New cam instaled- Big numbers but a problem
Thread Starter
Racer
Joined: Sep 2008
Posts: 435
Likes: 1
New cam instaled- Big numbers but a problem
Hey guy just installed a VRX6 into my 02 Z06. also did powerbond 25%, single roller timing chain, lunati double springs, trickflow 7.4 hardend rods, new ngk plugs with wires, vararam with velocity coupler, fast 90/90, OBX headers with stock TI and DMH cutouts. ran 449hp and 39 tq. i was ery happy with these number and the car runs very strong. the only problem im having is that at low rpms (below 1500) in first or second the car bucks very violently and when coming out of gear while driving the car will stall 2 out of 5 times. my tuner said my injectors were maxed and im going to go back with 42lbers. but i dont think thats my problem. anyone know what it could be? i got a dyno and street tune
Tech Contributor
Joined: Sep 2005
Posts: 1,731
Likes: 82
From: New Market AL
Your tuner doesn't know what he is doing. To blame injectors for stalling and low rpm buck is just wrong. At 450 whp you would be fine with 30-36 #/hr injectors.
You need to find someone who knows how to properly tune a cam'd engine, and who knows to correct injector values to enter. Where are you located?
You need to find someone who knows how to properly tune a cam'd engine, and who knows to correct injector values to enter. Where are you located?
Safety Car
Joined: Jun 2004
Posts: 4,987
Likes: 394
From: Stoney Creek Ontario
Your tuner doesn't know what he is doing. To blame injectors for stalling and low rpm buck is just wrong. At 450 whp you would be fine with 30-36 #/hr injectors.
You need to find someone who knows how to properly tune a cam'd engine, and who knows to correct injector values to enter. Where are you located?
You need to find someone who knows how to properly tune a cam'd engine, and who knows to correct injector values to enter. Where are you located?
Thread Starter
Racer
Joined: Sep 2008
Posts: 435
Likes: 1
im running stock z06 injectors-idk what they are
he didnt really blame it on that but thats all he gae me. and he said thats the nature of the cam and it takes getting used to so just sip the clutch
Your tuner doesn't know what he is doing. To blame injectors for stalling and low rpm buck is just wrong. At 450 whp you would be fine with 30-36 #/hr injectors.
You need to find someone who knows how to properly tune a cam'd engine, and who knows to correct injector values to enter. Where are you located?
You need to find someone who knows how to properly tune a cam'd engine, and who knows to correct injector values to enter. Where are you located?
Burning Brakes
Joined: Mar 2006
Posts: 1,095
Likes: 5
From: Oldham County Louisville, KY
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
I agree with the above posters. The reason I asked about size was the small possibility of a stuck injector, or them being grossly oversized.
While at your HP levels, you are close to maxxing them out, they are not the cause of the problems you describe.
~Rich
While at your HP levels, you are close to maxxing them out, they are not the cause of the problems you describe.
~Rich
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Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
What's the cam specs?
In all fairness, when you install a really BIG cam, unless you are REALLY tuned well, you can lose some low speed drivability. Low # LSA (110-111) lots of overlap, etc., can hurt low rpm performance.
I know that a great tuner can tune any cam, but there are a lot fewer of those great tuners out there than you would think
In all fairness, when you install a really BIG cam, unless you are REALLY tuned well, you can lose some low speed drivability. Low # LSA (110-111) lots of overlap, etc., can hurt low rpm performance.
I know that a great tuner can tune any cam, but there are a lot fewer of those great tuners out there than you would think
Thread Starter
Racer
Joined: Sep 2008
Posts: 435
Likes: 1
its a VRX6 - 238/240 .605/.609 112. i know its big but theres bigger out there with better driveabitility. it bucks so hard it looks like were head banging to heavy metal lol. and stalls alot, even more with the a/c on. i already paied the tuner plus i really dont feel like being a d**khead and demanding my money back : / idk what to do. He has HP tuners, what would you guys start with the get the problem fixed? VE tables? what is that anyway lol
Melting Slicks
Joined: Sep 2003
Posts: 2,062
Likes: 117
Hey guy just installed a VRX6 into my 02 Z06. also did powerbond 25%, single roller timing chain, lunati double springs, trickflow 7.4 hardend rods, new ngk plugs with wires, vararam with velocity coupler, fast 90/90, OBX headers with stock TI and DMH cutouts. ran 449hp and 39 tq. i was ery happy with these number and the car runs very strong. the only problem im having is that at low rpms (below 1500) in first or second the car bucks very violently and when coming out of gear while driving the car will stall 2 out of 5 times. my tuner said my injectors were maxed and im going to go back with 42lbers. but i dont think thats my problem. anyone know what it could be? i got a dyno and street tune
Take a look at the three videos below, tuning is key there:
Idle:
http://www.youtube.com/watch?v=zcRY0g2OHZM
Drive ability:
http://www.youtube.com/watch?v=PL7h3..._order&list=UL
Power:
http://www.youtube.com/watch?v=pYhRh..._order&list=UL
Christian
Drifting
Joined: Sep 2007
Posts: 1,649
Likes: 50
From: Goldsboro NC
I believe they are 28.5lbs. Yea i had a cam install recently too and mine are running at 90-92% at WOT. I have a 233/239 cam. Your cam is a lil bigger than mine. So you would be running them close to max but like others have stated its in the tune. I will say though with a cam that big i wouldnt expect it to drive like stock. That being said, your tune could be better.
