What is the average T/C slip on todays new converters?

[TURBOPOWERED68]

What does the car weigh and what rpm do you plan to shift at?

The 3.55 gear and a higher shiftpoint than 5200 will both increase efficiency. More power applied and a heavier car will decrease efficiency. It could be a wash so you'd see no difference in efficiency but it depends on the other factors. If you just wanted to guess at an efficiency number for your calculations I'd guess somewhere in the 10%-14% range.

the car weighs 3800 pounds.
i plan on letting the trans shift it self. i can ask the builder for ball park shift info

 

[TURBOPOWERED68]

A side question

On a heavy car
Is it better to go with a numerically higher gear and less stall?
OR a numerically lower gear and higher stall?

Am I right in thinking that a numerically higher gear “makes the car lighter” or “feel lighter”?
BTW this is all for a DD

Thanks guys for taking your time to answer all of my dumb questions, I am just another broke dude that can’t afford to buy the same part twice or the wrong part once.
So again thanks for your help.
David

 

[Dusty Bradford]

With the turbo car, the stall also has to get the turbo spooled.

The gear alone will change the flash stall of the same converter by placing more or less load on the converter once the car launches. You want as tight of a converter as you can stand to get the turbo spooled and then gear the car to be in the correct rpm range through the traps.

For instance. If a car traps 400 rpm lower than optimum but spools good. A gear change to a slightly higher numerical gear will help. It will get the engine more into it's power range as well as taking a slight load off the converter. This will make the converter more efficient on the top end as well as helping the car launch with the gear.

 

[Nick Micale]

With the turbo car, the stall also has to get the turbo spooled.

The gear alone will change the flash stall of the same converter by placing more or less load on the converter once the car launches. You want as tight of a converter as you can stand to get the turbo spooled and then gear the car to be in the correct rpm range through the traps...........

Just to add to what Dusty said, the stall not only has to get the turbo spooled, but launch the car w/o breaking the tires loose.

The RPM through the traps needs to be within the power band where the car is still pulling. In my racing experience, trap speed does not win races, E.T. does.

It usually takes us a season of racing to get a newly built car [and driver!] to get consistent enough to win. Of course it is not only the converter and its efficiency, but gearing, tire size, power band and other factors that all interact for the optimum performance desired.

In our experience over the years, we find that most owners start with a converter too tight. I would rather tighten a converter, than loosen it.

I did forget to add another comment, sorry.

Over the years I have used MANY different brands on converters, and worked with many different companies.

With that said, my experiences with Dusty, Chris and PTC have been the best from all perspectives - cost, performance, customer service and just plain honest dealings. Their experience with converters for turbo cars is better than any I have found.

Do NOT cheap out on a converter, it is key to optimum performance.

 

[vacuum 6]

...To get a 12" converter to stall 2800 rpm would require a very negative fin angle and it would be terrible in 3rd gear.

Terrible meaning what would someone see? Low 1/8 to 1/4 MPH pickup?

 

[Dusty Bradford]

Yes, low mph gain on the backhalf as well as high slip calculations.

 

[TURBOPOWERED68]

Yes, low mph gain on the backhalf as well as high slip calculations.

Do you have a phone number where i can reach you at??

 

[TURBOPOWERED68]

For comparison sake, What is the stall on a stock D-5?

 

[bison]

For comparison sake, What is the stall on a stock D-5?

About 2100 on a good day with a loose core and some timing thrown at it with good fuel. Some even less. You heavy car is screaming for a high efficiency non lockup 9.5" PTC with the hyd cammed low shift rpm combo with stock heads.

 

[Dusty Bradford]

For comparison sake, What is the stall on a stock D-5?

At 0, most go 1800.

 

[TURBOPOWERED68]

The more I know the more Fng I get. LOL

But the time is here I am going to have to make a decision and hope for the best.

So I am going to buy a TC for my present combo and hope that it works in my future build.

 

[vacuum 6]

Yes, low mph gain on the backhalf as well as high slip calculations.

Good to know, thanks.

 

[TURBOPOWERED68]

how does ts87ttype's turbo (PTE 6162) compare to my Turbo (PTE-6031) as far as Stall requirement?

 

[bison]

how does ts87ttype's turbo (PTE 6162) compare to my Turbo (PTE-6031) as far as Stall requirement?

The 6031 will spool decent with a Garrett .63 housing a a slightly looser than stock D5. About the same as a TE44 (5831)

 

[TURBOPOWERED68]

About 2100 on a good day with a loose core and some timing thrown at it with good fuel. Some even less. You heavy car is screaming for a high efficiency non lockup 9.5" PTC with the hyd cammed low shift rpm combo with stock heads.

At 0, most go 1800.

2100 + 1800 = 3900
3900 / 2 = 1950

How would a target of 2200-2400 work out?

