Downpipe questions and comparisons

[mesarec]

Im looking to get a downpipe before i get my cobb ap and tune but not sure which dp to get. the cobb dp is 700 bucks!!whereas the corksport is 350ish. Since i have more expensive things on the horizon id like to keep my cost down but not at the expense of performance. Does any1 have info in the cobb dp and corksport dp? pros and cons?

[Champloo]

The two biggest differences that I note is that the COBB DP has a cat and includes the test/race/mid pipe section as well. The Corksport DP is catless and does not include the test/race/mid pipe.

[bacarl]

Nice thread! ;)

There are two main differences. To start off, the MS3 exhaust has three sections: downpipe, midpipe aka race- or test-pipe, and cat-back. The Corksport is a downpipe only, meaning you have to get a seperate midpipe section (theirs costs $150). The Cobb combines the two, so it goes straight from your turbo to the cat-back.

Second, the Cobb has a cat converter, which is nice if you need to reduce emissions or just like the environment, but adds a chunk of cost.

Those are the big ticket differences, but people may also argue that the Cobb is better made. You'll also hear arguements for and against the divorced wastegate vs cast bell-mouth. Typically a divorced flow integrates the wastegate gases into the main exhaust stream more smoothly, but Corksport's design (probably due to packaging limitations) brings the wastegate flow in at an akward angle that kind of defeats the purpose.

[bacarl]

and my slow typing loses again!

[AutoEuphoria]

I have the corksport catless downpipe. No issues, good sound (not too loud), noticeable performance increase. I also have the corksport catless midpipe. Got both for less than a Cobb downpipe/midpipe, but they didn't have the added cost of the converters. Again, both look good and perform well.

[mesarec]

well see you can write a helpful post:p so in other words cobb may be best way to go even tho expensive. would the corksport dp and mp thro off a check engine? and if so is that why the sobb is more exp becasue it wont throw one due to the cat in it. goddam 1600 bucks for my spring mods ugh. (bang) nevermind after i do all this im sure ill need to get swaybars and or springs

[mesarec]

I have the corksport catless downpipe. No issues, good sound (not too loud), noticeable performance increase. I also have the corksport catless midpipe. Got both for less than a Cobb downpipe/midpipe, but they didn't have the added cost of the converters. Again, both look good and perform well.

i checked your mods and u have a cobb ap. yet ur only running a 13.78 with all those mods? say it aint so

[AutoEuphoria]

I didn't have the AP when I went to the track. I was running just a manual boost controller that was actually set for around stock boost pressures (it had been higher, but the weather made it less) on the stock tune. On that run I was making 13-15psi at the top of 4th I believe. I originally had it set for 17psi, but it was really all over the place that day. I didn't have it hooked up correctly. I don't think I had the downpipe at that time, either...can't remember. I then bought the AP and converted the boost control system back to stock, and now run 18 psi with little to no issues (sometimes it will boost more, sometimes I get a little knock retard...both are rare).

[mesarec]

with all that done now do u experience a lot of extra traction loss? is it a bitch to handle taking off or in the low gears. i would think wheel spin would be much more porminent

[AutoEuphoria]

Can't comment on that. The air and the ground got cold, so I'd be losing traction at stock levels now. Traction loss is generally always controllable, though...no matter what you are driving.

[mesarec]

true true. ya grounds cold now so cant tell anymore. granted always controllable. i just dont want it to be annoying when i get the mods i want. but theres always a way around traction loss.

[lestat13]

I have the corksport downpipe and midpipe. I got (and still get) CELs from time to time, even with the spacer for slow O2 sensor response. The car smells badly when vta and with a smoking turbo, it just makes things worse. Plus it's technically a federal offense to run without cats. I might have one welded in or swap to a cobb downpipe if I can fix my smoking problem with a catch can and heavier oil. If not, I will be using the factory downpipe. sigh.

