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Can you run a COBB stg3 tune without a Downpipe?

Hijinx

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#4
Here ya go.

Well stated guys!

[HR][/HR]

To add to this COBB (for example) strongly suggests having either a highflow catted downpipe or non-catted DP installed when using their stg3 OTS Map...There is no mention that installing their DP alone will produce gains...I suspect the rationale for doing so has moreso to do with the reasons already stated above...

I've reviewed the differences between COBB's stg1 and stg 3 OTS maps (through Cobb ATR) and the 2 primary changes made between the two maps are that timing is advanced by ~4.0 degrees (>5000rpm / > 1.6% load) and maximum boost is increased by another 2.0 psi...This will greatly increase EGTs where I can see where installing a highflow DP would be a wise choice as not to damage the stock CAT... Also boost response and spooling efficiency should great be improved and as mentioned by others earlier by not placing as much strain on the FiSTs stock turbo at these higher boost levels....

That said...It should be of no surprise that installing a non-catted DP on a stg1 tune would show any significant increase to hp....

[HR][/HR]

And thanks for posting this Adam!
 


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Thread Starter #5
Ok, raising boost increasea EGT I get it, hence burn out stock cat. So how does Adams tune create more power without some level of boost increase that doesnt create more heat. Not being a douche I just have never heard of DP not helping performance in a turbo car.
 


Hijinx

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#6
Ok, raising boost increasea EGT I get it, hence burn out stock cat. So how does Adams tune create more power without some level of boost increase that doesnt create more heat. Not being a douche I just have never heard of DP not helping performance in a turbo car.
That's a DAMN good question. I'm very skeptical of the answer myself, but "they" effectively say it's because this specific tiny turbo needs some back pressure. I cannot express how skeptical of this answer I am.

"THERE ARE FOUR LIGHTS!"
 


dyn085

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#7
There are a lot of tuning decisions that I've seen recently (and a handful of things from the past), from multiple FiST pro tuners, that make me think really hard about...things. I'll just leave it at that.
 


jeff

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#8
Ok, raising boost increasea EGT I get it, hence burn out stock cat. So how does Adams tune create more power without some level of boost increase that doesnt create more heat. Not being a douche I just have never heard of DP not helping performance in a turbo car.
That's a DAMN good question. I'm very skeptical of the answer myself, but "they" effectively say it's because this specific tiny turbo needs some back pressure. I cannot express how skeptical of this answer I am.

"THERE ARE FOUR LIGHTS!"
There are a lot of tuning decisions that I've seen recently (and a handful of things from the past), from multiple FiST pro tuners, that make me think really hard about...things. I'll just leave it at that.
I researched this carefully while planning out my mod path. Some get no gains with a DP while others get small gains. But they are very SMALL gains....only a few HP. Cobb, for example, got +7 HP on their OTS tune for "stage 3" after adding a DP and exhaust. I figure 2 of that is the DP, 2 the exhaust, and maybe 3 the tune tweak itself. Tuners have different tuning strategies...Adam claims it hurts the car while Cobb and Stratified say it helps. The thing is, on our cars, even if it does help it only helps a little. I decided against these "stage 3" mods because 7 HP was not worth $1000 to me. Plus I didn't want the noise. Plus I install myself which isn't exactly fun, or pay someone more money to install. IMHO that money can be used for other things including a custom tune which will gain me at least 7 HP or maybe more. I recommend "stage 2" mods and then a tune and some bracing.

As for using stage 3 tune without stage 3 mods, don't try to run your car on a map for parts you don't have - don't cheat the system, it isn't good for your car.

EDIT: ...and one more thing...again IMO the reason people act happy at their stage 3 arrival is not because the car is actually noticeably faster....it is because (1) the car is louder and placebo kicks in and they think it's faster (2) it does have a bit more torque (3) they are finally just like Matt Mr. Smoking Tire with a zillion views and have boasting rights. But I think the best price point for power gained is any stage 2 package.
 


dyn085

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#9
I researched this carefully while planning out my mod path. Some get no gains with a DP while others get small gains. But they are very SMALL gains....only a few HP. Cobb, for example, got +7 HP on their OTS tune for "stage 3" after adding a DP and exhaust. I figure 2 of that is the DP, 2 the exhaust, and maybe 3 the tune tweak itself. The thing is, on our cars, even if it does help it only helps a little. I decided against these "stage 3" mods because 7 HP was not worth $1000 to me. Plus I didn't want the noise. Plus I install myself which isn't exactly fun, or pay someone more money to install. IMHO that money can be used for other things including a custom tune which will gain me at least 7 HP or maybe more. I recommend "stage 2" mods and then a tune and some bracing.

As for using stage 3 tune without stage 3 mods, don't try to run your car on a map for parts you don't have - don't cheat the system, it isn't good for your car.
You can't 'add' mod gains like that. Furthermore, the reason that gains are minimal is because of how the OEM turbo is already basically maxed out-there's just not much more for it to give so you have to make the difference in timing. Finally, a custom tune on stage 3 parts would (should) give a gain over a custom tune on stage 2 parts, all things considered.

