Dyno Numbers are In!
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Joined: Dec 2000
Posts: 489
From: Chattanooga, Tennessee
Re: Dyno Numbers are In!
With that much duration on the cam, you are going to have to turn it higher to see peak hp--probably at least 6500-6600. I am not surprised that you didn't get better numbers stopping at 5900. Your set up looks good to me. Run it on up there and see what you get before you start thinking something is wrong and looking for problems. You may be worrying for nothing. Your next tuning session will probably give you better results. Just my guess and .02 worth. Keep us posted!
Post your torque numbers if you can remember or find them.
Post your torque numbers if you can remember or find them.
Last edited by David94TA; Feb 9, 2005 at 08:40 PM.
Thread Starter
Registered User
Joined: Jan 2004
Posts: 1,322
From: San Francisco
Re: Dyno Numbers are In!
here is the link to the graph...Sorry about the quality, dont have a scanner. Tell me what you guys see...
graph
graph
Last edited by Deenasty; Feb 9, 2005 at 09:54 PM.
Registered User
Joined: Aug 2000
Posts: 1,071
From: Dallas,TX
Re: Dyno Numbers are In!
Cant see your dyno graph 
30lb injectors should be fine...With those AFRs I would think you should be around 410-420rw...Yes the 12bolt and cats are hurting a lil hp(maybe 10-15) but not too much.....
I have close to same setup but am running stock lt1 castings and no tuning...I dynoed 390/390rwtq with atleast 10 degrees of knock(need to tune!)...I am running Autolite 103 or 104 plugs and they do great....
Cody
30lb injectors should be fine...With those AFRs I would think you should be around 410-420rw...Yes the 12bolt and cats are hurting a lil hp(maybe 10-15) but not too much.....I have close to same setup but am running stock lt1 castings and no tuning...I dynoed 390/390rwtq with atleast 10 degrees of knock(need to tune!)...I am running Autolite 103 or 104 plugs and they do great....
Cody
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Joined: Jan 2001
Posts: 608
Re: Dyno Numbers are In!
Originally Posted by Deenasty
well, I purchased this motor from a friend of mine, that at the time had a lt4 hotcam, and slp midlength headers on it. I put it in my car, and thought I would change the cam, being that the hotcam was kinda small for a stroker. TPiS had done the heads, as they are their own heads. (AFR castings, there port work) Who else would know these heads better than themselves, so I called TPiS and asked for a cam suggestion. They reccomended me their ZZX cam, 240 240 .595/ .595 112. I also put in a set of 1 3/4 stepped to 1 7/8 long tubes. They told me they do this setup all the time, and that they predict it would make about 515 fwhp, which at a 15% drivetrain loss, would put me at about 440rwhp. I still thought this was a bit high, and realistically thought, the car would put out about 420rwhp, unfortunately this was not the case. Are you aiming at possibly the header being to big?
the dyno was a dyno dynamics. I had got dynoed there before, with the hotcam. i did notice that the previous (conversion multiplier) on the dyno was 1.160, and now it is at 1.150. Although its is not much of a change, it would of only brought me up to 392rwhp..Im still down big time..
the dyno was a dyno dynamics. I had got dynoed there before, with the hotcam. i did notice that the previous (conversion multiplier) on the dyno was 1.160, and now it is at 1.150. Although its is not much of a change, it would of only brought me up to 392rwhp..Im still down big time..
Thread Starter
Registered User
Joined: Jan 2004
Posts: 1,322
From: San Francisco
Re: Dyno Numbers are In!
link is fixed....what is the likelyhood of the cam being degreed wrong? According to Injuneers formula on calculating injector size:
(fwhp x .50) / (8 x .80)= tells me that I need 40lb injectors?
(fwhp x .50) / (8 x .80)= tells me that I need 40lb injectors?
Thread Starter
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Joined: Jan 2004
Posts: 1,322
From: San Francisco
Re: Dyno Numbers are In!
no, there are two high flow cats in the system. I have done some research on this setup, and one fellow picked up 7 tenths in the quarter, by ditching the single 3" and going true duals...I dont think my exhaust system is limiting me, maybe I can try a cutout...
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Joined: Nov 1998
Posts: 71,086
From: Hell was full so they sent me to NJ
Re: Dyno Numbers are In!
You can get intake manifold vacuum direct from your freescan data. Vaccum = barometer minus MAP, obviously, all in the same units of measurement, like "Hg.
You can calculate injector duty cycle from your freescan data. You need to calculate the time the engine takes to make 2 complete crank revolutions - e.g. at 6,000rpm, you have 20mSec available - then divide that number into the injector pulse width in mSec, at that RPM. If you are using DataMaster, I have found that the pulse widths that DM logs, referenced as "BPW" and the resulting DC's that DM calculates sometimes don't make any sense.
