Moderator: Mod Squad
clintonvillian wrote:My calculator says i need 9 psi to move 409 cfm to reach 300hp.
Which head did you start with and who did the port work?Broncitis wrote:I would say 230/175 at .600 n/a is pretty far up there and it cost me plenty, but the performance is incredible.
Broncitis wrote:I would say 230/175 at .600 n/a is pretty far up there and it cost me plenty, but the performance is incredible.
pmuller9 wrote:clintonvillian wrote:My calculator says i need 9 psi to move 409 cfm to reach 300hp.
Yes, that's 409 cfm going into the intake of the S/C but the pressure ratio at 9 psi is 1.6.
The actual flow going out the S/C and into the engine is 409/1.6 or 255 cfm.
clintonvillian wrote:Do you all have any info / calculators / calculations for the effect of boost on torque? All I can find is HP stuff, and I could really care less about HP for this build.........I want the grunt!
StrangeRanger wrote:Ford gives 2 data points for the 300: 260 ft-lbs @ 2000 RPM and 150HP @ 3400 RPM
Because HP = T x RPM / 5252 you can calculate HP at 200 (99 HP) and the torque @ 3400 (232 ft-lbs.)
Plugging into pmuller9's equation VE = (9411 x HP x BSFC)/(CID x RPM)
VE @ 2000 = 77%
VE @ 3400 = 69%
His equation can also be re-written so it can be used be used to calculate VE from torque values since HP/RPM times a constant is torque
VE = 1.792 x T x BSFC / CID
From this version you can see that the VE curve will have the same shape as the torque.
clintonvillian wrote:OK couple of setup questions............
My goal was to have a high torque value around 1500-1700 rpms for highway speeds. (2.73 rear, .063 OD). That way there would be enough torque to push it down the highway without having to downshift for slight grades. I am thinking that 3500-4500 is strictly the fun range, won't be seen a lot.
Based on that calculator and different configurations, at 1500 rpms and 5 psi I am around 330 ftlbs, is that enough to push it down the road without having to downshift at every slight grade (3500 lb vehicle, poor areo, and 30" tires??
I see that you were definitely right now, 2:1 on that compressor is more than sufficient to reach the boost levels I want and will still require a wastegate at anything above 3000 rpms to keep it at 10 psi. Question is, can I run that off of my 6V belt and pulley on the harmonic balancer that is also running the AC, Alternator, PS pump, without slippage without breaking or stretching the belt? I mean I wouldn't mind changing it every 10k miles or so, just don't want it to be an every other day thing.
Broncitis wrote:My head was a 240 done by jerry Arnold, it cost me almost 1200 bucks less the rockers, I have a magnuson m112 direct mount carb or throttle body supercharger brand new, I think it is a good match for the 300, I see all the jumping around with the #'s that drives me a little crazy, in the real world I would choose a boost as a target with my build with the blower pulley being in the approximate middle, then you can move up are down to get it on spot without all the brainiacing, I nailed my m90 at 10 and 6 psi with pulleys the first time 3.4 and 3.8 respectively for the 200, but its not always the case, its not all that complicated.
clintonvillian wrote:Interesting that you mentioned edis and sequential fuel injection. Megasquirt states that it needs a cam position sensor, and not the crank........ im not sure that would matter since ours is gear driven??
Mine is an efi engine and uses tfi, megasquirt will run that system, i am just not sure it is as accurate as edis? If i were to rum tfi it would eliminate the need for a trigger wheel and still have a seperate coil pack.
I am also debating going to an enginequest head. I have a brand new 240 head on a shelf i had considered using but may sell now, and of course the stock efi head. I figure selling my heads, and the install of hardened seats would offset the cost of a new head.
clintonvillian wrote:I have not purchased the system yet.
Is the edis better than the tfi, will the tfi support sequential injection?
Engine quest head was aroumd 500-600 depending on shipping. Hmm i wonder if the hardened seats have enough material to cut the larger valvea in?
Hmm i wonder if the hardened seats have enough material to cut the larger valvea in?
clintonvillian wrote: Hmm i wonder if the hardened seats have enough material to cut the larger valve in?
clintonvillian wrote:Outta curiosity how come you ordered custom piatons for the students 300 since its not being boosted?
Users browsing this forum: No registered users and 3 guests