Tried different NA shift points

[qwikhuh]

There was a good thread in here about where everyone is shifting their NA cars to get the best ET. I have always shifted at 6200-6300 for my best tiimes but I got the pass I wanted the first pass so I decided to try different RPMS to see what I might be leaving on the table. This is what worked for MY combo, your results will vary

Launched at 5500, powershifted every gear as close to 6300 rpms as I could on the stock tach
1.64 60
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Launched at 5500, powershifted every gear at 6600 rpms
1.65 60
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Launched at 5500, powershifted every gear at 6800 rpms
1.68 60 (got a little wheel spin on this launch)
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My best ET/MPH came shifting the car lower in the powerband but the differences were negligable at best. If I did not powershift and the RPMS dropped a lot further down the higher RPM might have made a bigger difference. My car is also still on the stock CMCV plates so it probably is leaving some high RPM power on the table.

 

[Matt D]

I got the opposite results when I shifted higher... hmm (on my stock long block combo)

every application has it's own special spot

 

[HEMI LOL]

What are your mods? This may be interesting based on your set up. For my lowly setup o shift at what I believe is 6400 but who knows lol.

 

[qwikhuh]

Matt I think the CMCV plates might be part of the difference, they might become a larger restriction than I thought over 6000 rpms. I am running in a 12.0 index race next weekend, after that I might switch to an 09 intake I have here with the Steeda delete plugs and try higher rpms shifting again.

Hemi I have typical bolt ons - BBK longtubes with X pipe, FRPP stingers, JLT cold air, suspension, drag wheels, DS, shifter, CJ springs, UD pullies.

 

[1fastpony]

Matt I think the CMCV plates might be part of the difference, they might become a larger restriction than I thought over 6000 rpms. I am running in a 12.0 index race next weekend, after that I might switch to an 09 intake I have here with the Steeda delete plugs and try higher rpms shifting again.

Hemi I have typical bolt ons - BBK longtubes with X pipe, FRPP stingers, JLT cold air, suspension, drag wheels, DS, shifter, CJ springs, UD pullies.

I think you'll find once you remove those CMCV plates another 8-10 or so rwhp. At least that is what folks 3-5 yrs ago dyno sheets indicated. I'm suprised you haven't removed them. To get full benifit, Set the rev limiter to at least 6890rpm but shift at 6500rpm and see a good 1/10 et pickup. I picked up 1-2 tenths and almost 2mph. The car will pull better on the top end of each gear without any loss of low end. When these came out late 05 early 06 they were a bastard to tune...especially the diablo tunes.

Are you full weight or put the car on a diet?
What tune do you run?

 

[fdjizm]

Very intresting results on how our cars different I and a few people I know found the best ET's when shifting at 6500 rpm...I've tried from 6000 to 6700 6500 was always sweet

 

[NA-Stang]

Im shifting at 6200, but was always afraid to shift higher. Do you guys suppose I could improve on my ET if I shift Higher?

Check out my mods in my sig line and let me know where you think I should be shifting...

 

[PUNISHERSTANG]

ive been thinking about that too, im still making payments on this bad boy but id like to move the rev limiter up. anyone have any problems shifting at 6500? im full bolt ons and i think i might see a little gain by shifting higher but i dont want to send parts flying

 

[fdjizm]

The 08 bullitt has a stock limiter of 6500rpm and you have the same engine minus the cold air intake, so I think ford had confidence the engine is OK till 7k stock.

 

[1fastpony]

Guys... If you have CMCV deletes you aint getting the benifit if not setting the rev limiter higer as indicated and shift at 6500. Drop the clutch with stickies at least ~5500. With street tires, roll out at 2krpm slipping the clutch. If you have 3:55 gears pull third all the way through traps.

And, let us all not forget the dreaded headlight delete mod.

 

[gmantheman]

Isn't the "ideal" sweet spot around 500 RPMS above peak hp? Looking at my dyno sheet, my peak hp is around 6300 RPMS. Before dynoing the car, I was shifting around 6500 RPMs. Maybe I should up it to 6700 or so.

 

[RetroGT2006]

ive been thinking about that too, im still making payments on this bad boy but id like to move the rev limiter up. anyone have any problems shifting at 6500? im full bolt ons and i think i might see a little gain by shifting higher but i dont want to send parts flying

I've had my modded automatic GT set to shift at 6500 for the past 15k miles of full out drag racing and abuse.. No problems so far, runs like a champ! My tuner had set it for that when i had my new tune written for my mods.

 

[RedFire07GT]

Ill be banging gears tomarrow at around 7grand... ill try 6500 as well to see what happends. Going to launch at 5grand for my first run. Its a rental so track prep will be nice !



Brandon

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