Hp?
Hp?
OK so i was wondering what is the most HP you can gain from your 8 with it still be practical...
I'm talking just the basic stuff
like how much can you gain from intake ,exhaust and maby some other stuff.
and who has the most horsepower on this forum or fastest track time, etc...
I'm trying to get a check list going of what i will be buying performance wise...
so far i have
(any suggestions would be helpful)
1. Cobb tuner
2. intake
3. exhaust (don't know what brand i don't want a rice pipe)
I'm talking just the basic stuff
like how much can you gain from intake ,exhaust and maby some other stuff.
and who has the most horsepower on this forum or fastest track time, etc...
I'm trying to get a check list going of what i will be buying performance wise...
so far i have
(any suggestions would be helpful)
1. Cobb tuner
2. intake
3. exhaust (don't know what brand i don't want a rice pipe)
Not much.
Assume you have 100% VE in all RPM's (basically impossible; but assume you have the perfect NA engine) then do this math :
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
80 cu in * 9000 / 1728 = 417 CFM
VFRactual = (VFR100%)(VE) assume 417 still for best case
MFR = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR = 31 lb min air at 80 degrees F.
Horsepower = (MFR)(60)/(A/F Ratio)(BSFC) = about 248 Crank HP at 9000 RPM with a BSFC of .60 and an AFR of 12.5.
So the best you could ever do (theoretically) is 248-ish; and if you get 232 stock.... you figure it out.
Assume you have 100% VE in all RPM's (basically impossible; but assume you have the perfect NA engine) then do this math :
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
80 cu in * 9000 / 1728 = 417 CFM
VFRactual = (VFR100%)(VE) assume 417 still for best case
MFR = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR = 31 lb min air at 80 degrees F.
Horsepower = (MFR)(60)/(A/F Ratio)(BSFC) = about 248 Crank HP at 9000 RPM with a BSFC of .60 and an AFR of 12.5.
So the best you could ever do (theoretically) is 248-ish; and if you get 232 stock.... you figure it out.

I did a poor *** job on the 3071R clip (went from 47 mph to 75 then back down to 45), but this should give you an idea:
http://youtube.com/watch?v=a0RSPGoHgbw
Last edited by mysql; Jul 13, 2008 at 03:43 PM.
^ I think you linked to the wrong one. This clip is much better:
http://youtube.com/watch?v=GQ2myuLL480
http://youtube.com/watch?v=GQ2myuLL480
Not much.
Assume you have 100% VE in all RPM's (basically impossible; but assume you have the perfect NA engine) then do this math :
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
80 cu in * 9000 / 1728 = 417 CFM
VFRactual = (VFR100%)(VE) assume 417 still for best case
MFR = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR = 31 lb min air at 80 degrees F.
Horsepower = (MFR)(60)/(A/F Ratio)(BSFC) = about 248 Crank HP at 9000 RPM with a BSFC of .60 and an AFR of 12.5.
So the best you could ever do (theoretically) is 248-ish; and if you get 232 stock.... you figure it out.
Assume you have 100% VE in all RPM's (basically impossible; but assume you have the perfect NA engine) then do this math :
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
80 cu in * 9000 / 1728 = 417 CFM
VFRactual = (VFR100%)(VE) assume 417 still for best case
MFR = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR = 31 lb min air at 80 degrees F.
Horsepower = (MFR)(60)/(A/F Ratio)(BSFC) = about 248 Crank HP at 9000 RPM with a BSFC of .60 and an AFR of 12.5.
So the best you could ever do (theoretically) is 248-ish; and if you get 232 stock.... you figure it out.
Then how did TeamRx8 gain almost 40hp NA with a cat?
Assuming a VE of 100% - which at 9000 RPM I am SURE you will not have.
So if you move from a VE of 60% to a VE of 65% (with your mods); then you will have more power; then you have to factor in drive train losses ( don't forget loss of unsprung weight; etc) - all kinds of stuff to get your Wheel HP number..... but the only way to get to that level of detail is a lot of dyno time.
So if you move from a VE of 60% to a VE of 65% (with your mods); then you will have more power; then you have to factor in drive train losses ( don't forget loss of unsprung weight; etc) - all kinds of stuff to get your Wheel HP number..... but the only way to get to that level of detail is a lot of dyno time.
Last edited by Kane; Jul 13, 2008 at 04:59 PM.
hmmm... intresting
i will probably go turbo... one day... haha
iv seen a lot of videos on youtube of turbo rx8's im just trying to figure out the max hp i could get out of an rx8...
any one know how far the tuning limits go as far as N/A...?
i will probably go turbo... one day... haha
iv seen a lot of videos on youtube of turbo rx8's im just trying to figure out the max hp i could get out of an rx8...
any one know how far the tuning limits go as far as N/A...?
Not much.
Assume you have 100% VE in all RPM's (basically impossible; but assume you have the perfect NA engine) then do this math :
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
80 cu in * 9000 / 1728 = 417 CFM
VFRactual = (VFR100%)(VE) assume 417 still for best case
MFR = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR = 31 lb min air at 80 degrees F.
Horsepower = (MFR)(60)/(A/F Ratio)(BSFC) = about 248 Crank HP at 9000 RPM with a BSFC of .60 and an AFR of 12.5.
So the best you could ever do (theoretically) is 248-ish; and if you get 232 stock.... you figure it out.
Assume you have 100% VE in all RPM's (basically impossible; but assume you have the perfect NA engine) then do this math :
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
80 cu in * 9000 / 1728 = 417 CFM
VFRactual = (VFR100%)(VE) assume 417 still for best case
MFR = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR = 31 lb min air at 80 degrees F.
Horsepower = (MFR)(60)/(A/F Ratio)(BSFC) = about 248 Crank HP at 9000 RPM with a BSFC of .60 and an AFR of 12.5.
So the best you could ever do (theoretically) is 248-ish; and if you get 232 stock.... you figure it out.
i think i just had a seizure



