What rpm's should I shift at?

[DAVZKAR]

My car has watson headers, 4:10 gears, B&B 3" tri -flo, no cats, and a chip burned just for this combo. So what rpm should I be shifting at the strip.

 

[jhong321]

I would guess about 6800 to 7000 I tend to shift at that point and have just about the same as you minus headers

 

[DAVZKAR]

I have been shifting 7 in 1st, 6700-6800 2nd, 6500 in 3rd, and letting 4th pull me through the traps around 6500.

 

[vettl83]

DAVZCAR, I was shifting my 91 between 7000 and 7200 rpm before I ran it on the dyno. The dyno showed me the car made max hp at 6800 before it started to fall off. The dyno operator is an old school drag racer and suggested I shift the car at 6800 rpm right at the peak of it's power. He was right the et's improved shifting at 6800 rpm. Maybe you could make a dyno run and see where yours is making max hp, it will also give you your a/f ratio over the entire rpm range. That info will let you know what a/f ratio your chip is providing, if it's to lean or to rich you can send it back to your chip burner with a copy of the dyno sheet and they can make corrections. Later, 84 CF 91 ZR1

 

[WB9MCW]

6800 shift

I have come to the same conclusion to shift at 6800. I feel that going to 7200 has no advantage! In fact when I shift at 6800 by the time i'm done the rpm's are at 7200 anyway!! I have a custom chip also!

 

[Hib Halverson]

Stock LT5s make peak power between 5800 and 6000 rpm. An engine modified as is the one discussed in the first post may have a power peak a couple of hundred rpm higher. The LT5 is fairly peaky so I'd start by shifting at 6600 or so then vary your shift rpm 200 or so in either direction and see how that effects your e.t.

Reference is made to shifting at 7200. That's impossible with a calibration having a stock rev limit of 7072 rpm. Cals can have higher rev limits but that's pointless unless the engine has ported heads and higher lift cams.

 

[vettered91]

I´ve found this site just two days ago and it may help you find your shifting points. First you need a Dyno Chart of your car or one from another with similar mods and your gear ratios. The main thing is that the best shift point is after your power peak.

I hope these can help you: http://www.prestage.com/community/carmath/dynochart.asp

 

[WB9MCW]

GOOD POST AND NICE WEBSITE prestage.com

nice chart there vettered 91...good info there at prestage.com for drag racing guys!!!

 

[vettered91]

nice chart there vettered 91...good info there at prestage.com for drag racing guys!!!

Thanks,

I hope it helps, I'm in the same quest after my cam swap (I just finished a week ago)

BTW.- I could use any help: http://www.corvetteactioncenter.com/forums/showthread.php?t=58777