How much HP difference between single plane and dual plane intake??
10-27-2011, 08:13 PM
#21
Safety Car
Thread Starter
Hey I didn't say that you were a dumb ***. Because I have no idea what size your head ports are or even your specific intake. I was refering to people who have big heads and tiny dual planes and think that they will achive some magical low end tq. or little heads and a super big single plane
I do stand by the bogus desk top dyno 500 foot pounds at 2000 rpm figure. You can't apply 500 foot pound of resistance to a little 383 motor at 2000 rpm on a dyno. It would stop the motor. Look at Motor Heads dyno sheets. You have to do a few practise runs on each motor and get a feel for when it can start going (rpm) to take full throttle and where to start on the initial load and how fast you can bring in full load.
So look at his run #2 dyno guy started the test at something just over 2600 rpm and it ran fine. Then over a 40 days later and the intake change he was running the throttle on #4 and loading the motor to a balance of about 260 some foot pounds started the recorder, WOT, and fed in a higher load factor when the rpm came up
See the TQ wiggle at the start of 4 on the tq? The motor hesitated going to wot under only 260 foot pounds of load and low 2000 rpm. Going from 355 to 383 is worth about something less than 40 foot pounds.
You floor your 383 next week when you get it running and the TC will flash to something over 2400 rpm anyway and it will bring a smile to your face even if it didn't have what DD said anyway
I do stand by the bogus desk top dyno 500 foot pounds at 2000 rpm figure. You can't apply 500 foot pound of resistance to a little 383 motor at 2000 rpm on a dyno. It would stop the motor. Look at Motor Heads dyno sheets. You have to do a few practise runs on each motor and get a feel for when it can start going (rpm) to take full throttle and where to start on the initial load and how fast you can bring in full load.
So look at his run #2 dyno guy started the test at something just over 2600 rpm and it ran fine. Then over a 40 days later and the intake change he was running the throttle on #4 and loading the motor to a balance of about 260 some foot pounds started the recorder, WOT, and fed in a higher load factor when the rpm came up
See the TQ wiggle at the start of 4 on the tq? The motor hesitated going to wot under only 260 foot pounds of load and low 2000 rpm. Going from 355 to 383 is worth about something less than 40 foot pounds.
You floor your 383 next week when you get it running and the TC will flash to something over 2400 rpm anyway and it will bring a smile to your face even if it didn't have what DD said anyway
10-28-2011, 01:35 AM
#22
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Once again instead of listening to old wives tales I compared a Vic Jr to RPM Air Gap on the same motor. The motor was a 400HP or so 350ci and the Vic Jr made more HP and it made more TQ another misleading "fact" that never seems to go away.
I believe what fools people is that if you have some crappy smogmobile the Tq is going to be higher than the HP. Once you get a properly set up motor you should be making more HP and that is just what it is, more power, your HP doesn't go up and you Tq goes down, just the opposite your HP goes up and your Tq goes up, how can it not you are making more power.
Sometimes things get ingrained into people that it takes years before the overall opinion changes. This was my 355ci I had in my Vette 10 years ago and I purposely put on all the parts everyone at the time said wouldn't work on the street. The car ran great on the street even with the 3.08 rear end.
I put on a Holley 750 DP mechanical secondaries, Vic Jr single plane, solid lifter cam etc. Now it seems these parts are being more widely acceptable and more the norm than not.
RPM Air Gap
Vic Jr
I believe what fools people is that if you have some crappy smogmobile the Tq is going to be higher than the HP. Once you get a properly set up motor you should be making more HP and that is just what it is, more power, your HP doesn't go up and you Tq goes down, just the opposite your HP goes up and your Tq goes up, how can it not you are making more power.
Sometimes things get ingrained into people that it takes years before the overall opinion changes. This was my 355ci I had in my Vette 10 years ago and I purposely put on all the parts everyone at the time said wouldn't work on the street. The car ran great on the street even with the 3.08 rear end.
