224 Stage I Single Turbo Buick V6 does the impossible. 8.76 @ 158.7

[Alky V6]

Fluctuating as in spiking or just a small rpm wave? Is the track bumpy at that point in the run?

I'll post the datalog later.

 

[baadgn]

I went ahead and used my calculator to determine torque converter slippage without taking tire growth into consideration, since that seems to be the popular method on this site.
You guys really need to start taking tire growth into consideration. It skews the power curve and the TC slippage factor immensely, WARNING: These low numbers that everyone is throwing around for torque converter slippage on the top end are not realistic numbers!!!

Sorry for not figuring this out a lot sooner for you people.

Ok..................... you do understand that if we used 0 tire growth your slip numbers would be better!!!!!!. I stated over 21% slip with 2" tire growth if I figured it at 0 tire growth its 14 % you really need to make sure you know what your talking about when you make statement. Its better to have people "think" your ignorant than to open your mouth and remove all doubt

 

[Alky V6]

Dusty knows his stuff! I can't for the life of me understand why you choose to spend your hard earned $$$ elsewhere. Especially, if you are on a budget.

Once you get a driveshaft sensor, you will be amazed at how helpful it is. In addition to calculating convertor slip, you can actually know if your tires are really spinning and most importantly WHEN/WHERE they are spinning on your run. I GUARANTEE your AMS1000 Operation for Dummies thread will need a name change :smile:
I don't know if your engine management can support it, but they are relatively cheap, about the same as 3-4 tanks of NOS :wink:

LOL
Funny you should bring that up. My ecm firmware has been recently upgraded and I think I saw something about a speed sensor input. I'll check it out. Hmmm. I may install that DSS sooner than I thought.

 

[Alky V6]

Ok..................... you do understand that if we used 0 tire growth your slip numbers would be better!!!!!!. I stated over 21% slip with 2" tire growth if I figured it at 0 tire growth its 14 % you really need to make sure you know what your talking about when you make statement. Its better to have people "think" your ignorant than to open your mouth and remove all doubt

Leave it to Tony.
Did you add 2" to the stated 29.5 that is stated on the tire, or did you use an actual measured number? Rolling radius? Corrected circumference?
Just because there's a diameter number on the sidewall doesn't always mean that it's actual.
And yes, Tony. As my posts explain (post 82), the higher the tire growth percentage used in a TC slip calculation, the higher the resulting TC slip number. If you take the opposite of that statement, if you use a lower tire growth percentage, or zero in a TC slip calculation, the lower the resulting TC slip number. I hope that's clear for you now.

 

[Alky V6]

I'm really not concerned with what my exact TC slip number is right now. I know that is a big deal on this site, but it's just not a priority right now. I can see enough from my ecm datalog and the sim work that it's more than the NC was, but that is really not my big concern right now.
What is my big concern is the fueling system. After I can put more boost to this thing, I can get a much more realistic picture of what the true slippage of the TC is on the top end at power levels that may be significantly higher than they are now. That is the TC slip number that I really want to see.
Am I wrong about this, Dusty. Wouldn't you rather know what the slip numbers are after the engine is at a maximum power level? Or would you want to modify the TC now, and then wait to see what the numbers are after throwing maybe 10 more psi at the thing?

 

[baadgn]

Leave it to Tony.
Did you add 2" to the stated 29.5 that is stated on the tire, or did you use an actual measured number? Rolling radius? Corrected circumference?
Just because there's a diameter number on the sidewall doesn't always mean that it's actual.
And yes, Tony. As my posts explain (post 82), the higher the tire growth percentage used in a TC slip calculation, the higher the resulting TC slip number. If you take the opposite of that statement, if you use a lower tire growth percentage, or zero in a TC slip calculation, the lower the resulting TC slip number. I hope that's clear for you now.

Maybe you.... should reread post #102, your the one that stated that we figure our numbers at 0 percent. So what is your rolling radius, and circumference and while your answering my questions why did you take out your NC convertor dont dodge it don.. you made a bold statement in the beginning of your journey "tight convertor, big turbo NO PROBLEM" again if you need me to find it I will

 

[baadgn]

You're wise not to attempt a guess.

I made a guess months ago at what your combo was capable of running and it was a lot faster than what your at now !!! if you need me to post it up I will !!

 

[Alky V6]

I'm kidding guys. The tires won't take 10 more psi of boost. :biggrin:

 

[Dusty Bradford]

I'm really not concerned with what my exact TC slip number is right now. I know that is a big deal on this site, but it's just not a priority right now. I can see enough from my ecm datalog and the sim work that it's more than the NC was, but that is really not my big concern right now.
What is my big concern is the fueling system. After I can put more boost to this thing, I can get a much more realistic picture of what the true slippage of the TC is on the top end at power levels that may be significantly higher than they are now. That is the TC slip number that I really want to see.
Am I wrong about this, Dusty. Wouldn't you rather know what the slip numbers are after the engine is at a maximum power level? Or would you want to modify the TC now, and then wait to see what the numbers are after throwing maybe 10 more psi at the thing?

