2017 Dyno results/upgrades

I would be happy with it stalling around 2800rpm like it did with my old motor.

You say this for the same reason Neibert says this:

Yeah...I'm not really unhappy with how high it flashes when I'm at the track, just feels a little too slippy when cruising around and generates more heat than I like. I think 3000 stall that flashed to around 5000 would feel much better and run a little cooler.

David

And like Dalke said being on a Dyno is way different than at the track on Slicks.
 
I think you guys are confused. Nobody's converter here flashes that high. Sure it jumps to 5000rpm pretty quick on the dyno, but that is because you are already in 3rd going 50mph when you try to lock it up AND it's probably slipping the tires to boot. You all need to datalog your cars AT THE TRACK before starting these conversations. My 5.0 "flashes" as you say on the dyno to about 4800rpm, and anytime you mash the throttle on the street it hits 3500rpm instantly, but at the track with slicks on and from a stand still it flashes/stalls at 2800rpm. Period. You can't make it go over 2800rpm without moving the tires first.

Not saying some of you couldn't use lower stall speeds, but suggesting that it would be helpful to use correct terms correctly and to be quote actual data rather than perceptions based on fluid conditions. I don't think the converters are eating up as much HP as you guys seem to think either. Brian Whitfield's 4.2 routinely makes 380+rwhp through his AOD and runs low 12's. He has a loose converter too. There are others as well.

Just to make sure I'm using the correct terms and not confusing anything, I assume that rpm and mph are used to determine when the tires start to move (I also compared TP to see when I started the race). If that's the case, mine doesn't move until something greater than 3972 rpm and less than 4296 rpm. If there are different parameters required, please let me know so I log the best information. I imagine if I could measure driveshaft rpm, that would be a better way to see what the converter is doing.
 
Maybe "flash" isn't the correct term for what I was describing. It's supposed to be 3500 stall with direct drive deleted, same as Kurt's from Alan Brown. I can hold the brakes real hard and get close to 3300 rpm before tires start spinning or pushing the car forward. When hitting it hard from idle it's instantly at 5400-5500 rpm but tires are also spinning so maybe they spin at 3500 and just bust the tires loose causing it to spike up to 5500. Either way it's annoying because it feels too slippy when cruising. The 3500 stall converter in my old turbo car felt much less slippy cruising and I could get it up to 3300 rpm on the trans brake. It was also made by Alan but that transmission and converter was built to handle a lot more power.

David
 
Foot braking you cant get full flash stall because most of the time the brakes wont hold the power back. Now if you're on a trans brake, full throttle, boost, and power, rpm is going to go way up there. With that said my flash or stall speed is what ever I have my 2 step to:D
 
Kurt, you are perceiving correctly. True stall speed isn't a fixed #, it does vary based on load and leverage and for most of us at the track, datalogging speed sensor activity vs. rpm is our best indicator. Part of fixing an incorrect stall speed is knowing exactly what stall speed you are seeing under the most ideal of conditions you can generate. In other words, track-trans brake stall rpm doesn't matter if you don't actually have or use one. And yes, you can break your converter if you try to make it stall with a trans brake higher than it is capable of holding.

The other thing you need to know, if you think you are "blowing through" the converter, is what % of slippage you are seeing at WOT and peak rpm. I know mine has 13% slip at 6000rpm in 3rd based on my best estimates. It's high, but it's not unusual and it's consistent.

I agree that if you have a converter that stalls even at the perfect rpm for drag racing use but you only drag race 2x a year then you are likely going to miss the mark and should compromise with a lower stall speed. For some of you if your converter really stalls that high then you probably can't even use overdrive on the street without basically cooking your transmissions or at least the fluid every 500 miles. Transmission fluid has a surprisingly short life when taken over 180 deg.
 
The other thing you need to know, if you think you are "blowing through" the converter, is what % of slippage you are seeing at WOT and peak rpm. I know mine has 13% slip at 6000rpm in 3rd based on my best estimates. It's high, but it's not unusual and it's consistent.

So to calculate slippage, you would need to use the speed sensor and calculate the driveshaft speed based on gear ratio and tire size? Or am I missing something?
 
So to calculate slippage, you would need to use the speed sensor and calculate the driveshaft speed based on gear ratio and tire size? Or am I missing something?

First thing you need to do is calibrate your BE calculator for mph logging against your GPS, then datalog a full throttle 1/4 mile run and calculate effective rear end gear ratio vs. theoretic. The difference is your slip %.
 
First thing you need to do is calibrate your BE calculator for mph logging against your GPS, then datalog a full throttle 1/4 mile run and calculate effective rear end gear ratio vs. theoretic. The difference is your slip %.
So is that a table in BE? I knew something had to change since my 11.52 datalog only shows 103 mph and I know it was 118. When I replace the 103 with 118, I calculated about a 15% loss. However, I can see that have BE calibrated will be a lot easier than digging out all of my timeslips.
 
You have to do the run with street tires. This is also why you have to calibrate the speed sensor against your GPS. You need instantaneous speed and full load at the proper speed. With 1/4 mile slips 1) they are often wrong), 2) it's a calculated average speed, not instantaneous, and 3) race tires grow quite a bit at 100+ mph.
 
You have to do the run with street tires. This is also why you have to calibrate the speed sensor against your GPS. You need instantaneous speed and full load at the proper speed. With 1/4 mile slips 1) they are often wrong), 2) it's a calculated average speed, not instantaneous, and 3) race tires grow quite a bit at 100+ mph.
I'm aware of all of those factors, but knew it would be closer than the 103 mph that BE was showing. Went on a cruise yesterday and my BE reads a full 10% less mph than GPS mph (my speedometer was somewhere in between). Now I just need to figure out where to modify BE.
 
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I've been wanting to get to the track. It rains everytime the track is open lol I really need to see
where I am at. I hope my newfound power will squeeze a low 12 out of it. I am wanting to run
the 12.0 Index at the street car takeover on the 7th
 
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