SMB 4" - 3.5" DP for "twin" turbos!
 

Just got this email and had to pass it along. This looks amazing and makes me jelous. I can only imagine the results you could make with a BNR upgrade and 3.5" SMB all the way back. ...you bastards :fawk: "lol"

We can manufacture without the depression.(got your imagination going?)

Regards
Grant http://www.smb.net.au/
http://img.photobucket.com/albums/v2.../Photo0194.jpg
http://img.photobucket.com/albums/v2.../Photo0192.jpg
http://img.photobucket.com/albums/v2.../Photo0193.jpg

Price?

Yeah, SMB stuff is the JAM. I love my hiflow metal cat from them - DAMN fine workmanship and quality.

Dale

No price yet but you guys may want to start another group buy thread. From Broken09's thread with his single, he got the same HP with 3" DP back at 17psi as he did with 4" DP at 15psi. Even though it starts at 4" it tapers down to 3.5" which allows you to run a metal cat. Even so, I would think it would reduce back pressure by 1psi and make your system more efficient and possibly cooler. Most likely you would have to port your internal wastegate as well as use a 3.5" mid pipe/cat' and exhaust to take full advantage of this.

The stock turbine housing has been proven to be the restriction in the exhaust, as per bryan at BNR. Don't want to take the wind out of your sales, but I'm not sure this would yield a big benefit being that it's located downstream of the turbine housing. Having said that, if I was still running my BNRs I would probably pay the arm-and-a-leg for this piece just to try it out :D

:rlaugh: Good one. Was that intentional?

^ I was thinkin the same thing. :D

;) :angel:

That restrictive looking HKS-type inlet would probably cancel out any gains to be had.

Jack

Would be interested in this if it was 4" all the way through and not tappered to 3.5".....

Hmmm, id have to see dyno results. I have the HKS DP with the Same taper. If this one or even a 4 incher would produce dyno proven results id buy one this week. Companies should do this, it would make sales so much easier for them. Self explanatory "dyno proven" why would you pass that up??

smb are regarded very highly for rotors in Aus. Im pretty sure they also produced the exhaust for the Aus SP models too.

Well put, this is THE definitive answer. Yeah, SMB has fantastic quality and the unit looks great, but really....I seriously doubt there would be ANY performance gain over a standard 3" downpipe.

There was something about High flows around somewhere no? I have been searching for it but I was sure there was a GB going on.

I have nothing to do with the sale of this (no gains, no profit, no benefit) and only passing it forward for everyone else. If I didn't beleive in it, I wouldn't bother. I would have gladly paid double HKS for this myself. Yes, the turbo maifold is restrictive thus my mention of porting the internal wastegate to take advantage of it.

The crimp is not a restrive point as it is over 4" close to 5" as pointed out. If you read the thread it also metioned he can do a USDM version without the crimp. Personally I prefer the crimp and used HKS when I was on twins. It was easier to install/remove and looked exactly like OEM precat (less the cat).

Yes there would be perfomance gains over 3". Again, it was in the beginning of this thread. You would need 3.5" all the way. That means 3.5" mid pipe and exhaust. If you/anybody remembers Broken09's single turbo thread he achieved the same HP with 4" DP, MP & exhaust on 15lbs as he did with 3" DP, MP & Exhaust at 17lbs.

That's with a single turbo manifold, not the stock twins manifold. Porting the wastegate has nothing to do with flow restrictions through the manifold.

SMB makes great products. It is just debatable whether or not going over 3" exhaust actually shows gains with the stock manifold.

Exactamundo. Thanks for saving me the effort of typing all that ;)

As far as whether it shows gains, we need a guinea pig :bubrub:

Wastegates reduce boost pressure by bypassing the turbines (when open). Porting it will get rid of the boost creep this setup would cause, but cannot increase flow through the turbines. :)

EDIT: Jeez, typed this like 2 hrs ago & forgot to hit send...

I'll be on an engine dyno in a few months. Guinea Pigs don't pay, but they recieve free parts. @ least that's how it works in CT.

Stumbled on this one. Does this help?

I fitted a 3.5" SMB downpipe to my stock twins and I also swapped my Blitz NurSpec backbox for the SMB 3" twin backbox and I got an increase of 4rwhp @ 0.8bar

As ever, it is not conclusive because I changed two parts of the exhaust at once but I did it more for heat than power...and now I am looking at BNR stage 3's :naughty:

EDIT: Yes, four horsepower :lach:

Yes, but if boost came on quicker then there's more space under the curve. Just saying.

<<Waits for a victim erm... volunteer to produce results>>

In all seriousness, I'll be on an engine dyno in a few months. Does anyone have one of these? I already have a 3" SS DP and I can't see any benefit going bigger. The flange isn't even 3" from memory. The pipe fits around it in a few spots so how would making a bigger pipe provide any benefit without opening up at least the center section?

Regardless, if anyone has one and wants to know for sure, or if SMP is reading ......

As posted it starts out over 4" at the crimped curve section (I think that part is 5"), then the pipe is 4" and only tapers down to 3.5" by the flange. Now tog ett eh benefit of this, you would need 3.5" mid pipe and 3.5" exhaust (not 3"). If this increases boost as a result (like Efini y-pipe kit) then porting should be done on the internal wastegate.

I haven't built my exhaust yet & if I could get my hands on one of these for say the cost of shipping, I'll compare it to the 3" I have on the dyno. If it makes a difference, I'll build my exhaust accordingly. I plan on porting my wastegate anyway as some poeple have gotten boost creep with a 3" exhuast. I don't think it's going to make a worthwhile difference though. Even it was a 12" pipe, the restriction is in the turbos themselves I believe