I would want to engine at full power potential before trying to nail down the converter. An extra 10psi can make a huge difference, especially considering it seems your current converter is barely hanging on.

 

[Alky V6]

Maybe you.... should reread post #102, your the one that stated that we figure our numbers at 0 percent. So what is your rolling radius, and circumference and while your answering my questions why did you take out your NC convertor dont dodge it don.. you made a bold statement in the beginning of your journey "tight convertor, big turbo NO PROBLEM" again if you need me to find it I will

OK. So what calculator or formula do you use and what number do you input for tire growth?

28.6" is the tire diameter that I input. It's a corrected circumference number. 6% is the tire growth, which, as I've stated already, I believe to be on the low side. I'm beginning to think it's more like 8% tire growth.

So you don't consider a 3200 stall torque converter behind a 91mm to be a tight TC?
What's your idea of a tight TC, then?

 

[Alky V6]

I would want to engine at full power potential before trying to nail down the converter. An extra 10psi can make a huge difference, especially considering it seems your current converter is barely hanging on.

My thoughts exactly!

 

[Alky V6]

I made a guess months ago at what your combo was capable of running and it was a lot faster than what your at now !!! if you need me to post it up I will !!

That would be great, Tony. Dig it up for us.

 

[baadgn]

from Jan 4 2009

Another thing to ponder. As I increase the nitrous shot, I am increasing the stall of the t/c while, at the same time, lowering the stall requirement of the total combination.

So, as I increase the nitrous and stall speed, there will be a certain level where the optimum torque and converter stall matches the optimum requirement, since stall is increasing and requirement is decreasing.

I have to add something here. I know some of you are going to shake your heads, but this can't be ignored. The subject of the last paragraph was very, very clearly shown in the sim that I use. I mean VERY CLEARLY. I know that a lot of things about a sim can be grey area. No one knows that better than me. Especially if the input data is not correct. But, there is no mistaking on this.
__________________
Donnie

1984 BUICK Grand National 224 cid Stage I BUICK V6 burning CH3OH w/N2O, 91mm turbo. Configuration concept/engine/trans/tuning/fabrication by me.

Latest 1/8 mi. perf. (10/2010) w/FI91X (B/W Airwerks S510-91mm): 5.65@126.76mph, 1.28 60'.
Latest 1/4 mi. perf. (11/2010) w/FI91X: 8.769 et & 158.69 mph. And, more still in the tuneup.
5.27 Bhp/cid. Equivalent to a 500cid V8 producing 2,635 Bhp.
My pass @ Pinks All Out qualifying 11/2010, YouTube - 8 sec Grand National at Pinks All Out Firebird Int Raceway 2010
Tea Party!

--------------------------------------------------------------------------------
Last edited by DonWG; January 4th, 2009 at 05:59 PM.

Wow!!! i guess the data wasnt very clear after all and your were mistaking the info. Because this statement made by YOU was you were still running your "shelved" NC convertor :wink:

 

[Otto J]

So you don't consider a 3200 stall torque converter behind a 91mm to be a tight TC?
What's your idea of a tight TC, then?

This is not the only thing i look at when determining if the convertor is tight

you stated at the current tune you hit over 6000 on the nitrous,depending on how much boost at this point I think its loose.

You stated when the nitrous shuts off its settles around 5400,is this how hte car runs on a pass? if you launch at 6000 and it drop back to 5400 tha is not good,not sure if i am reading you post correctly on his or not.

I figure full stall on what the convertor actually drops to on a shift at FULL power.
If you shift at 7400 and it drops to 6800 on the shift. then you have at 6800RPM convertor.

 

[Dusty Bradford]

The pump is positive. It's not neutral. I could try to eyeball an angle for you if you think that would help.
I'm really not interested in giving up the manufacturer, for obvious reasons.
I'm going to wait until after I have the 3.42s, fuel system and yes, the DSS installed, and some data before I enlist your help, Dusty.
I will also be giving the manufacturer first shot at seeing if they can make a worthwhile change in this TC. I'm sure you would expect and appreciate the same if it were you that supplied it.
The timeline for all these changes will be like my usual. As funds are available.

A picture would tell me all I needed to know if you had one where the converter halves were laid side by side with the stator included.

Yes, you should continue to let your manufacturer work with you as you refine the combo. Most don't understand just how complicated a process it is to get something that works with off the wall combo's. Or combo's for that matter that are capable of much more than they are being used for. For example.........an 8 second capable combo but the owner is happy with 10.00's. I'm not ashamed to say I have one combo that is on it's 5th converter because the engine's output was so hard to predict.

I can understand why you don't want to give up the name but understand why I asked. It's not for a bashing. Some of the more popular companies have a certain way that they prefer to continue building converters. At some point most converter companies have restalled another companies product so we all have seen how others try to accomplish the goal. In some cases our thinking goes hand in hand.......other times it don't. Just like your NC...without even looking at it I could guess what stator and pump he was using. Just because we all have opened up another's product some time or another.

 

[Alky V6]

Another thing to ponder. As I increase the nitrous shot, I am increasing the stall of the t/c while, at the same time, lowering the stall requirement of the total combination.