I had a chance to measure my flywheel HP on an engine dyno with full intake and exhaust (486 flywheel), and then on a chassis dyno with the same intake and exhaust. I got 425rwHP, through a steel flywheel Street Twin, stock T56, 3" chrome moly DS, 3.73 Strange 12-bolt, and 17x9.5 wheels with 275/401-7 tires. That works out to a 12.6% loss.
Was your LT4 intake matched to the heads? Was it ported at all? As-cast, the LT4 intake can be a problem. It needs a lot of work to support decent heads. What kind of flow numbers did you have on the AFR 190's after they got done with them?
The 52mm TB should be enough. When I did my engine dyno work, the max airflow through the 58mm TB I used was reached at 77% open on the 58mm TB, which would indicate that a 52mm TB at 100% would have flowed enough air.
The formula you quoted is a way to APPROXIMATE the size injectors you need. In actuality, the ".50" shown multiplied times flywheel HP is the Brake Specific Fuel Consumption (BSFC) for your actual motor. On my setup, we got an acutal BSFC at peak fuel flow of 0.43 #/HR/HP. If you have a tune that good, you don't need as large an injector.
The equation also assumes that you want to limit the injector to an 80% DC (the ".80" in the equation). As pointed out in a post above, pushing to 90% for the brief interval of a dyno pull should not overload some injectors. Operating continuously at 90% DC will wear them out prematurely, and can affect the flow rate and the spray pattern.
It you simply substitute 0.45 for the BSFC, and 90% for DC, you get a 32# injector required for a 500 flywheel HP engine. Its always a good idea to select an injector based on 80% DC, and to be a little conservative (fat) in the BSFC if you don't have the actual numbers for your engine.
If your A/F ratio didn't lean out at 5,900rpm, your injectors weren't overloaded. If you spun it to 6,500 you might see a problem appear.
You can calculate injector duty cycle from your freescan data. You need to calculate the time the engine takes to make 2 complete crank revolutions - e.g. at 6,000rpm, you have 20mSec available - then divide that number into the injector pulse width in mSec, at that RPM. If you are using DataMaster, I have found that the pulse widths that DM logs, referenced as "BPW" and the resulting DC's that DM calculates sometimes don't make any sense.
I had a chance to measure my flywheel HP on an engine dyno with full intake and exhaust (486 flywheel), and then on a chassis dyno with the same intake and exhaust. I got 425rwHP, through a steel flywheel Street Twin, stock T56, 3" chrome moly DS, 3.73 Strange 12-bolt, and 17x9.5 wheels with 275/401-7 tires. That works out to a 12.6% loss.
Was your LT4 intake matched to the heads? Was it ported at all? As-cast, the LT4 intake can be a problem. It needs a lot of work to support decent heads. What kind of flow numbers did you have on the AFR 190's after they got done with them?
The 52mm TB should be enough. When I did my engine dyno work, the max airflow through the 58mm TB I used was reached at 77% open on the 58mm TB, which would indicate that a 52mm TB at 100% would have flowed enough air.
The formula you quoted is a way to APPROXIMATE the size injectors you need. In actuality, the ".50" shown multiplied times flywheel HP is the Brake Specific Fuel Consumption (BSFC) for your actual motor. On my setup, we got an acutal BSFC at peak fuel flow of 0.43 #/HR/HP. If you have a tune that good, you don't need as large an injector.
The equation also assumes that you want to limit the injector to an 80% DC (the ".80" in the equation). As pointed out in a post above, pushing to 90% for the brief interval of a dyno pull should not overload some injectors. Operating continuously at 90% DC will wear them out prematurely, and can affect the flow rate and the spray pattern.
It you simply substitute 0.45 for the BSFC, and 90% for DC, you get a 32# injector required for a 500 flywheel HP engine. Its always a good idea to select an injector based on 80% DC, and to be a little conservative (fat) in the BSFC if you don't have the actual numbers for your engine.
If your A/F ratio didn't lean out at 5,900rpm, your injectors weren't overloaded. If you spun it to 6,500 you might see a problem appear.
Registered User
Joined: Mar 2003
Posts: 159
From: San Jose
Re: Dyno Numbers are In!
Originally Posted by Deenasty
here is the link to the graph...Sorry about the quality, dont have a scanner. Tell me what you guys see...
graph
graph
Thread Starter
Registered User
Joined: Jan 2004
Posts: 1,322
From: San Francisco
Re: Dyno Numbers are In!
Originally Posted by Injuneer
You can get intake manifold vacuum direct from your freescan data. Vaccum = barometer minus MAP, obviously, all in the same units of measurement, like "Hg.