Fwiw, all I really ever recommend for engine is FMIC and DP, add E30 tune. That's basically the best bang for your buck for those only interested in performance.
 


OP
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Thread Starter #10
All good info and opinions, but my 2013 Abarth started as so.
1. Hpsi V2 intake
2. Modern Performance lightweight crank pulley
3. Modern Performance bored throttle body
4. GFB diverter valve
5. My firsr "tune" was Roadrace Mtrspta v3 piggy back. tricks map sensors etc.
My second was Unichip stage 2 HPSI map after Dp
6. ATP catless downpipe 3" HuGe diff in spool and would destroy tires 1st and 2nd
7 Magnaflow exhaust.
8 Brisk plugs.

Most people have no experience with the Fiat side. HPSI is THE tuner for FIAT and ALFA 4c.
Fiattech has plenty of before after dynos with stoxk cat and without and the difference was substantial.
When they came out with the Eurodrive they requires a Dp at certain levels. Of course also having switched out the Twin intercoolers that come stock to a single FMIC. Maybe it is the turbo???? But R.i.p. tuning here in Moore OKc has shown significant gains on the 2.3 Mustang with catless Dp. Yes I know its a twin scroll, just trying to learn.
 


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Thread Starter #11
Same "snake oil" talk when I had my 2007 G35S 4 door sedan with VQ35HR. Everyone said Stillen cold air. ( literally two k and n filters behind the Infiniti grill was useless as was My Stillen Underdrive lightweight pulley, My Z1 motorsports lightweight flywheel, and lastly my PPE True longtube headers jethot coated. Guess what with Uprev tune my G made more power than 370z and G37. And on the track........ my plates
 


dyn085

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#13
Um, what 'snake oil' talk? A turbo is the biggest restriction in an exhaust, but freeing up the air path before/after it can definitively produce gains depending on the OEM design of the parts.
 


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#15
Ok, raising boost increasea EGT I get it, hence burn out stock cat. So how does Adams tune create more power without some level of boost increase that doesnt create more heat. Not being a douche I just have never heard of DP not helping performance in a turbo car.
Sounds like a question for Adam. It's my understanding that our stock turbocharger is so small that additional exhaust pressure in the DP doesn't help spin the tiny guy up. Again, Adam can likely chime in on this. I went IC and no DP with an Adam tune+ tune and I am blown away with the car.
 


Kip2MyLou

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#16
With Adam showing me his tables and seeing Cobb's small gains I picked to not do a DP, and put that $400-$500 towards wheels and suspension mods. Maybe further down the line I might pick one up after I'm done and have nothing else to do to the car. Ha.
 


jeff

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With Adam showing me his tables and seeing Cobb's small gains I picked to not do a DP, and put that $400-$500 towards wheels and suspension mods. Maybe further down the line I might pick one up after I'm done and have nothing else to do to the car. Ha.
My thoughts exactly. Your custom tune probably gets you more HP/TQ than a stage 3 OTS map. We are going the same route.
 


BronxBomber

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#18
I also asked Adam about he DP to do or not. I have one sitting in my garage brand new in box for like 2 months. He showed me some dyno plots where the car gains quite a bit of torque and HP from adding the DP. Problem is, it's precisely where this car does not need it. 3,500 Rpm and below. My car already blows the tires off in third gear. Last thing I need is more low end torque. When going with a larger turbo, he downpipe will help spool it quicker and breathe better on the top end. Since our snails are so tiny and run out of breath by 6,000 rpm, we don't get to see the gains a DP would normally provide with a larger turbo set up.
 


jeff

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#19
I also asked Adam about he DP to do or not. I have one sitting in my garage brand new in box for like 2 months. He showed me some dyno plots where the car gains quite a bit of torque and HP from adding the DP. Problem is, it's precisely where this car does not need it. 3,500 Rpm and below. My car already blows the tires off in third gear. Last thing I need is more low end torque. When going with a larger turbo, he downpipe will help spool it quicker and breathe better on the top end. Since our snails are so tiny and run out of breath by 6,000 rpm, we don't get to see the gains a DP would normally provide with a larger turbo set up.
Well said. See Cobb's dyno chart below. Stage 3 gets heaps of low range torque which as you say is unusable. BTW my +7 HP figure shared earlier came from Smoking Tire's YouTube dyno results. Cobb has a bit different results on their website. But still the concept is the same - more low end power which means you're shredding tires in 1st or 2nd gear if you floor it. Not what I want every day I drive.

 


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#20
It sounds like for some a DP could be useful then. I enjoy low end power and being able to roast the tires when I want to. Right now I feel like it could use some more "down low", but I'm with the others, maybe when I have nothing else to upgrade...
 




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