1000+ RPM drop with PTC N/L on 10sec street car

[BEATAV8]

Cool,

Another thing to check is to do the same WOT 2-3 rpm drop test, but shift it at 5500 and see where the RPM drops to.

BTW, can you email me the logfile from that other test (2-3 rpm drop).

Bob

The lowest I've seen it pull down so far is 4800. That was from a 5300 shift point. In the end I want to get my governor dialed in to shift automatically at about 5700-5800.

My precision used to shift at 5700 and pull down to 5200. Once the PTC was in the shift points came way down. Better coupling!

 

[Dusty Bradford]

Cool,

Another thing to check is to do the same WOT 2-3 rpm drop test, but shift it at 5500 and see where the RPM drops to.

BTW, can you email me the logfile from that other test (2-3 rpm drop).

Bob

It's still going to drop back to 4900 or so. For someone wanting to shift at 5500 I would tighten it up a bit.

 

[Dusty Bradford]

Thanks for all the info MJRWOOD This is the kind of stuff that helps everyone in the future. I get to see what the converter is doing and can get a better idea of what's needed for the same combo and what adjustments need to be made for others. See you in BG.

 

[Dusty Bradford]

I am not brave enough to footbrake my car to that boost level in my driveway...I would need some serious house work to repair the hole I put in the back of the garage.

I guess its time to put some brakes on my ole bucket.


Whats the advertised stall again? Was it a 2800 or 3200?

Ed, this is an entirely different animal. The only comparison from a 9.5 non lock to your converter is that they both bolt between the motor and tranny

There's a reason for the extra $400 you spend for the 9.5. The 10" is more of a budget performer. Cost is kept lower by using off the shelf parts found in OEM converters. The 9.5 has a stator cut by a machinist with it's own blade count and angle and is designed to work with the pump for the most efficiency we can achieve. The time involved to build the 9.5 is much higher and the parts are much better designed to do their job.

 

[HP Man]

Caps on 1-2-3. #4 is stock. It's an old ANS motor. Been together for several years now. Boy do I miss ANS.

Yea, me too! Pete did build me a great engine, good oil pressure, no rear main leaks, 25# OP hot idle and 80# WOT with 10/30 Kendall GT1 oil. Sold the car but have another in the works. (86TType) Gene

 

[TurboBuRick]

Caps on 1-2-3. #4 is stock. It's an old ANS motor. Been together for several years now. Boy do I miss ANS.

I have the same set up with a steel crank also built by ANS. Been taking a beating for a while now as well. Thanks Pete! I know your still out there.

Now where do I order one of these converters from? :biggrin:

 

[WINDMILL]

PTC converter

Well i just got my PTC converter in too. It's the same as yours. It spools not as fast as yours but i'm not running a bb turbo. I'm going to try it out thur at the test and tune to see if picks my gn up any( was blowing thruuuuu mine). will post back thur night on the et's. Also i'm going to hook up my exhaust too finally got the v-band and pipe in.

Big thanks to dusty for getting me the converter, so far so good. keep your finger crossed

 

[bison]

Well i just got my PTC converter in too. It's the same as yours. It spools not as fast as yours but i'm not running a bb turbo. I'm going to try it out thur at the test and tune to see if picks my gn up any( was blowing thruuuuu mine). will post back thur night on the et's. Also i'm going to hook up my exhaust too finally got the v-band and pipe in.

Big thanks to dusty for getting me the converter, so far so good. keep your finger crossed

Post any data logs you can. Ill have some on Friday night after i get back from BG.

 

[BEATAV8]

Ran a 10.62@127 today. Went through the traps at 5600RPM. About 7.5% slippage.

 

[Alky V6]

Cool,

Another thing to check is to do the same WOT 2-3 rpm drop test, but shift it at 5500 and see where the RPM drops to.

BTW, can you email me the logfile from that other test (2-3 rpm drop).

Bob

X2!!! I was going to ask the same thing. You should try some passes with different shift points. If you see little difference in your time slip, it may be telling you that you're lunging the motor out farther than you need to. The horsepower curve could be dropping on you sooner than you think. If you lung a motor out far enough past peak hp, you will start seeing larger rpm drops on the shifts. I played around with that myself and found that I was winding her out farther than I needed to. I was getting 1400 to 1650 rpm drops by winding her out. After finding a sweeter shift point, now I'm seeing around 900 to 1,000 rpm drop on the shifts.

That second comparison graph is a little messed up really with the a/f going so rich, so soon. Not a fair comparison in my book. All in all, good numbers.

 

[TurboBuRick]

Ran a 10.62@127 today. Went through the traps at 5600RPM. About 7.5% slippage.

Nice!

