.

Water is the only substance on the planet that expands when frozen. That is the reason that you're confused. Everything else shrinks when cold and expands when hot. This is from 8th grade science class.

Eric

[ryan hagen]

isnt moisture(h2o) a product of combustion, making it part of your exhuast?

[NismoSilvia270R]

you want it hot. chem major