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[Drag]FI/big cam/MN6 stock bottom guys, how high i should shift ?

Old 04-30-2013, 06:36 PM
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Steve@C56
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Default [Drag]FI/big cam/MN6 stock bottom guys, how high i should shift ?

Regarding my supercharger interpeller max speed/pulley, the max is 6550rpm (but have seen A LOT who dont care)
Regarding my cam, the powerband finish at 6900rpm
Ragarding stock LS1 (65000 miles, just put centri, 2" header, cam/spring/pushrod/retainer, 1000cc inj, E85 agressive tune, NEVER PUT OFF HEADS ) ???

Can you give advises for the shift rpm should i use for drag race with my MN6 this weekend ?
Highest should be better for staying in high HP at each shifting... 7000 is ok ?
Best is stay under xxxx for rods or other ?
Old 04-30-2013, 06:42 PM
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Y2KRoadster
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Got a couple questions for you first. Do you already have money set aside to fix/buy anything that might break (including your motor)? What supercharger, psi, and what power are you making?
Old 04-30-2013, 07:06 PM
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joshtownsend
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no questions.. 7100...did it for 1.5 years... sure the values stems were on the way out when i pulled the motor but who cares.. its a stock motor anyways.. why have 2 in headers if you dont use them!!!
Old 04-30-2013, 07:07 PM
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Steve@C56
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Originally Posted by Y2KRoadster
Got a couple questions for you first. Do you already have money set aside to fix/buy anything that might break (including your motor)? What supercharger, psi, and what power are you making?
I have the money if it's appears, but realy dont want to break for , it's my DD

Supercharger : Vortech V3 Si
PSI : 12lbs
Power : 650/700rwhp according to some CF guys

Last edited by Steve@C56; 04-30-2013 at 07:10 PM.
Old 04-30-2013, 07:17 PM
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Y2KRoadster
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Originally Posted by Steve@C56
I have the money if it's appears, but realy dont want to break for , it's my DD

Supercharger : Vortech V3 Si
PSI : 12lbs
Power : 650/700rwhp according to some CF guys
Just make sure you have plenty of fuel, and the tune is safe. If you have all of that, you should be okay to 6800.

In my personal opinion, I wouldn't shift it over 7000 but that's just me. Many others (like Josh) have done it for years with no problems. If this is your DD...you might want to take that into consideration.

Last edited by Y2KRoadster; 04-30-2013 at 08:05 PM.
Old 04-30-2013, 08:02 PM
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Steve@C56
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Originally Posted by Y2KRoadster
Just make sure you don't know, have plenty of fuel, and the tune is safe. If you have all of that, you should be okay to 6800.

In my personal opinion, I wouldn't shift it over 7000 but that's just me. Many others (like Josh) have done it for years with no problems. If this is your DD...you might want to take that into consideration.
RIGHT !
I'm the tuner, and will change the tune at each run if needed
I havent test AFR over 6550rpm (converting from E85 ratio to Fuel ratio, have hit 12, exactly what i expect on 6400 cell) since my cam change
For security, i expect 11.6 at 6800
I will probably have to test the track the day before the race (usually, they ask me), so, i will valid my tune
Old 04-30-2013, 08:06 PM
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Y2KRoadster
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Originally Posted by Steve@C56
RIGHT !
I'm the tuner, and will change the tune at each run if needed
I havent test AFR over 6550rpm (converting from E85 ratio to Fuel ratio, have hit 12, exactly what i expect on 6400 cell) since my cam change
For security, i expect 11.6 at 6800
I will probably have to test the track the day before the race (usually, they ask me), so, i will valid my tune
Oh good. Yeah the A/F up there is what can do you in if it's too lean!
Old 04-30-2013, 08:10 PM
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Originally Posted by Y2KRoadster
Oh good. Yeah the A/F up there is what can do you in if it's too lean!
No risk from my 1000cc, but always surprise to have good A/F on STOCK FUEL LINE ! (returnless style 2000 vette !!!)
Old 04-30-2013, 08:59 PM
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Originally Posted by joshtownsend
no questions.. 7100...did it for 1.5 years... sure the values stems were on the way out when i pulled the motor but who cares.. its a stock motor anyways.. why have 2 in headers if you dont use them!!!
+7000 ! Great
I will test

Thanks
Old 04-30-2013, 09:27 PM
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joshtownsend
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I truly believe the key is...... not to care... hahaha It seems if you don't really care what happens, things always go good..... look at all them 4.8/5.3 junk yard motors that they put so much power thru without breaking because they just don't care...
Old 04-30-2013, 09:28 PM
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Have you determined at what rpms your car makes peak horsepower and torque?
Old 05-01-2013, 12:08 AM
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winters97gt
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A dyno graph is always good to have before going to the track, as Turbo Geist mentioned to see where the peek power and curve is. You can kind of get an idea of where you should shift and then go up and down slightly based on that. It might save you some abuse of making more passes on the car to get it dialed in. As a general rule, I shift around 500rpm past peak power for best ET and then go up and down from there and watch what the MPH does.
Old 05-01-2013, 05:08 AM
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Originally Posted by joshtownsend
I truly believe the key is...... not to care... hahaha It seems if you don't really care what happens, things always go good..... look at all them 4.8/5.3 junk yard motors that they put so much power thru without breaking because they just don't care...
In fact, it's exactly what i do for my trans (everything is stock 2000 c5 ;-)
Old 05-01-2013, 05:11 AM
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Originally Posted by Turbo-Geist
Have you determined at what rpms your car makes peak horsepower and torque?
not yet, i always mod my car (cam is my last one, 3.5" or 4" tubing for intake will be next)
Old 05-01-2013, 05:46 AM
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Originally Posted by winters97gt
A dyno graph is always good to have before going to the track, as Turbo Geist mentioned to see where the peek power and curve is. You can kind of get an idea of where you should shift and then go up and down slightly based on that. It might save you some abuse of making more passes on the car to get it dialed in. As a general rule, I shift around 500rpm past peak power for best ET and then go up and down from there and watch what the MPH does.
Here is dyno of same block/sc quite similar spec cam but with less psi :
Old 05-01-2013, 11:44 AM
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winters97gt
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Shift it high. You're likely peaking power wise at 6700-6800rpm or so and your torque looks pretty flat up top. I'd shift it at 7000.
Old 05-01-2013, 12:53 PM
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Originally Posted by winters97gt
Shift it high. You're likely peaking power wise at 6700-6800rpm or so and your torque looks pretty flat up top. I'd shift it at 7000.
7100, 7000, i will hit 7050

I think... i HAVE to install my shiftlight !

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To [Drag]FI/big cam/MN6 stock bottom guys, how high i should shift ?

Old 05-01-2013, 01:45 PM
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Arun@Dasilvamotorsports
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Peak power rpm + 400-if you can slam gears fast and hard.

If not shift at peak power on the graph.

Buy a shift light.
Old 05-01-2013, 03:51 PM
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Originally Posted by Arun@Dasilvamotorsports
Peak power rpm + 400-if you can slam gears fast and hard.

If not shift at peak power on the graph.

Buy a shift light.
A have it
Just have to put it
Old 05-01-2013, 03:56 PM
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robz
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Originally Posted by Steve@C56
A have it
Just have to put it
I'm setting the shift light @ 6800 for a stock ls6 with stock rod bolts.

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