bucking after cam install?
02-26-2008, 06:04 AM
#1
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bucking after cam install? does anyone experience " bucking" when your cruising in 5th gear or if your going threw a parking lot in 1st gear at low rpms 1500 and below?
i got the car tuned and it didnt take care of the problem? is this normal?
i got the car tuned and it didnt take care of the problem? is this normal?
02-26-2008, 06:26 AM
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Whats the size of the cam? With a lot of cams some bucking at low RPM's is hard to avoid, sometimes tweaking the timing tables can help it out though.
02-26-2008, 07:39 AM
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welcome to the exciting world of CAM SURGE
happens to me in certain conditions, just like you list.
alot of times you'll only get a WOT tune, and then a mild tweaking of the part throttle tune...which doesn't help much with the surge.
get a street tune
happens to me in certain conditions, just like you list.
alot of times you'll only get a WOT tune, and then a mild tweaking of the part throttle tune...which doesn't help much with the surge.
get a street tune
02-26-2008, 08:26 AM
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i had my car dyno tuned at harris speed works they did part throttle and cold start up one day and WOT the next day. they said that they might be not able to get it all out but i was just wondering if this is normal the specs are 234int 236ext 594int 598 ext and 112 he told me he might not be able to get rid of it is that acceptable for 400 dollar tune?
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02-26-2008, 10:56 AM
#9
Cam surge is what 90% of people who put a cam in dont mention. Pretty much every aftermarket cam, no matter how good the tune, will experience more bucking than a stock LS1/LS6 cam. Your going to have to adjust your driving style to avoid it.
02-26-2008, 11:15 AM
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Lean it out in those certain cells and its fine. I have a TA w/a 224/230 cam and 3.23 gears. I can now putt around town in 4th gear almost idling and it dont buck anymore at all. Lots of info about this in the TUNING section.
02-26-2008, 12:35 PM
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ok i understand about getting a better tune but dont you think they should have done it right in the first place? i didn't do the tune my self and i do not know how to do any tuning i can install parts but computer stuff is above my head. do you think i should complain and see if they will re-tune it?
02-26-2008, 01:03 PM
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Talk to the tuner, he can try a couple things to see if it will make it a bit better. Most places do not do a complete street tune because it is time consuming to do and they would have to charge more for it. Most $400-500 tunes are just WOT, Idle set, torque management removal, code removal, WOT Spark and maybe tune the RAF a tad. Most will not include Maf and VE tuning which are the things that will help with Part Throttle and off idle issues.
With the size of your cam you should be able to minimize most of the bucking and surging but not get rid off it all toghether.
With the size of your cam you should be able to minimize most of the bucking and surging but not get rid off it all toghether.
02-26-2008, 01:08 PM
#17
The most important thing is to nail your airflow tables. Your IAC counts must be between 40-60 at hot idle with the ac off. To do this, you'll either need to open up the TB blade or drill a hole in the TB blade. Once you do that, you'll want to get your running airflow tables good at all temps (ie short term idle trims should be under 1 gram/sec correction). Once you do this, then you can turn off your MAF and start VE tuning. Timing tables will help some, but improper airflow is the biggest culprit to bucking and surging. Improper fueling would be next. Improper timing after that.
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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.
02-26-2008, 01:15 PM
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when he called me to tell me how the car was doing he told me to get rid of the slp mass air flow sensor and get a stock one. i am going to do that but he said it might not eliminate the problem. other than the low end problem the car runs and drives great. do you think if i switch back to a stock mass air that it will throw off the tune he just did?
02-26-2008, 02:07 PM
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ok i understand about getting a better tune but dont you think they should have done it right in the first place? i didn't do the tune my self and i do not know how to do any tuning i can install parts but computer stuff is above my head. do you think i should complain and see if they will re-tune it?
Your cam is small enough that you should be able to address the bucking and surging without drilling the TB. That should be a last resort after all else has been tried.
02-26-2008, 02:22 PM
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As someone stated above, most shops that do a dyno tune concentrate on 3 things. MAF, PE and timing. This will get your car to put down the HP and address 80% of driveability but without remapping the VE table, they are incomplete tunes at best. A true tune will address all of these and idle airflow and timing but it takes some time.
Your cam is small enough that you should be able to address the bucking and surging without drilling the TB. That should be a last resort after all else has been tried.
Your cam is small enough that you should be able to address the bucking and surging without drilling the TB. That should be a last resort after all else has been tried.