Changing Rev Limit from 6000 to 6200 on 5.7L HEMI 91 CAI Tune

[DarthXan]

So after reading around the forums, I think I understand a little better about shifts and revs. Here's my understanding and please let me know if it is sound or if I'm totally lost lol...

The shift points can be increased to 6000 rpm, which means at WOT (flooring it) the car, in auto mode, will shift at that rpm setting. With this, you must also raise the rev limit so the shift & rev limit aren't the same, so I would set that to 6200 rpm. When not flooring it, the car will auto shift at much lower rpm to conserve fuel.

Also, in auto stick mode, the car auto shifts at some point regardless of when you want to, so in order to shift as close to the rev limit as possible, you must disable auto shift mode.

Overall, I would like to change...

Shift Points: 6000 rpm
Rev Limit: 6200 rpm
Auto-Stick Shift: Disabled

I already have...

91 Octane CAI Tune
MDS Disabled
Shift Firmness Increased
Speed Limit Uncapped

Will those shift point & rev limit changes be safe for my car, & will my performance (0-60 time) improve?

[DarthXan]

I won't make the changes without some feedback on whether its worth it / safe, so any advice would be much appreciated guys. Thanks

[silver06hemic]

Truthfully its debatable... some say that the stock points work better as the stock valve train is not going to help you produce any extra power above 5700rpm... so why float the valves a little for no extra power....

Personally when my mods were just a predator, CAI and a tstat I bumped the limits as you have said... to me I liked it as when it did shift it put me right in the power band on the next gear. I ran that way for 50,000 miles and when the heads were pulled to be changed along with my cam they looked as good as new... so no damage as the few people who may mention it may claim... but that's just my finding.

My 2 cents is that it is a good way to go so as to put you square in the power on the next gear... I believe the motor is 6400 rpm balanced so no issues with the bottom end limits. I say go with it and see how it feels to you..

[onesickhotrod]

Why would you want to raise the shift points so high? Your losing power at that high of an rpm. what about looking at some dyno charts of someone with similar mods and determine what shift points would be best for you!

[silver06hemic]

Oh... and beware of switching off the auto upshift (if you can anyway in your software revision) as it's tough to shift up at 6k in 1st and 2nd without bouncing the limiter... if you leave it on it will auto upshift at 6k anyway!

...and also FYI one of my best times with a 91 tune, CAI and a tstat was with raised shift settings... I attribute it to putting the car in the power band better... losing HP for the 1-2 seconds taken into consideration, I found it better to lose the power there while in momentum than to have to climb back into the power band after a shift.

[DarthXan]

So then I should increase Rev Limiter to 6200 (it was at 6000 to begin with) & increase shift points to 6000, but keep auto shift on (not disable it) since it will auto shift anyways at 6000?

If that's the case and from what you guys say its safe then ill do that and try it out.

[silver06hemic]

Yes its safe enough to do... you won't gain any lost HP and will lose some up there actually but you may like the effect of landing a little higher up in the next gear... have at her! Good luck... let us know if you like it!

Rob

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[MADDOG]

There's no real advantage to this. Shift point RPM's should be closer to the spot there the vehicle makes the most power, not nearer to the redline. You are not seeing any increase in HP near redline and it's a waste of time to be there...

Stock 5.7L HP & torque ratings at the crankshaft are:

1. 368 hp @ 5150 RPM

2. 389 lb @ 4250 RPM

Personally, I'd set my shift point closer to where the car makes max HP + 500 RPM so that it doesn't lag between current and next gear as it shifts.

[DarthXan]

I went & changed the shift points but the only options were 6200 & 6400, so I picked 6200 & set Rev Limiter to 6400.

I woulda liked 6000 shift with 6200 rev but that wasn't an option.

Is the 6200 shift point with 6400 rev limiter ok, or will it be bad for the engine? I just don't wanna harm my engine so if its pushing it, ill just keep these stock.

[DarthXan]

Originally Posted by MADDOG

There's no real advantage to this. Shift point RPM's should be closer to the spot there the vehicle makes the most power, not nearer to the redline. You are not seeing any increase in HP near redline and it's a waste of time to be there...

Stock 5.7L HP & torque ratings at the crankshaft are:

1. 368 hp @ 5150 RPM

2. 389 lb @ 4250 RPM

Personally, I'd set my shift point closer to where the car makes max HP + 500 RPM so that it doesn't lag between current and next gear as it shifts.

K I may just change them back if that's the case. Thx.