Up-Pipe - Stock or aftermarket...?

[scooby-wrx]

My factory up-pipe has finally developed a leak... :'( I bought a stainless steel one off Trademe two months ago, I paid $89 but it never showed up, so I bought another standard one (yesterday) which has had the heat shields removed and been heat wrapped. I get home from work today and the SS one is sitting on my front step...

Anyway after doing a bit of research, I've read larger diameter Up-Pipe's increase lag... Has anyone experienced this...? If so, I'd rather fit the factory pipe... ??? :

A pic of each:

[cpt kernow]

I was under the impression that anything free-er between the heads and turbo would decrease lag and quicken throttle response?

[EJ20T]

yes and no, when you increase the pipe size in the manifold it decreases the gas speed and reduces the temperature some what, so can increase the boost threshold, on the flipside at high gas flow and temp (high revs and boost) a small pipe is a restriction and will increase backpressure, so a trade off like just about every other thing you can do to a car

[off2harrys]

looks identical to my sta 1 def made it laggier for me but then others say it helped theres,so up to you bro try them if you can be bothered,but id say unless youre chasing quite big numbers (a/m turbo blah blah blah)i wouldnt bother

[scooby-wrx]

Great, thanks for your responses. I'm going to remove the heat wrap from the stock one and if its in good condition I'll probably just fit it. Gives me something to do this wkend as rain's forecast...

[EJ20T]

what ever you do heatwrap what ever you use, keeping the heat and energy in the gas helps with spooling

[Tony]

 scooby-wrx said:

Great, thanks for your responses. I'm going to remove the heat wrap from the stock one and if its in good condition I'll probably just fit it. Gives me something to do this wkend as rain's forecast...

It is in good condition, and I only re-wrapped it just before I installed my new engine in the car about a month ago. The wrap has only been on while I ran my engine in so will be fine still

Did the pipe arrive today? I got the wife to send it yesterday...

[scooby-wrx]

 Tony']

[quote name='scooby-wrx said:

Great, thanks for your responses. I'm going to remove the heat wrap from the stock one and if its in good condition I'll probably just fit it. Gives me something to do this wkend as rain's forecast...

/quote]

It is in good condition, and I only re-wrapped it just before I installed my new engine in the car about a month ago. The wrap has only been on while I ran my engine in so will be fine still

Did the pipe arrive today? I got the wife to send it yesterday...

Excellent, thanks mate. Appreciate it. Didn't arrive today, but I'm in no rush as long as it arrives by the wkend that is...

[Tony]

 scooby-wrx']

[quote name='scooby-wrx said:

Great, thanks for your responses. I'm going to remove the heat wrap from the stock one and if its in good condition I'll probably just fit it. Gives me something to do this wkend as rain's forecast...

/quote]

It is in good condition, and I only re-wrapped it just before I installed my new engine in the car about a month ago. The wrap has only been on while I ran my engine in so will be fine still

Did the pipe arrive today? I got the wife to send it yesterday...

Excellent, thanks mate. Appreciate it. Didn't arrive today, but I'm in no rush as long as it arrives by the wkend that is...

OK, it should arrive tomorrow then. If it doesnt show by late afternoon, let me know and I will do a trace on it. My wife said it was supposedly an overnight delivery?

[scooby-wrx]

Tony - The up-pipe arrived today and is in great condition. Thanks again.

There's quite a big difference in diameter! I think I'll go with the SS one just to see how much of a difference I notice (will fit this wkend). If its really noticable I know what I'll be doing next Sunday...

Factory pipe ID (inside diameter) - 45.5mm

SS ID - 64.5mm

Factory pipe ID (inside diameter) - 47mm

SS ID - 55mm

[Tony]

Cool

FYI - with my new headers the flange for the up-pipe is 2.5 inch ID/63mm at the collector (custom made headers so the factory pipe wouldnt bolt up anyways), I am currently making an up-pipe to suit. It is 2.5 inch stainless tube from the flange, which then has a 2.5"-2" reducing cone then 2" pipe up into the top flange.

If I went 2.5" all the way up I would run into a big "step" type restriction where the turbo bolts on - which is what you will also run into with the stainless pipe pictured above, as the factory VF/TD turbine inlet is not that big. Unsure if it is a real issue or not, but I just preferred to just keep things flowing smoother.

Will be interested to hear your thoughts after you fit the stainless pipe.

[scooby-wrx]

Ah, not another issue...! You'r right about there being a step. Sounds like I may have to take my digrinder out M... I'll update this thread once I've done the job.

[EJ20T]

In a way theres no point in it being bigger than the inlet of exhaust housing, and anything thats much bigger and leaves a step down is stupid

[Guest boostcut]

^+1 there will be turbulence and will be worse than a standard one in my opinion. and dont touch your turbo with the die grinder mark.

[scooby-wrx]

It was a joke mate. I wouldn't dream of it... I just remembered a mate that did that to his, but sold the car before he got it going, so didn't know if it made a difference. I agree, anyone want to buy a SS up-pipe...?

[Guest boostcut]

thats good, i never know with you!!!

[off2harrys]

Give it a go bro it meant to rain on the wkend anyway

[scooby-wrx]

 boostcut said:

thats good, i never know with you!!!

Appears you guys know what you're talking about... I just went and got my old VF23 out of the shed to measure it. The hole the up-pipe mates up with is 45mm so there will be a 10mm step if I fit the SS pipe.

M... maybe I should use the die grinder on the VF23 housing and bolt this onto my VF22... Come to think of it, could use the mill at work... :-\

[Guest boostcut]

do you want to sell that 23?

[scooby-wrx]

 boostcut said:

do you want to sell that 23?

You sure you want it... ?

[Guest boostcut]

if the bearings are fine, yep.

[gazzy2000]

I have one of those SS UPs, i took it in to an engineers with the turbo gasket for a template and had it port matched to that (turbo end). I did wonder about the big step down at the other end with turbulance etc.

Hvnt been for a decent drive yet so i am un sure of the results. I still have the stock UP too just in case the SS one is shyte.

[scooby-wrx]

 boostcut said:

if the bearings are fine, yep.

Damn... Thought that pic would put you off... You're the third person wanting to buy it.

I'd rather not sell it as I wanted to re-con it and re-fit it. It was definitely more responsive than the 22! I bought a VF36 today though, so may sell eventually... I'll let you know. If my car doesn't sell by the time I hit 180 000km's I'm going to get a V7 /V8 shortblock so will fit the 36 then.

[scooby-wrx]

 gazzy2000 said:

I have one of those SS UPs, i took it in to an engineers with the turbo gasket for a template and had it port matched to that (turbo end). I did wonder about the big step down at the other end with turbulance etc.

Hvnt been for a decent drive yet so i am un sure of the results. I still have the stock UP too just in case the SS one is shyte.

Yes, so I wouldn't be the first! It will be interesting to hear whether or not you notice a difference.

[gazzy2000]

 scooby-wrx']

[quote name='gazzy2000 said:

I have one of those SS UPs, i took it in to an engineers with the turbo gasket for a template and had it port matched to that (turbo end). I did wonder about the big step down at the other end with turbulance etc.

Hvnt been for a decent drive yet so i am un sure of the results. I still have the stock UP too just in case the SS one is shyte.

/quote]

Yes, so I wouldn't be the first! It will be interesting to hear whether or not you notice a difference.

Yip well i got them to basically match the port to the same size as the turbo... teh stock size. So who knows if it will do anything