Blown Boss
Blown Boss
Just curious if anyone out there is planning on putting a supercharger on their Boss.
I know a lot of people want to preserve the value of their "rare" car or are worried about upsetting the weight balance, so most will probably just do bolt-ons if not leave it all stock.
But it seems to me the car has a lot of potential with a blower, especially a centrifugal. The '11 GT are making serious power at 8-9 lbs of boost and the Boss has better airflow and forged pistons/rods. 11:1 compression isn't that much of a problem with a blower when you have knock sensors, variable valve time to bleed off cylinder pressure, and oil squirters under the pistons.
I know a lot of people want to preserve the value of their "rare" car or are worried about upsetting the weight balance, so most will probably just do bolt-ons if not leave it all stock.
But it seems to me the car has a lot of potential with a blower, especially a centrifugal. The '11 GT are making serious power at 8-9 lbs of boost and the Boss has better airflow and forged pistons/rods. 11:1 compression isn't that much of a problem with a blower when you have knock sensors, variable valve time to bleed off cylinder pressure, and oil squirters under the pistons.
i think one of those black vortech blowers would be awesome under the hood. i am sure we will seem some of them with blowers once people get the cars delivered. it depends on what sort of racing you plan on doing. folks like me with 5 drag strips within 1.5 hrs and the closest road course 6 hrs away would appreciate the extra power a blower brings.
The information I have read states that the 5.0 has under-piston oil squirters just like the high performance 5.4's have (GT500/FGT). These squirters are there to cool the underside of the piston by transferring piston heat to the oil which is then dissipated in the oil heat sink. This feature has applicability on engines which have high output demands and thus it does not make any sense that Ford would purposefully remove this feature from a high performance Boss engine. (does it?)
Compressors are usually divided into two groups, axial or centrifugal. Unless you are trying to lump roots or Lyschom positive displacement rotors into the mix.(?) Turbocharging and/or supercharging all employ centrifugal compressors. I have never seen or heard of an axial compressor being used for an automotive application. Note, my avitar shows use of an axial compressor.
IMO the Boss engine is not a good candidate for forced induction without major internal modificaitons. The engine was DESIGNED as a normally asperated engine, and if you think you can just slap on an 8-10 psi blower on an engine which already has 11:1 CR pristons, you need to do a bit more studying.
Yea, it is great the engine has knock sensors to pull spark advance if you give the engine a low octane fuel, but if you increase BMEP by installing a blower on the engine you will be on the knock sensors all the time (unless you are willing to run C16 fuel (at about $11.50 per gallon) all the time. Unlikely....
If you want a blown engine in you mustang, get the GT500.
Just curious if anyone out there is planning on putting a supercharger on their Boss.
But it seems to me the car has a lot of potential with a blower, especially a centrifugal. The '11 GT are making serious power at 8-9 lbs of boost and the Boss has better airflow and forged pistons/rods. 11:1 compression isn't that much of a problem with a blower when you have knock sensors, variable valve time to bleed off cylinder pressure, and oil squirters under the pistons.
But it seems to me the car has a lot of potential with a blower, especially a centrifugal. The '11 GT are making serious power at 8-9 lbs of boost and the Boss has better airflow and forged pistons/rods. 11:1 compression isn't that much of a problem with a blower when you have knock sensors, variable valve time to bleed off cylinder pressure, and oil squirters under the pistons.
IMO the Boss engine is not a good candidate for forced induction without major internal modificaitons. The engine was DESIGNED as a normally asperated engine, and if you think you can just slap on an 8-10 psi blower on an engine which already has 11:1 CR pristons, you need to do a bit more studying.
Yea, it is great the engine has knock sensors to pull spark advance if you give the engine a low octane fuel, but if you increase BMEP by installing a blower on the engine you will be on the knock sensors all the time (unless you are willing to run C16 fuel (at about $11.50 per gallon) all the time. Unlikely....
If you want a blown engine in you mustang, get the GT500.
...IMO the Boss engine is not a good candidate for forced induction without major internal modificaitons. The engine was DESIGNED as a normally asperated engine, and if you think you can just slap on an 8-10 psi blower on an engine which already has 11:1 CR pristons, you need to do a bit more studying.
...
If you want a blown engine in you mustang, get the GT500.
...
