Timing in nitrous, theoretical question??
07-23-2002, 09:21 AM
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Timing in nitrous, theoretical question?? If through the use of some rpm based progressive controller you were able to manage a perfectly flat TQ curve of 550 ft/lbs from 3000 rpm all the way out to 6500 rpms...would the timing requirements for best power be exactly the same at 3000 as they would at 6500? since TQ was the same throughout the rpm band cylinder pressure would be constant as well. According to David Vizard the relationship between rate of burn and RPM is nearly proportional due to increased activity in the combustion chamber as rpm goes up. If thats true....and the density of the AF charge remains the same for each cylinder event throughout the rpm band...best timing would be constant through that band ( i think). Anyone have any thoughts on this.
The reason for the question is my new system will be shooting for this goal of a flat TQ line of 550 ft lbs from 3000-6500. That equates to 680 rwhp at 6500. More HP than the old setup but without that huge TQ/cylinder pressure spike down low. The avg tq over the useful rpm range would be higher than my old setup...but seems that only seeing a max tq of 550 would be infinately easier on the motor. Aslo seems this would help make tuning easier and more reliable than trying get the most efficient/safe timing with 750 ft/lbs at 3200 rpm followed by a drastic drop off down to 470 ft/lbs at 6500.
Does this make any sense? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
The reason for the question is my new system will be shooting for this goal of a flat TQ line of 550 ft lbs from 3000-6500. That equates to 680 rwhp at 6500. More HP than the old setup but without that huge TQ/cylinder pressure spike down low. The avg tq over the useful rpm range would be higher than my old setup...but seems that only seeing a max tq of 550 would be infinately easier on the motor. Aslo seems this would help make tuning easier and more reliable than trying get the most efficient/safe timing with 750 ft/lbs at 3200 rpm followed by a drastic drop off down to 470 ft/lbs at 6500.
Does this make any sense? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
07-23-2002, 04:47 PM
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Re: Timing in nitrous, theoretical question?? I'm very interested in this topic, but quite honestly, it's over my head. Maybe someone else can help me understand it in simpler & more concise terms. Thanks.
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07-23-2002, 07:29 PM
#3
Re: Timing in nitrous, theoretical question?? I understand what your saying.
Basically what he wants to know is if you a progressive controller that goes by RMP and not time, and he wants to keep a constant 550 RWTQ throught the RPM range, does he need to adjust the timming or keep it constint as the Air to N2O/ fuel ratio never changes. get it?! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Now maybe for an answer. You would have to intinally retard it at the beginning of the hit (3000 RPM), but you should be able to keep it constint (say 21*) through the rest of the range. If you watch the timming via AutoTap on an N/A application, it goes to ~25* - 28* (depending on tune and car) and stays there through the WOT run, thus would be the same as keeping the porpotion of N2O the same in the AF ratio.
That would be hard to do, to keep the N2O at the right porpotin with the AF comming in. Depending on how the progressive controller works.
You get that Al <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Basically what he wants to know is if you a progressive controller that goes by RMP and not time, and he wants to keep a constant 550 RWTQ throught the RPM range, does he need to adjust the timming or keep it constint as the Air to N2O/ fuel ratio never changes. get it?! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Now maybe for an answer. You would have to intinally retard it at the beginning of the hit (3000 RPM), but you should be able to keep it constint (say 21*) through the rest of the range. If you watch the timming via AutoTap on an N/A application, it goes to ~25* - 28* (depending on tune and car) and stays there through the WOT run, thus would be the same as keeping the porpotion of N2O the same in the AF ratio.
That would be hard to do, to keep the N2O at the right porpotin with the AF comming in. Depending on how the progressive controller works.
You get that Al <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
07-23-2002, 07:51 PM
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Re: Timing in nitrous, theoretical question?? Controlling the N2o part will be easy. I have some tricks up the old sleeve. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
07-24-2002, 07:19 AM
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Re: Timing in nitrous, theoretical question?? Well, I can say the stock timing curves do not keep the timing at a set value. If you look at it using ls1edit, you see where gm put a dip in the 'high flow' curves(indicating WOT), right about where the TQ peak is I think. But I have no idea on the original question. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> If I could find a dyno where I could make a crap load of passes for next to nothing, I'd try it out for ya. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
07-24-2002, 08:12 AM
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Re: Timing in nitrous, theoretical question?? Azzhauler...that bit of info helps. It confirms what Ive been thinking.
You can see the delemma here. It sounds as though a good NA timing curve follows the TQ curve. Problem with nitrous...even if you pull out 3 degrees for a specific size shot it pulls out that 3 degrees over the current NA timing map. Basically you are trying to tune the timing for the safe limit at the TQ peak on nitrous...which would be at the lowest point it is engaged for a large single stage. But as rpm increases and the TQ drops off drastically and timing will be out of whack.
Sorry for the rambling..Im just trying to figure the best way to run large shots on LS1's since we have no timing control devices currently. Not just timing but nitrous delivery too. After looking at it...some type of multiple stage or better yet RPM based controller is obviously better than a large single as it will cut down on that huge TQ spike down low. I still need to learn quite a bit..but it seems to me there should be a better way of doing this, as well as being able to switch between optimal tune for nitrous and on motor...not choosing one or the other.
