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Can you run a COBB stg3 tune without a Downpipe?

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72
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stpaul/mpls
#81
i don't ride around all night long beating on the car like i did while in the the navy or like some in high school do. however i have run it pikes peak airstrip attack, will do it again this year. and i have run my car in brainerd street car night. it is full throttle to max rpm and a quick shift to the next gear using the clutch. stock rmm>sounds like the engine is coming in the passenger compartment or the half shaft are gonna break. bob
 


Messages
326
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50
Location
greensboro
#82
Yeah, I hardly beat on or abuse my car. But day one, I just nailed it to see what it did all out...wheel hop, shifted into 2nd, RMM bottomed out...this was on stock power. Got Cobb stage one, obviously nothing changed because you're just adding power. Literally the next day I installed the Cobb RMM and that solved almost everything, there was a little bit of wheel hop if I pushed it but it was much improved. I had the BC coils and 4pt brace installed at the same time so idk which really helped, but there is absolutely no wheel hop at all. To be clear, I had the alignment done the first week I bought the car, then again after the coil overs.
 


Messages
142
Likes
8
Location
Los Angeles
#83
Running Stage 3 without downpipes

As the title states I'm confused as to whether or not I can do this. As of now all I have is the Mountune ap v3 with 24 pounds of boost tops and a high flow filter and a muffler delete. Sounds good not trying to change to a downpipe and I would need to buy a catted downpipe in California which is a waste of money. Anyways, I've been looking at the Depo Racing intercooler and I like simplicity+price of it. Can I run OTS Stage 3 map with just intercooler and keeping the stock downpipe. Also I know for Depo intercooler you can use the same piping but Cobb has their own piping in their package does it matter?

Any help is greatly appreciated I just don't think every one of their parts is necessary especially intake and exhaust.
 


Butterybunz

Active member
Messages
538
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184
Location
Minneapolis
#85
Don't miss match parts and run ots tunes you don't have the exact mods to be running. Get a protune designed for your car/mods.
 


dyn085

2000 Post Club
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Vancouver
#86
Covered ad nauseam in all of the other 'stage 3, no downpipe' threads.
 


DP03

Member
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183
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21
Location
Owings
#88
Its fine to run without the DP. I am doing it pro tuned. My pro tuner, and recently, Mishimoto, who is very transparent with their research, has found no gains with a dp on a stock turbo. Here's their quote:

"There were no improvements with our Mishimoto downpipe when we tested it against a stock Fiesta ST with a tune. We first ran the completely stock Fiesta ST for a baseline. We then loaded a tune and ran the an otherwise stock Fiesta ST on the dyno. Finally, we ran the Fiesta with the addition of the downpipe and our tune, and there were no improvements in horsepower or torque when comparing the runs with only a tune to the runs with a tune and a downpipe.

So the downpipe alone did not make any additional power, but could certainly be used as a supporting modification.

-Sara"

Others will argue that it can't hurt, and that's true, (although there could be a small loss of hp up top). But I wouldn't spend the money until you upgrade the turbo.

I can afford the dp. And if there were proven gains, I'd be all over it. But since there aren't, I'm glad I save the money, and I will add the dp at the same time as the turbo upgrade. Some speculate that the larger DP will not stress the turbo as much and increase its longevity, but that is, of course, speculation with no data to support it.

At the end of the day, do what makes you feel comfortable. Opinions here may vary greatly, but the research does not.
 


dyn085

2000 Post Club
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Location
Vancouver
#89
Yeah, I think you're right that people should probably just run stage 3 without any upgraded parts. Or maybe just an intake. An intercooler drops temps but, if we're real with ourselves, a 30 degree increase isn't much compared to other turbo cars, and we know that all other parts do nothing so we should basically just crank up the boost up and run the speed line all the way down. After all, turbocharging theory is new to many people that now own their first turbocharged car so everything is just speculation.

In4 long-term test candidates.
 


DP03

Member
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183
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21
Location
Owings
#90
Yeah, I think you're right that people should probably just run stage 3 without any upgraded parts. Or maybe just an intake. An intercooler drops temps but, if we're real with ourselves, a 30 degree increase isn't much compared to other turbo cars, and we know that all other parts do nothing so we should basically just crank up the boost up and run the speed line all the way down. After all, turbocharging theory is new to many people that now own their first turbocharged car so everything is just speculation.

In4 long-term test candidates.
Busy day today, so no time for arguing with you. But you should stay focused on the question. The OP never asked about running without the intercooler. He asked about the DP. The answer is that its ok, that the power levels are the very close with or without (plus or minus), and that there are people doing it with great results.