If you want a blown engine in you mustang, get the GT500.
https://themustangsource.com/f726/5-0-vs-5-4-a-494104/
He's not the only one who needs to do "a bit more studying."
https://themustangsource.com/f726/5-0-vs-5-4-a-494104/
https://themustangsource.com/f726/5-0-vs-5-4-a-494104/
Couple of questions:
From the article,
"Another Coyote advantage is compression ratio. The GT500 puffs up 8.4:1 compression, while the Coyote puts the squeeze on things with 11.0:1 compression. This is significant because compression is a fundamental aspect of power production. The whole idea in a piston engine is to build cylinder pressure, and higher compression puts more oomph into the power stroke."
Agreed! The easiest way to increase an Internal Combustion (IC) engine overall efficiency to to increase Compression Ratio (CR). You want high combustion pressures for high density power output. But there are limits. Why don't we run 15:1 or 20:1 CR pistons in IC engines? Because the fuels available will not prevent detonation at these high compression pressures and the engine will soon fail. Or the knock detectors will retard spark as much as available to prevent detonation and thus compromise the whole reason for running a high CR.
Ford engineers designed the 5.4 for forced induction and used a CR of 8.4:1. The Coyote engine was designed as a Normally Aspirated (NA) engine and uses a CR of 11:1. Why do you think the engineers did that? Although not privy to the Ford design data, I would think the BMEP of both engines is probably quite close. And Ford has to give the consumer a product which will last a reasonable amount of time. We as vehicle purchasers would not be too pleased if our engines gave us these tremendous amounts of peak horsepower but the engine blows up in 50 miles.
KB may be able to put a blower atop an engine designed for NA and report tremendous power. This certainly can (and has) been done. What type of warranty comes with the blown Coyote? You get what you pay for. High power can be obtained. The trade off is engine life. If you are willing to accept (and pay for) increased engine failures, go for it.
Interestingly in the short testing period KB did on the blown 5.0, they experienced detrimental crankshaft harmonics which led to catastrophic oil pump failure. From the article,
"There is no 18 psi of boost run for the 5.0 because the two times the test car was tuned up that far, it blew up its oil pump. Yes, the oil pump. This happened because to get past 15 pounds of boost, a larger crankshaft pulley is needed, which means changing the integral harmonic dampener. Something in the aftermarket dampener and the oil pump didn’t get along, resulting in a shattered inner oil pump gear each time the larger aftermarket damper was tried. A stronger pump gear will soon be available to cure that problem."
This small little footnote seems to imply the crankshaft harmonic dampener had been changed ("Something in the aftermarket dampener and the oil pump didn’t get along"). The article did not indicate any engine modifications were made to the blown Coyote ("There is no new hardware involved in this story"). It is certainly reasonable to assume if internal combustion pressures are changed due to forced induction, rotating harmonics can and would be altered. Few if any non-OEM vendors have the ability to map, understand and design countermeasures for these engine dynamic considerations. If this internal mechanical problem was encountered in the short power documentation period of Coyote forced induction, what "weak-link" is next to surface?
IMO the Boss engine is not a good candidate for forced induction without major internal modificaitons. The engine was DESIGNED as a normally asperated engine, and if you think you can just slap on an 8-10 psi blower on an engine which already has 11:1 CR pristons, you need to do a bit more studying.
Sorry but that's just wrong. The whole mindset of "you need low compression like 8:1 to run boost" dates back to the days of carburetors and distributors when precise timing and mixture control was impossible. I remember back in the day when people were saying you couldn't run more than 9.5:1 even NA on unleaded gas. Nowadays we have NA cars running over 11:1 all the time. People are running blowers on 11 GT's (which have 11:1 comp and cast pistons) at 8-10 lbs with no problem at all. Ford even offers a warranty on the 525 HP Whipple that they sell for the '11 GT - 7 psi and 11:1 compression with cast pistons and Ford is comfortable providing a warranty for it. Think about that for a second, and tell me why the same exact motor with FORGED pistons and rods suddenly is a bad candidate for boost.
The information I have read states that the 5.0 has under-piston oil squirters just like the high performance 5.4's have (GT500/FGT). These squirters are there to cool the underside of the piston by transferring piston heat to the oil which is then dissipated in the oil heat sink. This feature has applicability on engines which have high output demands and thus it does not make any sense that Ford would purposefully remove this feature from a high performance Boss engine. (does it?)
Compressors are usually divided into two groups, axial or centrifugal. Unless you are trying to lump roots or Lyschom positive displacement rotors into the mix.(?) Turbocharging and/or supercharging all employ centrifugal compressors. I have never seen or heard of an axial compressor being used for an automotive application. Note, my avitar shows use of an axial compressor.
