• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Explorer ST Forum and Explorer ST community dedicated to Explorer ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Explorer ST Forum today!


deleted

TMac

1000 Post Club
Messages
1,706
Reactions
1,494
Points
262
Location
Knoxville, TN
#41
Taking a look at that pump from your link, you can't possibly know unless you know the actual flow in lbs/minute of the new pump/stock injector combo. If we calculate the ST engine at 6000 rpm at 100% VE at 3 bar or 29 PSIg (you are planning on running more mass airflow, right?), it comes out to 66 lbs/min air. At a .8 lambda (WOT), that means for e85 (and understand that e85 marked at the pump could only be e60 or so), you would get a 7.8 A/F ratio. 66 / 7.8 = 8.46 lbs/min of fuel flow. Show me where anything the marketing materials list give you that kind of flow, and I'd say you're good. Now, if you're running much less boost, you need less fuel, but if you're looking to max out the platform, that's what you need.
Of course, the turbos have run out of steam well before that point, but why buy something that only gets you partway?

The take-away from this is unless the manufacturer is going to list the lbs/min flow it's useless.
 

Last edited:
Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#42
Taking a look at that pump from your link, you can't possibly know unless you know the actual flow in lbs/minute of the new pump/stock injector combo. If we calculate the ST engine at 6000 rpm at 100% VE at 3 bar or 29 PSIg (you are planning on running more mass airflow, right?), it comes out to 66 lbs/min air. At a .8 lambda (WOT), that means for e85 (and understand that e85 marked at the pump could only be e60 or so), you would get a 7.8 A/F ratio. 66 / 7.8 = 8.46 lbs/min of fuel flow. Show me where anything the marketing materials list give you that kind of flow, and I'd say you're good. Now, if you're running much less boost, you need less fuel, but if you're looking to max out the platform, that's what you need.
Of course, the turbos have run out of steam well before that point, but why buy something that only gets you partway?

The take-away from this is unless the manufacturer is going to list the lbs/min flow it's useless.
so this evo HPFP would be enough to just run a e85 tune (e60)?
The tune shouldn’t increase psi that dramatically getting a slight increase in boost should be accompanied by a aFe intake which should boost the air density a tab from stock intake. Alongside with a Ultimate Performance intercooler keeping the air density ever high from the heat being removed.
 

TMac

1000 Post Club
Messages
1,706
Reactions
1,494
Points
262
Location
Knoxville, TN
#43
I'm saying there isn't enough information to know and you need a lot more information based on your comments before you think about running an ethanol tune. Walk before you run...see a knowledgeable tuner once you get your intercooler and CAI installed (@ZFGracing) and follow their advice.
 

ARC

Member
Law Enforcement
Messages
314
Reactions
102
Points
37
Location
Oak Lawn, IL, USA
Vehicle
2022 ST Black
#44
There’s hundreds of satisfied customers. There was apparently a run of bad mufflers…most of which have been replaced from reading on the FB groups. This guy and one other made a huge deal because Thermal has a refund/replace/whatever policy they don’t like. Don’t let one guy bitching and another one that bitches but doesn’t own the product sway your decision.
I agree with you, just wanted to see some main players on here say they support the company.
 

ARC

Member
Law Enforcement
Messages
314
Reactions
102
Points
37
Location
Oak Lawn, IL, USA
Vehicle
2022 ST Black
#45
Just deeps on where you going to take your ST leave at stock or go for hp?
I have waited on pulling the trigger for exhaust due to limited aftermarket diameter exhaust from 2.25-2.5 duel exits. I will soon be putting a custom 3” exhaust and was quoted 1500 and up. That would be a true cat back exhaust. I just want a better flow setup until I want to tune for 91 octane, but would like just a pump e85 tune without adding any gas equations.
So far I have a 93 tune with the mbrp 2.5 inch x pipe exhaust. In addition to a drop in K&N.
 

Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#46
So far I have a 93 tune with the mbrp 2.5 inch x pipe exhaust. In addition to a drop in K&N.
The tune should put you around 415-440hp (engine displacement hp) which should be enough area of air flow to support that build. Any further horsepower probability should put you at 2.75”-3” dual exhaust exit.
 

