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True Hotrodder
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Discussion Starter · #1 ·
I have a copy of Dyno 5 Sim which has really helped me to figure out some parts selection for my engines. Like any software package the more I use it the better I get at figuring out how to operate it and get the most out of it. I've gotten to where I have a couple of my personal engines mapped in now and it's interesting that the correlation between the software and real dyno numbers is incredibly close.

Beyond that, the cost effectiveness can't be beat. We can all figure that going from a 1.5 rocker on a SBC to a 1.6 is going to help power production, but without spending a penny for parts I can tell you what you should expect switching all of the rockers to a 1.6 ratio, what switching just the intakes will do and the same with just changing the exhausts. Will moving from that 750 CFM carb to a 850 unit be worth the cost? What about a different timing curve or running 42 degrees instead of 36 degree total. I can make these changes, run the simulation and know whether that took the engine in the direction I want to go with it or not. And of course lets not forget the heart of an engine - the camshaft. Should I go with that much bigger cam or would I be better off just increasing the exhaust lift on the stick I have now. There's so many options to think about plus if you're building a new engine, inputting the known specifications can generate a list of camshafts that will work with the components you are using and put the power and torque curve where you want it.

A big part of this software package has simply been learning how to use it and as I mentioned I am still learning something almost every time I sit down with it. And like anything else, the more precise you can be with the entered information, the better the results outputted will be.

I am currently looking at getting Dyno 6 Sim which is a huge step up but also comes with a rather substantial price tag. It also has an entirely new range of information that you can input giving you even better results however I think some of those inputs might be outside the scope of a typical hot rodder simply due to the information gathering tools you need for it. But here's hoping that Santa might just help me out this year!

So what I would like to do is offer this service to my HotRodders friends here.

If you're interested, there is a list of information that I would need about the engine in question and again, the more precise your responses are the closer the program can get to providing realistic numbers. Also, this is something that I do in my spare time - and I mean spare time. If you send me information expecting numbers the following day - that's probably not going to happen, but I am not putting you off for weeks on end either. So, if you can work with that limitation, I will be glad to help you out.

Send me a PM (conversation) and I will forward you the list of information needed to perform a Dyno Simulation run on your engine combination. You'll also be able to tell me what you goals are and what parts you would consider changing.
 

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I have a copy of Dyno 5 Sim which has really helped me to figure out some parts selection for my engines. Like any software package the more I use it the better I get at figuring out how to operate it and get the most out of it. I've gotten to where I have a couple of my personal engines mapped in now and it's interesting that the correlation between the software and real dyno numbers is incredibly close.

Beyond that, the cost effectiveness can't be beat. We can all figure that going from a 1.5 rocker on a SBC to a 1.6 is going to help power production, but without spending a penny for parts I can tell you what you should expect switching all of the rockers to a 1.6 ratio, what switching just the intakes will do and the same with just changing the exhausts. Will moving from that 750 CFM carb to a 850 unit be worth the cost? What about a different timing curve or running 42 degrees instead of 36 degree total. I can make these changes, run the simulation and know whether that took the engine in the direction I want to go with it or not. And of course lets not forget the heart of an engine - the camshaft. Should I go with that much bigger cam or would I be better off just increasing the exhaust lift on the stick I have now. There's so many options to think about plus if you're building a new engine, inputting the known specifications can generate a list of camshafts that will work with the components you are using and put the power and torque curve where you want it.

A big part of this software package has simply been learning how to use it and as I mentioned I am still learning something almost every time I sit down with it. And like anything else, the more precise you can be with the entered information, the better the results outputted will be.

I am currently looking at getting Dyno 6 Sim which is a huge step up but also comes with a rather substantial price tag. It also has an entirely new range of information that you can input giving you even better results however I think some of those inputs might be outside the scope of a typical hot rodder simply due to the information gathering tools you need for it. But here's hoping that Santa might just help me out this year!

So what I would like to do is offer this service to my HotRodders friends here.

If you're interested, there is a list of information that I would need about the engine in question and again, the more precise your responses are the closer the program can get to providing realistic numbers. Also, this is something that I do in my spare time - and I mean spare time. If you send me information expecting numbers the following day - that's probably not going to happen, but I am not putting you off for weeks on end either. So, if you can work with that limitation, I will be glad to help you out.

Send me a PM (conversation) and I will forward you the list of information needed to perform a Dyno Simulation run on your engine combination. You'll also be able to tell me what you goals are and what parts you would consider changing.
I happen to have the dynosim6 software. This is good software but the numbers produced seem to be incredibly conservative. My experience has been that the dynosim5 software spits out more realistic numbers. I ran a 489 BBC through both sims and the dynosim6 software was like a hundred lbft lower than what can be expected from such a build. I couldn't even break the 500 horsepower mark with it. Same engine run through the dynosim5 software put both numbers north of the 500 mark. Just some food for thought.
 