That being said, your tune could be better.
Burning Brakes
Joined: Mar 2006
Posts: 1,095
Likes: 5
From: Oldham County Louisville, KY
its a VRX6 - 238/240 .605/.609 112. i know its big but theres bigger out there with better driveabitility. it bucks so hard it looks like were head banging to heavy metal lol. and stalls alot, even more with the a/c on. i already paied the tuner plus i really dont feel like being a d**khead and demanding my money back : / idk what to do. He has HP tuners, what would you guys start with the get the problem fixed? VE tables? what is that anyway lol
Where to start? A new tuner...
Tech Contributor
Joined: Sep 2005
Posts: 1,731
Likes: 82
From: New Market AL
Where are you located?
It's a shame this "tuner" is out there taking people's money when he really doesn't have the experience to properly adjust a tune for a good size cam. This fellow is probably out $100 for the license of your car with HP Tuners. That is money spent. Anything that you paid him over $100 should be refunded unless he can fix your car to where it doesn't stall and only has minimal cam surge at low rpm in gear. The sad thing is, even big cam'd LS engines can be tuned to have excellent street manners and very respectable mileage. But a large number of "tuners" don't know how to properly tune idle and low rpm ranges. So many folks end up suffering with poor driveability, and they think that is "just the nature of having a cam'd LS engine". I'm not a professional tuner by any means, but I've tinkered with my car and a couple friend's Corvettes enough to learn a few things. I hope you can find someone to treat you right. If you are anywhere near Virginia Beach, go to Ed at Virginia Speed!!!
It's a shame this "tuner" is out there taking people's money when he really doesn't have the experience to properly adjust a tune for a good size cam. This fellow is probably out $100 for the license of your car with HP Tuners. That is money spent. Anything that you paid him over $100 should be refunded unless he can fix your car to where it doesn't stall and only has minimal cam surge at low rpm in gear. The sad thing is, even big cam'd LS engines can be tuned to have excellent street manners and very respectable mileage. But a large number of "tuners" don't know how to properly tune idle and low rpm ranges. So many folks end up suffering with poor driveability, and they think that is "just the nature of having a cam'd LS engine". I'm not a professional tuner by any means, but I've tinkered with my car and a couple friend's Corvettes enough to learn a few things. I hope you can find someone to treat you right. If you are anywhere near Virginia Beach, go to Ed at Virginia Speed!!!
Race Director
Joined: Mar 2008
Posts: 12,413
Likes: 502
From: Rio Rancho NM
You need a new tuner and don't let him get away without resolving your issue or your money back. Honestly just hearing his excuse just means he doesn't know how to tune the tables correctly. It's not the cam you know this.
Melting Slicks
Joined: Jun 2007
Posts: 2,172
Likes: 1
From: Sartell Minnesota
Where are you located? Might help you track down a better tuner. Here in MN we have a few EXCELLENT LS tuners and they can tune out just about any bad habits. My car, even when untuned, had decent manners just putting around town. To me it sounds like cam surge that's causing the bucking feel. That is a tuning issue. Mine did it at first and after some tweaking of the tune, after the initial tune, it was taken care of mostly. DRM(Doug Rippies) did mine. I also upgraded to Lucas 42lb injectors because i was worried about maxing out my stockers. It also left room for later mods and still have big enough injectors
Last edited by ColeTrain'sC5; May 3, 2011 at 08:59 PM.
Drifting
Joined: Sep 2007
Posts: 1,649
Likes: 50
From: Goldsboro NC
i just re-read somthing you posted...you said SINGLE ROLLER chain?!? I dont understand that move with such a large cam. I dunno maybe its just me but id feel like i was on borrowed time tracking the car. And NOT that often either.