So spend the extra $$ now to be happier with your setup later on. Plus with an upgraded intercooler I was having overboost problems, apparently from the corksport design not allowing my wastegate flapper to open fully. Go cobb and be done with it

[AutoEuphoria]

Plus it's technically a federal offense to run without cats

Then most of Michigan will be going to federal prison I guess. I don't have smoke so much...only a bit of black smoke when WOT from running rich. Also, no CEL's for me. I'm not running VTA, though...I tried that for 1 day and got tired of it quickly.

[Champloo]

How important is an upgraded intercooler if you have a downpipe? I'm planning on a downpipe but keeping the stock TMIC. Am I going to run into heat issues?
Actually, what about a fuel pump? Will a downpipe over-extend the stock (updated from TSB) fuel pump?

[PCspeed3]

rally sport direct . com has the Cobb DP for $625 I believe.

[PCspeed3]

BTW will the Cobb DP work with stock cat back?

[lestat13]

I don't know if it's just me, but as soon as I upgraded the intercooler I started getting boost creep almost anytime I went WOT. Just got off the phone with Derek at Corksport, I emailed cause someone said the wastegate flapper clearance would be an issue. NOPE! They did a mock up and took pictures to show that there is plenty of clearance, I am just past the efficiency of the wastegate and it needs to be ported out. Pics attached!!
http://i56.photobucket.com/albums/g165/lestatthirteen/WGopen.jpg
http://i56.photobucket.com/albums/g165/lestatthirteen/WGopenflange.jpg

[lestat13]

BTW will the Cobb DP work with stock cat back?

You can use just the downpipe, just the testpipe, or both with the stock catback. I have both on the stock cbe

[PCspeed3]

You can use just the downpipe, just the testpipe, or both with the stock catback. I have both on the stock cbe

Thanks man, Cobb's DP includes the race pipe. Does DP cause boost to spike at all? I thought that was only with an FMIC.

[lestat13]

When I ran (and now again) the downpipe and racepipe with stock intercooler I would see spike upto 20psi that immediately settled down to 16psi to hold. Occasionally I would creep in 5th or 6th gear, but it was hit or miss and didn't happen that often. It wasn't a big deal.

Once I added the new tmic, I started either creeping straight past 16, or spiking 20-22 and holding, scary. Talking to Derek at Corksport he said you really need to port out the wastegate cause at that point you are overflowing the wastegate. Then again, a lot of people upgrade intercoolers with downpipes and don't have any issues. I am thinking (since I am smoking anyway) to reinstall my factory racepipe (leaving the corksport downpipe) and then using the ETS 3.5 TMIC. Derek said that might give me enough backpressure to get the wastegate back into the efficiency range and should help with the smoking problem.... if you call covering it up fixing.

[mesarec]

so basically with the cobb dp and mp although expensive it negates any issues ud have with the wastegate or spiking? plus wont throw a check engine? if thats so and i wouldnt have to upgrade my tmic on top of it, cobb sounds like the way to go. plus since i plan on getting cobb ap and pro tune, dont know if id have the money to do tmic also.

[lestat13]

so basically with the cobb dp and mp although expensive it negates any issues ud have with the wastegate or spiking? plus wont throw a check engine? if thats so and i wouldnt have to upgrade my tmic on top of it, cobb sounds like the way to go. plus since i plan on getting cobb ap and pro tune, dont know if id have the money to do tmic also.

cobb unit is one piece that replaces the downpipe and midpipe, I think you are thinking off the corksport which is 2 separate pieces. By itself, any exaust mod won't be enough to cause any crazy spiking or boost cut or creep. The only CEL I get is slow O2 sensor response. corksport said if I drill the hole out a bit it would go away, but the CEL weny away on its own so I didnt touch it. Makes no difference what you get if you are going to use an ap.... ESPECIALLY if you plan on pro-tune.

