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Re: Unexpected Dyno Results [Re: MarkZ] #2528409
07/28/18 09:01 PM
07/28/18 09:01 PM
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So. Burlington, Vt.
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fast68plymouth Offline
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That 2800 would probably work well for the OP.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Unexpected Dyno Results [Re: MarkZ] #2528423
07/28/18 09:41 PM
07/28/18 09:41 PM
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Pattison Texas
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If he was closer I would give it to him, it still worked great.


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: Unexpected Dyno Results [Re: fast68plymouth] #2528456
07/28/18 11:26 PM
07/28/18 11:26 PM
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Originally Posted By fast68plymouth
Russ, what are the dips on the upward slope...... tire slip?


I believe it was from the way we throttled up. We stepped it up to get above 3500 before dropping the hammer because my full auto tranny would otherwise kick down to first.

Re: Unexpected Dyno Results [Re: BSB67] #2528470
07/29/18 12:19 AM
07/29/18 12:19 AM
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Originally Posted By BSB67
Originally Posted By fast68plymouth
Russ, what are the dips on the upward slope...... tire slip?


I believe it was from the way we throttled up. We stepped it up to get above 3500 before dropping the hammer because my full auto tranny would otherwise kick down to first.
they look like shift spikes to me,....?

Re: Unexpected Dyno Results [Re: CSK] #2528473
07/29/18 12:27 AM
07/29/18 12:27 AM
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Michigan
MarkZ Offline OP
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Originally Posted By csk
If he was closer I would give it to him, it still worked great.


Seriously? I would be more than willing to compensate you for your time and shipping.

Andy, the converter feels fine out on the street, but I never really take it to full throttle.


1987 Fifth Avenue - 512/518/D60
Re: Unexpected Dyno Results [Re: MarkZ] #2528484
07/29/18 12:58 AM
07/29/18 12:58 AM
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Bend,OR USA
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Originally Posted By MarkM
[quote=csk] the converter feels fine out on the street, but I never really take it to full throttle.

Why not? confused
how are you going to know what it does on the street at WOT so you can provide some feedback to the converter shop that your dealing with? work


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Unexpected Dyno Results [Re: MarkZ] #2528535
07/29/18 08:23 AM
07/29/18 08:23 AM
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Originally Posted By MarkM
...
Some additional information: tires are 285 Nitto NT555, kick-down cable was disconnected from the throttle body, overdrive was turned off and the pulls were made in third gear.


No-one picking up on the bold-text?

I say there's a great possibility the transmission was slipping also.

I thought it was well-known fact one never disconnects the Throttle Pressure linkage on a Mopar transmission, unless you have a modified valvebody.

Re: Unexpected Dyno Results [Re: lewtot184] #2528557
07/29/18 11:28 AM
07/29/18 11:28 AM
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Originally Posted By lewtot184
Originally Posted By BSB67
Originally Posted By fast68plymouth
Russ, what are the dips on the upward slope...... tire slip?


I believe it was from the way we throttled up. We stepped it up to get above 3500 before dropping the hammer because my full auto tranny would otherwise kick down to first.
they look like shift spikes to me,....?


Could be Lew. But that would make the pull in 3rd, plus one.

Re: Unexpected Dyno Results [Re: BigBlockMopar] #2528568
07/29/18 11:53 AM
07/29/18 11:53 AM
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Originally Posted By BigBlockMopar
Originally Posted By MarkM
...
Some additional information: tires are 285 Nitto NT555, kick-down cable was disconnected from the throttle body, overdrive was turned off and the pulls were made in third gear.


No-one picking up on the bold-text?

I say there's a great possibility the transmission was slipping also.

I thought it was well-known fact one never disconnects the Throttle Pressure linkage on a Mopar transmission, unless you have a modified valvebody.
you may be right. no shift spikes.

Re: Unexpected Dyno Results [Re: BSB67] #2528570
07/29/18 11:58 AM
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Originally Posted By BSB67
Originally Posted By lewtot184
Originally Posted By BSB67
Originally Posted By fast68plymouth
Russ, what are the dips on the upward slope...... tire slip?


