Anyone have experience LSx vs carb vs sheetmetal and how it affects power peak perIVC
12-12-2006, 09:35 AM
#1
Anyone have experience LSx vs carb vs sheetmetal and how it affects power peak perIVC Weve done some testing on LSx style plenum intakes vs some carb style stuff, and for a given IVC and intake lobe we know how the power curves shift/carry up top. Were talking average 40x inch motors per se, not 346s, not 500 ci's
Do you think that a well design sheetmetal intake would do the same thing to the peak hp rpm just because it eliminates the restriction in the head the same way the carb style does, or possibly higher or lower dependin on runner length? Most sheetmetal intakes are slightly shorter runners than a carb counterpart from what weve dealt with.
Im thinking given say a 250 duration lobe on a 113 ICL would peak first on FAST, then a carb style, then your average sheetmetal intake
What length runners have you found in the carb and sheetmetal intakes? I believe the fast is somethign like 13-15 inches I think?
Has anyone else done any back to back testing going from different style intakes on motors that might warrant it?
Do you think that a well design sheetmetal intake would do the same thing to the peak hp rpm just because it eliminates the restriction in the head the same way the carb style does, or possibly higher or lower dependin on runner length? Most sheetmetal intakes are slightly shorter runners than a carb counterpart from what weve dealt with.
Im thinking given say a 250 duration lobe on a 113 ICL would peak first on FAST, then a carb style, then your average sheetmetal intake
What length runners have you found in the carb and sheetmetal intakes? I believe the fast is somethign like 13-15 inches I think?
Has anyone else done any back to back testing going from different style intakes on motors that might warrant it?
12-12-2006, 01:40 PM
#2
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its not only the restriciton thats removed with the sheetmetal stuff but also runners that are tuned to your specs for the cam you have. theirs a back to back dyno of the fast to the carb style intake that was done and it was a negligable gain. i think thats because the member who did it, didnt match the rest of the setup to take advantage of it.
i would think that you would gain power going from the fast to a sheetmetal, especially if it was designed to take advatage of what you have. the runner length on the vics is obviously much shorter(maybe 12 inches or smaller). then the sheetmetals might be even shorter. the design of the cam and intake together will determine how and where you make your power. hope that helped a little
i would think that you would gain power going from the fast to a sheetmetal, especially if it was designed to take advatage of what you have. the runner length on the vics is obviously much shorter(maybe 12 inches or smaller). then the sheetmetals might be even shorter. the design of the cam and intake together will determine how and where you make your power. hope that helped a little
12-19-2006, 11:15 AM
#4
Fireball did back to back testing with a FAST vs a single plane on his ET headed 346.
Using a 242/248 110LSA +2 T-Rex as a starting point, the single plane was behind the FAST at most rpm until 6000 rpm (using the 108 intake centerline). By advancing the cam to 106 ICL, the car picked up average/peak power and was equal to the FAST in average power and better in peak. Power peak was 6500 rpm.
He then swapped to a 244/245 105LSA +0 cam, and it picked up power over the T-Rex above 5500 rpm. The gain was around 10 rwhp at 6000 and above. Power peak was still at 6500. The moral? I guess the short runners of the single plane intake don't need as late of an intake valve close to make power at higher rpm compared to when running a FAST 90/90.
Using a 242/248 110LSA +2 T-Rex as a starting point, the single plane was behind the FAST at most rpm until 6000 rpm (using the 108 intake centerline). By advancing the cam to 106 ICL, the car picked up average/peak power and was equal to the FAST in average power and better in peak. Power peak was 6500 rpm.
He then swapped to a 244/245 105LSA +0 cam, and it picked up power over the T-Rex above 5500 rpm. The gain was around 10 rwhp at 6000 and above. Power peak was still at 6500. The moral? I guess the short runners of the single plane intake don't need as late of an intake valve close to make power at higher rpm compared to when running a FAST 90/90.