IMO the Boss engine is not a good candidate for forced induction without major internal modificaitons. The engine was DESIGNED as a normally asperated engine, and if you think you can just slap on an 8-10 psi blower on an engine which already has 11:1 CR pristons, you need to do a bit more studying.
Yea, it is great the engine has knock sensors to pull spark advance if you give the engine a low octane fuel, but if you increase BMEP by installing a blower on the engine you will be on the knock sensors all the time (unless you are willing to run C16 fuel (at about $11.50 per gallon) all the time. Unlikely....
If you want a blown engine in you mustang, get the GT500.
Compressors are usually divided into two groups, axial or centrifugal. Unless you are trying to lump roots or Lyschom positive displacement rotors into the mix.(?) Turbocharging and/or supercharging all employ centrifugal compressors. I have never seen or heard of an axial compressor being used for an automotive application. Note, my avitar shows use of an axial compressor.
IMO the Boss engine is not a good candidate for forced induction without major internal modificaitons. The engine was DESIGNED as a normally asperated engine, and if you think you can just slap on an 8-10 psi blower on an engine which already has 11:1 CR pristons, you need to do a bit more studying.
Yea, it is great the engine has knock sensors to pull spark advance if you give the engine a low octane fuel, but if you increase BMEP by installing a blower on the engine you will be on the knock sensors all the time (unless you are willing to run C16 fuel (at about $11.50 per gallon) all the time. Unlikely....
If you want a blown engine in you mustang, get the GT500.
He's not the only one who needs to do "a bit more studying."
https://themustangsource.com/f726/5-0-vs-5-4-a-494104/
https://themustangsource.com/f726/5-0-vs-5-4-a-494104/
Glad you pointed out that article, it is good. Does not change my opinion though. Read the article. What gas was used during the test?
Couple of questions:
From the article,
"Another Coyote advantage is compression ratio. The GT500 puffs up 8.4:1 compression, while the Coyote puts the squeeze on things with 11.0:1 compression. This is significant because compression is a fundamental aspect of power production. The whole idea in a piston engine is to build cylinder pressure, and higher compression puts more oomph into the power stroke."
Agreed! The easiest way to increase an Internal Combustion (IC) engine overall efficiency to to increase Compression Ratio (CR). You want high combustion pressures for high density power output. But there are limits. Why don't we run 15:1 or 20:1 CR pistons in IC engines? Because the fuels available will not prevent detonation at these high compression pressures and the engine will soon fail. Or the knock detectors will retard spark as much as available to prevent detonation and thus compromise the whole reason for running a high CR.
Ford engineers designed the 5.4 for forced induction and used a CR of 8.4:1. The Coyote engine was designed as a Normally Aspirated (NA) engine and uses a CR of 11:1. Why do you think the engineers did that? Although not privy to the Ford design data, I would think the BMEP of both engines is probably quite close. And Ford has to give the consumer a product which will last a reasonable amount of time. We as vehicle purchasers would not be too pleased if our engines gave us these tremendous amounts of peak horsepower but the engine blows up in 50 miles.
The Coyote has the advantage of variable cam timing. Guess what? Dynamic compression ratio can be altered as necessary, a luxury the 5.4 does not enjoy.
KB may be able to put a blower atop an engine designed for NA and report tremendous power. This certainly can (and has) been done. What type of warranty comes with the blown Coyote? You get what you pay for. High power can be obtained. The trade off is engine life. If you are willing to accept (and pay for) increased engine failures, go for it.
How much engine life are we "giving up"?
My PJ wasn't "designed" for a blower either (higher compression na) yet it makes good power (10.80's @ 128) and is at 20k miles now. A strong bottom end and a good tune go a LONG way.
Interestingly in the short testing period KB did on the blown 5.0, they experienced detrimental crankshaft harmonics which led to catastrophic oil pump failure. From the article,
"There is no 18 psi of boost run for the 5.0 because the two times the test car was tuned up that far, it blew up its oil pump. Yes, the oil pump. This happened because to get past 15 pounds of boost, a larger crankshaft pulley is needed, which means changing the integral harmonic dampener. Something in the aftermarket dampener and the oil pump didn’t get along, resulting in a shattered inner oil pump gear each time the larger aftermarket damper was tried. A stronger pump gear will soon be available to cure that problem."
