Desktop Dyno Questions
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Desktop Dyno Questions
I've got the Desktop Dyno 2000 and I'm trying to figure out how to do my engine. Couple of questions in for you experienced users.
1.) Is the LT1 intake manifold a single plane, dual plane, Tuned Port, or sequential fire?
2.) How do I set the cam durations? They are whited out and I can't chang them.
1.) Is the LT1 intake manifold a single plane, dual plane, Tuned Port, or sequential fire?
2.) How do I set the cam durations? They are whited out and I can't chang them.
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Desktop Dyno Questions (mn_vette)
From playing with Desktop Dyno 2000 and 2003 I've found that you get more LT1 like Dyno curves from selecting single plane intake manifold rather than sequential fire. This is because an LT1 manifold shares similarities with a carbed single plane i.e. short high flowing runners on a common open plenum. One or the other would work, but to me the single plane looks more accurate, and the LT1 is definitely not TPI or dual plane.
You can set up the cam either of two ways open up a "cam file" from selecting "cam file" in the camshaft section and choose "open" by clicking on the drop down menu with the "down arrow" on it. Then find where your cam files are.
Or on the top on the screen you will the menu item "Tools" click on that and open up "Cam Math" Or there is a shortcut button on the second row that looks like a camshaft and a "+" sign. There enter in all the cam specs in "advertised duration" which is the same as "seat to seat"
You can set up the cam either of two ways open up a "cam file" from selecting "cam file" in the camshaft section and choose "open" by clicking on the drop down menu with the "down arrow" on it. Then find where your cam files are.
Or on the top on the screen you will the menu item "Tools" click on that and open up "Cam Math" Or there is a shortcut button on the second row that looks like a camshaft and a "+" sign. There enter in all the cam specs in "advertised duration" which is the same as "seat to seat"
Le Mans Master
Joined: Nov 2002
Posts: 7,080
Likes: 0
From: Corvette valley Georgia
St. Jude Donor '06
Re: Desktop Dyno Questions (WickedC4)
From playing with Desktop Dyno 2000 and 2003 I've found that you get more LT1 like Dyno curves from selecting single plane intake manifold rather than sequential fire. This is because an LT1 manifold shares similarities with a carbed single plane i.e. short high flowing runners on a common open plenum. One or the other would work, but to me the single plane looks more accurate, and the LT1 is definitely not TPI or dual plane.
You can set up the cam either of two ways open up a "cam file" from selecting "cam file" in the camshaft section and choose "open" by clicking on the drop down menu with the "down arrow" on it. Then find where your cam files are.
Or on the top on the screen you will the menu item "Tools" click on that and open up "Cam Math" Or there is a shortcut button on the second row that looks like a camshaft and a "+" sign. There enter in all the cam specs in "advertised duration" which is the same as "seat to seat"
You can set up the cam either of two ways open up a "cam file" from selecting "cam file" in the camshaft section and choose "open" by clicking on the drop down menu with the "down arrow" on it. Then find where your cam files are.
Or on the top on the screen you will the menu item "Tools" click on that and open up "Cam Math" Or there is a shortcut button on the second row that looks like a camshaft and a "+" sign. There enter in all the cam specs in "advertised duration" which is the same as "seat to seat"
:iagree:
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Desktop Dyno Questions (grapeknutz)
I took 2 screen shots too, just incase you need a visual :cheers:
http://vetteman.8k.com/desktopdyno4.jpg
http://vetteman.8k.com/desktopdyno5.jpg
http://vetteman.8k.com/desktopdyno4.jpg
http://vetteman.8k.com/desktopdyno5.jpg
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Re: Desktop Dyno Questions (WickedC4)
Cool thanks. One last question, is it better to go with seat to seat or duration @.050? I tried it with a zz9 cam and I have both, but they give me two totally different outputs.