My opinion is that if you know you are going for pro-tune, it wont be available for a while and only from a few people at least at first, so just got with a cp-e standback and plug n play harness. you can even run maps on that or tune yourself. better investment imo.

[dandydaniel]

When I ran (and now again) the downpipe and racepipe with stock intercooler I would see spike upto 20psi that immediately settled down to 16psi to hold. Occasionally I would creep in 5th or 6th gear, but it was hit or miss and didn't happen that often. It wasn't a big deal.

Once I added the new tmic, I started either creeping straight past 16, or spiking 20-22 and holding, scary. Talking to Derek at Corksport he said you really need to port out the wastegate cause at that point you are overflowing the wastegate. Then again, a lot of people upgrade intercoolers with downpipes and don't have any issues. I am thinking (since I am smoking anyway) to reinstall my factory racepipe (leaving the corksport downpipe) and then using the ETS 3.5 TMIC. Derek said that might give me enough backpressure to get the wastegate back into the efficiency range and should help with the smoking problem.... if you call covering it up fixing.

lestat are you the first of the 08.5's to have a smoking turbo? I'll be running the cs dp/rp on a hks cbe and I'm real worried that I'm going to smoke. is it really the loss of back pressure with these catless systems that causes over spooling which blows the seals? let me know about what you think I should do cause I really want the power gains but don't know how the dealership would be if i came in with a smoking turbo with a full tbe on :X

[lestat13]

Yeah, I think I am the first 2008.5 to smoke, which pisses me off. I am sitting at 11k miles today. I have heard people say the downpipe doesnt cause seals to blow, just lets you see that they are blown. I don't know if I believe that anymore. If you are worried about warranty, I would say throw on a catless midpipe and catback if you want, leave the downpipe, and then add an upgraded tmic. VERY EASY to switch back for dealer visits and also helps free up upto another 2psi people say. Probably take it into the dealer in stock trim after the Holidays and see if I can get a new blower for free

[phantomranger]

Yeah, I think I am the first 2008.5 to smoke, which pisses me off. I am sitting at 11k miles today. I have heard people say the downpipe doesnt cause seals to blow, just lets you see that they are blown. I don't know if I believe that anymore. If you are worried about warranty, I would say throw on a catless midpipe and catback if you want, leave the downpipe, and then add an upgraded tmic. VERY EASY to switch back for dealer visits and also helps free up upto another 2psi people say. Probably take it into the dealer in stock trim after the Holidays and see if I can get a new blower for free

(iagree) i like your thinkig. i am running a DP back and i get a little blueish smoke at idle. i can easily put the stock test pipe back on and take it to the dealer. i wonder will they say anything about my BOV. should i put the stock one back on before i go? i have a MAZDASPEED intake so i will just leave that on.

[hawaii3]

(iagree) i like your thinkig. i am running a DP back and i get a little blueish smoke at idle. i can easily put the stock test pipe back on and take it to the dealer. i wonder will they say anything about my BOV. should i put the stock one back on before i go? i have a MAZDASPEED intake so i will just leave that on.

so phantomranger, no DP for the meet?

[phantomranger]

so phantomranger, no DP for the meet?

no, just the testpipe. i think it's a PCV issue cause i only get the smoke at idle.

[lestat13]

My last attempt is 5w40 oil change (I went to get it done this weekend but 2 guys called out and I only trust one shop to work on my car, they said yeah, we can do it, but you gotta leave it for 8 hours..... I had stuff to do) and an oil catch can. Maybe krank vents. I would really love to NOT have to put this car back to stock.

As for dealer visits, new bov/bpv are things they hate to see because they affect boost and if you are vta running rich *can* damage some things. I would say put it ALL completely back to stock. If I need to go in I am only going to my shifter bushings, dashhawk, HIDs, and cosmetic mods.

[joeybisson]

ok so...whats the best choice :P i was originally looking at the turboxs dp/rp cuz i heard it was good, and i was thinking of going catless, and it was a good price, should i still go that way or should i go for the cobb instead? will it have the same power gains and sound?