UNBROKEN

4000 Post Club
Messages
4,587
Reactions
5,362
Points
352
Location
Houston, TX, USA
#47
The tune should put you around 415-440hp (engine displacement hp) which should be enough area of air flow to support that build. Any further horsepower probability should put you at 2.75”-3” dual exhaust exit.
There’s maybe 2-3 ST’s that “might” need larger than 2.5”…and that’s a huge night. There’s not an ST on the planet that needs dual 3”. Hell the stock exhaust at 2.25” is plenty for basically every bolt on/Tune ST on the street.
 

Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#48
There’s maybe 2-3 ST’s that “might” need larger than 2.5”…and that’s a huge night. There’s not an ST on the planet that needs dual 3”. Hell the stock exhaust at 2.25” is plenty for basically every bolt on/Tune ST on the street.
the 2.5 duel exhaust would support up 450 hp (engine displacement) but to achieve easy turbo spooling and help with back pressure for higher hp numbers, for sure hit 3” exhaust from turbo back. I would imagine he would like to save his turbo for awhile before maxing out and needing a bigger turbo which still would have turbo lag if having a 2.5” exhaust. Easy statement “bigger straw to breathe better.” Imagine running with a straw an exhaling…smaller better or bigger better?
Now to bring up elevation and air density… I could probably get away with a 2.5” if I keep blow 500 hp (engine displacement) due to my elevation 5,000-8,000 ft avg. but sea level should be fine at 2.5”.
 

TMac

1000 Post Club
Messages
1,706
Reactions
1,494
Points
262
Location
Knoxville, TN
#49
@UNBROKEN is exactly right. a SINGLE 3" exhaust will support 7-800 horsepower on a turbocharged vehicle. A dual 2.25" system is actually slightly larger in terms of area than a 3". If you're looking to change the sound of the exhaust, then do whatever to make it sound good. But to claim you need a 2.75-3" dual exhaust for over 415-440 hp? Comparisons with "straw an exhaling"? Who is giving you this information??? There are STs at this very minute running 520 whp with completely stock exhaust and downpipes- that equals about 580 crank horsepower. And what does elevation have to do with exhaust size?
 

Last edited:

UNBROKEN

4000 Post Club
Messages
4,587
Reactions
5,362
Points
352
Location
Houston, TX, USA
#50
Very lit
the 2.5 duel exhaust would support up 450 hp (engine displacement) but to achieve easy turbo spooling and help with back pressure for higher hp numbers, for sure hit 3” exhaust from turbo back. I would imagine he would like to save his turbo for awhile before maxing out and needing a bigger turbo which still would have turbo lag if having a 2.5” exhaust. Easy statement “bigger straw to breathe better.” Imagine running with a straw an exhaling…smaller better or bigger better?
Now to bring up elevation and air density… I could probably get away with a 2.5” if I keep blow 500 hp (engine displacement) due to my elevation 5,000-8,000 ft avg. but sea level should be fine at 2.5”.
Not much in this post is correct. That’s just not the way it works.
 

Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#51
It’s just common sense we have a long way to exit exhaust pressure compared to a Subaru sti exhaust length. The less restrictions the better of exit flow.
I’m talking about engine displacement of hp not whp.
A 2.5 turbo duel exhaust can support up 500 engine hp (most v8 N/A use 2.5-2.75”) any further you cause back pressure and turbo spooling delay. AGAIN considering elevation into the problem. We all don’t live sea level.
I’m saying if he’s shooting for fame of high hp go 3” with slamming the gas but just street cruising speed with a stock dp or performance dp 2.5 is fine for considering your not on the autobahn.
 

UNBROKEN

4000 Post Club
Messages
4,587
Reactions
5,362
Points
352
Location
Houston, TX, USA
#52
I don’t have time to argue…but your understanding of how exhausts work is obviously limited to things you’ve read online from other uninformed folks. It’s fine…you’ll likely learn a few things if you’re willing….but as it stands you’re way off base. TMac has posted the most in depth discussions about it…it would behoove you to find and read those posts.
 

Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#53
Very lit

Not much in this post is correct. That’s just not the way it works.
air comes in cold (dense air) into turn pushed in the engine and combustion happens (boom) then leaves out the back of turbo which exhaust hot air (heated thin air) pushed into tight cat and cooled slightly then need a small diameter pipe to recharge air to get hot again cause hot air moves easily. Then the air hits resonators (referred as restricters) to help damp noises and exhaust exits quite for the friendly neighbors. Simple terms
 

UNBROKEN

4000 Post Club
Messages
4,587
Reactions
5,362
Points
352
Location
Houston, TX, USA
#54
I don’t need simple terms…I can talk about exhaust in big words. Again, there’s very very good posts on the subject here. You may find them interesting and you’ll definitely learn something.
 

Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#56
I don’t have time to argue…but your understanding of how exhausts work is obviously limited to things you’ve read online from other uninformed folks. It’s fine…you’ll likely learn a few things if you’re willing….but as it stands you’re way off base. TMac has posted the most in depth discussions about it…it would behoove you to find and read those posts.
drive a sea level tuned car at higher elevations you’ll see a big difference at timings and a/f ratio. Thus flow rate of exhaust gases will change. If we where talking about liquid it would be the opposite, so you need to go smaller for it to move from place to place. A mile high is where I live and would love to have my turbo have less back pressure.
 

TMac

1000 Post Club
Messages
1,706
Reactions
1,494
Points
262
Location
Knoxville, TN
#57
W
drive a sea level tuned car at higher elevations you’ll see a big difference at timings and a/f ratio. Thus flow rate of exhaust gases will change. If we where talking about liquid it would be the opposite, so you need to go smaller for it to move from place to place. A mile high is where I live and would love to have my turbo have less back pressure.
Since you're new here, we're trying to be nice. Look at the link in my previous post. As far as elevation, air density is less, no doubt. But that doesn't have anything to do with flow through the exhaust which is a function of mass airflow which only decreases as air density decreases. As far as liquid vs gases- well they definitely behave somewhat differently because one is compressible and one is not, but they are definitely not "opposite".
 

Messages
118
Reactions
16
Points
17
Location
Albuquerque, NM, USA
#58
I don’t need simple terms…I can talk about exhaust in fluid dynamics and laminar flow. Again, there’s very very good posts on the subject here. You may find them interesting and you’ll definitely learn something.

im not saying your stupid or anything just helping a fellow guy understand what happens in a exhaust in a simple turbo engine. Yet we have a advanced engineering in this engine which delete a BOV in 2021 models and doesn’t seem we have DV either. Im still new to this engine haven’t own it more than 4 months so forgive me if I have sinned in answering a question wrong but yet I’m correct in sense of flow response and restrictions.
I ran a A4 (e85 tune, ko4 turbo, intake, dp, coil pack, HPFP/LPFP, beefed intake manifold, 2x cooling fans, a lot of bigger silicone tubing for air flow) made 435hp and 470 trq. Ran a single turbo 3” down pipe to 2.5 mid pipe and axle back was 3” so I understand a 2.5 supports the hp but longtime use and abuse should serve a 3” exhaust.
 

UNBROKEN

4000 Post Club
Messages
4,587
Reactions
5,362
Points
352
Location
Houston, TX, USA
#60
im not saying your stupid or anything just helping a fellow guy understand what happens in a exhaust in a simple turbo engine. Yet we have a advanced engineering in this engine which delete a BOV in 2021 models and doesn’t seem we have DV either. Im still new to this engine haven’t own it more than 4 months so forgive me if I have sinned in answering a question wrong but yet I’m correct in sense of flow response and restrictions.
I ran a A4 (e85 tune, ko4 turbo, intake, dp, coil pack, HPFP/LPFP, beefed intake manifold, 2x cooling fans, a lot of bigger silicone tubing for air flow) made 435hp and 470 trq. Ran a single turbo 3” down pipe to 2.5 mid pipe and axle back was 3” so I understand a 2.5 supports the hp but longtime use and abuse should serve a 3” exhaust.
You can’t help people when you don’t understand the subject matter…much like making shit up about fiberglass and health hazards. Read post #65…
 



Top