What is your downpipe set up? Full DP? Race or test pipe?

[Marauder.45]

Stock? I'd like to hear about it all. I copied this from the MS6 forum but wanted to see what you guys thought.

So in my learning on this site, I'm sold on the TIP. I'll be ordering the Cobb. I'm on the fence on a new BPV, I'd go Forge if I did, but I think it can wait. I'll probably get the new Cobb AP as well.

Who is running what downpipe setup? And of course why? And what if anything do you not like about it?

I have seen contrary opinions. Don't get a full DP, just get a test pipe. Or get the racepipe. My concerns on that are sufficient backpressure if you delete that second cat. I think I'd be fine with a full DP with 2 hiflow cats. But if lots of guys are doing something else..........


The corksport racepipe looked interesting.

ETA: Concerned about noise as well. Testpipe seems like it's loud. I don't need ridiculous noise. Plus throwing codes.

 

[karl hungus]

corksport tp leaks w/o the dp. recommend the speed action tp from ebay for $140 if you don't want a dp.

you need not worry about cels, backpressure, or noise w/ a tp.

that 2nd cat is ghey and needs to be removed.

 

[AutoEuphoria]

Corksport catless DP to catless TP

http://www.youtube.com/watch?v=vORIBmBsLtQ

 

[MM BOOST]

Turbo XS catless downpipe to stock mid-pipe to racing beat exhaust with resonator removed (VA laws, so I have to have a cat for inspections, no worries...I didn't notice a decrease in performance changing the mid-pipe out from the turbo xs race pipe). Overall excellent deep gurgle tone and nice performance gains

 

[Marauder.45]

That sounds purty.


How many pieces are there to this thing?

Is there a nifty diagram somewhere?

 

[dandydaniel]

corksport and turboxs TBE kits (turbo-back exhaust) are 3 pieces. 1 dp to replace the first cat, 1 test pipe to replace the 2nd cat, and their respective cat back exhaust.

cobb and cp-e and a couple other brands (stainless steel) run a single piece design for their DP (replaces both the first and second cat) and leaves you to run a CBE after that

 

[240ka]

corksport tp leaks w/o the dp. recommend the speed action tp from ebay for $140 if you don't want a dp.

you need not worry about cels, backpressure, or noise w/ a tp.

that 2nd cat is ghey and needs to be removed.

mine doesnt leak and im running stock DP and CBE with longer bolts and stock CBE springs

 

[Moody]

mine doesnt leak and im running stock DP and CBE with longer bolts and stock CBE springs

Thank Jesus. I just bought a cs testpipe. any fitment issues i should worry about???

 

[240ka]

Turbo XS catless downpipe to stock mid-pipe to racing beat exhaust with resonator removed (VA laws, so I have to have a cat for inspections, no worries...I didn't notice a decrease in performance changing the mid-pipe out from the turbo xs race pipe). Overall excellent deep gurgle tone and nice performance gains

i have. i gained quite a bit on the top end.

stock MP vs TP. around the 1/8 ive picked up speed.

you see my mods below. my buddy has the same mods minus the TP but has an AP.

before i got the TP and he got a AP.

i was running MSCAI, MM, deleted resonators, springs and BOV vs his CPE SRI, MM, deleted resonators, springs and BOV.

when running my MSCAI in CAI mode. i would pull slightly on him on the top end, after 90 i would creep ahead as we went longer. but up to 90 we were neck and neck.

when i ran my MSCAI in SRI mode we were neck and neck everytime. pure drivers race.

so CAI would yield a slightly better top end.

i now have a CPE SRI but before i got the TP he and i again were neck and neck the whole way. and this was before i installed my system too

added TP. i would pull on him around 75mph beyond. and keep pulling

now he has an AP with the same mods (CPE SRi, MM, deleted resonators, springs and BOV) vs my current list plus i have a system installed now.

we did a few runs. from 2nd and 3rd gear. but from a 2nd roll, he would jump ahead but atlest a half a car and pulled to a bit over 3/4s of a car. his cars boost is spiking around 18 and settling to 16psi and pulls to Redline.

im still on stock tune. but anyways.

he would jump and pull to alittle over 3/4s of a car and he could stay in his gears much longer than I. i was shifting gear so much quicker than him. i was always reving to about 6-6100k when i shoudl have shifted between 5600-5800. so we will be doing more runs to test the powerband of the cars and shift points

but arouund the top of 3rd he would stop pulling on me and once i got into 4th, i would gain on him. i would close the gap and pull ahead by a 1/3 of a car. each run was up to about 120. the longer we went the more i would slowly pull on him

for those who say TP doesnt net gains are smoking something b/c its on the top end where the gains of the TP are produced. or better yet, from 75 beyond.

