overrevving

My friend over-revved his 5.0 (3rd to 2nd shift on the drag strip...dumb move) - bent valves, damaged pistons, roller rockers, had to replace his engine - unless yours was built for high RPM's I'd refrain from it. Mine shifts at about 6700 RPM's, and it's designed for higher RPM.

my .02 is set you limiter to like 6200rpms so you don't ahve to worry about it.

did you raise you limiter all the way to 7k? you relize you power band proably ends at like 5800 or something. with your mods I don't see the point in have the limiter any higher than stock really. 6200-6300 max.

short story long it is very bad. that is the whole reason a rev limiter was invented.

rule of thumb I have read is 6500rpm is max on the stocker. that is only nessary if you are actually making power up that way.

Is it good for the car... NO but I have hit the rev limiter countless times on all the mustangs I have ever owned (All 4.6's) and have never spun a bearing, thrown a rod ect...

Oh I didnt see that you hit 7k... Yeah thats bad.

Your driving a mustang not a RX8, 7k is a bad thing for are cars.

If you don't hear ticking, knocking, or have smoke clouds behind you now, you're probably alright.. but I wouldn't do it on purpose.

I'm surprised that yours can wind that high. Mine hits the rev limiter around 6200. I see from your sig that you have a SCT tuner. Which may mean your limiter was bumped up.

steveb24 said:

yea the guy who tuned it set it at like 8000 rpm..basically turned it off.

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I would run away QUICK from anyone dumping the rev limiter on a light-mildly modded mustang GT.


-J

steveb24 said:

yea the guy who tuned it set it at like 8000 rpm..basically turned it off.

Click to expand...

i would reset that rev limiter back to 6500 TOPS..

my car survived a 2-1 powershift. that was bad.

Mines set @ 6500 and I have hit it on a few occasions....and with EASE. Im VERY glad its set there. Get your set back down to 6300RPMs.

The reason he did it is because he thinks that its better for it to quickly spin to 7K than hit the limiter @ 6K...I have met a few people like that.

steveb24 said:

yea the guy who tuned it set it at like 8000 rpm..basically turned it off.

Click to expand...

I think he wants some return business out of you. You should drop it back down to 6,200. Every engine is different. Who knows how many times you can rev to seven grand before the engine says bye-bye.

Contrary to consensus, I would set it even lower than 6200, maybe 5700-6000. Because a stock 4.6L quits making power after 5500 rpm. There's no reason to rev any higher.

I'll leave mine at 6,800.

TQ peak is at 4000

HP peak is at 5250

generally you want to be shifting right into the powerband, or basically at baout 4000 rpm, so going about 5700 is just wasting time

yeah thats true about the power peaking at about 5500. when i said 6500 i meant that is the absolute max you can get away with reving one of these..

You do not shift at peak power to make the best times. You want to maximize power across the shift range. Shifting at peak will drop you lower in the power band at the beginning of the next shift. Here are some shift point calulations using my old dyno numbers before the supercharger.

Optimum Shift Calculator by Bowling and Grippo
Input Parameters Are the Following:
Transmission Ratio One = 3.37 to 1
Transmission Ratio Two = 1.99 to 1
Transmission Ratio Three = 1.33 to 1
Transmission Ratio Four = 1.00 to 1
Horsepower = 100 at 2000 RPM
Horsepower = 130 at 2500 RPM
Horsepower = 150 at 3000 RPM
Horsepower = 200 at 3500 RPM
Horsepower = 240 at 4000 RPM
Horsepower = 260 at 4500 RPM
Horsepower = 270 at 5000 RPM
Horsepower = 265 at 5500 RPM
Horsepower = 220 at 6000 RPM

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Computation Results
Using the Criterion for Maintaining the Same Horsepower Before and After Shift:
Finding Best Shift Placement Points For Ratio 3.37 to 1.99: Error: Search outside range - need more RPM range in HP table! Finding Best Shift Placement Points For Ratio 1.99 to 1.33:

Found optimum shift RPM at 5882, which achieves 236 horsepower and lowers the RPM To 3931 after shift
Finding Best Shift Placement Points For Ratio 1.33 to 1.00:

Found optimum shift RPM at 5702, which achieves 253 horsepower and lowers the RPM To 4288 after shift


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Maximizing the Area Under the Horsepower Curve:
Finding Best Shift Placement Points For Ratio 3.37 to 1.99:

Found optimum shift RPM at 5995, which achieves maximum area under horsepower curve, and lowers the RPM to 3540 after shift
Finding Best Shift Placement Points For Ratio 1.99 to 1.33:

Found optimum shift RPM at 6000, which achieves maximum area under horsepower curve, and lowers the RPM to 4010 after shift
Finding Best Shift Placement Points For Ratio 1.33 to 1.00:

Found optimum shift RPM at 5998, which achieves maximum area under horsepower curve, and lowers the RPM to 4510 after shift

http://www.bgsoflex.com/shifter.html

wow....please dont post anything like that again...makes us look bad.