My exhaust system is little funky. I always thought that my exhaust system is one of most recommended by everyone. Crucial Racing UP Ceramic Coated Crucail Racing DP Ceramic Coated 3" Stromung High Flow Cat 3" (then tapers down to 2.5") Stromung Mid Pipe 3" (Starts with 2.5" to mate up with the cat) Stromung Dual-Tip 3" I'm thinking about switching out the axle back with Prodrive one to quiet noise down. But if I do that, I'm afraid that this might mess up smooth exhaust flow It's like 3" -> 2.5" -> 3" -> 2.5". The 2.5" section where HF Cat and 3" Mid pipe is someout smooth. It's not a abrupt change in diameter. But If i mate up Prodrive to stromung 3" midpipe, then there will be 1/2" change of diameter instantly which will raise back pressure. Any one here has Prodrive axle back with more than 300whp???
I made 417 whp with my TXS Magnaflow axelback (2.5") I'll trade you my magnaflow for the stromung dual tip.
I will consider it IF I don't find Prodrive. I assume that you have TXS stealthback, right?? I'm also wondering about how to mate 2.5" axle back to 3" midpipe. On nasioc, one vendor is selling an adapter for $60 bucks which I think too much.
I have the full TXS TBE. 4" Bellmouth -> 3" Cat (or race pipe) -> 3" intermidiate pipe tapers to 2.5 -> 2.5 axel back. Its a little louder than stock at cruise and idle but reall opens up when you get on it. If it wasn't going to hold me back on my new setup I'd keep it.
I have the Prodrive Oval Tip and it's a very nice sounding piece, although it's quieter than pretty much everything else I think. Apparently Prodrive actually claimed that even though it sounds really restrictive it still flows well enough to support some huge HP numbers. I heard this from an extremely reliable source but I don't want to quote him.
We made 436 wlb-ft and 420+ whp on a Prodrive Axleback. Granted that was an STi with a Green and meth... but it still flowed it SS
now I know that prodrive can handle the power without too much choking. Thanx for proven infos. but how about the sudden interruption of flow from 3"->2.5" piping difference??
Where is that bottleneck again? I'm not familiar with the term Intermediate Pipe........... I hope it's not just me. hnoes:
According to TSX it is between the where the Axle back and the muffler. Is the pipe you have narrowing in the mid pipe? As a side note I was researching this some and some of the Ausie guys are running full 4" all the way back! 4" muffler too. I imagine it is loud as can be, but talk about free flowing. Edit: Ok went out and looked at mine as best I could. It is 3" all the way back on the mid pipe...there us some weird flange on the back that has 2 places to bolt up...one for 3" and one for 2.5". But it still looks to be 3" at that point. Can anyone shed more light? I have never undone my axle back.
The question though is, how much more power would a 3" system have made? It's like with the stock intake.. it's "good for 500hp" but obviously it's not going from super free flowing to complete road block at some point. It'd be really interesting to see some comparisons of intakes and cat/axle backs on higher horsepower cars to see how much of a difference things make. Personally I have no clue, but it's always fun to learn. It would be very cool to plot some data to see where the bigger intakes/exhausts REALLY start to make a noticable difference.
That's what I'd like to know. Or more specifically what all would I need to upgrade to a 3 inch exhaust. I assume I'd need a full TBE.
It's not a sudden interruption. It'll provide better lowend torque than a full # inch exhaust. You gotta remember than when off boost you're relying on the low compression engine to move you.
Has anyone unbolted their TSX axle back and see what is really there? Supposedly they claim that they have some propreitary flangethat allows either the 3" or 2.5" to be bolted to the same pipe.
Right Alex I saw that too, but is the pipe a full 3" diameter or is it 2.5 with the ability to bolt up a 3"?
Finally, The Prodrive is in along with stock 2.25" Mid pipe w/ resonator. The sound is definately quieter now, but my ears picked up more of road noise and tire noise instead. haha Also, new combo has slightly better low end, BUT it did take away some torque in mid-range and up. Overall, it's working just as I expected --> Quieter sound :bigthumb:
I posted this in the For Sale section, but just as reference here they are again. Stock (2.25") vs Prodrive (2.5") vs Stromung (3") Stock Midpipe (2.25") vs Stromung (3")
On today's tuning, It was proven that 2.25" mid pipe and 2.5" prodrive axle back does cause enough restriction for exhaust flow. Without change of any maps, it hit peak boost @ 4k, but it barely made 19psi after that (my boost map is set @ 20.5 psi). I had to bump up nearly 5-8% more of WDC to hit my desired boost curve. What this means is that because of increased back pressure, my turbo (TD05H-18G) has to work harder to make similar power that it used to make.