there are some really good gains from the TP alone man, get one if you dont want DP yet.(drive2)

mind you. i have a system in my car which consist of a 15" sub, two JL audio amps(one 300/4 and one 500/1 monoblock) plus a Pioneer Z1 headunit. so i have added atleast 75lbs

and the car still pulled the way it did.

either my car is running really well or the TPs gains is better than people think

 

[240ka]

Thank Jesus. I just bought a cs testpipe. any fitment issues i should worry about???

in terms of looks, the fitment doesnt look snug as youd expect b/c TP is 3" and the stock CBE isnt. but all you need are the longer bolts that should have come with it and use the springs thats comes with the stock Midpipe(on the CBE side.)

that way you can tighten the s*** out of the CS TP for no leakage.

also, i think someone said the CS TP leaks on the DP side but its actaully on the CBE side where it could leak. the TP fits up well on the DP side, but not so much on the CBE, so use those springs to get it nice and tight

 

[Moody]

awesome help. thanks. i guess a little elbow grease goes a long ways.

 

[MM BOOST]

i have. i gained quite a bit on the top end.

stock MP vs TP. around the 1/8 ive picked up speed.

you see my mods below. my buddy has the same mods minus the TP but has an AP.

before i got the TP and he got a AP.

i was running MSCAI, MM, deleted resonators, springs and BOV vs his CPE SRI, MM, deleted resonators, springs and BOV.

when running my MSCAI in CAI mode. i would pull slightly on him on the top end, after 90 i would creep ahead as we went longer. but up to 90 we were neck and neck.

when i ran my MSCAI in SRI mode we were neck and neck everytime. pure drivers race.

so CAI would yield a slightly better top end.

i now have a CPE SRI but before i got the TP he and i again were neck and neck the whole way. and this was before i installed my system too

added TP. i would pull on him around 75mph beyond. and keep pulling

now he has an AP with the same mods (CPE SRi, MM, deleted resonators, springs and BOV) vs my current list plus i have a system installed now.

we did a few runs. from 2nd and 3rd gear. but from a 2nd roll, he would jump ahead but atlest a half a car and pulled to a bit over 3/4s of a car. his cars boost is spiking around 18 and settling to 16psi and pulls to Redline.

im still on stock tune. but anyways.

he would jump and pull to alittle over 3/4s of a car and he could stay in his gears much longer than I. i was shifting gear so much quicker than him. i was always reving to about 6-6100k when i shoudl have shifted between 5600-5800. so we will be doing more runs to test the powerband of the cars and shift points

but arouund the top of 3rd he would stop pulling on me and once i got into 4th, i would gain on him. i would close the gap and pull ahead by a 1/3 of a car. each run was up to about 120. the longer we went the more i would slowly pull on him

for those who say TP doesnt net gains are smoking something b/c its on the top end where the gains of the TP are produced. or better yet, from 75 beyond.

there are some really good gains from the TP alone man, get one if you dont want DP yet.(drive2)

mind you. i have a system in my car which consist of a 15" sub, two JL audio amps(one 300/4 and one 500/1 monoblock) plus a Pioneer Z1 headunit. so i have added atleast 75lbs

and the car still pulled the way it did.

either my car is running really well or the TPs gains is better than people think

thats cool and everything and I understand, but i never drive my car over 90 mph, especially on the street, so to me the gains is not worth it. My car was loud as **** and would echo off everything and plus was asking for a ticket from a va nazi cop if I was to get pulled over. The 2nd cat pipe calmed the tone down and made it deeper and got rid of the cracking and popping. Worth it to me!

 

[240ka]

thats cool and everything and I understand, but i never drive my car over 90 mph, especially on the street, so to me the gains is not worth it. My car was loud as **** and would echo off everything and plus was asking for a ticket from a va nazi cop if I was to get pulled over. The 2nd cat pipe calmed the tone down and made it deeper and got rid of the cracking and popping. Worth it to me!

remember he is running stock exhaust with 2 resonators cut out. im running stock dp and cbe with two resonators gone. no popping for me unless my BOV is tuned too hard and making the car run even richer

the car is louder but not LOUD LOUD. i love the sound, passengers dont complain(females), my boys love the sound.


you see the gains in the 1/4 mile if you to the track. around the 1000' is where they show up and especially by the 1/8

 

[MM BOOST]

You should try the setup I had bro. Turbo xs catless downpipe, turbo xs catless race pipe, and racing beat 3" exhaust with resonator removed, only the main muffler at the back. Talking about LOUD. I would go deaf going through tunnels getting down on it. It sounded mean as s***. I loved how it sounded, but it had too much of that srt-4 tractor sound down low when I was driving the car normal, drove me nuts. Now with the stock mid-pipe it has that deep uneven gurgle like the suby's, very very nice

 

[240ka]

yeah, nah i dont want an overbearing exhaust. im going with a cs dp, love the sound of their dp, rps and cbe. but im keeping the stock cbe and if iits too loud with the cs dp plus rp and both resonators cut out, then i throw one back in

 

[Marauder.45]

Then is there any real performance change if you use the baffled racepipe vs just the test pipe?