Have you gone through the Mishimoto posts and research? I won't convince you myself, but they do a pretty through job with their stuff.

You very much match the profile of "do what I did or its wrong", on just about every post I've seen you on. If you regret spending money on some things that did not pan out, its ok, I think everyone has in the path to modding cars. I tried four different torque converters in my quest for 10's on my Camaro. I got there, but it wasn't free. I'm the first to admit I could have saved money if I tried them in a different order. Try to stay objective and help those that are looking for unbiased opinions.
 


dyn085

2000 Post Club
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Location
Vancouver
#91
Busy day today, so no time for arguing with you. But you should stay focused on the question. The OP never asked about running without the intercooler. He asked about the DP. The answer is that its ok, that the power levels are the very close with or without (plus or minus), and that there are people doing it with great results.

Have you gone through the Mishimoto posts and research? I won't convince you myself, but they do a pretty through job with their stuff.

You very much match the profile of "do what I did or its wrong", on just about every post I've seen you on. If you regret spending money on some things that did not pan out, its ok, I think everyone has in the path to modding cars. I tried four different torque converters in my quest for 10's on my Camaro. I got there, but it wasn't free. I'm the first to admit I could have saved money if I tried them in a different order. Try to stay objective and help those that are looking for unbiased opinions.
I think it's funny that I finally try to agree with you and then you accuse me of arguing, even though it's a 'discussion' thread. And I didn't change the discussion by bringing up the FMIC, I simply gave you more ammo for your cause. Finally, you just told the (arguably) most objective and unbiased member on the forum to be objective and unbiased.

I'm not going to explain how a compressor map works, how certain modifications affect it, or post the one that I have. Turbo theory is not new to the rest of the world just because it's new to many here. 'Argue' out of sheer ignorance if you want, but I'm simply discussing.

You have brought up my modifications at least a couple of times now even though I thought I put it to rest last time. In being objective I have never recommended what I've done, as an entire system or individual parts, as being superior to anyone else's choices. Most people are aware of that but there are a few recently that would rather twist things to fit there prerogative than to actually take a few moments to think of why I do/don't say the things I say.
 


Messages
446
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164
Location
Arlington, VA
#92
You can run whatever the hell you want honestly. The car will run fine either way. It's possible you are stressing the DP or the turbo a little more, but nobody here can tell you how much more or how that will translate into failure rates, if at all. Your warranty is fucked either way if something goes. It's your car. Just do what you want.

Also, can one of the mods sticky one of the "stage 3, no downpipe" threads and delete any new ones that pop up.
 


BoostBumps

4000 Post Club
Staff Member
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1,031
Location
Arizona
#93
Just merged 2 similar discussion threads which both discuss if a DP is necessary for running a COBB stg3 tune...

carry on...
 


Messages
210
Likes
59
Location
Metro Detroit
#94
What is the point of this thread? It reads like "Can I get away with XYZ because I'm cheap and want to announce I'm at Stage 3 but without spending the money on hardware or a Pro Tune?"

It's your car, you're free to screw it up as you please. If you want to run OTS maps, then be smart and buy the matching hardware for those maps. If you want to mix-n-match in a fairly random way to suit whatever the goals that sound good in your head, then belly-up with your wallet and get a Pro Tune.
 


OP
M
Messages
197
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17
Location
oklahoma city
Thread Starter #95
Oh well doesnt matter now, Craigslist came through for me once again. I got a used Depo catless downpipe and custom exhaust with vibrant resonator and magnaflow muffler for $200!!!! Kid traded in Fiesta to get a family car.Welds are good but ugly, but exhaust on these cars are just for sound anyway. Its just aliminized pipin, im just going to sand her down and hit with black rustoleum, the entire thing.
 