ZZ-9 HydraulicRoller:
Intake Exhaust Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112
ZZ-9 HydraulicRoller:
Intake Exhaust Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Desktop Dyno Questions (mn_vette)
Oh, seat to seat is always better. Because that IS the actual duration of the camshaft. Duration @ .050" lift is nice for us to look at to get a general idea of cam in a catalog or something. But when you only put in the duration @ .050" the program is trying to guess what the advertised duration is. So the results get kind of messed up.
This because there is no set formula to figure out the advertised given duration @ .050" if you take 2 different cams, lets say one comp, and one TPIS :D they could both have similar durations @ .050" but totally different advertised duration let's say the TPIS is just like the one you have. And the Comp's advertised is 278 283. They would not make the same HP. The comp has fast "ramp rate" which the rate at which the lifter accelerates. The smaller the difference from the advertised to the .050" the steeper the lobe is. Usually cams with steeper ramp rates will make more power since the valve opens quicker.
282 - 212 = 70
278 - 212 = 66 <-- faster ramp rate
With the seat to seat timing. The program uses a generic ramp rate to figure out the .050" and whatever else it needs. Which is more accurate than it the other way. Doing it backwards kind of does strange things. Sorry for so much information, but well... you asked for it! :cheers:
[Modified by WickedC4, 1:58 AM 2/22/2004]
This because there is no set formula to figure out the advertised given duration @ .050" if you take 2 different cams, lets say one comp, and one TPIS :D they could both have similar durations @ .050" but totally different advertised duration let's say the TPIS is just like the one you have. And the Comp's advertised is 278 283. They would not make the same HP. The comp has fast "ramp rate" which the rate at which the lifter accelerates. The smaller the difference from the advertised to the .050" the steeper the lobe is. Usually cams with steeper ramp rates will make more power since the valve opens quicker.
282 - 212 = 70
278 - 212 = 66 <-- faster ramp rate
With the seat to seat timing. The program uses a generic ramp rate to figure out the .050" and whatever else it needs. Which is more accurate than it the other way. Doing it backwards kind of does strange things. Sorry for so much information, but well... you asked for it! :cheers:
[Modified by WickedC4, 1:58 AM 2/22/2004]
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Re: Desktop Dyno Questions (WickedC4)
That makes total sense to me except for one thing. How does the computer figure out the ramp rate? I would think that you would need both the seat to seat and .050 durations to figure out exactly what the cam it doing. Wouldn't it also apply that genaric ramp rate to the seat to seat to figure out how fast the valves open on the seat to seat calculation?
Here are the peak numbers that I get when I put the above cam into my engine:
Seat to Seat: 282/287 112LSA .515/.527
MAX TQ: 474 @ 5000
MAX HP: 477 @ 6000
Duration @ 0.050: 212/226 112LSA .515/.527
MAX TQ: 486 @ 3500
MAX HP: 410 @ 5000
As you can see the difference is HUGE. Peak torque rpm went up 1500 rpms and 1000 for the peak HP. And the value for the peak HP went up 67 HP. That's a HUGE difference.
Just looking at the numbers the intake and exhaust ramp functions seem to be different with in themselves. Since tehre is a 5 degree difference in the seat to seat and a 14 degree difference in the .050. X = ramp time (one up and one down)
282 - 2*x = 212 x = 35 ramp
287 - 2*x = 226 x = 30.5 ramp
I'm assuming the program will make a guess of 30* ramp giving the .050 specs to be 222/227. But I'm sure it's got a better guess than just 30. When I tried to reproduce the same HP and TQ numbers as the seat to seat I ended up with some huge cam like 230/245 @ .050. Something is amiss I'm just not sure what it is yet.
Should I be using "Hydrolic flat tappet" or "Roller Solid or hydrolic lifters"?