You can calculate injector duty cycle from your freescan data. You need to calculate the time the engine takes to make 2 complete crank revolutions - e.g. at 6,000rpm, you have 20mSec available - then divide that number into the injector pulse width in mSec, at that RPM. If you are using DataMaster, I have found that the pulse widths that DM logs, referenced as "BPW" and the resulting DC's that DM calculates sometimes don't make any sense.
I had a chance to measure my flywheel HP on an engine dyno with full intake and exhaust (486 flywheel), and then on a chassis dyno with the same intake and exhaust. I got 425rwHP, through a steel flywheel Street Twin, stock T56, 3" chrome moly DS, 3.73 Strange 12-bolt, and 17x9.5 wheels with 275/401-7 tires. That works out to a 12.6% loss.
Was your LT4 intake matched to the heads? Was it ported at all? As-cast, the LT4 intake can be a problem. It needs a lot of work to support decent heads. What kind of flow numbers did you have on the AFR 190's after they got done with them?
The 52mm TB should be enough. When I did my engine dyno work, the max airflow through the 58mm TB I used was reached at 77% open on the 58mm TB, which would indicate that a 52mm TB at 100% would have flowed enough air.
The formula you quoted is a way to APPROXIMATE the size injectors you need. In actuality, the ".50" shown multiplied times flywheel HP is the Brake Specific Fuel Consumption (BSFC) for your actual motor. On my setup, we got an acutal BSFC at peak fuel flow of 0.43 #/HR/HP. If you have a tune that good, you don't need as large an injector.
The equation also assumes that you want to limit the injector to an 80% DC (the ".80" in the equation). As pointed out in a post above, pushing to 90% for the brief interval of a dyno pull should not overload some injectors. Operating continuously at 90% DC will wear them out prematurely, and can affect the flow rate and the spray pattern.
It you simply substitute 0.45 for the BSFC, and 90% for DC, you get a 32# injector required for a 500 flywheel HP engine. Its always a good idea to select an injector based on 80% DC, and to be a little conservative (fat) in the BSFC if you don't have the actual numbers for your engine.
If your A/F ratio didn't lean out at 5,900rpm, your injectors weren't overloaded. If you spun it to 6,500 you might see a problem appear.
You can calculate injector duty cycle from your freescan data. You need to calculate the time the engine takes to make 2 complete crank revolutions - e.g. at 6,000rpm, you have 20mSec available - then divide that number into the injector pulse width in mSec, at that RPM. If you are using DataMaster, I have found that the pulse widths that DM logs, referenced as "BPW" and the resulting DC's that DM calculates sometimes don't make any sense.
I had a chance to measure my flywheel HP on an engine dyno with full intake and exhaust (486 flywheel), and then on a chassis dyno with the same intake and exhaust. I got 425rwHP, through a steel flywheel Street Twin, stock T56, 3" chrome moly DS, 3.73 Strange 12-bolt, and 17x9.5 wheels with 275/401-7 tires. That works out to a 12.6% loss.
Was your LT4 intake matched to the heads? Was it ported at all? As-cast, the LT4 intake can be a problem. It needs a lot of work to support decent heads. What kind of flow numbers did you have on the AFR 190's after they got done with them?
The 52mm TB should be enough. When I did my engine dyno work, the max airflow through the 58mm TB I used was reached at 77% open on the 58mm TB, which would indicate that a 52mm TB at 100% would have flowed enough air.
The formula you quoted is a way to APPROXIMATE the size injectors you need. In actuality, the ".50" shown multiplied times flywheel HP is the Brake Specific Fuel Consumption (BSFC) for your actual motor. On my setup, we got an acutal BSFC at peak fuel flow of 0.43 #/HR/HP. If you have a tune that good, you don't need as large an injector.
The equation also assumes that you want to limit the injector to an 80% DC (the ".80" in the equation). As pointed out in a post above, pushing to 90% for the brief interval of a dyno pull should not overload some injectors. Operating continuously at 90% DC will wear them out prematurely, and can affect the flow rate and the spray pattern.
It you simply substitute 0.45 for the BSFC, and 90% for DC, you get a 32# injector required for a 500 flywheel HP engine. Its always a good idea to select an injector based on 80% DC, and to be a little conservative (fat) in the BSFC if you don't have the actual numbers for your engine.
If your A/F ratio didn't lean out at 5,900rpm, your injectors weren't overloaded. If you spun it to 6,500 you might see a problem appear.
Thread Starter
Registered User
Joined: Jan 2004
Posts: 1,322
From: San Francisco
Re: Dyno Numbers are In!
Originally Posted by MaxLean
Dude, on a side note I had a TPIS ZZ9 cam and it had that EXACT same power dip at the top end! For me, it was valve train as it sounded like thay were floating just in that range. It was wierd. Gotta be something with TPIS grinds.