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?

cam?
converter?
gear?
weight?
CR?
Heads?
Cubic Inch?


then sure lol :D

Everythings the same just lowering shift points down a bit.

I guess it should say higher ET's not lower.:thinker:

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! :bang: 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:D

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.....

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.

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.

stock 10 bolt rear end with 3.73's? or what?

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.

Yes


What do these questions have to do with my original question? Just curious?

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.

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.

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.....

I guess only time will tell now. thanks guys.

Shazam!

Agreed.

Bull...shit...

WTF. Get off my nuts Grob.

Where's my peak power at Colorado man?