3.3TT KHARTUNERZ - NEW CATLESS SECONDARY DOWNPIPES Ark Performance

[Gtecko]

12 pages and we still dont have an accurate before and after dyno results ?

 

[MrSmoofy]

12 pages and we still dont have an accurate before and after dyno results ?

Pretty sure the conclusion was there are no significate gains from ANY secondary downpipe.

 

[Gtecko]

Pretty sure the conclusion was there are no significate gains from ANY secondary downpipe.

was not too sure but that is what I thought, thanks for the reply !

 

[StungBlueGT2]

If I remember correctly secondary DPs gave quicker turbo spooling and an extra ~10wtq at the lower rpm range, but not any noticeable top end HP gains.

I’ve been in Stingers with and without secondary DPs and could feel a difference in acceleration but nothing huge. Just felt like it hit boost quicker and had more torque at throttle tip-in. Nice improvement for daily driving but not really for quicker 1/4m, etc.

I’m sure they do something removing the big restriction of 2 cats, but not the 20whp+ some claimed.

 

[Manaz]

If I remember correctly secondary DPs gave quicker turbo spooling and an extra ~10wtq at the lower rpm range, but not any noticeable top end HP gains.

I’ve been in Stingers with and without secondary DPs and could feel a difference in acceleration but nothing huge. Just felt like it hit boost quicker and had more torque at throttle tip-in. Nice improvement for daily driving but not really for quicker 1/4m, etc.

I’m sure they do something removing the big restriction of 2 cats, but not the 20whp+ some claimed.

Removing exhaust restriction is one way to get a turbo to spool earlier, so this is possible.

 

[Jonathan Lasich]

If I remember correctly secondary DPs gave quicker turbo spooling and an extra ~10wtq at the lower rpm range, but not any noticeable top end HP gains.

I’ve been in Stingers with and without secondary DPs and could feel a difference in acceleration but nothing huge. Just felt like it hit boost quicker and had more torque at throttle tip-in. Nice improvement for daily driving but not really for quicker 1/4m, etc.

I’m sure they do something removing the big restriction of 2 cats, but not the 20whp+ some claimed.

If you read posts from members with tuned cars, it seems that there is a perceptible increase in performance with the catless secondary pipes. The quicker turbo spooling and the slight increase in low RPM torque is likely what they are feeling. The lack of high end gains and lack of 1/4 mile difference is secondary. At the end of the day, we do these sorts of things to make our cars feel faster. Worth while mod in my opinion.

 

[Tonkabob]

While i could not prove the secondary made my car any faster it seemed more consistently fast. With OEM back on its often as fast but sometimes slower. Strange. (Maybe this is why the dynos vary as well?)
Tork is making a silenced secondary mid pipe that i will try out next week. The silencer looks like a cat, good for fooling the dealer, and shouldn't add much sound as I already have a catback.

 

[Gtecko]

@NICK_KHAR - any update from your end you would like to share ?

 

[Callum]

While i could not prove the secondary made my car any faster it seemed more consistently fast. With OEM back on its often as fast but sometimes slower. Strange. (Maybe this is why the dynos vary as well?)
Tork is making a silenced secondary mid pipe that i will try out next week. The silencer looks like a cat, good for fooling the dealer, and shouldn't add much sound as I already have a catback.

I've felt this as well. There are days where I put my foot down and it's a rocket ship. There are days where I put my foot down and I'm thinking "this doesn't feel that fast, I should either visit the dealer or hit up JB4".

I can't put my finger on it, it's like only certain times my car rips ass and the other time it's just chillin

 

[washguy]

I havnt forgot to get the dps put on and dyno tested.....theres just major crap going on right now for me....and its also 102 every day Wash

 

[Tonkabob]

Here is another dyno from fb showing the secondary dp does just a little tq way down low and no net hp gains. Since the original dyno posted here had some question marks.
FB is lap3 usa.

 

[Chris71]

Can’t read the numbers, little blurry... good info though. Can u list the gains over stock at the low end?

 

[Tonkabob]

Its not my chart but here is the original. Still hard to read. Chase Bellott
Looks like power under the HP curve is the same or slightly less with the secondary.

 

[Chris71]

I did say I felt the tq if I’m reading that correctly that is just over 30lbs more in tq at lower rpm and tq stays consistently higher.

 

[Tonkabob]

I did say I felt the tq if I’m reading that correctly that is just over 30lbs more in tq at lower rpm and tq stays consistently higher.

I'm reading it as 15 Tq (maybe 20) between 2400 and 2800 RPM. At full throttle you are never in that RPM range except from a dead stop for a fraction of a second. There is a 15-20 Tq loss between 4800 and 5200 RPM which is hit in every gear. Hoping that part is a run to run fluke.

 

[Chris71]

Not until 5800 rpm does tq drop, not 4800.

 

[Chris71]

My take after looking at it in more detail as that the slight rise at start and decrease at end create a wash. But for the majority of current u are pulling 18-28(30) more lbs of tq

 

[Cyrus Duong]

All this thread has done is made me more confused on if the secondary DPs do anything. I'm going to summarize what I've read and understood so far. And considering I'm in the market for either an exhaust, secondary DPs, or both - I want to share what I understand and make sure it isn't wrong.