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True Hotrodder
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Discussion Starter · #3 ·
I happen to have the dynosim6 software. This is good software but the numbers produced seem to be incredibly conservative. My experience has been that the dynosim5 software spits out more realistic numbers. I ran a 489 BBC through both sims and the dynosim6 software was like a hundred lbft lower than what can be expected from such a build. I couldn't even break the 500 horsepower mark with it. Same engine run through the dynosim5 software put both numbers north of the 500 mark. Just some food for thought.
That's really interesting and you might have just saved me a few dollars! I was looking through the new additions to the software and it appeared that with the ability to "tighten up" the specs somewhat it would be a better, more refined output. But there could be a programming error too - are you running the latest and greatest version? You would think that some high end builders would be bringing it to the designers' attention being that far off on prediction outputs.
 

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That's really interesting and you might have just saved me a few dollars! I was looking through the new additions to the software and it appeared that with the ability to "tighten up" the specs somewhat it would be a better, more refined output. But there could be a programming error too - are you running the latest and greatest version? You would think that some high end builders would be bringing it to the designers' attention being that far off on prediction outputs.
I found some errors in my inputs between the two simulations, so here's the actual data between the two programs:
engine is a 489 BBC with Brodix racerite ovals. 10.3 to one comp, and large tube headers. Howards hydraulic roller 282/288, 229/235 @ .050 and .589/.601 lift. 108* LSA with ICL @ 104*. Dual plane intake and 950 carb.

Dynosim5
606 ft/lbs @2500rpms
487 hp @5000rpms

Dynosim6
555 ft/lbs @4000rpms
464 hp @5000rpms

I double checked that all the data I entered on both programs was the same and this is what I got. Torque has a pretty serious difference in both numbers and rpms.
Thoughts?
 

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True Hotrodder
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Discussion Starter · #5 ·
I must be off somewhere.

I have max HP at 529 @ 5000
TQ 647 @ 2500
Ignition timing runs from 26.9 @ 1000 to 39.4 @ 5000

Can you give me the cam part# or the intake/exhaust open/close numbers?

And I put this in at 10.3 but that shows a 103.2 chamber, I show those heads have 119 - have they been cut? If not that puts compression down to 9.1 but the engine doesn't lose that much. 510 HP @ 5000, 632 TQ @ 2500.
 

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I must be off somewhere.

I have max HP at 529 @ 5000
TQ 647 @ 2500
Ignition timing runs from 26.9 @ 1000 to 39.4 @ 5000

Can you give me the cam part# or the intake/exhaust open/close numbers?

And I put this in at 10.3 but that shows a 103.2 chamber, I show those heads have 119 - have they been cut? If not that puts compression down to 9.1 but the engine doesn't lose that much. 510 HP @ 5000, 632 TQ @ 2500.
Wow! One of us is off somewhere. The cam part # is 120325-08. It's a Howards hydraulic roller. The heads are not cut. The pistons have a 23cc dome on them and will be .005" in the hole. One thing I forgot about was for the environment, I used 77*, 1000 feet above sea level and 50% humidity instead of the standard correction factor. With the correction factor I was about dead on with your numbers, but with the dynosim6 program max torque was 603 @ 3750rpms and 497hp @5000rpms with the correction factor. I just can't understand why there is such an rpm difference for the torque between the two programs. And yes, I check for the latest updates every month.
Now in dynosim6's defense, They do warn that the numbers my seem more conservative but are more accurate and representative of what the engines will actually produce. I guess with the correction factor used with both programs 32hp difference isn't earth shattering. But the torque rpm difference is significant. The only way for me to get to the bottom of which simulator is more accurate is to have my engine dynoed once it is finally built.

I do have to say that 647 ftlbs @2500 rpms seems awfully optimistic. If however this proves accurate, then I screwed up and it's gonna get real expensive setting up the suspension in order to put that torque to the ground.
 

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Rod...from a Chrysler?
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It would take a seriously mild cam to get the torque so high at so low of an RPM.
That's something I'll be shooting for on my 496.
I have Engine Analyzer and was getting results like that until I changed a setting and the RPM's came up after that, similar to what Eric mentioned above.
 

