Anyone Running A Power Adder And An Auto?

[Deleted member 38176]

Ok so I'm barely beginning to learn that WOT + O/D = no bueno!

So that means I have to run with OD off at the track.....meaning that I've only got 3 gears!!!

Obviously my 4.10's are history. I was going to go with 3.73's, but I think that will still be too much with 3 gears and 500rwhp. Are stock 3.27's the best route?

This is all new to me and Im freaking out!

 

[Deleted member 38176]

Fuq it. Im going to run into OD and if the OD disc poops out then so be it....

 

[Three50won]

Well if you get to redline before the end of the track then you would either have to dead rev and cease all forward acceleration or shift into overdrive to get a little more acceleration. You really won't know until you get out there and make a few runs. It all depends on when you hit red line. But no, the stock 3.27s would not offer an advantage over the 4.10s.

 

[Deleted member 38176]

That's just it, I know that Im going to max out before the finish. Even 3.55's sound too steep for only 3 gears and 1320 feet, hence the 3.27's

 

[Three50won]

I don't know man. I would have to say that you're better off with 4.10s over 3.27s.

 

[restomod66]

The 3rd gear in your auto is still a 1:1 gear the same as 4th gear in a 5 spd car. There are other factors involved such as what wheel/tire size you're running in the rear that would determine if you're going to run out of gear on the big end. With a set of 3.73's I doubt you'd be running out of gear at the track, but it all comes down to the math. I'd look into an RPM calculator to determine what best suits your needs. One thing is an absolute here, if you continue to bang wide open throttle shifts into OD you will toast that transmission. At the very least turn OD completely off while at the track, it will cost you less, and keep you off the tow truck haha.

 

[Deleted member 38176]

Wont upshifting to OD @ WOT only damage/destroy the OD band and not any of the other clutches? Wouldn't 1-3 still work?

 

[sneaky98gt]

WOT shifts into overdrive at your power level WILL toast the overdrive band in quick order. You are correct in that it won't directly damage the other gears, but all that band material circulating around in your oil will likely damage the entire transmission. Bottom line: WOT shifts into overdrive are completely out of the question at your power level.

3.73s are still your best bet. I answered this in a thread you posted a few weeks ago: "With stock size tires (25.66") and 3.73s, 120 mph would be 5863 rpm. 125 mph would be 6107 rpm. 130 mph would be 6352 rpm. So as long as you are ok with turning 6300-6400 rpm, and don't plan to go over 130 mph, the 3.73s are certainly ideal for the track."

Even assuming your car really does trap 130 mph (no offense, but I don't see it happening), you're at less than 6400 rpm in 3rd when crossing the traps. You said your valvetrain is completely upgraded (which means it should be good to probably 7000 rpm), so I don't see why you're worried about anything.

Honestly, your 4.10s would actually probably be alright. 6700 in 3rd on a stock height tire with 4.10s still gets you 125 mph. Step it up to a 27" tire and you get 131 mph, and a 28" tire gets you 138 mph. I'm going to guess that it traps in the 123-127 range, in which case your 4.10s will still work if you turn 6700-6800 rpm, but I may be mistaken in my guess of how fast it'll run. If it really did go faster than your gearing/rpm would allow, you will probably need to seriously think of getting a taller tire to help hook up that much power any. Regardless, I wouldn't touch a thing until I had some 1/8 mile slips giving you an idea of how fast it'll run in the 1/4 (probably add 25-27 mph onto your 1/8 trap for your setup).

One thing I know for sure: 3.27s, a low stall (I think I've seen you say 3000-3200 rpm, which is fairly low), and a centri blower is going to be a dog out of the hole, relatively speaking. A properly setup street car making 500 rwhp should easily cut 1.6x 60's, probably down into the upper 1.5x range. I highly doubt your setup with 3.27s will cut better than a mid 1.7x, which is going to result in disappointing ETs relative to your traps. More gear (3.73s or better) is required for your setup to properly leave the line. I can guarantee that.

 

[Deleted member 38176]

WOT shifts into overdrive at your power level WILL toast the overdrive band in quick order. You are correct in that it won't directly damage the other gears, but all that band material circulating around in your oil will likely damage the entire transmission. Bottom line: WOT shifts into overdrive are completely out of the question at your power level.

3.73s are still your best bet. I answered this in a thread you posted a few weeks ago: "With stock size tires (25.66") and 3.73s, 120 mph would be 5863 rpm. 125 mph would be 6107 rpm. 130 mph would be 6352 rpm. So as long as you are ok with turning 6300-6400 rpm, and don't plan to go over 130 mph, the 3.73s are certainly ideal for the track."

Even assuming your car really does trap 130 mph (no offense, but I don't see it happening), you're at less than 6400 rpm in 3rd when crossing the traps. You said your valvetrain is completely upgraded (which means it should be good to probably 7000 rpm), so I don't see why you're worried about anything.

Honestly, your 4.10s would actually probably be alright. 6700 in 3rd on a stock height tire with 4.10s still gets you 125 mph. Step it up to a 27" tire and you get 131 mph, and a 28" tire gets you 138 mph. I'm going to guess that it traps in the 123-127 range, in which case your 4.10s will still work if you turn 6700-6800 rpm, but I may be mistaken in my guess of how fast it'll run. If it really did go faster than your gearing/rpm would allow, you will probably need to seriously think of getting a taller tire to help hook up that much power any. Regardless, I wouldn't touch a thing until I had some 1/8 mile slips giving you an idea of how fast it'll run in the 1/4 (probably add 25-27 mph onto your 1/8 trap for your setup).

One thing I know for sure: 3.27s, a low stall (I think I've seen you say 3000-3200 rpm, which is fairly low), and a centri blower is going to be a dog out of the hole, relatively speaking. A properly setup street car making 500 rwhp should easily cut 1.6x 60's, probably down into the upper 1.5x range. I highly doubt your setup with 3.27s will cut better than a mid 1.7x, which is going to result in disappointing ETs relative to your traps. More gear (3.73s or better) is required for your setup to properly leave the line. I can guarantee that.

Ok this makes me feel A LOT better. Thanks sneaky!