New LS1 Owners - Newbie Tech - Highest safe range for REV/Shift Points. DYNO SHEET PIC!!!

I posted this thread in the Automatic trans section, and as usual no reply's.

Please help...


A buddy of mine, Help me out Identify my TA's poor performance.
First of all, My rev limiter... Its set to 6500 RPM, but of course i payed no mind to that.
My shiftpoints on the other hand! I noticed my ride being a lil sluggish, but many said its just the stall feel, and it shifts right at 6000 RPM, which should be a lil higher, considering i have 3800 stall and needs that extension shift.

Im a lil bummed out about it, just want my ride to be tuned right, and me being pretty new to Modding, dont know what to ask for, and trust the pros to help me with my Ignorance.


So my question is, What would you set your rev limiter and shiftpoints too? And Whats the unsafe point with stock ls1 bottom end.

MODS IN SIG...


Thoughts welcome...

I don't think the gauges are exactly accurate. Your cam won't like to be tuned any higher. Who tuned it?

I don't think the gauges are exactly accurate. Your cam won't like to be tuned any higher. Who tuned it?

Doesnt the stall need that extra rev so it wont start at lower rpm's once it has shifted?

I know the gauge is not very accurate, but I have friends with similar set ups and their cars rev (SOUND) much higher than mine.

yes, have you been retuned since your cam install? and is your trans ok?

Doesnt the stall need that extra rev so it wont start at lower rpm's once it has shifted?

:confused:

I think you may be confused. You don't need higher shift points simply due to adding a higher stall converter. The higher stall speed will actually increase your shift extension even with the stock shift points.

The ideal shift rpm for a given application will depend on your power curve. In a perfect world, you'd want to upshift at the point of peak horsepower and then have the rpms drop (shift extension) no lower than your torque peak. Then you'd want to be geared in such a way that you'd climb right back to peak horsepower again at the moment you cross the traps. But the world is not perfect, and neither are most street combos, so best results will usually come from shifting slightly higher than your peak horsepower, unless stall speed and gearing is perfectly optimized for your powerband.

You need to run a data log of your current shift points to see if your tach is accurate. With your cam and stock heads, I would think that shift points in the 6300-6400 range would usually be just about right, but those shorty headers you have might not allow the cam to reach full potential in that rpm range. It would be better to see a dyno sheet of your exact setup rather than to just guess.

Agree with RPM WS6 100%, and since ur talking shift points, you also need a valve train that can support higher rpms.

:confused:

I think you may be confused. You don't need higher shift points simply due to adding a higher stall converter. The higher stall speed will actually increase your shift extension even with the stock shift points.

The ideal shift rpm for a given application will depend on your power curve. In a perfect world, you'd want to upshift at the point of peak horsepower and then have the rpms drop (shift extension) no lower than your torque peak. Then you'd want to be geared in such a way that you'd climb right back to peak horsepower again at the moment you cross the traps. But the world is not perfect, and neither are most street combos, so best results will usually come from shifting slightly higher than your peak horsepower, unless stall speed and gearing is perfectly optimized for your powerband.

You need to run a data log of your current shift points to see if your tach is accurate. With your cam and stock heads, I would think that shift points in the 6300-6400 range would usually be just about right, but those shorty headers you have might not allow the cam to reach full potential in that rpm range. It would be better to see a dyno sheet of your exact setup rather than to just guess.


Here is my dyno sheet, And I have to agree that the shorties are holding me back.
I do have a set of long tubes and Y pipe heading my way in the mail as we speak. So that will take care of the restriction in air flow.

If you look at the dyno sheet, my Hp is still climbing at 6000RPM, not by much, but do feel my shifts should be around 6200-6300.

You guys input is much appreciated!!!...


355961



355962



355963


The lines in red is with a Locked TQ, and the Blue is with it being unlocked.

yes, have you been retuned since your cam install? and is your trans ok?

Yes sir, it has been tuned for cam and retune once the trans/stall upgrade was done.
The transmission is working great, strong and fast shifting.

Help anyone...

Rev limiter 6800-7k, shift around 5.8-6k. By the time you actually react to a RPM or shift light you will be 6.5k RPMs.

6400.

The rev limiter is there for 'OH SHIT' moments you don't want to touch it. I'd rather over rev by a few hundred RPM than be against the limiter.

Thought you meant actually shifting the car... disregard the last post- tell the computer to shift around 6.2k. But the best way would be at a track and keep moving the shift points til the car slows down.

Do you ever lock the TC other than on the dyno? If not, then based on the blue (unlocked) line, I would shift the car at no less than 6300rpm.

This might change once you do the LT headers. You'll need to re-dyno to know for sure.

Do you ever lock the TC other than on the dyno? If not, then based on the blue (unlocked) line, I would shift the car at no less than 6300rpm.

This might change once you do the LT headers. You'll need to re-dyno to know for sure.

Yes, the only time the converter is locked, is at the dyno. With long tubes and y pipe, Do the shifts and rev go higher?

I do not think that LT's should have any real effect on when the car shifts or how high it revs

I do not think that LT's should have any real effect on when the car shifts or how high it revs

Ok, so if im having them intalled i wont need to retune, just shift point adjustment.

With long tubes and y pipe, Do the shifts and rev go higher?

You may want them to go higher, but it won't happen automatically - you would have to make adjustments to the shift points in your tune.

You may find that horsepower won't drop off as much or as early with the LTs. So the ideal shift point for your setup may be different once the LTs are in place.

Ok, so if im having them intalled i wont need to retune, just shift point adjustment.

I would get another tune. Shorties are barely any different than stock manifolds, so the ideal tune for a shorty setup will not be the same as for LTs. Install the LTs, then re-tune and see what the new power curve looks like.

Thank you all very much guys!!! Always great help...

RPM WS6, Great breakdowns for us noobs as usual :cheers:

Shift at 6300 and set the limiter at 6800 max to stay safe with the stock bottom end. The long tubes will help the top end a lot while moving everything up a bit. I would wait till you get the lt's before paying to reset everything.

Shift at 6300 and set the limiter at 6800 max to stay safe with the stock bottom end. The long tubes will help the top end a lot while moving everything up a bit. I would wait till you get the lt's before paying to reset everything.

I wont have to pay fo the shift points, I already payed a fee for that. If they are not right, they have to warranty the tune. Good ppl by the way, so i know they'll work with me.

Headers and y pipe check/tune, maybe a different story.

we have had people gain tenths buy lowering shift points. look at where the average power is and go a lil beyond that, and depending on your gears in the rear, check to see how far it drops. 3:73's really kept me in the power band on my auto. id say shift at 6350-6400 and 6500 on out. the rods dont like that shit.

we have had people gain tenths buy lowering shift points. look at where the average power is and go a lil beyond that, and depending on your gears in the rear, check to see how far it drops. 3:73's really kept me in the power band on my auto. id say shift at 6350-6400 and 6500 on out. the rods dont like that shit.


Thats the range I have in mind... Thanks for the input.

One thing tho, will installing LT and ORY change the rpm shift points?

Good info. Doing a ls1 swap with a glide so this is right up my alley

Now with the long tubes and ORY, my power drops around 6600, and im shifting at 6400.

Its a lil frustrating, specially when its been retuned for this same purpose. Not sure if they are playing it safe or what. Feels like i should be at 6500 to 6600 with rev limiter at 6700