SPRAYED 01

iTrader: (22)

Im running a 370 right now and im running out of gear going low 10s. Im adding about 75whp for next year and I want to go numerically lower. Im using a 28inch tall tire and want to end the traps at about 6k. Right now im pushing 6800rpm. Id like to keep it lower along with shift points to give the 4l65e a chance.

Alex

droksformula

iTrader: (18)

Well, for a 9" you got 3.5 and 3.25 that you can step down to.

Is that a non lock up converter ? Just using the mph in your sig, your rpm's would be around 6k if there was absolutely no slip.

Also going through the traps at 6k with a 370 sounds like you would not be using its full powerband.

SPRAYED 01

iTrader: (22)

Its a lock up converter but I don't lock it in 3rd at the track. Just to clarify I'm running a 370 gear not engine. What do u think a good rpm would be to finish at. Motor will now make its peak power at around 6500

droksformula

iTrader: (18)

Oops, idk what I was thinkin about the 370 engine instead of gear. You probably want to cross the traps at the peak hp rpm or just after.

This is just me, but maybe instead switching rear gears, look into getting a premium lockup converter that you Can lock up in 3rd. Your rwhp, trap speed would go up and and your rpms might drop a little through the traps.

Just sayin.

SPRAYED 01

iTrader: (22)

I am running a 3 disc vig verter. I just don't trust locking it up with that much hp and torque.

dudeman

iTrader: (43)

how much boost and timing are you running?

tomz28

iTrader: (20)

what is the limit for hp on that converter? and how hard are you pushing your setup now? (boost, rpm and shift pionts)

how fast do you want to go? is this a street car or track car or 50/50 need some more info bro to help out. what is your rpm drop when you shift gears

SPRAYED 01

iTrader: (22)

Its 80% street running 15psi shifting at 6200 now. With bigger exhaust housing id like to shift at 6800. It will make peak power at 6500 so I'm think finishing the traps at 6800ish

LASTLS1

iTrader: (7)

Go with a 3.23-3.40 I ran one for a long time. My car loves to be loaded.

SPRAYED 01

iTrader: (22)

Im running 10.4 @133 now but I plan on adding about 75 more whp with alot bigger ar housing on the tc 78. My goal is 9.8 @ 137ish

tomz28

iTrader: (20)

ok you are in the same boat as I. do you have a 2-step if not get one of those. We need to get that 60 foot down i have the same **** 60 foot as you LOL(see my sig for time). how does the car feel when you spin the engine past 6500rpm? try spining the rpm alittle high from 1st to 2nd and into 3rd this will help. granny shift the hell out of my car when i ran my PB so i need to do the same thing.
try doing this before you change your gear out. it might save you some cash and time, and if it doesnt help go for that 3.25 gear that way you have room to grow as you more power as time goes on.

ps do you data log your runs

Bob@BruteSpeed

iTrader: (16)

Running low 10's with a 3.70 gear and 28" tall tires and going through at 6800 rpm sounds to me like you're driving through that non locked Vigilante converter. Bob

tomz28

iTrader: (20)

i was thinking that as well

Pro Stock John

iTrader: (34)

I'd keep in mind that 3.50 gears are good for mid 150's mph... jus' saying.

I ran 3.50 gears blower and turbo, and I was nowhere near 6800 in the 1/4 even at my lowly 145 mph.

SPRAYED 01

iTrader: (22)

I think the 323 might be my best bet. I'm also excited about the better mpgs. I get 22mpg on the highway now. Il drop 400rpm at 75mph with those gears. Not that I built the car for fuel economy but its cool having a 9sec daily driver that gets 25mpg on a trip on pump gas

Pro Stock John

iTrader: (34)

I think you might want to get your new combo sorted out, and then calculate the amount of slippage you are getting from that converter. Going 133 mph, 3.70's, on your 26's seems like the slippage is more of a problem, and it could get worse once you put more power through it.

28's and 3.23's will end up being like 2.73's & 26's, and I'd only drop down to 3.50's at the most.

SPRAYED 01

iTrader: (22)

I am using 28s. I have never ran a 26. The converter is very tight.

Pro Stock John

iTrader: (34)

What are you shifting at?