LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Lower Shift Points = Lower ET's??

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Old 06-28-2011, 02:37 PM
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Default Lower Shift Points = Lower ET's??

Using my current best time of 11.63 @ 116.42, anyone care to guess how much my ET's will change if I drop my shift points from 65-6700 to 62-6400 RPM's?
Old 06-28-2011, 02:38 PM
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Originally Posted by Mystery Bird
Using my current best time of 11.63 @ 116.42, anyone care to guess how much my ET's will change if I drop my shift points from 65-6700 to 62-6400 RPM's?
cam?
converter?
gear?
weight?
CR?
Heads?
Cubic Inch?


then sure lol
Old 06-28-2011, 02:42 PM
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Everythings the same just lowering shift points down a bit.
Old 06-28-2011, 02:48 PM
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I guess it should say higher ET's not lower.
Old 06-28-2011, 02:54 PM
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Originally Posted by Mystery Bird
Everythings the same just lowering shift points down a bit.
This is probably a good idea unless you have a forged bottom end or at least some ARP rod bolts....I tried spinning my stock LT1 with a cam to 6500-6600 or so and it went POP! How others can get away with 6700-6800 RPM on a stock block I don't know...lucky I guess. Lesson learned; forged bottom end, rev limiter and shift light are all going in my car for the next round. You will certainly be faster with a motor that is intact the entire run
Old 06-28-2011, 02:57 PM
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Originally Posted by ahritchie
This is probably a good idea unless you have a forged bottom end or at least some ARP rod bolts....I tried spinning my stock LT1 with a cam to 6500-6600 or so and it went POP! How others can get away with 6700-6800 RPM on a stock block I don't know...lucky I guess. Lesson learned; forged bottom end, rev limiter and shift light are all going in my car for the next round. You will certainly be faster with a motor that is intact the entire run
i ran my 355 with arp rod bolts with stock crank and rods 6800-7000 constantly for three years and it stayed together......they will last......




anyways..........idk its something you'd have to try......i can tell you non-stroker motors LOVE to rev........the higher i shifted my 355 the faster it went.....fastest it ever went was 11.40@ 122 and that was shifting at 7100 right at the edge of the PCM's capabilites at the time.......

now my current motor if i shift a bit lower it will slow down but not too much........more torque than my 355.....
Old 06-28-2011, 03:02 PM
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Originally Posted by quik95lt1
i ran my 355 with arp rod bolts with stock crank and rods 6800-7000 constantly for three years and it stayed together......they will last......
That's why I asked if he had ARP rod bolts or not....I seriously doubt the stock bolts will hold to 6800-7000 RPM for any length of time.
Old 06-28-2011, 03:44 PM
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Nope, stock bottom end. I was running a stocker for four years shifting at 65-6700 till I just recently spun a bearing. That is why I will be running a bit lower with this one.
Old 06-28-2011, 03:53 PM
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stock 10 bolt rear end with 3.73's? or what?
Old 06-28-2011, 03:59 PM
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A big question for me is how well do the heads flow and what valve springs? all other stuff can be assumed unchanged and not need to be addressed.
Old 06-28-2011, 04:08 PM
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Originally Posted by nitrous2fast
A big question for me is how well do the heads flow and what valve springs? all other stuff can be assumed unchanged and not need to be addressed.
Home ported heads, must be flowing ok if I"m running 11's and CC 918's.

Originally Posted by trilkb
stock 10 bolt rear end with 3.73's? or what?
Yes


What do these questions have to do with my original question? Just curious?
Old 06-28-2011, 04:18 PM
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Originally Posted by Mystery Bird
I guess it should say higher ET's not lower.
Never know till you try it; hell you might even be faster since your cam peaks at 6000 RPM....not 6500+ Ever had it dyno tuned? The dyno graph might tell you a lot at where it's making peak power and best shift points.
Old 06-28-2011, 05:01 PM
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Well for the head and springs question....

If the head is heavily ported to get high lift flow numbers then no the lower shift points aren't going to help you since that type of port makes the power band way up there in the rpms.

As for springs iirc the 918's are good but for 6800 rpms I don't know if they are the best. If the spring is not strong enough the valve may be a little slow to close causing the DCR to drop at those rpms.

I'm just saying that if the heads aren't ported properly causing the powerband to be too high and you weren't running enough spring you wouldn't be in a good situation to do anything different.
Old 06-28-2011, 07:10 PM
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The answer to this question lies completely in your power band. Without knowing where your power peak is nobody can answer tbis question. I have the same problem, I'm guessing my peak power, I NEED to dyno it to find out where I should shift.
Old 06-28-2011, 07:26 PM
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Originally Posted by LSWHO
The answer to this question lies completely in your power band. Without knowing where your power peak is nobody can answer tbis question. I have the same problem, I'm guessing my peak power, I NEED to dyno it to find out where I should shift.
bingo.....
Old 06-29-2011, 07:05 AM
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I guess only time will tell now. thanks guys.
Old 06-29-2011, 07:13 AM
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Originally Posted by LSWHO
The answer to this question lies completely in your power band. Without knowing where your power peak is nobody can answer tbis question.
Shazam!
Old 06-29-2011, 08:21 AM
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Originally Posted by LSWHO
The answer to this question lies completely in your power band. Without knowing where your power peak is nobody can answer tbis question. I have the same problem, I'm guessing my peak power, I NEED to dyno it to find out where I should shift.
Agreed.
Old 06-29-2011, 01:48 PM
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Originally Posted by LSWHO
I have the same problem, I'm guessing my peak power, I NEED to dyno it to find out where I should shift.
Bull...****...
Old 06-29-2011, 01:59 PM
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Originally Posted by gregrob
Bull...****...
WTF. Get off my nuts Grob.

Where's my peak power at Colorado man?


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