Thanks to King Lear for running some info for me! Here is some of our correspondence: 63mako
CF Senior Member





Member Since: May 2005
Location: Millington Illinois Re: Dyno Sim help

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Quote:
Originally Posted by King Lear
Quote:
Originally Posted by 63mako
much better your cam ramp rate is 2.8, going by seat to seat timing and .05 timing combined your number at 10:1 are
526hp @ 6500 rpm & 479 ft lbs @ 4500 rpm & 5000 rpm
you also reach 100% volumetric efficiency from 5000 rpm through 6500 rpm then drop below 100 VE.
-4 = 542hp @ 6500 rpm & 484 ft lbs @ 5000 rpm

If you go up to 10.2:1:
530hp @ 6000 rpm & 482 ft lbs @ 4500 rpm
-4 = 547hp @ 6500 rpm & 487 ft lbs @ 5000 rpm

10.4:1 is
535hp @ 6000 rpm & 485 ft lbs @ 4500 rpm
-4 = 551hp @ 6500 rpm & 490 ft lbs @ 5000 rpm

So there you have it, much better numbers when the actual cam seat timing is added to the equation. I flat milled my heads 3cc to 61cc to get a 9.9 CR and really don't see what everyone is so scared of. I definitely would not angle mill cause then you have to mill the intake also to match. Most heads can be flat milled 4cc until you have to worry about getting into the intake valve seating area. That is what I have read anyway. I also called RHS to make sure they could be milled this far safely. If you are going to mill them I would call AFR and see how far they can be milled within tolerances safely before issues could arise.
Enjoy,
Rich

Hi Rich. Thanks a lot! I will mill the heads .012 which will put me at 10.2 to 1. I think I will leave the cam straight up for better low end torque. The torque band is probably flatter with it straight up also. I do have the AFR rev kit but hate to push the RPM to get power or I would have went solid roller. My tripower will give me a lot of midrange power as well. I got a 150 nitrous shot too so that will be plenty. The VE helps a lot with nitrous also. That is why I went with the 114 LSA. Less overlap for better efficiency. Might pull close to 700 HP with the NOS. Not bad for 383, 10.2 to 1, hydraulic roller with moderate lift and 190 heads! Kevin

I just put the 150 lbs nitrous shot on you figures at 10.2 straight up and here, WOW!:
693HP @ 6500 Rpm @ 656 ft lbs @ 4500, 679 ft lbs @ 3000 rpm. In the 63, I think that will be plenty. I might actually have too look at that myself, although I will have to get a new TC. Rich :

 

679 FT LBS @ 3000!! WOW!! So much for having to have 454 CI, 220 CC heads, a solid roller and run it to 7500 RPM's to generate big power. Can't wait to get this thing on the dyno for real. Sounds like a Tom's differential is in my future $$$. Thanks for all your help![/quote]

No problem, your welcome, let me know when you get it dyno'd how close it is too what the CC dyno figured,
Rich

 

I have a neighbor with a 69 Chevelle, mostly strip and some street. 383 h-roller on a 200 hp shot. Very consistent 10.2 quarters @135 mph. He told me that he might have right at 700 hp on the bottle according to drag simulations for his weight/tranny/gearing/slick size. His car really goes through the twin bottles and separate fuel cell with VP 115 octane fuel for the spay solenoids. He has an impressive amount of electronics and delay boxes.

Someone here on the forum did a really nice cost analysis of bottle rockets vs just getting a supercharger. It didn’t really matter which type of super charger you used. Centrifical, Roots or Whipple. Carbed or injected. They were all cheaper than N2O within a couple of years.

The real difference between N2o and any other method is full time power.


Around here it is something like $35 for a fill on a big bottle. That just has to suck owning several bottles just to make it through a race day.

 

I will be running N/A on the street almost all of the time. The bottle is a once in a while thing. This is not a race car but a dedicated street machine that will not be cut up to install the required NHRA mods needed to race in the class I would be in. That said over 500 HP and almost the same torque with a Fully forged, roller 383, 10.2 to 1 compression, .520 .540 lift hydraulic roller with 190 heads should be responsive, dependable and long lived on the street. I won't be beating my motor and drivetrain up the whole time I am driving like a supercharger would. If I do want to go, it's just a flip of the switch and I should be at close to 700 HP with a relatively mild 150 shot. This is the goal I was hoping to achieve, dependability, longevity and power when I want it. It will work for me and still fit under the hood. EDIT: If I was building this as a race car I would have bumped the compression, went with a solid roller, bigger heads, more cubic inches and the tripower would not have been my choice of carburation.

 

Is your tri-power the new demon unit?

 

No. They won't feed enough CFM. I built it. It is 3- 378 CFM Large base rochesters with a custom plate nitrous system and split single plane Offenhauser 360 degree intake. Total adjusted CFM 816. Here are pictures with the nitrous system installed:

 

Will do. You will be notified and dyno results will be posted!

 

That set up looks sharp

 

Thanks Rich. Just hope it performs as expected! Thanks again for the info.

 

bitchin

 

Well, if it don't go it will look good when it gets there.

 

Very cool setup!

 

Actually according to the desktop dyno it says you are hitting 840 ft lbs at 1500 rpms if you are hitting the Nitrous already. It drops from there progressively to 560 ft lbs at 6500 rpms. I am real curious after you get it dyno'd to see how accurate these numbers are!
Rich