CorvetteForum - Chevrolet Corvette Forum Discussion

CorvetteForum - Chevrolet Corvette Forum Discussion (https://www.corvetteforum.com/forums/)
-   C5 Forced Induction/Nitrous (https://www.corvetteforum.com/forums/c5-forced-induction-nitrous-86/)
-   -   [Drag]FI/big cam/MN6 stock bottom guys, how high i should shift ? (https://www.corvetteforum.com/forums/c5-forced-induction-nitrous/3263097-drag-fi-big-cam-mn6-stock-bottom-guys-how-high-i-should-shift.html)

Steve@C56 04-30-2013 06:36 PM

[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 ?

Y2KRoadster 04-30-2013 06:42 PM

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?

joshtownsend 04-30-2013 07:06 PM

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!!!

Steve@C56 04-30-2013 07:07 PM


Originally Posted by Y2KRoadster (Post 1583779605)
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

Y2KRoadster 04-30-2013 07:17 PM


Originally Posted by Steve@C56 (Post 1583779785)
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.

Steve@C56 04-30-2013 08:02 PM


Originally Posted by Y2KRoadster (Post 1583779876)
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

Y2KRoadster 04-30-2013 08:06 PM


Originally Posted by Steve@C56 (Post 1583780319)
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!

Steve@C56 04-30-2013 08:10 PM


Originally Posted by Y2KRoadster (Post 1583780360)
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 !!!)

Steve@C56 04-30-2013 08:59 PM


Originally Posted by joshtownsend (Post 1583779778)
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 :D

Thanks

joshtownsend 04-30-2013 09:27 PM

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...

Turbo-Geist 04-30-2013 09:28 PM

Have you determined at what rpms your car makes peak horsepower and torque?

winters97gt 05-01-2013 12:08 AM

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. :cheers:

Steve@C56 05-01-2013 05:08 AM


Originally Posted by joshtownsend (Post 1583781117)
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 ;-)

Steve@C56 05-01-2013 05:11 AM


Originally Posted by Turbo-Geist (Post 1583781123)
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)

Steve@C56 05-01-2013 05:46 AM


Originally Posted by winters97gt (Post 1583782466)
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. :cheers:

Here is dyno of same block/sc quite similar spec cam but with less psi :
http://www.aacorvette.com/blog/wp-co...011/04/001.jpg

winters97gt 05-01-2013 11:44 AM

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.

Steve@C56 05-01-2013 12:53 PM


Originally Posted by winters97gt (Post 1583785513)
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 :D

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

Arun@Dasilvamotorsports 05-01-2013 01:45 PM

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.

Steve@C56 05-01-2013 03:51 PM


Originally Posted by Arun@Dasilvamotorsports (Post 1583786647)
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 :thumbs:

robz 05-01-2013 03:56 PM


Originally Posted by Steve@C56 (Post 1583787715)
A have it
Just have to put it :thumbs:

I'm setting the shift light @ 6800 for a stock ls6 with stock rod bolts.


All times are GMT -4. The time now is 09:59 PM.


© 2024 MH Sub I, LLC dba Internet Brands