Rpm trap speed

[larrym]

If I trap at 115mph on a 26 inch tire what sort of rpm should I be at if my converter working well.
I did a test run on the hwy locking the converter at 95 mph and ran it out to 110 it was spinning at about 5500 rpm.


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[pacecarta]

5500.. at 110 ,locked....
assume thats in 3rd gear
3.42 gears?
what did you get the rpm info from ?
whose (what) converter
if you are locked and the lockup holds than what the converter efficiency is has no meaning as you should be 1 to 1 (zero slip)
but if the info you posted in 3rd ,locked and rpm is accurate .... your lockup clutch isnt holding as slip is almost 15%
it looks like you are trying to lock a converter that wasn't built for WOT lockup

locking up a converter that is slipping the lockup clutch is very bad thing to and generates a lot of heat, much more heat than 15% slippage non lock converter
a good non lock is under 6% slip but ive seen art carr 9" nonlocks slip from 15- 22% depending on power applied


now if you race unlocked or your lockup doesnt hold than you will trap with more rpm

locked up (zero converter slip) with 26 tire in 3rd... 115mph should trap 5100

with your 15% slip thats 5750 rpm for 115
115mph will need 450hp at 3700lb race weight,
injector duty cycle should be around 60% with 60 motorons

 

[larrym]

The mph could have been off I will get another set of eyes the middle daughter likes to help me tune. And maybe capture some more accurate data on the scan tool.
Had her watch the gen 2 the other day to see what the correction was at she was grinning from eat to ear after wanted to go again and again and again .......


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[pacecarta]

you would put your daughter at risk at speeds around 110
im done with you
..get a datalogger

 

[larrym]

She is not a child she is 18 and enjoys the car.
Have not let her drive it that would be putting her at risk!
Did not mean to offend.
So my scan tool showed 114 mph at 5175rpm
Was at 5300 at 94 then 5225 at 109.


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[pacecarta]

was that locked and left in 3rd gear ?
if so your lockup clutch or trans is slipping

5300 @ 94 you had 25% slippage
5225 @ 109 its slipping 10%

the 114 data it wasnt slipping much based on the two figures , but on the mph /rpm you stated at 95 and at 109 it was slipping and i can only assume you werent pulling the same hp after 95 as the slippage lessened . slippage wont get better unless hp drops. just easing to 114 does not take the same hp as it does to get to 114 in 1/4 mile so you cant evaluate slippage unless you are WOT at the power level you will have at the track

 

[larrym]

Thanks for the insight I have the chip programmed to lock at 95 mph.
This was a wot run from about 70 mph my scan tool only captures so many frames and they are not that close together.


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[larrym]

I figured I was losing something out the back I ran an 11.73 and I thought the MPH was 115 unlocked last year, I would switch to a good nonlock converter but I only make one trip to the track a year and the rest time I spend cruising mostly hwy miles with the lock up and lean cruise its pretty good on gas.
This converter stalls at around 2800 0 psi its a hybrid with the half the bolts to the flywheel is 12" and the other is 10" or 9".
Not sure who made it but the guy I got it from had it behind a big block and found it too loose if its slipping 25% I can see why..........