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True Hotrodder
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Discussion Starter · #9 ·
These particular programs work best if you are putting in the intake/exhaust - open/close points. Not doing that and letting the program "figure it out" from @.050 settings and LCA gives some strange results. Now that I have the cam # it'll probably bring it inline. I'm not surprised too much at the lower RPM area - this cam for a BBC that size is on the mild side and the 108* LCA pushes the power curve to the lower range.

Heading to my daughter's for Thanksgiving - I'll work on it more tomorrow.

Hope everyone has a good Thanksgiving Holiday!
 

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I was going to say the 647 ft lbs @ 2500 rpm is no way, even 606 ft lbs is way optimistic for that low rpm.

Sure 600-ish ft lbs @ 4500 ish rpm , I could believe that.
Eric, I'm glad you chimed in here. Given your vast experience, with me running those Brodix heads with a 270cc runner and the cam I picked wouldn't peak torque come in at or below 4000rpms? And what about the horsepower, does 500ish seem about right at 5000rpms given the parameters? I know it's all spit balling at this point, and there's no real substitute for real dyno figures, but I have seen many 454 builds on actual dynos give way more horsepower and around 550 ftlbs or better. And, it's done on 781 heads. The none part I have not bought yet is the cam due to core shortages so is more cam the way to go, or are the heads the limiting factor?
 

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These particular programs work best if you are putting in the intake/exhaust - open/close points. Not doing that and letting the program "figure it out" from @.050 settings and LCA gives some strange results. Now that I have the cam # it'll probably bring it inline. I'm not surprised too much at the lower RPM area - this cam for a BBC that size is on the mild side and the 108* LCA pushes the power curve to the lower range.

Heading to my daughter's for Thanksgiving - I'll work on it more tomorrow.

Hope everyone has a good Thanksgiving Holiday!
I have always used the advertised and .050" numbers and lsa along with icl and let the program figure it out. I'll ask you the same thing I asked Eric, should I use more cam or are the heads the limiting factor? This is going in a 1980 Elcamino with a ford9 and 3.25 gear. I want the car to be a nice streetable pleasure to drive at 40mph as well as on the interstate. It has a turbo 400 in it and I'm not interested in an overdrive at this time.
 

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More for Less Racer
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229°/235° @ .050" is not going to have a 2500 rpm torque peak in a 489" BBC.
I would expect probably 3800 at the lowest but would be surprised at that, I would expect 4200-4400 rpm peak actually.

It's just not moving enough air to have a 2500 rpm torque peak with pump gas and low compression.
if you could feed it high enough octane gasoline and jack the compression ratio up to 17-1 then you might get that 2500 rpm torque peak....did anyone say Deisel?? LOL

You're at the point that the cam is limiting horsepower, but going bigger sacrifices street manners in trade for the higher rpm HP.
The heads could get you to 750HP with enough cam if you wanted to be rowdy
 

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229°/235° @ .050" is not going to have a 2500 rpm torque peak in a 489" BBC.
I would expect probably 3800 at the lowest but would be surprised at that, I would expect 4200-4400 rpm peak actually.

It's just not moving enough air to have a 2500 rpm torque peak with pump gas and low compression.
if you could feed it high enough octane gasoline and jack the compression ratio up to 17-1 then you might get that 2500 rpm torque peak....did anyone say Deisel?? LOL

You're at the point that the cam is limiting horsepower, but going bigger sacrifices street manners in trade for the higher rpm HP.
The heads could get you to 750HP with enough cam if you wanted to be rowdy
Okay, good to know. The software, (dynosim6) says just under 500 horsepower. It shows torque dropping off fairly quick after peak. This seems low to me. I know the cam is the limiting factor but I thought sure it would be north of 500hp. Would I be better off with a 110 LSA over 108, or no big difference?
 

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Apparently Howards does not provide the specs on their website. I will try to give them a call tomorrow and see if I can get them.
Here's what I have:
282/288 advertised
229/235 @0.050"
108 LSA
106 ICL
advertised @ valve
IVO 35*/IVC 67*
EVO 74*/EVC 34*
@ 0.050" At lobe
IVO 8.5*/IVC 40.5*
EVO 47.5*/EVC 7.5*

Using dynosim6 standard atmospheric conditions I get 575ftlbs @4000rpms and 480hp @5000rpms.
Horsepower seems low to me.
 

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True Hotrodder
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Discussion Starter · #16 ·
The program is giving me the same I/E numbers.

Dealing with Flu right now, wife is really sick.

I tried to call Howards the other day but it just kept ringing.

Cam choices are always a compromise - on this one, I think a touch more cam would help it and the cubic inches could cover a bit of the bottom end without a lot of fuss. It will take some sharp tuning to be happy.
 
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