I believe it was from the way we throttled up. We stepped it up to get above 3500 before dropping the hammer because my full auto tranny would otherwise kick down to first.
they look like shift spikes to me,....?


Could be Lew. But that would make the pull in 3rd, plus one.
I just pulled my dyno sheet out and there are only 2 shift spikes. I was guessing. I may try to post my sheet. the spikes are clear to me on my sheet.

Re: Unexpected Dyno Results [Re: MarkZ] #2528577
07/29/18 12:16 PM
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hopefully this is clear. the humps are shift spikes.

100_0437.jpg
Last edited by lewtot184; 07/29/18 12:17 PM.
Re: Unexpected Dyno Results [Re: MarkZ] #2528598
07/29/18 01:24 PM
07/29/18 01:24 PM
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So. Burlington, Vt.
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The reason the kick down is disconnected is to allow the trans to shift into high at a low rpm and hopefully stay in high after going to wot.

Lew, what was the change from November 98 to May 99?


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Unexpected Dyno Results [Re: fast68plymouth] #2528648
07/29/18 03:41 PM
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Originally Posted By fast68plymouth
The reason the kick down is disconnected is to allow the trans to shift into high at a low rpm and hopefully stay in high after going to wot.

Lew, what was the change from November 98 to May 99?
I had a suspect head gasket on the #1-#7 side and changed gaskets, one of my pocket port jobs (don't laugh) and a hugh's/engle 2330 cam (replaced the 272/.455 cam). think it picked up 38hp at the wheels. those numbers are spike readings and don't count. real horsepower was around 325-327. they couldn't get a tach reading so I had to do the math for rpm. things started to go flat around 4300rpm.

Re: Unexpected Dyno Results [Re: MarkZ] #2528671
07/29/18 04:50 PM
07/29/18 04:50 PM
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I know you want to prevent kickdown from happening at a dyno-run, but disconnecting the linkage totally is not the way to do that. You should just do some short tip-in testruns to re-set the linkage so it doesn't downshift.
I've had my car on the dyno and with just 2 or 3 dry-runs the downshifting was taken care off.

Lowering the transmission's oilpressure and make it unsusceptible to throttle changes, just when you're about to do the most straining test of all on the driveline (just when you need the most clamping force/oil pressure on the clutches) isn't the healthiest situation for the trans.

Re: Unexpected Dyno Results [Re: MarkZ] #2528817
07/29/18 10:50 PM
07/29/18 10:50 PM
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As far as the horsepower goes, I wouldn’t expect this combo to make much more than 400whp.
I agree with others. You need a much tighter converter.

Re: Unexpected Dyno Results [Re: MarkZ] #2528953
07/30/18 11:23 AM
07/30/18 11:23 AM
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The problem with trying to “ramp up” on a dynojet is, the bearings for the drum are extremely low resistance.
It takes much less energy to turn the drums at driving speeds than it does to push the car down the road at those same speeds.
So, if you gradually ramp up to wot, by the time your foot hits the floor the rollers might be going 50-60mph.
This loads the converter in a way the will provide lower numbers, because there is less speed differential between the engine and input shaft(less tq multiplication), as well as allowing the motor to be at an even higher rpm.
This is similar to trying to do the high gear stall test while going 50-60mph.
The observed flash stall speed will be higher and you’re not going to get an accurate picture of the true stall speed.

The only real “load” you get from a dynojet is when trying to change the speed of the drum.
You don’t get to ramp up to wot against a predetermined start rpm like you would on a dyno with a load cell.

With a high stall converter, the longer it takes and the higher the speed of the drum before you get to wot and pushing hard against the weight of the drums........ the smaller the window of usable data there will be on the sheet.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Unexpected Dyno Results [Re: viperblue72] #2528961
07/30/18 11:38 AM
07/30/18 11:38 AM
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Originally Posted By viperblue72
As far as the horsepower goes, I wouldn’t expect this combo to make much more than 400whp.
I agree with others. You need a much tighter converter.