[Modified by mn_vette, 4:24 PM 2/22/2004]
[Modified by mn_vette, 2:01 AM 2/24/2004]
Here are the peak numbers that I get when I put the above cam into my engine:
Seat to Seat: 282/287 112LSA .515/.527
MAX TQ: 474 @ 5000
MAX HP: 477 @ 6000
Duration @ 0.050: 212/226 112LSA .515/.527
MAX TQ: 486 @ 3500
MAX HP: 410 @ 5000
As you can see the difference is HUGE. Peak torque rpm went up 1500 rpms and 1000 for the peak HP. And the value for the peak HP went up 67 HP. That's a HUGE difference.
Just looking at the numbers the intake and exhaust ramp functions seem to be different with in themselves. Since tehre is a 5 degree difference in the seat to seat and a 14 degree difference in the .050. X = ramp time (one up and one down)
282 - 2*x = 212 x = 35 ramp
287 - 2*x = 226 x = 30.5 ramp
I'm assuming the program will make a guess of 30* ramp giving the .050 specs to be 222/227. But I'm sure it's got a better guess than just 30. When I tried to reproduce the same HP and TQ numbers as the seat to seat I ended up with some huge cam like 230/245 @ .050. Something is amiss I'm just not sure what it is yet.
Should I be using "Hydrolic flat tappet" or "Roller Solid or hydrolic lifters"?
[Modified by mn_vette, 4:24 PM 2/22/2004]
[Modified by mn_vette, 2:01 AM 2/24/2004]
Pro
Joined: May 2002
Posts: 678
Likes: 2
From: Lengede
Re: Desktop Dyno Questions (mn_vette)
Hope you don't mind me chiming in on this, but I would like to know what exhaust system I should use. Small-tube headers with mufflers????
I have 1 3/4 shorty headers without cat's.
Thanks
I have 1 3/4 shorty headers without cat's.
Thanks
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Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Desktop Dyno Questions (vettef6)
Hope you don't mind me chiming in on this, but I would like to know what exhaust system I should use. Small-tube headers with mufflers????
I have 1 3/4 shorty headers without cat's.
Thanks
I have 1 3/4 shorty headers without cat's.
Thanks
If you have the cam card you can check the timing numbers in Dyno2000 are the same as on the card. Once you change from .050 to seat-to-seat and vice versa, go back into Cam Math and make sure the correct numbers are entered.
Jake
[Modified by JAKE, 6:11 PM 2/22/2004]
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Desktop Dyno Questions (vettef6)
This is from the manual
So another big big factor is whole relation of cam to piston. ThatÂ’s why it looks like seat to seat is more accurate.
Vettf6: This is hard to say, according the manual, it says shorty headers are like “high performance manifolds”. But I was thinking if you have shorty headers with a very good flowing exhaust system. Then it might be able to flow as much as the “small-tube headers with mufflers” option. As a side note: I bet you’re tearing up the Autobahn with your Corvette :thumbs: Germany is such a cool place, I was there a few years ago. My German is very poor now. Good luck! :cheers:
[Modified by WickedC4, 4:23 PM 2/22/2004]
The Dyno2000 will simulate camshaft motion for both seat to seat and .050” inch cam timing. However, the internal simulation model requires seat to seat event timing to accurately calculate the beginning and end of mass flow in the ports and cylinders and must derive seat to seat timing from .050” inch figures. Unfortunately, this cannot be done with high accuracy. So, whenever possible enter seat to seat timing to obtain the most accurate simulation results.
Seat to seat timing method – This timing method measures the valve timing – relative to piston position – when the valve or lifter has only just begun to rise or has almost completely returned to the base circle on the closing ramp. Unfortunately, there are no universal seat to seat measuring standards. These are some of the more common seat to seat timing methods:
0.004 inch valve rise for both intake and exhaust
0.006 inch valve rise for both intake and exhaust
0.007 inch open/0.010 close valve rise for both valves
0.010 inch valve rise for both intake and exhaust
0.020 inch lifter rise for both intake and exhaust
The timing specs measured using these methods are meant to approximate the actual valve opening and closing points that occur within the running engine. Because of this, seat to seat valve events are often called advertised or running timing. The Dyno 2000 needs this information to calculate the beginning and end of cylinder pressures and power output. Because of this, directly entering seat to seat timing specifications will produce the most accurate simulation results.