[lestat13]

ok so...whats the best choice :P i was originally looking at the turboxs dp/rp cuz i heard it was good, and i was thinking of going catless, and it was a good price, should i still go that way or should i go for the cobb instead? will it have the same power gains and sound?

I hear that the cobb has a fantastic sound, plus with a high flow cat (so you can pass inspection/emissions) and that flex section, you can't go wrong. Everything Cobb makes is quality. Do it once and do it right. Us that are catless are having issues overflowing the wastegate, mine was a HUGE problem. Whatever you go with, port out the wastegate a bit while you are there. It will save you money and hassel later

[joeybisson]

thanks! that sounds a+ i think i will go for the cobb

[0nsp]

I can't believe that no one mentioned the CP-e downpipe. Same price as Corksport if you get the catless, if not a bit cheaper. Supposed to be one of the best pieces out there. The catted version is supposed to perform the same as Cobb, and is cheaper (589). Just something to mull over. I'm running stock, so keep in mind that this info is gleaned from lots of reading/shopping around.

[dandydaniel]

I have the corksport dp/rp sitting in my room right now... I sort of want to run the cp-e catless piece cause of its single piece design. but I don't know if I can sell the cs set up since I bought both for only $250 shipped. seems like too good of a deal to sell just so i could be a cp-e fanboy

[C.A.T.A.P]

I am runnin the turbo xs test pipe and down pipe and love them

[k-speed]

my dilemma is choosing between Cobb or CP-E. Cobb sounds like a good way to go but havn't really read much about CP-E. any input on both would be great. thanks

[Circle9]

I normally would go with CP-E, but it costs a tiny bit more than the Cobb if you get a cat with it, yet the Cobb, in my opinion, looks better in quality.

[numbnuts22715]

I normally would go with CP-E, but it costs a tiny bit more than the Cobb if you get a cat with it, yet the Cobb, in my opinion, looks better in quality.

There are vendors who make the cp-e dp extremely cheap..
Cobb on the otherhand-pretty much costs the same price no matter where you go.

Neither are better than the other in my opinion.

[Circle9]

How cheap? I've only seen them on SU for $550+/-, then you have to pay $150 for the cat.

[MSMS3]

I am runnin the turbo xs test pipe and down pipe and love them

Same here. If you can run catless, this is a very high quality polished stainless dp/rp combo. I paid about $430 plus shipping about 6 months ago.

[fastguy]

i have a cs testpipe and it sounds nice and got a decent power increse with my hks cbe exhaust but the cs dp is by far a bad dp. if you saw the power pages in import tuner it only dynoed 5whp for a dp thats horrible most cars get between 20-30 hp from a dp and they mentioned it was to small and constructed wrong. imo i feel that cobb has great products and there dp is constructed great and big and i m plaining on buying it asap alos there smic you cant go wrong with cobb but cs dp pretty musc fails

[lestat13]

Just to clarify, I saw that article too and I believe it was a 5whp max gain, and that's also after the second cat was already deleted and dyno'd with the cbe. Also, look at the power curve, not just max hp. Most people pick up gobs of power in the mid range. That's the 20-30hp people are talking about, not necessarily max

[AutoEuphoria]

Yup...area under the curve, not just peak WHP

[MSMS3]

Agreed. Area under the curve or a "fattened" curve (same thing) for hp and especially for torque is what usually wins races, rather than a big but peaky max hp gain.

But I have no experience with the CS DP. All I can say is that going to a full 3 inch DP/RP (the one in my sig), with both cats eliminated, mated to the stock 2.8 inch stock system behind the RP dropped my 60-100 mph times a whole second. That is huge And that was with the stock intake. I have just installed a good CAI and will retest soon to see how they work together. If you can run catless, this is a much more power generating mod than any aftermarket cat back. IMHO.