converter slippage

[jbigbootsy]

What percentage of driveline slippage should 9-9.5sec car have, is 20% too much?

[spdracr]

What percentage of driveline slippage should 9-9.5sec car have, is 20% too much?
:scared: :spots: :spots: :spots: :yup:

[Newbomb]

2.2str.....


I have no idea what that means :laughing:

[jbigbootsy]

My buddy has a 9.30 143mph best and says he screams through the traps at 8500rpm he has a sbf c4, W/4.10s. I did the math and at 143, rpm should be 7000rpm so I call him out, and he gives me this "driveline slippage" reason, so I find a "driveline slippage calculator "online and it says 20% just wondering if he's full of shit or what.

[Newbomb]

Tell him to buy a new converter....and just add that price onto the wager :yup:

[pkracing]

both cars (your and his) are sbf's????

[Newbomb]

If you're talking about the percent of HP lost through the drivetrain then about 15%-18% is probably correct....

I still have no idea what the hell you're talking about..

And God Damn do you look like an elf :laughing:

[spdracr]

I still have no idea what the hell you're talking about..
Is anyone surprised by this? I don't think so.

I have done the math on this same subject and it is always higher than what the car actually mph's. I don't know the percentage, but 20% sounds like a-lot:2cents:

[Newbomb]

???

What is Drivetrain Slippage?

Either

Converter Slippage

OR

Drivetrain Loss

Maybe you should be Dr. Tech? :laughing:

[spdracr]

???

What is Drivetrain Slippage?

Either

Converter Slippage

OR

Drivetrain Loss

Maybe you should be Dr. Tech? :laughing:
Maybe!

Drivetrain slippage is when the torque converter does not spin as fast as the engine rpm's do. The converter actually SLIPS a little bit. That's where you might here the term, lock up converter. That is an electronic sensor inside the converter that actually 'locks up' at cuising speed to help gas mileage, the same thing as a stick-shift car, positive lock-up between the engine and transmission.

[Newbomb]

I understand that....thus "stall speed".....but its near impossible to judge a converter's stall speed and "str" by what it runs in the quarter....

Dr. Newbomb

Nurse- John

[spdracr]

I understand that....thus "stall speed".....but its near impossible to judge a converter's stall speed and "str" by what it runs in the quarter....

Dr. Newbomb

Nurse- John
You're a dumb-ass
Stall speed and converter slippage are two different things. A stock torque converter has slippage at cruising or top end speed.

[Draggin My X]

My buddy has a 9.30 143mph best and says he screams through the traps at 8500rpm he has a sbf c4, W/4.10s. I did the math and at 143, rpm should be 7000rpm so I call him out, and he gives me this "driveline slippage" reason, so I find a "driveline slippage calculator "online and it says 20% just wondering if he's full of shit or what.
:think: ........... how tall is the tire?????

[Newbomb]

You're a dumb-ass
Stall speed and converter slippage are two different things. A stock torque converter has slippage at cruising or top end speed.

Ok....

of course it slips up top....like you said the lock up converter (some activated with a switch) hold it at a certain RPM....

Do I have to take you back to basics?

A 8 or 9'' converter will slip more up top than a 10-11'' correct?

That is why some 10'' converters "stall" at 3000 rpms, and some at 4000rpms


I know, I know....the engine's torque output will change the stall speed......so the same converter will stall slightly different behind one engine than another....

Yes stall speed and slippage are two different things....:piss:

[pkracing]

here's a site that may help

http://www.ford-fox.org/phpbb/slippage.php

[spdracr]

Ok....

of course it slips up top....like you said the lock up converter (some activated with a switch) hold it at a certain RPM....

Do I have to take you back to basics?

A 8 or 9'' converter will slip more up top than a 10-11'' correct?

That is why some 10'' converters "stall" at 3000 rpms, and some at 4000rpms


I know, I know....the engine's torque output will change the stall speed......so the same converter will stall slightly different behind one engine than another....

Yes stall speed and slippage are two different things....:piss:
:sleep: :beat:

[Vega406]

Ok....

of course it slips up top....like you said the lock up converter (some activated with a switch) hold it at a certain RPM....

Do I have to take you back to basics?

A 8 or 9'' converter will slip more up top than a 10-11'' correct?

That is why some 10'' converters "stall" at 3000 rpms, and some at 4000rpms


I know, I know....the engine's torque output will change the stall speed......so the same converter will stall slightly different behind one engine than another....

Yes stall speed and slippage are two different things....:piss:

Well, I can get a 8" converter that could be alot tighter than an 10" if you wanted.

Seems that the more torque an engine is putting out (talking bigger cube motors) you're going to have to step up to bigger diameter converters b/c the smaller converters begin to become inefficient due to the increasing amount of torque the engine is putting out while trying to put the car in the stall ranges to put it in its powerband.

Eh, who knows, maybe i'm all wrong :spots:

-=Josh=-

[dbs]

My buddy has a 9.30 143mph best and says he screams through the traps at 8500rpm he has a sbf c4, W/4.10s. I did the math and at 143, rpm should be 7000rpm so I call him out, and he gives me this "driveline slippage" reason, so I find a "driveline slippage calculator "online and it says 20% just wondering if he's full of shit or what.


I have the same damn problem. but 3 seconds slower....:confused: seriously though. I plan on taking the car to a chassis dyno and have them put a pick up on the crank to verify rpms on the motor. just to get an ideal as to what i am exactly looking at. i would say you would want nothing more than 10% after stall speed. but anything below that i would guess your will pay it out the pisser cause i would immagine the price sky rockets the tighter you have a converter built.