This small little footnote seems to imply the crankshaft harmonic dampener had been changed ("Something in the aftermarket dampener and the oil pump didn’t get along"). The article did not indicate any engine modifications were made to the blown Coyote ("There is no new hardware involved in this story"). It is certainly reasonable to assume if internal combustion pressures are changed due to forced induction, rotating harmonics can and would be altered. Few if any non-OEM vendors have the ability to map, understand and design countermeasures for these engine dynamic considerations. If this internal mechanical problem was encountered in the short power documentation period of Coyote forced induction, what "weak-link" is next to surface?
Couple of questions:
From the article,
"Another Coyote advantage is compression ratio. The GT500 puffs up 8.4:1 compression, while the Coyote puts the squeeze on things with 11.0:1 compression. This is significant because compression is a fundamental aspect of power production. The whole idea in a piston engine is to build cylinder pressure, and higher compression puts more oomph into the power stroke."
Agreed! The easiest way to increase an Internal Combustion (IC) engine overall efficiency to to increase Compression Ratio (CR). You want high combustion pressures for high density power output. But there are limits. Why don't we run 15:1 or 20:1 CR pistons in IC engines? Because the fuels available will not prevent detonation at these high compression pressures and the engine will soon fail. Or the knock detectors will retard spark as much as available to prevent detonation and thus compromise the whole reason for running a high CR.
Ford engineers designed the 5.4 for forced induction and used a CR of 8.4:1. The Coyote engine was designed as a Normally Aspirated (NA) engine and uses a CR of 11:1. Why do you think the engineers did that? Although not privy to the Ford design data, I would think the BMEP of both engines is probably quite close. And Ford has to give the consumer a product which will last a reasonable amount of time. We as vehicle purchasers would not be too pleased if our engines gave us these tremendous amounts of peak horsepower but the engine blows up in 50 miles.
The Coyote has the advantage of variable cam timing. Guess what? Dynamic compression ratio can be altered as necessary, a luxury the 5.4 does not enjoy.
KB may be able to put a blower atop an engine designed for NA and report tremendous power. This certainly can (and has) been done. What type of warranty comes with the blown Coyote? You get what you pay for. High power can be obtained. The trade off is engine life. If you are willing to accept (and pay for) increased engine failures, go for it.
How much engine life are we "giving up"?
My PJ wasn't "designed" for a blower either (higher compression na) yet it makes good power (10.80's @ 128) and is at 20k miles now. A strong bottom end and a good tune go a LONG way.
Interestingly in the short testing period KB did on the blown 5.0, they experienced detrimental crankshaft harmonics which led to catastrophic oil pump failure. From the article,
"There is no 18 psi of boost run for the 5.0 because the two times the test car was tuned up that far, it blew up its oil pump. Yes, the oil pump. This happened because to get past 15 pounds of boost, a larger crankshaft pulley is needed, which means changing the integral harmonic dampener. Something in the aftermarket dampener and the oil pump didn’t get along, resulting in a shattered inner oil pump gear each time the larger aftermarket damper was tried. A stronger pump gear will soon be available to cure that problem."
This small little footnote seems to imply the crankshaft harmonic dampener had been changed ("Something in the aftermarket dampener and the oil pump didn’t get along"). The article did not indicate any engine modifications were made to the blown Coyote ("There is no new hardware involved in this story"). It is certainly reasonable to assume if internal combustion pressures are changed due to forced induction, rotating harmonics can and would be altered. Few if any non-OEM vendors have the ability to map, understand and design countermeasures for these engine dynamic considerations. If this internal mechanical problem was encountered in the short power documentation period of Coyote forced induction, what "weak-link" is next to surface?
Sorry but that's just wrong. The whole mindset of "you need low compression like 8:1 to run boost" dates back to the days of carburetors and distributors when precise timing and mixture control was impossible. I remember back in the day when people were saying you couldn't run more than 9.5:1 even NA on unleaded gas. Nowadays we have NA cars running over 11:1 all the time. People are running blowers on 11 GT's (which have 11:1 comp and cast pistons) at 8-10 lbs with no problem at all. Ford even offers a warranty on the 525 HP Whipple that they sell for the '11 GT - 7 psi and 11:1 compression with cast pistons and Ford is comfortable providing a warranty for it. Think about that for a second, and tell me why the same exact motor with FORGED pistons and rods suddenly is a bad candidate for boost.
Last edited by PACETTR; Apr 15, 2011 at 02:46 PM.
Just curious if anyone out there is planning on putting a supercharger on their Boss.
I know a lot of people want to preserve the value of their "rare" car or are worried about upsetting the weight balance, so most will probably just do bolt-ons if not leave it all stock.