 

[AutoEuphoria]

Any restriction will degrade performance...baffles add restriction.

 

[MSMS3]

Here's my two cents worth (well maybe a bit longer than two cents worth, but value is in the eyes of the beholder):

1. You need a good CAI or SRI before addressing the exhaust side. The worst limitation on air flow is the stock air box. Get rid of that. I prefer CAI. There are many threads on the debate of CAI v. SRI. Make your own choice. Either way, you will get huge gains right there and will be prepared to address the exhaust side.

2. Once the intake is giving you air flow better than the stock exhaust side, the best bang for the buck will be a catless DP/RP. Right next to it in performance will be a DP/RP into high flow cat. One cat should get the job done and still pass sniffer test and avoid CEL's.

3. I will not enter the debate on whether the TP alone does or does not produce gains as I have not gone that route. I can see 240ka's point that once you open up the intake side, eliminating that second cat is producing some gain up top. That makes sense.

4. On the exhaust side, once you have a good intake, the restriction is the very sharp bend and strange shape of the neck of the stock dp, and those two poorly flowing cats. It is NOT the stock CBE, which flows extremely will up to at least 300 whp. Replacing the stock CBE should be reserved for personal taste on the sound of the exhaust not for power gains.

5. The reso and or muffler delete issues fall in the same category as a CBE upgrade. Play with them if you want to change the sound. Deleting them will not appreciably increase power. I disagree that any restriction automatically degrades performance. If the piping is large enough and it's CFM flow is greater than that being produced from the turbo exhaust outlet, the "restriction" is not a restriction. Blow into a soda straw -- there is restriction. Exhale just a hard into an empty auditorium - no restriction. Blow into a room half the size of the auditorium -- it is smaller. But it still presents no restriction to the volume of air you are capable of exhaling, because its capacity exceeds the ability of your lungs. So is the case with our K04 turbo having less maximum flow capacity than our stock CBE.

6. Regarding noise. A catless DP/RP even into a completely stock CBE is LOUD. Did I say it is LOUD? And worse than loud, it creates a lot of headache producing drone when cruising at 60 mph in high gear (2400-2500 rpm). I could not live with that noise in a daily driver. Since my TurboXS DP/RP is a three inch system, I looked for and found a very sound absorbing, but full straight through 3 inch reso (see sig), and had it welded into the middle of the RP. Drone and noise level solved. Very smooth, very quiet.

7. If you go with good intake and DP AND RP catless or catted, you will have improved flow enough that under certain conditions, the engine may try to pull timing advance back due to impending detonation (knock). Going one step colder with your spark plugs - either Densos or NGKs (read the threads here on each, I run the NGK's), will help you avoid or reduce knock and let timing advance stay up there under WOT conditions.

8. Get some type of monitoring device to see what your mods are doing. Many here like the Dash Hawk. It is good. I don't have one because I had already invested in a manual vacuum/boost gauge and a good accelerometer. But you need to know what is going on with your mods. Dash Hawk uses input from the OBD2 port. I tend to trust mechanical devices, like the manual gauge and the accelerometer (which makes calculations based on measurement of time and g forces, but pulls its tach readings through the electical system of the car), but all have their value. Get something.

For me the proof is in the pudding. I have a stock BPV. I have stock tires and rims. I do not have aftermarket tubes or turbo inlet. I do not have any ECU mod (no AP, no Standback, etc.), I run the stock CBE, but I am able under good track conditions to run 13.4 quarters at 107, even with crappy 60 ft. times. The car just builds power once you get away from the power hold back of the engine nanny in first and second gear.

A good CAI and catless DP/RP with one step colder plugs is basically all I have. I'm producing these numbers (see chart below from a typical accelerometer run back in April). Note that "up top" the 60-100 mph time interval is more than two whole seconds better than stock. That is huge. It is easily verifiable with a stop watch. And the car is as quiet as stock with no drone.

 

[Marauder.45]

Nice response,

I agree with with all of the theory, I'm just not familiar with how it applies to this specific car. Seeing what everyone is running is helpful.

I thought I had stated in the OP that I had the CP-e Ecel CAI and Magnaflow cat-back. I'm the second owner so it came that way.

When I have a minute I'm going to check out your sig, I don't mind noise. But I can't have it super obnoxious.


ETA: Just looked at your graph, I must be dropping power down the track. My 60's are 1.90s, yet I'm only getting mid 14s at 95ish.

 

[240ka]

awesome post MSMS3

so with dp/rp and stock cat back and one or two of the resonators added, you still think the drone will be bad?

i love the current volume level of my car, its prefect. tp with 1st and 2nd resonators cut out.

so with a dp/rp, what do you think id have to do to equal but not exceed my current volume?