To me nitrous should be a blank sheet of paper as far as power is concerned. It seems with a little enginuity and research you should be able to devlope a system that can control engine tq (and thus HP) throughout the rpm range as the operator sees fit. Basically draw your own TQ curve. Not just cram a constant 150 shot in there from 3000 rpm to 6500 rpm. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
<small>[ July 24, 2002, 08:17 AM: Message edited by: 383LQ4SS ]</small>
You can see the delemma here. It sounds as though a good NA timing curve follows the TQ curve. Problem with nitrous...even if you pull out 3 degrees for a specific size shot it pulls out that 3 degrees over the current NA timing map. Basically you are trying to tune the timing for the safe limit at the TQ peak on nitrous...which would be at the lowest point it is engaged for a large single stage. But as rpm increases and the TQ drops off drastically and timing will be out of whack.
Sorry for the rambling..Im just trying to figure the best way to run large shots on LS1's since we have no timing control devices currently. Not just timing but nitrous delivery too. After looking at it...some type of multiple stage or better yet RPM based controller is obviously better than a large single as it will cut down on that huge TQ spike down low. I still need to learn quite a bit..but it seems to me there should be a better way of doing this, as well as being able to switch between optimal tune for nitrous and on motor...not choosing one or the other.
To me nitrous should be a blank sheet of paper as far as power is concerned. It seems with a little enginuity and research you should be able to devlope a system that can control engine tq (and thus HP) throughout the rpm range as the operator sees fit. Basically draw your own TQ curve. Not just cram a constant 150 shot in there from 3000 rpm to 6500 rpm. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
<small>[ July 24, 2002, 08:17 AM: Message edited by: 383LQ4SS ]</small>
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07-24-2002, 10:12 AM
#8
Re: Timing in nitrous, theoretical question?? What you are wanting to do is what I plan on doing. Progressive RPM-based nitrous control is the key to making your motor live under the spray. Death to motors (besides going lean) is too much cylinder pressure at low rpms. One of the reasons turbo motors last so long is that they can be easily tuned to make max boost ABOVE peak torque.
For me, I will be running my stock short block for a while longer, but I'd like to run a 200 shot. Not going to live long when spraying 100% at 4000 rpms, but a progressive rpm-based controller could help. 50% nitrous at 4000 rpms (100 shot), 75% at 5000 (150 shot), and 100% by 6000 rpms (200 shot).
Timing is another matter. GM got it right by backing the timing off at peak torque and bringing it back as rpms rise. My cheap solution is to add an inline resistor to trick my IAT sensor into thinking the incoming air temperature is very high...which would back timing off several degrees (I'm at 28 degrees max right now). This resistor would be relay-activated and would only come on when the nitrous was engaged. Otherwise, I would have stock timing. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Final piece of the puzzle for me is a separate fuel system for the nitrous. I plan on adding a small fuel cell (filled with race fuel) and a Holley pump and regulator. This way, I can use my in-tank pump just to supply the fuel for my N/A heads/cam motor, and the fuel cell/Holley pump to supply a 200+ nitrous shot. It's about the only way I can think of making a stock short block survive on such a big shot. Once I build the bottom end, I can go stupid with the jetting size.
For me, I will be running my stock short block for a while longer, but I'd like to run a 200 shot. Not going to live long when spraying 100% at 4000 rpms, but a progressive rpm-based controller could help. 50% nitrous at 4000 rpms (100 shot), 75% at 5000 (150 shot), and 100% by 6000 rpms (200 shot).
Timing is another matter. GM got it right by backing the timing off at peak torque and bringing it back as rpms rise. My cheap solution is to add an inline resistor to trick my IAT sensor into thinking the incoming air temperature is very high...which would back timing off several degrees (I'm at 28 degrees max right now). This resistor would be relay-activated and would only come on when the nitrous was engaged. Otherwise, I would have stock timing. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Final piece of the puzzle for me is a separate fuel system for the nitrous. I plan on adding a small fuel cell (filled with race fuel) and a Holley pump and regulator. This way, I can use my in-tank pump just to supply the fuel for my N/A heads/cam motor, and the fuel cell/Holley pump to supply a 200+ nitrous shot. It's about the only way I can think of making a stock short block survive on such a big shot. Once I build the bottom end, I can go stupid with the jetting size.