Early on it looked like there was some potential gain in the low-end and maybe response (faster turbo spool). The graph, however, looked completely wrong and did not make any sense to me. HP was indicated as decreasing, the TQ numbers were indicated as increasing. An abnormal spike at the end (maybe gear shift? or skip?) And the numbers didn't cross at 5252 (EE youtube video explaining why this occurs) where I would expect it. If it didn't correctly cross there I'm going question the accuracy of the run. So I personally ignored this result.

Then lots of people using their butt dyno again reporting they feel this additional low-end torque and response. Some of it might have to do with sound output, which I will talk about in a bit. But primarily I think, the placebo effect is strong often when money is involved because people want to feel justified in their purchases. I'm also very suspect of this when I buy things. However, for big purchases, I try to do as much research to avoid unnecessary spending on something that doesn't give me the desired effect.

Recently, looking at the last graph from the FB user, comparing intakes+JB4 to intakes+DP+JB4 it looks like it's within margin of error for the run. Meaning no low-end torque gain or top-end HP gain. Because the graph is clean and it lines up with @Tonkabob 's findings, I'm concluding the secondary DPs don't do anything except for increase sound output - which could cause a false sense of feeling faster. This is why manufacturers have gone and put in fake or enhanced engine noises using the speakers or other methods. It makes the driver and passengers feel the car is faster.

Considering the last graph is the best looking one/best executed by the person running the dyno - I personally would put the money to something other than secondary DPs. And follow something along the lines below.

If you want performance and you don't have it - grab a piggyback or tune, JB4 is what I run.
If you a little performance and some sound grab a CAI or DIY intake (spool/intake noises).
If you want more sound - Cat-back exhaust (Borla exhaust if you want to be real loud).
And if you have all the above, then maybe consider primary then secondary DPs.

I'm not here to hate on anyone or say their purchases aren't justified. You do you. I personally don't want to be spending money on something that isn't going to do what I want and hopefully share that information with others in the same boat. And this might change once we can fully unlock/tune the ECU.

Just trying to help sort out the confusion. Have I missed anything?

 

[Chris71]

All this thread has done is made me more confused on if the secondary DPs do anything. I'm going to summarize what I've read and understood so far. And considering I'm in the market for either an exhaust, secondary DPs, or both - I want to share what I understand and make sure it isn't wrong.

Early on it looked like there was some potential gain in the low-end and maybe response (faster turbo spool). The graph, however, looked completely wrong and did not make any sense to me. HP was indicated as decreasing, the TQ numbers were indicated as increasing. An abnormal spike at the end (maybe gear shift? or skip?) And the numbers didn't cross at 5252 (EE youtube video explaining why this occurs) where I would expect it. If it didn't correctly cross there I'm going question the accuracy of the run. So I personally ignored this result.

Then lots of people using their butt dyno again reporting they feel this additional low-end torque and response. Some of it might have to do with sound output, which I will talk about in a bit. But primarily I think, the placebo effect is strong often when money is involved because people want to feel justified in their purchases. I'm also very suspect of this when I buy things. However, for big purchases, I try to do as much research to avoid unnecessary spending on something that doesn't give me the desired effect.

Recently, looking at the last graph from the FB user, comparing intakes+JB4 to intakes+DP+JB4 it looks like it's within margin of error for the run. Meaning no low-end torque gain or top-end HP gain. Because the graph is clean and it lines up with @Tonkabob 's findings, I'm concluding the secondary DPs don't do anything except for increase sound output - which could cause a false sense of feeling faster. This is why manufacturers have gone and put in fake or enhanced engine noises using the speakers or other methods. It makes the driver and passengers feel the car is faster.

Considering the last graph is the best looking one/best executed by the person running the dyno - I personally would put the money to something other than secondary DPs. And follow something along the lines below.

If you want performance and you don't have it - grab a piggyback or tune, JB4 is what I run.
If you a little performance and some sound grab a CAI or DIY intake (spool/intake noises).
If you want more sound - Cat-back exhaust (Borla exhaust if you want to be real loud).
And if you have all the above, then maybe consider primary then secondary DPs.

I'm not here to hate on anyone or say their purchases aren't justified. You do you. I personally don't want to be spending money on something that isn't going to do what I want and hopefully share that information with others in the same boat. And this might change once we can fully unlock/tune the ECU.

Just trying to help sort out the confusion. Have I missed anything?

lol u both are right, I was reading the graph wrong based on that dyno now that I’m reading it correctly, 480-500+ would be better spent elsewhere. I like mine but I am no longer confused

 

[Chris71]

Ok... that last dyno gives a good look(now that I’m not misreading it) ha!
So I added two resonators to the mid-pipes and very happy. Still have the gurgling sound when coasting but sound is back near stock! These are straight through honeycomb resonators by Borla. 2.5 opening 3.5 max width. We added two washers to the brace that holds the mid pipes to ensure clearance.