I put on a Holley 750 DP mechanical secondaries, Vic Jr single plane, solid lifter cam etc. Now it seems these parts are being more widely acceptable and more the norm than not.
RPM Air Gap
Vic Jr
10-28-2011, 10:45 AM
#24
Race Director
Dyno operator said my 406ci and my 427ci felt like he could go full throttle at 2000RPM's. He actually started this chassis pull at about 1800RPM with my 427ci. It's all in way you match parts, match them correctly and it shouldn't bog at 2000RPM, can't lay my hands on the 406ci chassis dyno but it started at ~2000RPM too.
I even had the Vic Jr intake port matched to the AFR 227 heads by AFR, they did a good job as on the flow bench there was only a 3% loss with the intake bolted to the head.
I even had the Vic Jr intake port matched to the AFR 227 heads by AFR, they did a good job as on the flow bench there was only a 3% loss with the intake bolted to the head.
10-28-2011, 10:50 AM
#25
Race Director
The reason for the different starting points was because most dyno operators know a motor will bog if you start to low, most of them start at 2500-3000RPM's to avoid this.
Last edited by MotorHead; 10-28-2011 at 10:52 AM.
10-28-2011, 10:53 AM
#26
Safety Car
Thread Starter
FYI:
Have a look at this http://www.youtube.com/watch?v=i2DvnoHWagk
Have a look at this http://www.youtube.com/watch?v=i2DvnoHWagk
Last edited by MakoShark72; 10-28-2011 at 10:55 AM.
10-28-2011, 11:16 AM
#27
Team Owner
Again we have to talk Apples and Apples. You have a solid roller cam and the post has a 230/236 H-Flat cam. Sollid rollers have a higher vacuum, smoother idle, and more TQ at lower rpm.
11-02-2011, 03:15 PM
#28
Race Director
MotorHead, See that little TQ dip right over 2000 rpm? I suspect that was when the squiters hit going WOT.
Again we have to talk Apples and Apples. You have a solid roller cam and the post has a 230/236 H-Flat cam. Sollid rollers have a higher vacuum, smoother idle, and more TQ at lower rpm.
Again we have to talk Apples and Apples. You have a solid roller cam and the post has a 230/236 H-Flat cam. Sollid rollers have a higher vacuum, smoother idle, and more TQ at lower rpm.
11-02-2011, 04:00 PM
#29
Melting Slicks
Once again instead of listening to old wives tales I compared a Vic Jr to RPM Air Gap on the same motor. The motor was a 400HP or so 350ci and the Vic Jr made more HP and it made more TQ another misleading "fact" that never seems to go away.
I believe what fools people is that if you have some crappy smogmobile the Tq is going to be higher than the HP. Once you get a properly set up motor you should be making more HP and that is just what it is, more power, your HP doesn't go up and you Tq goes down, just the opposite your HP goes up and your Tq goes up, how can it not you are making more power.
Sometimes things get ingrained into people that it takes years before the overall opinion changes. This was my 355ci I had in my Vette 10 years ago and I purposely put on all the parts everyone at the time said wouldn't work on the street. The car ran great on the street even with the 3.08 rear end.
I put on a Holley 750 DP mechanical secondaries, Vic Jr single plane, solid lifter cam etc. Now it seems these parts are being more widely acceptable and more the norm than not.
RPM Air Gap
Vic Jr
I believe what fools people is that if you have some crappy smogmobile the Tq is going to be higher than the HP. Once you get a properly set up motor you should be making more HP and that is just what it is, more power, your HP doesn't go up and you Tq goes down, just the opposite your HP goes up and your Tq goes up, how can it not you are making more power.
Sometimes things get ingrained into people that it takes years before the overall opinion changes. This was my 355ci I had in my Vette 10 years ago and I purposely put on all the parts everyone at the time said wouldn't work on the street. The car ran great on the street even with the 3.08 rear end.
I put on a Holley 750 DP mechanical secondaries, Vic Jr single plane, solid lifter cam etc. Now it seems these parts are being more widely acceptable and more the norm than not.
RPM Air Gap
Vic Jr