Messages
120
Likes
37
Location
Columbus, Ohio
#96
Are they designed differently to protect anything from the hotter gases of the Stage3 (o2 sensors - cat) or is it just for the extra flow?
 


danbfree

3000 Post Club
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Location
Tigard, Oregon, USA
#98
(Cross-posted to similar old thread for visibility and future reference)

Wow, we've all learned a lot in the 3+ years since this thread was started... Thanks to Jason at Dizzy we have seen that yes, intake mods do help, from VERY little (drop in only) to a fairly decent amount (2JR with 10hp/20tq) and somewhere in between (crossover and induction hose upgrade or other complete intakes) but gains are mainly just more TORQUE that many of us already have an excessive of on the low RPM end with a stock turbo... But most importantly, Jason also has proven through multiple runs that the stock DP/exhaust period is simply not very restrictive at ALL, only a 3whp and 7wtq on an X47R turbo running completely catless over stock! Also, as you see in the pic below of Jason's testing, ignore the part that the tests were started at different RPM's and focus closely on how steep the torque curves go upward. On the catless, it does go up more smoothly while the stock DP starts out less steep but then shoots up more steeply as it "catches up", so that's the difference in spool time, very minimal and on a much higher flowing turbo than stock, so there you go, the stock exhaust system is not very restrictive at ALL, even with a hybrid! NOW, if you insist on trying to set world record power levels, insist on having an annoying pops and crackles tune when a reasonable amount is easy to get with a simple muffler swap or you do participate in actual racing where you are going to be running the car hard constantly, then a catless DP will give you that touch of added power, touch of faster spool, but also lower EGT's and underhood temps for more reliability, but mainly only in those extreme cases...

View attachment 20505

Now as far as my own trials with running Cobb Stage 3 tune, you can see my list of mild mods in my signature below but notice I have a STOCK intercooler and STOCK DP... I have had my FiST for about 15 months now but have always assumed you needed to at least be close to having most of Cobb's required mods, but Cobb tunes suck anyway so I've used Stratified and Dizzy after using only the Stage 1 on my AP when I first got it, but did try Stage 2 briefly once but never even considered trying stage 3 without an IC upgrade. So over time as I've learned more and realized that Cobb's Stage 3 power levels were simply close to Stage 1 Pro Tuner flash tunes, I figured it shouldn't hurt to try to try it out so I recently ran through a full tank on Cobb Stage 3 to compare it to Dizzy and Stratified that I have, all on 93. Unfortunately I only got one datalog and I still need to pull it and drop it in to vDyno, but I can tell you that compared to the "Stage 1" tunes from Dizzy and Stratified, my charge temps didn't go up any faster upon multiple pulls, didn't have any more negative corrections than the other 2 either. Now it did build boost more slowly compared to the Pro Tunes, but I think that's simply part of Cobb's tuning strategy, is to add lots of timing first and have boost fill in later, not my favorite way to go to begin with... But also I felt like little bits of stuttering as I went WOT as the RPM's climbed, but again no negative corrections, so that's very weird... After filling up, I went back to the Dizzy tune that's absolutely fantastic, and that stuttering wasn't there... So I have no idea other than straight up wanting to sell more unneeded bolt ons, but it seems Cobb's Stage 3 is less aggressive than the Pro Tuners flash tunes so any of their requirements are simply horseshit, period and as we know, their tunes aren't that good, it made decent power but also the stuttering was a bit unnerving and not right so I won't be going back to their tunes again.

So yeah, go ahead and run Cobb Stage 3 stock, it's likely not going to hurt anything to try when first buying an AP, maybe stick to Stage 2 if you are 100% stock and it helps you sleep better at night, but it also doesn't feel that great compared to a good flash tune like Dizzy so I say it's worth paying for a real tune to use instead.
 


Messages
301
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344
Location
Pharr, TX, USA
#99
I loaded Cobb stage 1 93 with only a drop in ITG filter, a whoosh symposer delete, and an AWR 88a RMM. Initial impression were good but after a few days and after reading this whole thread I decided to load stage 3 93 and noticed it is a lot smoother during startup and warm up. Stage 1 had a lot more NVH during the whole drive when compared to stage 3. I'll be sticking with stage 3 with stock IC, DP, and exhaust. I will be upgrading to a better IC ASAP. The extra boost is great and I'm excited to get to a better tune.
 


Last edited:

danbfree

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Tigard, Oregon, USA
I loaded Cobb stage 1 93 with only a drop in ITG filter, a whoosh symposer delete, and an AWR 88a RMM. Initial impression were good but after a few days and after reading this whole thread I decided to load stage 3 93 and noticed it is a lot smoother during startup and warm up. Stage 1 had a lot more NVH during the whole drive when compared to stage 3. I'll be sticking with stage 3 with stock IC, DP, and exhaust. I will be upgrading to a better IC ASAP. The extra boost is great and I'm excited to get to a better tune.
That's weird that you got more vibes using Stage 1, could be that the Stage 3 idle is set a bit higher, you do have a pretty stiff RMM... but Stage 3 does run pretty hot, I'd stick with Stage 2 until you at least get an intercooler.
 




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