I think it would be somewhere in that range, but since the curve is already sloping downward slightly after the converter starts locking up, it would appear the peak is probably slightly below 5200rpm....... at the wheels.
On the chassis dyno there are a lot more variables that determine where it happens.
I would have expected 530-540hp..... maybe 550, from that combo(using the car headers) on the engine dyno here....... then it’s usually about a hundred less at the wheels for a typical street/strip car at that power level.
So, I would have thought 425-440rwhp....... which I could easily see happening with a tighter converter....... something that had the load coupled to the motor at wot several hundred rpm below the point of peak hp.

Of course........ that doesn’t mean it wouldn’t be quicker at the track the way it is now....... especially since to this point, we don’t know what the actual flash stall is.

If you poke around a while on the net you can find a lot of info......
I saw one thread where someone was testing a car with a lockable converter.
There was over 100ft/lbs observed difference between locked and unlocked in the lower rpms....... with locked being the higher numbers(displayed on a tq/rpm graph).


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Unexpected Dyno Results [Re: MarkZ] #2528964
07/30/18 11:40 AM
07/30/18 11:40 AM
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Aurora, Colorado
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Have the dyno shop E-Mail you the data files.
Goto Dynojet and download the WinPep 7 Dyno Run Viewer software on your computer and you can display the run data in different forms.

http://www.dynojet.com/downloads/downloads.aspx?dc=Software/Firmware

When I ran on the chassis dyno, I was told to roll into the throttle, not stab it. I haven't had issues with spinning the tires on the dyno rollers with the Charger that has M/T Street ET tires, but my Truck with street tires (Cummins TD) would spin the tires on the rollers if I "stabbed" the throttle. This would looks alot like a really loose torque converter. That is why plotting power vs MPH may show how well the engine is coupled to the rollers might be converter or tire slippage, maybe even transmission clutch slippage if it is having issues?

Re: Unexpected Dyno Results [Re: 451Mopar] #2529108
07/30/18 03:57 PM
07/30/18 03:57 PM
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Michigan
MarkZ Offline OP
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Originally Posted By 451Mopar
Have the dyno shop E-Mail you the data files.
Goto Dynojet and download the WinPep 7 Dyno Run Viewer software on your computer and you can display the run data in different forms.

http://www.dynojet.com/downloads/downloads.aspx?dc=Software/Firmware

When I ran on the chassis dyno, I was told to roll into the throttle, not stab it. I haven't had issues with spinning the tires on the dyno rollers with the Charger that has M/T Street ET tires, but my Truck with street tires (Cummins TD) would spin the tires on the rollers if I "stabbed" the throttle. This would looks alot like a really loose torque converter. That is why plotting power vs MPH may show how well the engine is coupled to the rollers might be converter or tire slippage, maybe even transmission clutch slippage if it is having issues?


That is very good to know, thanks! I called Jake's and left my email, so I should be getting the raw data files. Once I have those I'll post up the graphs: RPM vs time and drum speed vs time.

Tonight I'll see if I can get the car out on some quiet stretch of road and deduce what the converter is flashing to.

I also dumped the video from my phone of that last pull:



Should have posted this sooner, sorry.


1987 Fifth Avenue - 512/518/D60
Re: Unexpected Dyno Results [Re: MarkZ] #2529117
07/30/18 04:12 PM
07/30/18 04:12 PM
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So. Burlington, Vt.
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It’s rolling along pretty good before it goes to wot....... which should make the converter look like it has more stall on the sheet than it would “on the starting line”.

Looks like it’s at full power/load for about 4 seconds.
I’ve watched several times now...... you can hear the rpm hover a bit after it gets up on the converter, then start to accelerate afterward.
That point right before you hear the pitch start to change......that should be where the spike on the sheet is.

On an engine dyno, a 3000-6000 pull at 300rpm/sec rate would be ten seconds.

The motor sounds pretty good.
As long as nothing seems “broken”, I’d def head to the track before I changed anything.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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