 

[BEATAV8]

Thanks for the feedback Donnie, I appreciate it. I've been shifting around 5800-5900 or so. Today I manually shifted at 5960 and it pulled down to 5120.

The vigilante shifted 2-3 at 5750 at ~55mph all by itself. The improved coupling with the PTC puts me at almost 80mph on the 2-3 at 5900. I really like seeing all those extra mph's in 2nd gear with the better mechanical advantage. The vigilante couldn't do that.

It's definitely got more in it. I might get it tightened another 200RPM or so next time it is apart.

 

[Dusty Bradford]

I was getting 1400 to 1650 rpm drops by winding her out. After finding a sweeter shift point, now I'm seeing around 900 to 1,000 rpm drop on the shifts.

This is what you should see with an efficient converter. The higher you spin it the more efficient it should get.

As far as where it drops back to. This is what the true flash stall of the converter is. If you shift at 7k and it drops to 6k....6k is your true flash stall. Your rpm should rise rapidly on launch and bend the motor over around this same rpm. Therefore, if you shift at 7500 it should still drop to 6k. The only thing that should effect this flash stall is the amount of power put to the converter. This is why the converter needs to be matched to the rpm range of the motor as well as the cam being matched to the head size.

Too tight of a converter can be just as bad as being too loose. If a car needs to shift at 7500 to make the best power but drops too much on the gear change it needs a looser converter.

 

[Twistin6]

I have been following this thread and this converter has my interest up. I was curious however with its greater coupling under moderate throttle what your cruise rpm is at 70mph on stock 3:42 gears?

 

[Turbo1dr]

Dusty, when you can get a lock-up converter to do what a non lock does.....put me first in line. I can't do without my lock-up. I travel on the interstate too much not have a locked up converter.


I still can't not see why someone can't build a lockup converter that performs exactly like the non lock you're selling. In my mind, all that has to be done is add a clutch inside of a NL and there you have it! Easy as pie!

 

[Dusty Bradford]

Dusty, when you can get a lock-up converter to do what a non lock does.....put me first in line. I can't do without my lock-up. I travel on the interstate too much not have a locked up converter.


I still can't not see why someone can't build a lockup converter that performs exactly like the non lock you're selling. In my mind, all that has to be done is add a clutch inside of a NL and there you have it! Easy as pie!

I wish it was that easy

 

[Alky V6]

This is what you should see with an efficient converter. The higher you spin it the more efficient it should get.

As far as where it drops back to. This is what the true flash stall of the converter is. If you shift at 7k and it drops to 6k....6k is your true flash stall. Your rpm should rise rapidly on launch and bend the motor over around this same rpm. Therefore, if you shift at 7500 it should still drop to 6k. The only thing that should effect this flash stall is the amount of power put to the converter. This is why the converter needs to be matched to the rpm range of the motor as well as the cam being matched to the head size.

Too tight of a converter can be just as bad as being too loose. If a car needs to shift at 7500 to make the best power but drops too much on the gear change it needs a looser converter.

You know, that's funny you would bring that up. It seems as though whether I shift at 7,800 rpm or 7,200 rpm, the engine drops down to around 6,000 rpm either way. Interesting. Could you explain this 'flash stall' any different? I always thought that flash stall was just another term for 'stall speed'.

 

[bison]

Dusty, when you can get a lock-up converter to do what a non lock does.....put me first in line. I can't do without my lock-up. I travel on the interstate too much not have a locked up converter.


I still can't not see why someone can't build a lockup converter that performs exactly like the non lock you're selling. In my mind, all that has to be done is add a clutch inside of a NL and there you have it! Easy as pie!

Have him build you one like i have in my sig. Only slipping about 5% on light cruise. Not going to effect mileage or driveability much at all. You would not get the same effect out of the converter if they simply made a LU unit based on the pump and stator. For one it would be heavier. It would also build more heat in the trans when run unlocked just like all LU converters. Your engine is crying to be backed by one of those 9.5" units.

 

[Turbo1dr]

Your engine is crying to be backed by one of those 9.5" units.

I know...I know...PLEASE keep reminding me...

 

[Dusty Bradford]

You know, that's funny you would bring that up. It seems as though whether I shift at 7,800 rpm or 7,200 rpm, the engine drops down to around 6,000 rpm either way. Interesting. Could you explain this 'flash stall' any different? I always thought that flash stall was just another term for 'stall speed'.

Flash stall is one of those terms that has different meanings depending on who you speak with. When looking at a converter on a log your flash stall is the point at which the rpm line on your log takes a right hand turn When you launch the rpm on the log will go upwards until it begins to bend over towards the right. This point should be near the same rpm as the converter drops back to on the gear change. This is what people should call flash stall.

As you increase power, the point it bends the motor over and the point it drops back to on the gear change may increase.