i'm sorry but i can't hold this back.... if you care for the car, you want the best. in this case, the best is the bipipe. yes it's more expensive, but if you want the car to last, and believe me, you want the car to last, then get the bipipe. it'll be so worth it! it not only rids of the easily broken TBB but also replaces those plastic pieces of crap tubes connected to the intercooler and TBB.

as for the fitment question, i had the same problem. but close to all s4's have this problem with the fan. all i did was shave down the side with some sand paper and it worked like a charm. it would've been faster if i had an air tool, but sand paper worked just fine.

 

Do they come in silver like you have or did you do that yourself? Also what did you do to you y pipe? It looks glossy.

 

There is quite a debate in the B5 S4 community going on right now over the APR bi-pipe. Some say it has reduced airflow over the stock TBB and the Samco piece - however I don't know if this is true and I have a hard time thinking that APR would use a piece that would restrict airflow measureably. Some also are concerned about the (hard) attachment to the intercoolers replacing flexible tubing - I gather the concern is regarding tranfer of engine torque to the intercoolers where they might crack or develop leaks...again I don't know the validity of the issue but it makes some degree of sense. I considered the bi-pipe but ended up going with the Samco piece (thinking it should be good enough). I had an early problem with it popping off (once) but since it was reclamped (in May or June) it has kept its seal and is looking good. As I have the phenolic(?) heat shield on my manifold it adds some space (height) and stretches the Samco TBB to near its limit (was difficult to get on) - but so far - since the reclamp its stayed in place. This could also perhaps affect the bi-pipe connection distance/fitment as well (I recall seeing a complaint about this some months back on another forum). Everything is pretty tight in there. Plenty of people have the bi-pipe and are very happy with it - likewise the Samco. I even understand that the stock TBB is OK with a proper (non cutting -smooth edged) clamp. So perhaps it all comes down to what floats your boat. bi-pipe is certainly more expensive and totally eliminates the concern for torn TBB - though there are potentially other issues it seems (or at least some claim such). Samco could still tear or clamp come loose but its silicone and pretty tough. And perhaps just using the right clamp on the stock TBB will eliminate much of the tearing concern as well and its pretty cheap to replace even if it does tear (may be worth getting a second and having it around just in case). Hope this helps your decision.

 

We all agree that the stock TBB sucks. In fact a lot of S4 owners carry a spare in the trunk (seriously!). It works & it's totally fine, you just got to be ready to change it out at the first sign of a leak.

Samco, new there a PITA to install, they can also leak, & pop off. They can leak around the pressure sensor. But it should not tear, & it should last a long time.

APR Bi-pipe, yes the casting is not perfect. But that's Ok, anyone who has any Flow Dynamic knowledge knows that air will travel faster over a dimpled surface. It's really not that bad, The worst part is at the junctions of the 2 pipes. I cleaned mine up with a Dremal. Fit is good, but can take a little tweaking. Mine hit the fan blades a little, it took me 20min to fix. Also I had to clean up one of the mounting holes to the TB cover.

Since the piece has bigger outside pipes then stock, & it's not that much thicker then the stock pieces I don't see how it can flow any worse then the stock pieces. I like the fact that the TB is no swelling & contracting under boost. This can affect performance & change the boost @ the sensor.

But once you put the Bi-Pipe on you are DONE, never again will it leak!

Roadhawk, it DOES not hard attach to the IC's, it uses the stock hoses form the IC to the Bi-Pipe. It is hard attached to the engine, just like the stock pieces. It will not put any more/less strain on the IC over the stock pieces.


Anyone you choice is not a performance mod, it's a lets save the turbo mod! It's just insurance over boost leaks, & over-spooling the turbo's.

"The Best" is what ever works for you. I didn't want to carry a TBB in the trunk, & didn't want to have the Samco pop off. So the Bi-pipe was for me.
IMHO, the "Best" would be the RS4 hard pipes. They flow more then stock, look sick, & will never have a problem. But you have to have custom IC hoses, RS4 TB, RS4 intake Mani, then the Rs4 fuel rail, you get where I'm going here.... LOTS, & LOTS of $$$$$

You need this piece then the 2 "pressure pipes" The 3 pieces are almost $1000!!!!!!!!

 

i got the apr- bi pipe and no regrets here..

 

If your looking for the best then go with the Full intercooler, and or hard pipes. Thats the best. The Bi-pipes also is made of plastic and dosent transfer heat as well. 2k s4 has an alluminum bi-pipe that looks like it solves this problem. But remember the the bi-pipe have a smaller interior diameter which restricts airflow a bitmore, of course your not going to notice a diffrence but it could affect your car if you decide to go bigger turbos. All in all take this info and learn from it. The samco has been know to pop off, but its a better than the stock throttle body boot. Get the samco and buy this billet brace (eliminate all tbb flexing and tearing issues) http://www.hoppenmotorsport.com/ybrace.htm

 

How hard is the install, my biggest concern is attaching the pipes at the bottom end down in the bay. How would you rate the install?

 

$$$ Wasnt really the prob for me, the APR bi pipe is very rough cast inside and ware they meet B4 the TB is smaller than stock, surely this is going backwards from the stock setup?[:'(]It does look good but looks are can be decieving[]

I got the MTM TBB+Brace, made from tougher rubba than stock + has brace which still wasnt cheap

Fits as good as stock, looks factory and if MTM uses it it must be good

Must be a reason why AWE, MTM etc havent developed there own bi pipes?











Hay 2k wat are the 2 plugs nex to u MAF for, the big green and brown one nex to it?

 

looks good, I still have the stock TBB, and no leaks yet. I'll be getting the samco pretty soon. I know one of them if for your oxygen sensors, give me a min i'll find out what it is.

 

They look like 02 sensor plugs to me, dr. S4