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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
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12-19-2006, 12:12 PM
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Originally Posted by GrannySShifting
Weve done some testing on LSx style plenum intakes vs some carb style stuff, and for a given IVC and intake lobe we know how the power curves shift/carry up top. Were talking average 40x inch motors per se, not 346s, not 500 ci's
Do you think that a well design sheetmetal intake would do the same thing to the peak hp rpm just because it eliminates the restriction in the head the same way the carb style does, or possibly higher or lower dependin on runner length? Most sheetmetal intakes are slightly shorter runners than a carb counterpart from what weve dealt with.
Im thinking given say a 250 duration lobe on a 113 ICL would peak first on FAST, then a carb style, then your average sheetmetal intake
What length runners have you found in the carb and sheetmetal intakes? I believe the fast is somethign like 13-15 inches I think?
Has anyone else done any back to back testing going from different style intakes on motors that might warrant it?
Do you think that a well design sheetmetal intake would do the same thing to the peak hp rpm just because it eliminates the restriction in the head the same way the carb style does, or possibly higher or lower dependin on runner length? Most sheetmetal intakes are slightly shorter runners than a carb counterpart from what weve dealt with.
Im thinking given say a 250 duration lobe on a 113 ICL would peak first on FAST, then a carb style, then your average sheetmetal intake
What length runners have you found in the carb and sheetmetal intakes? I believe the fast is somethign like 13-15 inches I think?
Has anyone else done any back to back testing going from different style intakes on motors that might warrant it?
Don;t forget exhuast efficnecy and tunning.I have noticed engine with short runners on the intake tend to like longer primarys with shorter collectors. Just a trend i have taken note of. to early of a EVO and you will bleed off tons of cylinder pressure to late and you will kill upper end breathing. In effect detunning the engine and making it insensitive to manifold and tunning changes. This would most likely be the culprit behind the non responsiveness of the camshaft mentioned by patrick G
I have seen huge power with the single plane intakes but it requires a total rethink of the engine in terms of camshaft etc. It should be approached as a total system first and camshaft selection LAST. you might wantto check into wegner engine development they have done alot of work with sinlg eplane intakes for the ASA cars.
12-19-2006, 12:28 PM
#6
Originally Posted by Patrick G
Fireball did back to back testing with a FAST vs a single plane on his ET headed 346.
Using a 242/248 110LSA +2 T-Rex as a starting point, the single plane was behind the FAST at most rpm until 6000 rpm (using the 108 intake centerline). By advancing the cam to 106 ICL, the car picked up average/peak power and was equal to the FAST in average power and better in peak. Power peak was 6500 rpm.
He then swapped to a 244/245 105LSA +0 cam, and it picked up power over the T-Rex above 5500 rpm. The gain was around 10 rwhp at 6000 and above. Power peak was still at 6500. The moral? I guess the short runners of the single plane intake don't need as late of an intake valve close to make power at higher rpm compared to when running a FAST 90/90.
Using a 242/248 110LSA +2 T-Rex as a starting point, the single plane was behind the FAST at most rpm until 6000 rpm (using the 108 intake centerline). By advancing the cam to 106 ICL, the car picked up average/peak power and was equal to the FAST in average power and better in peak. Power peak was 6500 rpm.
He then swapped to a 244/245 105LSA +0 cam, and it picked up power over the T-Rex above 5500 rpm. The gain was around 10 rwhp at 6000 and above. Power peak was still at 6500. The moral? I guess the short runners of the single plane intake don't need as late of an intake valve close to make power at higher rpm compared to when running a FAST 90/90.