[Scrappy_racer]

What percentage of driveline slippage should 9-9.5sec car have, is 20% too much?


It depends on how big the converter is, the smaller the converter the more slippage you have....With a big converter, the norm. is 8-10% slippage.....

[ratgp]

The only way to accurately get converter slippage figured out is with a data logger. There are too many variables to figure in. If the car is on slicks it makes it nearly impossible to accurately determine. You HAVE GOT to know the exact engine rpm, and the exact driveshaft rpm to accomplish this. Otherwise you are basing your conclusion on theoretical numbers, the 143 "trap speed" may not be the speed of the car at 8500 RPM your 28x10(or whatever) slick isn't 28x10 at 143mph. To answer your original question, YES if the converter really is slipping 20% he is sacrificing some ET and MPH. I wouldn't want to have more than 12% slippage tops. I use an RPM Performance data logger which tells me my slippage is in the 9-11% range. This logger isn't a huge investment $575 and is fully upgradeable to whatever you have in mind. www.rpmperformance.com They are super cool people to do business with, I was referred to them by Marty Chance.

[GMCRACER]

Well, I can get a 8" converter that could be alot tighter than an 10" if you wanted.

Seems that the more torque an engine is putting out (talking bigger cube motors) you're going to have to step up to bigger diameter converters b/c the smaller converters begin to become inefficient due to the increasing amount of torque the engine is putting out while trying to put the car in the stall ranges to put it in its powerband.

Eh, who knows, maybe i'm all wrong :spots:

-=Josh=-


This is what I have found playing back the dig 7....

I had an 8" that stalled around 4200.... but during shifts RPM only dropped 600, thus showing the the convertor was slipping it's ass off...

MTS had a 10" put together for me that stalls 5000... now during shifts the RPM drops 1200.... Better, but I think we can still go tighter....


my :2cents:

[dbs]

you have to remember, a STALL all has to due with the rotors in the converter and thier surface area, and the angle they are set at and the properties of your hydraulic fluid. Stall is a hydraulic couple between the vains and the hydraulic fluid. lock, as previously stated, is mechanical, instead of a hydraulic couple. I am pretty much trying to say that after the vains inside the converter start moving fast enough, the hydraulic fluid can't move inside the converter (i think) so the hydraulic fluid actually stalls and all the parts pretty much move as one, so you get you your stall speed and give or take full power. but you have to remember ,on a non lock up converter, it's still just a hydraulic couple (stalled fluid) so it will still slip some. but,

now here is what i think, it was mentioned earlier, I believe the stall speed is indirectly proportional to the torque and the diameter of the converter (like a torque wrench, more leverage). IE, the larger the diameter, the faster it will lock up. Now the actually "tight" slip value is directly related to the tolerances inside the converter. smaller passages, less slip.


OK, tired of typing now...:think:

[dbs]

This is what I have found playing back the dig 7....

I had an 8" that stalled around 4200.... but during shifts RPM only dropped 600, thus showing the the convertor was slipping it's ass off...

MTS had a 10" put together for me that stalls 5000... now during shifts the RPM drops 1200.... Better, but I think we can still go tighter....


my :2cents:

well i guess i may be wrong about what i just said in regards to diameter.

maybe the more diameter, the cooler it keeps the fluid, maybe thats why stock is bigger.

what does your MTS guy have to say about this.

[GMCRACER]

well i guess i may be wrong about what i just said in regards to diameter.

maybe the more diameter, the cooler it keeps the fluid, maybe thats why stock is bigger.

what does your MTS guy have to say about this.


He'd need a speak and spell to type it in...

Maybe he can get Scrappy to translate....

[dbs]

He'd need a speak and spell to type it in...

Maybe he can get Scrappy to translate....

Hey, didn't mean to quote, but BTW,

remember that video you had in the shop with that gear shifting thing...

I finally found it at Spencer's.:yup:

[Scrappy_racer]

He'd need a speak and spell to type it in...

Maybe he can get Scrappy to translate....


Look back at post #19.....that's what he told me to type in....Or you guys have to wait til later, for more from TurboEd.....:yup:

[GMCRACER]

It depends on how big the converter is, the smaller the converter the more slippage you have....With a big converter, the norm. is 8-10% slippage.....


Okay...

[Shon Webb]

Why are posting et's on here?

[dbs]

Why are posting et's on here?

I don't see why that matters. do you know who his friend is. or how about the damn "Lutz in the 6's" whole entire, 100 post thread?????

[GMCRACER]

I don't see why that matters. do you know who his friend is. or how about the damn "Lutz in the 6's" whole entire, 100 post thread?????


:laughing:

Shon = :own:

[pkracing]

:laughing:

Shon = :own::laughing: :laughing: :new: :scared:

[aquick68]

I don't see why that matters. do you know who his friend is. or how about the damn "Lutz in the 6's" whole entire, 100 post thread?????
so do we owe him some different ammount of respect or something? just cuz he is lutz friend? he puts his pants on one leg at a time just like everybody else on this site!!!

[dbs]

:think: so do we owe him some different ammount of respect or something? just cuz he is lutz friend? he puts his pants on one leg at a time just like everybody else on this site!!!

[aquick68]

:dunno:

[dbs]

:dunno:

OK...........AGREED!

:D

[gasguzzler]

I think what is acceptable is somewhat subjective also. I think the norm for a convertor that is "right" for a car is around 4-7%. With some of the newer convertors (also high dollar) out there, I'm told they can get down in the 2-3% range. If you are running a really close heads-up race, I'd love to have use of the 3-4 (or 15 in this case)% more power.

- Brian