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2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
07-24-2002, 06:33 PM
#10
Re: Timing in nitrous, theoretical question?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 383LQ4SS:
<strong>I was going to keep this secret so I could use it first. <img src="http://www.cranecams.com/whatsnew/images/meddigcontrol.gif" alt=" - " />
This is Crane Cams new RPM controller. You basically set start rpm, then 100% rpm, then stop rpm. So you might set it to start flow on a 250 shot at 2500 rpm and it will ramp up to 100% at say 5800 rpm and then cut off at 6500 rpm. Really with two of these set up at different rpms with different pill shots you could have very good controll of your Tq line as tested on a dyno. Only problem is the max load is 10 amps. Not enough to run dual noids for a wet kit. Maybe two small powershots but thats it. I have a cheater that is rated at 10 amps so I should be ok up to a 250 shot. I think its a good start point for where I want to be. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats what I figured <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
<strong>I was going to keep this secret so I could use it first. <img src="http://www.cranecams.com/whatsnew/images/meddigcontrol.gif" alt=" - " />
This is Crane Cams new RPM controller. You basically set start rpm, then 100% rpm, then stop rpm. So you might set it to start flow on a 250 shot at 2500 rpm and it will ramp up to 100% at say 5800 rpm and then cut off at 6500 rpm. Really with two of these set up at different rpms with different pill shots you could have very good controll of your Tq line as tested on a dyno. Only problem is the max load is 10 amps. Not enough to run dual noids for a wet kit. Maybe two small powershots but thats it. I have a cheater that is rated at 10 amps so I should be ok up to a 250 shot. I think its a good start point for where I want to be. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats what I figured <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
07-25-2002, 12:25 AM
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Re: Timing in nitrous, theoretical question?? I was going to keep this secret so I could use it first. <img src="http://www.cranecams.com/whatsnew/images/meddigcontrol.gif" alt=" - " />
This is Crane Cams new RPM controller. You basically set start rpm, then 100% rpm, then stop rpm. So you might set it to start flow on a 250 shot at 2500 rpm and it will ramp up to 100% at say 5800 rpm and then cut off at 6500 rpm. Really with two of these set up at different rpms with different pill shots you could have very good controll of your Tq line as tested on a dyno. Only problem is the max load is 10 amps. Not enough to run dual noids for a wet kit. Maybe two small powershots but thats it. I have a cheater that is rated at 10 amps so I should be ok up to a 250 shot. I think its a good start point for where I want to be. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
This is Crane Cams new RPM controller. You basically set start rpm, then 100% rpm, then stop rpm. So you might set it to start flow on a 250 shot at 2500 rpm and it will ramp up to 100% at say 5800 rpm and then cut off at 6500 rpm. Really with two of these set up at different rpms with different pill shots you could have very good controll of your Tq line as tested on a dyno. Only problem is the max load is 10 amps. Not enough to run dual noids for a wet kit. Maybe two small powershots but thats it. I have a cheater that is rated at 10 amps so I should be ok up to a 250 shot. I think its a good start point for where I want to be. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
07-25-2002, 12:44 AM
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Re: Timing in nitrous, theoretical question?? Not many people are carrying it yet since its a new product. Youll have to do a search. This is off Crane Cams website. I believe cost is gonna be around $250, not bad.
07-25-2002, 12:46 AM
#14
Re: Timing in nitrous, theoretical question?? Jacobs Mastermind controller may be even better than the Crane unit. RPM-based control.
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2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
07-25-2002, 12:52 AM
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Re: Timing in nitrous, theoretical question?? The Jacobs mastermind i think only has start and 100% rpm. This Crane gives the advanatge of keeping 100% rpm and stop RPM seperate if needed, just a bit more adjustability. Also the Jacobs has a few features that cant be used on the LS1 such as timing controls.
*edit*
Patrick...does the Jacobs give a way to adjust how the nitrous comes on...or is it a fixed linear application betwen start and stop?
<small>[ July 24, 2002, 12:55 PM: Message edited by: 383LQ4SS ]</small>
*edit*
Patrick...does the Jacobs give a way to adjust how the nitrous comes on...or is it a fixed linear application betwen start and stop?
<small>[ July 24, 2002, 12:55 PM: Message edited by: 383LQ4SS ]</small>
07-25-2002, 10:28 AM
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Re: Timing in nitrous, theoretical question?? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 383LQ4SS:
<strong> <img src="http://www.cranecams.com/whatsnew/images/meddigcontrol.gif" alt=" - " />
This is Crane Cams new RPM controller. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">i was reading on their site, looks like this RPM controller is only for dry kits??
<strong> <img src="http://www.cranecams.com/whatsnew/images/meddigcontrol.gif" alt=" - " />
This is Crane Cams new RPM controller. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">i was reading on their site, looks like this RPM controller is only for dry kits??
06-25-2003, 06:09 PM
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Re: Timing in nitrous, theoretical question?? anybody know if the crane unit can be used with a wet system...I looked up some info on their site and it said it is engineered for dry systems????
06-26-2003, 03:54 AM
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Re: Timing in nitrous, theoretical question??
anybody know if the crane unit can be used with a wet system...I looked up some info on their site and it said it is engineered for dry systems????
As for the flat TQ, excellent idea and should be doable, just need more knowledge on it.
06-26-2003, 11:04 AM
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Re: Timing in nitrous, theoretical question?? Do these controls basically send a digital frequency to power the noids? If so, is there longevity concerns with cycling the noids that quick??? This sounds like an excellent way to keep the power up high in rpm band...
06-26-2003, 12:02 PM
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Re: Timing in nitrous, theoretical question?? Man I really want one of these. I wonder if it would work with two of them one for fuel and one for n20 like mentioned above. That could get nasty if they didn't work in perfect tandem with each other.
