3.3TT What's the truth about downpipe/midpipe performance?

[Mr. Tech]

Hey guys, I've been off the forums for quite some time since I got my JB4 tune working well. Now I've got the itch for more upgrades.

I started researching exhausts and midpipes and I'm finding completely conflicting posts with no proof about whether or not midpipes and catback exhausts make any difference if you already have a JB4.

Some say you'll shave .2 seconds off your 0-60, others say your car will sound better, but you won't see performance gains.

After over two hours of scouring the threads for every post with either "midpipe" or "downpipe" in it, I can't find a definitive answer. Does anyone have any personal experience with results before and after adding a catback or midpipe on a tuned Stinger?

I've got a JB4 and intakes so far and I'm looking for the next logical upgrade. If a midpipe can really shave even .1 seconds off, then I'll go with that. Otherwise, I might upgrade the intercooler or get lighter wheels (still on stock 19s).

If it helps, I care much more about 0-30 times than 30-60 times. I've seen that some of the faster 0-60 time cars are actually a little slower 0-30 and make up for it from 30-60. Basically, if a midpipe would drop my 0-30 times and only give me gains on the top end, I'd rather keep my faster 0-30 setup.

Thanks in advance to anyone who can shed some light on this for me!

 

[Hockster]

Cat back before down/mids. Just MHO.

As for definitive proof, yes it will, no it won't, maybe, perhaps.

 

[SnowyGT2]

Improved throttle response is what I mostly see advertised. Having my Ark Downpipes with the MBRP exhaust, I can't really say for sure if there a noticeable difference, although I don't have the JB4 installed. Looking to see what others may have on this.

Cat back before down/mids. Just MHO.

As for definitive proof, yes it will, no it won't, maybe, perhaps.

This!

 

[Toddasaurus]

I put my midpipes on before the catback and even the intake. I really couldn't tell much of a difference in performance other than the sound, and even that was minimal.

Still have them on, though. At the very least they weigh a little less than OEM, so I figure that's reason enough to keep them. Still, it would make sense that they'd add power, or even widen the powerband some. No real definitive proof of it, though, from what I've seen.

 

[MrSmoofy]

5hp max from what I've seen but it does make it sound a lot nicer

 

[DMM]

Improved throttle response is what I mostly see advertised. Having my Ark Downpipes with the MBRP exhaust, I can't really say for sure if there a noticeable difference, although I don't have the JB4 installed. Looking to see what others may have on this.



This!

Improved throttle response is what I mostly see advertised. Having my Ark Downpipes with the MBRP exhaust, I can't really say for sure if there a noticeable difference, although I don't have the JB4 installed. Looking to see what others may have on this.



This!

How does it sound, my MBRP is quiet and i plan on getting midpipes and hoping it gets louder

 

[MrSmoofy]

How does it sound, my MBRP is quiet and i plan on getting midpipes and hoping it gets louder

MBRP Catback, Ark DP, Intake

 

[Talloneus Khan]

@Mr. Tech , if you want to keep the stock wheel size, I highly recommend brealin wheels. You can keep the same tires, and be much lighter

 

[Oryan]

Certainly felt a difference with mine. Granted, I put my catback and mids on at the same time, but the car got up noticeably better afterwards.

A lot of people get hung up on changes in peak or max power and just ignore what something does throughout the rev range, or what it does to change the shape of the powerband. Also, some mods may not do much by themselves but become more important as you build more, especially with tuning. Or, enables you to become more consistent with that power. Or enables you to more efficiently make said power which usually translates into less heat to deal with. I may have gotten a little carried away. But point is, IMO there's benefits to midpipes, that could go beyond just making a bigger number on a dyno. If nothing else, there's sound as well and if that's what you want that's ok too.

 

[Adamdan]

I did just mids before my cat back jb4 and intakes. It makes the car sound deeper. I felt more lower end torque, maybe from earlier turbo spool.

 

[Mr. Tech]

Thanks for all the feedback, guys! It's interesting to see that some people say they really noticed a difference while others didn't. I may just do the intercooler for now then since I know for a fact that my IATs are a solid 20+ degrees over ambient when I'm NOT pushing the car in the summer (as measured by my JB4). Dropping my IAT will at least give me consistent performance this coming summer. Anyone have any recommendations on an intercooler? Preferably one that doesn't require cutting, modifying, or removing non-intercooler related components?

Or, if you've upgraded your intercooler, did you notice a big drop in IAT?

I'm still planning on adding the midpipe at some point. When I do, I'll get some before and after Dragy runs with JB4 logs and see what happens.

 

[CoconutRob]

MBRP Catback, Ark DP, Intake

It should be a few Dbs louder and the tone will be deeper

 

[Tonkabob]

For 0-30 go wheels. Then fmic if you want to go over 60.
I measured the crap out of my mids before and after 2 rounds and could not measure any gains on dragy or slip.

 

[Mr. Tech]

For 0-30 go wheels. Then fmic if you want to go over 60.
I measured the crap out of my mids before and after 2 rounds and could not measure any gains on dragy or slip.

Wow, thanks for the datapoint! Now if I could only find lighter wheels that won’t cost $2k haha. What did you end up running on your Stinger?

And did you try a catback with the mids? If so, did that make a difference?

 

[Tonkabob]

Wow, thanks for the datapoint! Now if I could only find lighter wheels that won’t cost $2k haha. What did you end up running on your Stinger?

And did you try a catback with the mids? If so, did that make a difference?

I did momo rf5-cs that were over $2k.
I had the catback on first so no reliable data. I did make 10 hp more than other stock stingers untuned on the same dyno but like the big mid pipe claims on a stock car they raise boost and that gain goes away when boost is cranked up in a tune. But logic would say less restriction is good and replacing the catback helps. So at minimum replace catback or mids but don't expect big gains.

 

[Mr. Tech]

I did momo rf5-cs that were over $2k.
I had the catback on first so no reliable data. I did make 10 hp more than other stock stingers untuned on the same dyno but like the big mid pipe claims on a stock car they raise boost and that gain goes away when boost is cranked up in a tune. But logic would say less restriction is good and replacing the catback helps. So at minimum replace catback or mids but don't expect big gains.
View attachment 40957

Wow, those wheels look incredible!

Did you measure the gains from just the wheels with a dragy or 1/4 mile run? If so, how much of an improvement did you see?

Also, any other recommendations for improving 0-30 beyond the intake and JB4 I currently have?

 

[Tonkabob]

Wheels dropped 0-60 .1. 40 lbs reduction of rotational weight.
Ecu brake wire cut would do the most by far but hard on the trans.

 

[Stiletto]

@Mr. Tech I've got empirical data. Several dyno plots showing the power difference. And I'm just like you (intakes and JB4...and colder plugs). If low end "grunt" is your goal, you don't want secondary pipes. IATs are important, but only for back to back runs. You'll net more power with cat back exhaust than pipes.

 

[turboAWD]

Enkei flow-formed wheels are generally considered decent bang-for-buck AFAIK - I found TY-5s in black for under $300/wheel for 18s from getyourwheels.com. The Pilot Sport 4s (245 front, 285 back) cost more than the wheels . TFR is even a bit cheaper. Depends on what look you're going for.

Prices seem to have gone up a bit, but still under $300 for TFR in 18 or 19, under $350 for 18/19 TY-5.

WAY lighter than OEM.

 

[Mr. Tech]

Wheels dropped 0-60 .1. 40 lbs reduction of rotational weight.
Ecu brake wire cut would do the most by far but hard on the trans.

Thanks! I did look into the brake wire mod, but that's way too much risk for my daily driver haha. Definitely tempting through. I've seen some incredible results from people doing that.