Eventually the engine is going to get done, this the wish list for the future
A numerically higher rear gear set
Front mount IC (just because I hate the air scoop hanging down under the car)
Rebuilt short block
Ported OE irons
Ported intake
Roller cam

I figure that with these mods the converter will stall higher anyway so hopefully it should work.

 

[bison]

2100 + 1800 = 3900
3900 / 2 = 1950

How would a target of 2200-2400 work out?

Eventually the engine is going to get done, this the wish list for the future
A numerically higher rear gear set
Front mount IC (just because I hate the air scoop hanging down under the car)
Rebuilt short block
Ported OE irons
Ported intake
Roller cam

I figure that with these mods the converter will stall higher anyway so hopefully it should work.

With the Garrett housing it will be ok but id rather have a 2400 @0

 

[TURBOPOWERED68]

With the Garrett housing it will be ok but id rather have a 2400 @0

Yes the garret housing is staying on the turbo it makes a world of a deference.

 

[TURBOPOWERED68]

I WAS ready to buy but since i have reading the two new TC threads i am back to the drawing board.

Starting over. LOCK UP A MUST

Any way this sortta sums me and my build up.

The car IS a daily driver and it gets plenty of long trips (200 plus miles) I do go to the track at least 3-5 times a season my ET goal is 11.50s but wouldn't mind a fluke low 11.00s.
I don't want the car to feel LOOSE when normally driving around, If any thing needs to be compromised i would compromise performance over a loose feeling converter. i am thinking of 2200 to 2400 stall range. The car had a Stock D-5 i actually liked how tight it felt driving around i would have liked just 400-500 rpm at WOT.
this is my last and best run on the D-5 before it broke in the burn out box.
held about 1-3 PSI at line on the foot brake with 26X10-15 slicks
60'-----1.936
330'----5.307
1/8------8.137
mph----86.21
1000'--10.586
1/4-----12.686
mph---105.15
on the scanmaster Zero KR and O2s in the 890s-900s at 25PSI with a short spike of 30 Psi at take off.
These are my specs
1-86-87 GN drive train
2-Stock long Block
3-Stock cam
4-TE-6031 Journal bearing With the Garret 63 exhaust housing
5-Stock IC with the Dutt neck
6-Power Plate
7-42 lbs injectors
8-TT 93 Alky chip
9-Alky injection
10-Built 2004R Trans
11-the trans will be shifting it self
12-The rear gears are 3.08s BUT i might change them to 3.36 OF 3.55
13-The car weighs 3800.

 

[bison]

I WAS ready to buy but since i have reading the two new TC threads i am back to the drawing board.

Starting over. LOCK UP A MUST

Any way this sortta sums me and my build up.

The car IS a daily driver and it gets plenty of long trips (200 plus miles) I do go to the track at least 3-5 times a season my ET goal is 11.50s but wouldn't mind a fluke low 11.00s.
I don't want the car to feel LOOSE when normally driving around, If any thing needs to be compromised i would compromise performance over a loose feeling converter. i am thinking of 2200 to 2400 stall range. The car had a Stock D-5 i actually liked how tight it felt driving around i would have liked just 400-500 rpm at WOT.
this is my last and best run on the D-5 before it broke in the burn out box.
held about 1-3 PSI at line on the foot brake with 26X10-15 slicks
60'-----1.936
330'----5.307
1/8------8.137
mph----86.21
1000'--10.586
1/4-----12.686
mph---105.15
on the scanmaster Zero KR and O2s in the 890s-900s at 25PSI with a short spike of 30 Psi at take off.
These are my specs
1-86-87 GN drive train
2-Stock long Block
3-Stock cam
4-TE-6031 Journal bearing With the Garret 63 exhaust housing
5-Stock IC with the Dutt neck
6-Power Plate
7-42 lbs injectors
8-TT 93 Alky chip
9-Alky injection
10-Built 2004R Trans
11-the trans will be shifting it self
12-The rear gears are 3.08s BUT i might change them to 3.36 OF 3.55
13-The car weighs 3800.

With your heavy car the LU's will feel relatively loose in around town driving until they are locked. I doubt you will run faster than 11.50 unless you want to more aggressive with the turbo and converter.

 

[GNVYUS 1]

I don't see the point in having anything less than a 28" tire in any street/track car so you're going to want to swap out the 3.08 IMO. How I see it is if you keep that gear and a 28" tire, the cars going to need more stall to move that heavy car out of the hole. Add more stall, leave with more torque and now you have to make sure the rear suspension can apply this to the ground. Pick a rear end gear and tire, then hunt for the proper converter.

I thought some where showing the PTC 9.5" are around 4% loose. I don't see the worry while cruising then, 2000rpm with it locked is 2080 with the PTC, not a biggie IMO.