Seat to seat timing method – This timing method measures the valve timing – relative to piston position – when the valve or lifter has only just begun to rise or has almost completely returned to the base circle on the closing ramp. Unfortunately, there are no universal seat to seat measuring standards. These are some of the more common seat to seat timing methods:
0.004 inch valve rise for both intake and exhaust
0.006 inch valve rise for both intake and exhaust
0.007 inch open/0.010 close valve rise for both valves
0.010 inch valve rise for both intake and exhaust
0.020 inch lifter rise for both intake and exhaust
The timing specs measured using these methods are meant to approximate the actual valve opening and closing points that occur within the running engine. Because of this, seat to seat valve events are often called advertised or running timing. The Dyno 2000 needs this information to calculate the beginning and end of cylinder pressures and power output. Because of this, directly entering seat to seat timing specifications will produce the most accurate simulation results.
Vettf6: This is hard to say, according the manual, it says shorty headers are like “high performance manifolds”. But I was thinking if you have shorty headers with a very good flowing exhaust system. Then it might be able to flow as much as the “small-tube headers with mufflers” option. As a side note: I bet you’re tearing up the Autobahn with your Corvette :thumbs: Germany is such a cool place, I was there a few years ago. My German is very poor now. Good luck! :cheers:
[Modified by WickedC4, 4:23 PM 2/22/2004]
Pro
Joined: May 2002
Posts: 678
Likes: 2
From: Lengede
Re: Desktop Dyno Questions (WickedC4)
Tim,
you are right, I live in Germany and it does make a lot of fun driving a 400 Hp Vette. My new project is a 396 with about 500+ HP.
A friend in the US. sent me the Desktop Dyno 2000 as a present. Is the 2003 version an update?
I’ve been trying to find out how many HP/TQ I have, but the intake and exhaust are my biggest problems. I get about 507 Hp/6000 rpm by using the duel intake manifold and small tube headers with mufflers; which should be approx. correct.
If I use the single plane manifold my Hp goes up to about 550 HP which will definitely be too high. Using something else on the exhaust side as to the small tube headers with mufflers, will bring me way down or the Hp will rise about 50+HP.
I can send my data to someone that is interested in helping me and see if he can do it better than myself with my old version.
Thanks
Arnold
you are right, I live in Germany and it does make a lot of fun driving a 400 Hp Vette. My new project is a 396 with about 500+ HP.
A friend in the US. sent me the Desktop Dyno 2000 as a present. Is the 2003 version an update?
I’ve been trying to find out how many HP/TQ I have, but the intake and exhaust are my biggest problems. I get about 507 Hp/6000 rpm by using the duel intake manifold and small tube headers with mufflers; which should be approx. correct.
If I use the single plane manifold my Hp goes up to about 550 HP which will definitely be too high. Using something else on the exhaust side as to the small tube headers with mufflers, will bring me way down or the Hp will rise about 50+HP.
I can send my data to someone that is interested in helping me and see if he can do it better than myself with my old version.
Thanks
Arnold
Burning Brakes
Joined: Jan 2004
Posts: 933
Likes: 0
From: Inland Empire CA
Re: Desktop Dyno Questions (vettef6)
Arnold,
I'd be more than happy to help you. The Desktop Dyno 2003 is new version of the software. It looks like it gives more accurate HP than Dyno 2000. All the information I need is in your signature except the detailed information on the cam. So you could post that here, or just send me an email. Right now it is saying 513 HP with a single plane @ 6000 RPM.
I'd be more than happy to help you. The Desktop Dyno 2003 is new version of the software. It looks like it gives more accurate HP than Dyno 2000. All the information I need is in your signature except the detailed information on the cam. So you could post that here, or just send me an email. Right now it is saying 513 HP with a single plane @ 6000 RPM.