Fireballs setups didnt make very much more power at all and really killed the meat of the powerband for a drag application even. The carb style to FAST stuff weve worked with and made pretty good power (408 iron, powerglide, 5000 stall, hyd roller made little over 500 on our mustang dyno)
12-19-2006, 12:32 PM
#7
Originally Posted by Sean Collins
Your IVO needs attention. The shorter the runner the earlier the IVO. This is a fiarly straightforward trend i have seen on almost every motor i have every played with.The real question is what is the tunning FQ of the runner and what IVO works best to capture that tunning FQ. the other component in play will obviously be lobe duration. You will have an ideal filling cycle time with any runner but it will be based on volume and tpaer and it will also interact with the intake port. Your IVC will basically be about keeping your charge in the cylinder. Both require equal attention. Whats intresting is that you may need a longer lobe with a Single plane then with a comparable tunned Lsx style intake to get the same amount of TQ.
Don;t forget exhuast efficnecy and tunning.I have noticed engine with short runners on the intake tend to like longer primarys with shorter collectors. Just a trend i have taken note of. to early of a EVO and you will bleed off tons of cylinder pressure to late and you will kill upper end breathing. In effect detunning the engine and making it insensitive to manifold and tunning changes. This would most likely be the culprit behind the non responsiveness of the camshaft mentioned by patrick G
I have seen huge power with the single plane intakes but it requires a total rethink of the engine in terms of camshaft etc. It should be approached as a total system first and camshaft selection LAST. you might wantto check into wegner engine development they have done alot of work with sinlg eplane intakes for the ASA cars.
Don;t forget exhuast efficnecy and tunning.I have noticed engine with short runners on the intake tend to like longer primarys with shorter collectors. Just a trend i have taken note of. to early of a EVO and you will bleed off tons of cylinder pressure to late and you will kill upper end breathing. In effect detunning the engine and making it insensitive to manifold and tunning changes. This would most likely be the culprit behind the non responsiveness of the camshaft mentioned by patrick G
I have seen huge power with the single plane intakes but it requires a total rethink of the engine in terms of camshaft etc. It should be approached as a total system first and camshaft selection LAST. you might wantto check into wegner engine development they have done alot of work with sinlg eplane intakes for the ASA cars.
I was thinking for IVO, as its not choking the intake and you dont need to start the cylinder fill process as early. On the exhaust, weve made SERIOUS power up top with a rediculous early EVO and a very unrestrictive exhaust (talking 3.5 inch true duals)
Early EVO helps blow down the cylinder at rpm from what Ive seen. On high compression fast expansion motors never much seen a downside
I thought that carb style setup would be adog on motor everywhere, but it actually was in the same torque range but pulled away HARD up top over a FAST 90, same exact intake lobe and ICL, and cubes/cyliner heads. the carb style car had much more exhaust system, and opened the exhaust valve 10-15 degrees earlier. It outright pooed all over the FAST at 7000, and wasnt any worse on torque from 4500-5500
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12-19-2006, 01:33 PM
#8
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Originally Posted by GrannySShifting
I was thinking for IVO, as its not choking the intake and you dont need to start the cylinder fill process as early. On the exhaust, weve made SERIOUS power up top with a rediculous early EVO and a very unrestrictive exhaust (talking 3.5 inch true duals)
Early EVO helps blow down the cylinder at rpm from what Ive seen. On high compression fast expansion motors never much seen a downside
I thought that carb style setup would be adog on motor everywhere, but it actually was in the same torque range but pulled away HARD up top over a FAST 90, same exact intake lobe and ICL, and cubes/cyliner heads. the carb style car had much more exhaust system, and opened the exhaust valve 10-15 degrees earlier. It outright pooed all over the FAST at 7000, and wasnt any worse on torque from 4500-5500
Early EVO helps blow down the cylinder at rpm from what Ive seen. On high compression fast expansion motors never much seen a downside
I thought that carb style setup would be adog on motor everywhere, but it actually was in the same torque range but pulled away HARD up top over a FAST 90, same exact intake lobe and ICL, and cubes/cyliner heads. the carb style car had much more exhaust system, and opened the exhaust valve 10-15 degrees earlier. It outright pooed all over the FAST at 7000, and wasnt any worse on torque from 4500-5500
As for exhuast it will be extremly critical in making efficient power and if yoiu have a very good exhuast system some overlap may help. I will however stipulate that i picked up power recently with my own grinds going from 114 to 116 lsa's and i kept the IVO the same. This stell me that i was blowing down to much cylinder pressure and overscavenging the motor. Most people do not do this type of testing but i was curious due to some BSFC numbers comming out of the machine so we changed the cmshaft. viola 30hp and 25lb ft all the way up the curve.
