raising compression ratio
#1
raising compression ratio
Ok, I've got a 04 F250 V10 6sp with 78,230 miles. I want more simple, all the time power and I want it to be worth the money. I'm not looking for a huge increase, just around 40 hp and maybe 60 flbs. If I were to bump compression to 11.2:1 and throw in stage II cams, What could I expect in terms of power and driveability? How much of a difference would it really make? Fuel wouldn't be an issue as I ONLY run 92+ anyway....
It has a K&N filter and intake, duals exauhst, 8" pro comp lift, 37" Dick Cepeks, 4.88's, LS rear and spooled up front. She's a big girl
Or maybe I should ditch the cams to try and keep the power band down... IDK..... with the upped compression I'd probably have to upgrade coils too.... So?
It has a K&N filter and intake, duals exauhst, 8" pro comp lift, 37" Dick Cepeks, 4.88's, LS rear and spooled up front. She's a big girl
Or maybe I should ditch the cams to try and keep the power band down... IDK..... with the upped compression I'd probably have to upgrade coils too.... So?
#2
There are no reliable "upgraded" coils to be had.
Upping the CR that high will require more than 92+ octane fuel if you're gonna keep the OEM intake manifold on the truck. otherwise you're gonna be making a custom one-off sheetmetal intake that will not be suitable for a truck.
Good luck finding cams.
You want more power? The best thing you can do is have the PCM reprogrammed by somebody that knows what they're doing. The OEM tune is terrible.
JL
Upping the CR that high will require more than 92+ octane fuel if you're gonna keep the OEM intake manifold on the truck. otherwise you're gonna be making a custom one-off sheetmetal intake that will not be suitable for a truck.
Good luck finding cams.
You want more power? The best thing you can do is have the PCM reprogrammed by somebody that knows what they're doing. The OEM tune is terrible.
JL
#3
I have to agree fully with Johnny.
For me, with ebay headers, y-pipe and Volant CAI intake with 3.73 gears and 285/75R16 tires, using Mike's (5-star) 87 octane tune, I dropped from a 10 second 0-60 with all those goodies, down to a 9.02-9.04 0-60 time.
That's 87 octane, and the 10-second 0-60 was with the headers/y-pipe/volant before the tune.
Uploaded his 87 performance tune, and BINGO.
All times were measured with data logging (LiveLink).
For me, with ebay headers, y-pipe and Volant CAI intake with 3.73 gears and 285/75R16 tires, using Mike's (5-star) 87 octane tune, I dropped from a 10 second 0-60 with all those goodies, down to a 9.02-9.04 0-60 time.
That's 87 octane, and the 10-second 0-60 was with the headers/y-pipe/volant before the tune.
Uploaded his 87 performance tune, and BINGO.
All times were measured with data logging (LiveLink).
#4
Sounds like you need to find yourself a roots supercharger kit and get a good tune. Don't have to run much boost either to make a good amount of power. 11.2:1 is a good amount of squeeze you'd probably want to run nothing but E85 or race gas with that much compression.
Anyone tried these coils. http://www.performancedistributors.com/soscoils.htm
Anyone tried these coils. http://www.performancedistributors.com/soscoils.htm
#5
Anyone tried these coils. http://www.performancedistributors.com/soscoils.htm
Most aftermarket replacement COPs are just as good as thier crap. Raising spark voltage is useless when our engines never see over 5500 rpm.
#6
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#8
OK, let's say 9.5:1. CAMS: http://www.compcams.com/Technical/Ca...2007/pdf/3.pdf
the coil upgrade would be for higher voltage, not for high rpm accuracy.
higher voltage will bridge the plug gap easier under increased cylinder pressures. higher voltage in stock engines will allow you to run a bigger gap and hotter spark for more effiecent combustion.
Accel, MSD, MotoBlue, and Granatelli all make higher performance coils and have warantees.
A supercharger is appealing, but the mileage and high cost aren't.
Higher compression would increase effiecency without any decrease in mileage and allow me to take full advantage of always using a higher grade fuel.
the coil upgrade would be for higher voltage, not for high rpm accuracy.
higher voltage will bridge the plug gap easier under increased cylinder pressures. higher voltage in stock engines will allow you to run a bigger gap and hotter spark for more effiecent combustion.
Accel, MSD, MotoBlue, and Granatelli all make higher performance coils and have warantees.
A supercharger is appealing, but the mileage and high cost aren't.
Higher compression would increase effiecency without any decrease in mileage and allow me to take full advantage of always using a higher grade fuel.
#10
be250:
Yes, a supercharger is too much money and raising compression isn't.... A supercharger is going to cost me (from what I've seen) $4500-$5500 plus worse mileage, increased ignition and tuning maintenance (especially if you don't upgrade your ignition system), and one day down time. Through just initial and extra fuel cost alone, how much extra do you think I'll be spending on this truck during its lifetime?? Quite a bit...
Now, if you were paying attention to the content in this thread, you'd have noticed that I mentioned lowering the proposed compression ratio to 9.5 and that I ALWAYS use at least 92+ oct anyway. The cost of a full set of forged Manley 11cc dish pistons (with an end cr of 9.5:1) would cost about $850. Add new gaskets, TTY hardware, and upgraded ignition and you would be at about $1400-$1500 and about two days downtime. More real power, BETTER fuel mileage, no additional maintenance, and the chance to tear into your beast and make a true modification and not just another air intake, tune, or exuahst. I'm tired of hearing about these generic bolt-ons, aren't any of you??
Yes, a supercharger is too much money and raising compression isn't.... A supercharger is going to cost me (from what I've seen) $4500-$5500 plus worse mileage, increased ignition and tuning maintenance (especially if you don't upgrade your ignition system), and one day down time. Through just initial and extra fuel cost alone, how much extra do you think I'll be spending on this truck during its lifetime?? Quite a bit...
Now, if you were paying attention to the content in this thread, you'd have noticed that I mentioned lowering the proposed compression ratio to 9.5 and that I ALWAYS use at least 92+ oct anyway. The cost of a full set of forged Manley 11cc dish pistons (with an end cr of 9.5:1) would cost about $850. Add new gaskets, TTY hardware, and upgraded ignition and you would be at about $1400-$1500 and about two days downtime. More real power, BETTER fuel mileage, no additional maintenance, and the chance to tear into your beast and make a true modification and not just another air intake, tune, or exuahst. I'm tired of hearing about these generic bolt-ons, aren't any of you??
#12
Krewat:
When I said "More real power, BETTER fuel mileage,ect", I meant from stock. I guess I should have said "increased power, BETTER fuel mileage, ect". I am NOT trying to say that a cr bump is a better performance mod than forced induction, only that it is a better mod for ME...
SO.............. With a cr bump to 9.5:1 and an upgraded ignition (lets forget the cams),How much of a power increase could I expect? What changes in driveability might I have? And are there any good reasons as to why everyone is so close-minded to this??
When I said "More real power, BETTER fuel mileage,ect", I meant from stock. I guess I should have said "increased power, BETTER fuel mileage, ect". I am NOT trying to say that a cr bump is a better performance mod than forced induction, only that it is a better mod for ME...
SO.............. With a cr bump to 9.5:1 and an upgraded ignition (lets forget the cams),How much of a power increase could I expect? What changes in driveability might I have? And are there any good reasons as to why everyone is so close-minded to this??