But it seems to me the car has a lot of potential with a blower, especially a centrifugal. The '11 GT are making serious power at 8-9 lbs of boost and the Boss has better airflow and forged pistons/rods. 11:1 compression isn't that much of a problem with a blower when you have knock sensors, variable valve time to bleed off cylinder pressure, and oil squirters under the pistons.
I know a lot of people want to preserve the value of their "rare" car or are worried about upsetting the weight balance, so most will probably just do bolt-ons if not leave it all stock.
But it seems to me the car has a lot of potential with a blower, especially a centrifugal. The '11 GT are making serious power at 8-9 lbs of boost and the Boss has better airflow and forged pistons/rods. 11:1 compression isn't that much of a problem with a blower when you have knock sensors, variable valve time to bleed off cylinder pressure, and oil squirters under the pistons.
So let's see... keep the same (N/A) compression ratio, increase cylinder pressure with a blower, but pull timing, and use VCT to avoid too much pressure induced knock by keeping the valves open a tad.
And you gained what in the end?
Last edited by cdynaco; Apr 15, 2011 at 12:35 PM.
Well, a stock Boss 302 traps in the mid 1-teens. I will make a large wager that a blown version will trap 130+. How's that?
vmp has an 11 gt auto with 3.31's running 10.000 on stock everything. the blower is the roush tvs with a vmp tune and smaller pulley, the 5.0 can take boost no problems and the boss will take more boost with the forged internals. this car and a centri will be a qtr mile beast. i say centri because i don't think mos of us will be willing to give up the boss intake. vortec, paxton, procharger, take your pick.
i read an article in 5.0 recently about one of the tuners, i want to say lethal, was goign to movve thier 11 gt to a built motor but after umpteen 10second passes the motor and tranny were still good and they are now hunting for 9's on the stock motor. if someone else read that story correct me if i am saying the wrong company name.
FTR the only kit that really keeps the warranty is that roush 3/36 kit all the others significantly alter whatever short warranty they give you. i beleive that FRPP blower gives you the same 12/12 warranty that the 10 kits did. that voivds the normal warranty and only covers things that break if the blower is defective, if you blow the motor form too much boost or kill the tranny its on you. that is straight from FRPP told to me when i was researching blowers for my 10.
i read an article in 5.0 recently about one of the tuners, i want to say lethal, was goign to movve thier 11 gt to a built motor but after umpteen 10second passes the motor and tranny were still good and they are now hunting for 9's on the stock motor. if someone else read that story correct me if i am saying the wrong company name.
FTR the only kit that really keeps the warranty is that roush 3/36 kit all the others significantly alter whatever short warranty they give you. i beleive that FRPP blower gives you the same 12/12 warranty that the 10 kits did. that voivds the normal warranty and only covers things that break if the blower is defective, if you blow the motor form too much boost or kill the tranny its on you. that is straight from FRPP told to me when i was researching blowers for my 10.
Last edited by ShaneM; Apr 15, 2011 at 12:45 PM.
Originally Posted by cdynaco
So let's see... keep the same (N/A) compression ratio, increase cylinder pressure with a blower, but pull timing, and use VCT to avoid too much pressure induced knock by keeping the valves open a tad.
And you gained what in the end?

Apparently I didn't make my point clear. If you are pulling timing and releasing compression thru VCT doesn't that counteract the increased pressure from the blower?
Seems to me if you're going to add a blower, do it. Don't add on and then defeat it. If that means you should have a stronger bottom end and/or a change in c/r, then don't half azz it up.
Seems to me if you're going to add a blower, do it. Don't add on and then defeat it. If that means you should have a stronger bottom end and/or a change in c/r, then don't half azz it up.
Apparently I didn't make my point clear. If you are pulling timing and releasing compression thru VCT doesn't that counteract the increased pressure from the blower?
Seems to me if you're going to add a blower, do it. Don't add on and then defeat it. If that means you should have a stronger bottom end and/or a change in c/r, then don't half azz it up.
Seems to me if you're going to add a blower, do it. Don't add on and then defeat it. If that means you should have a stronger bottom end and/or a change in c/r, then don't half azz it up.
*sigh
Originally Posted by cdynaco
Apparently I didn't make my point clear. If you are pulling timing and releasing compression thru VCT doesn't that counteract the increased pressure from the blower?
Seems to me if you're going to add a blower, do it. Don't add on and then defeat it. If that means you should have a stronger bottom end and/or a change in c/r, then don't half azz it up.