Everything has to be though of as a system. I would agree that exhuast will be critical. Focusing on IVC however will lead you down a bad road if its all you focus on.
12-20-2006, 11:05 AM
#9
going from a 114 LSA to a 116 LSA, keeping IVO and IVC the same, and same exhaust lobe, will blow down the cylinder earlier, an reduces overlap your moving exhaust timing forward into the power stroke and opening intake same time. Or are you saying you changed more than just the LSA? Pm me if you need
I assume you were seeing very high fuel consumption, as too much overlap will make a motor thirsty for no reason
I assume you were seeing very high fuel consumption, as too much overlap will make a motor thirsty for no reason
12-22-2006, 08:42 AM
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Originally Posted by GrannySShifting
going from a 114 LSA to a 116 LSA, keeping IVO and IVC the same, and same exhaust lobe, will blow down the cylinder earlier, an reduces overlap your moving exhaust timing forward into the power stroke and opening intake same time. Or are you saying you changed more than just the LSA? Pm me if you need
I assume you were seeing very high fuel consumption, as too much overlap will make a motor thirsty for no reason
I assume you were seeing very high fuel consumption, as too much overlap will make a motor thirsty for no reason
12-22-2006, 01:36 PM
#12
No spreading LSA opens exhaust valve earlier. ???
Steve ecessive fuel consumption happens at part and WOT when you have a very earlier exhaust valve opening in my opinion. Your dumping useable cylinder pressue (on motor at least) out the exhaust valve.
Steve ecessive fuel consumption happens at part and WOT when you have a very earlier exhaust valve opening in my opinion. Your dumping useable cylinder pressue (on motor at least) out the exhaust valve.
12-22-2006, 03:47 PM
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Originally Posted by GrannySShifting
I know he did that testing on my dyno Fireballs setups didnt make very much more power at all and really killed the meat of the powerband for a drag application even. The carb style to FAST stuff weve worked with and made pretty good power (408 iron, powerglide, 5000 stall, hyd roller made little over 500 on our mustang dyno)
Fireballs setups didnt make very much more power at all and really killed the meat of the powerband for a drag application even. The carb style to FAST stuff weve worked with and made pretty good power (408 iron, powerglide, 5000 stall, hyd roller made little over 500 on our mustang dyno)I didn't test the tight LSA stuff on your dyno....you never saw the curves
12-22-2006, 07:53 PM
#15
Originally Posted by GrannySShifting
No spreading LSA opens exhaust valve earlier. ???
Steve ecessive fuel consumption happens at part and WOT when you have a very earlier exhaust valve opening in my opinion. Your dumping useable cylinder pressue (on motor at least) out the exhaust valve.
Steve ecessive fuel consumption happens at part and WOT when you have a very earlier exhaust valve opening in my opinion. Your dumping useable cylinder pressue (on motor at least) out the exhaust valve.
Bret
12-22-2006, 09:39 PM
#17
Originally Posted by Fireball
I didn't test the tight LSA stuff on your dyno....you never saw the curves
Last edited by GrannySShifting; 12-22-2006 at 09:47 PM.
12-23-2006, 09:17 AM
#18
Originally Posted by GrannySShifting
They were all within 8 hp nothing moved around much at all! What did you test the trex and the other cma that opened the exhaust valve way later? You should have tried the cam Im running now with that setup.
why would he want to do that ? the other local dyno spits out prettyer numbers
12-23-2006, 12:23 PM
#19
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Originally Posted by GrannySShifting
They were all within 8 hp nothing moved around much at all! What did you test the trex and the other cma that opened the exhaust valve way later? You should have tried the cam Im running now with that setup.