So, as I increase the nitrous and stall speed, there will be a certain level where the optimum torque and converter stall matches the optimum requirement, since stall is increasing and requirement is decreasing.

I have to add something here. I know some of you are going to shake your heads, but this can't be ignored. The subject of the last paragraph was very, very clearly shown in the sim that I use. I mean VERY CLEARLY. I know that a lot of things about a sim can be grey area. No one knows that better than me. Especially if the input data is not correct. But, there is no mistaking on this.
__________________
Donnie

1984 BUICK Grand National 224 cid Stage I BUICK V6 burning CH3OH w/N2O, 91mm turbo. Configuration concept/engine/trans/tuning/fabrication by me.

Latest 1/8 mi. perf. (10/2010) w/FI91X (B/W Airwerks S510-91mm): 5.65@126.76mph, 1.28 60'.
Latest 1/4 mi. perf. (11/2010) w/FI91X: 8.769 et & 158.69 mph. And, more still in the tuneup.
5.27 Bhp/cid. Equivalent to a 500cid V8 producing 2,635 Bhp.
My pass @ Pinks All Out qualifying 11/2010, YouTube - 8 sec Grand National at Pinks All Out Firebird Int Raceway 2010
Tea Party!

--------------------------------------------------------------------------------
Last edited by DonWG; January 4th, 2009 at 05:59 PM.

Wow!!! i guess the data wasnt very clear after all and your were mistaking the info. Because this statement made by YOU was you were still running your "shelved" NC convertor :wink:

So what's the point you're trying to make? I stated an observation. What's the problem with that?

 

[Alky V6]

This is not the only thing i look at when determining if the convertor is tight

you stated at the current tune you hit over 6000 on the nitrous,depending on how much boost at this point I think its loose.

You stated when the nitrous shuts off its settles around 5400,is this how hte car runs on a pass? if you launch at 6000 and it drop back to 5400 tha is not good,not sure if i am reading you post correctly on his or not.

I figure full stall on what the convertor actually drops to on a shift at FULL power.
If you shift at 7400 and it drops to 6800 on the shift. then you have at 6800RPM convertor.

I don't understand. If I take a car with a stock TC and shift it at 4800 rpm and it drops 1000 rpm, does that mean the stall is 3800 rpm?

On your other question, it depends on whether it's a pro light, how long the pro light is strung out, or a sportsman. When your dealing with nitrous to spool the turbo, you don't have many attractive options to pick from on how your engine is on the torque converter at the launch. You take what you're given at the moment, unless you want to keep the nitrous on the whole time you're sitting at the light waiting for it to come down, wastegate and bov slammed open to control to a sane launch rpm and boost level.
I did post in another thread about a latest deal that's going on with the launch attitude on a sportsman tree. I think it's in the alky, nitrous section. It's titled something like cool trick with the nitrous. Check it out.

 

[Otto J]

I don't understand. If I take a car with a stock TC and shift it at 4800 rpm and it drops 1000 rpm, does that mean the stall is 3800 rpm?

This way works ONLY if the stall is higher than the transmissions actual rpm drop.
With the ratios a turbo 400 has what would the shift drop to if it shifted at 7000 and it had a lockup convertor?

If you shift at 7000 and it drops to 6600 i would say the TRUE stall is 6600.

A convertor someone calls a 3200, this is the stall i would expect at 0 #s of boost and where it flashes to upon snapping the throttle open.

That same convertor once it comes into full power goes to 5800.
I would say this is a 5800 rpm convertor.

 

[Alky V6]

A picture would tell me all I needed to know if you had one where the converter halves were laid side by side with the stator included.

Yes, you should continue to let your manufacturer work with you as you refine the combo. Most don't understand just how complicated a process it is to get something that works with off the wall combo's. Or combo's for that matter that are capable of much more than they are being used for. For example.........an 8 second capable combo but the owner is happy with 10.00's. I'm not ashamed to say I have one combo that is on it's 5th converter because the engine's output was so hard to predict.

I can understand why you don't want to give up the name but understand why I asked. It's not for a bashing. Some of the more popular companies have a certain way that they prefer to continue building converters. At some point most converter companies have restalled another companies product so we all have seen how others try to accomplish the goal. In some cases our thinking goes hand in hand.......other times it don't. Just like your NC...without even looking at it I could guess what stator and pump he was using. Just because we all have opened up another's product some time or another.

Very good post, Dusty.

 

[Dusty Bradford]

If you shift at 7000 and it drops to 6600 i would say the TRUE stall is 6600.

Otto is right. This is what most will call the true flash stall of the converter.

Talking stall's on turbo combinations would be another 20 page thread.

You have the initial flash stall which is where the engine flashes to at the hit of the throttle and the boost reads 0-1#. Then you have the true flash stall which is where the rpm drops to on the gear changes.

Otto made another good point about the gear ratio's. Just the change from a T-400 to a glide will change the rpm drop as well because the amount of ratio change is different. A t-400 will drop less on the gear change than a glide.