Art Carr vs PTC converter results

VadersV6

Active Member
You disagree, yet confirm my point. What I said was
The only time brand names make a difference, is in terms of engineering practices which support strength and reliability.
Your main complaint was the lack of strong and/or reliable components. I know the AC's are rated pretty high in terms of power, but it seems to take alot of power to get them to work right....in off the shelf form. My main point was that slippage has nothing to do with brand. Its the fin/turbine setup. Alter fin angle and the TC will have different characteristics. You can make an AC TC slip less. Getting them to do it may be a different story. I havent heard a whole lot of good stories about customer service....but I havent heard alot of bad ones either....other than people taking their cars back 20 times to get it to shift where they want it to....
 

Dusty Bradford

Well-Known Member
The part is disagreed with is what I quoted for you to see;)

AC could have taken your datalogs and all your other info, and made a TC that performs exactly like this PTC one, if not better.

There it is again so there's no confusion.

We did change the internals of the AC core to make it ALOT better but it still took rpm (not power) to make it work....6600 was the shift point. 99% of the TR's out there will never shift this high so the AC will never get it done like our's can. If AC made it tight enough to see 3-4% slip you'd never get it spooled. There's much more to it than simple fin angle adjustments.
 

Reggie West

Well-Known Member
TurboBuick.Com Supporter!
Another factor that came into play is that since the PTC converter is more efficient, at the current boost it drops the rpms down below the power range of the cam after the shifts and all the way through third. I'm figuring that once the boost and power is raised, the stall will increase to right where I want it to be and the rpms where be right on at the end of third. Both of the runs above were in the 15-17psi boost range. Next time boost will be in the low 20's.

Murph you are not dropping out of the torque curve with that cam or just about any other. Buick motors are making max torque by 3800 rpms or less in some cases. With a 224 cam yours is probably at 3800 or so. You have greater rpm drop now with the converter and that is a good thing. And from looking at the data logs you are loading the motor harder which is great too. Hence same speed at lower rpms.

I would say turn to boost up with that 70 you have and check the tune you may be running rich now.

Good numbers and info.
 

murphster

Well-Known Member
Ran the T again last night at Englishtown. Installed a manual boost controller onto the external wastegate so that I could turn up boost past the spring pressure. The boost was set at 23psi (previous runs were 17psi and 15 psi).

The converter and the combo defintely liked the higher boost. I manually shifted at around 6300 rpm again. This time the converted dropped down to 5150 on the shifts. Previously the PTC converter dropped down to 4750 when I was running 17psi boost and even less with testing on lower boost.

Unfortunately I didn't get a whole run in. I don't have a roll bar yet and I'm trying to decide whether to get a roll bar or a full cage so I want to test the combo first. I launched fairly soft at about 5-6psi boost and pulled out a 1.6 60ft. I let off right after the 1/8th mile but still ran a 10.99@100mph. Oops. :D In the 1/8th I ran 6.8@103.8mph. Figure a solid mid 10sec run and maybe a lower 10sec run with a good 60ft like 1.4 or so. I would have liked to have seen the rpm and mph on the top end to see how the converter was doing, but the track officials weren't that happy as it was. heh. They didn't give me a timeslip and sent me to the tower for a pep talk.

I'll post up a Directscan screenshot later tonight. Hopefully I'll have a bar/cage soon so I can get some data at the end of the track with high boost for some converter efficiency numbers.
 

TURBO 6

Beer Snob
Staff member
I was seeing 20% slip with my "off the shelf" 10.5" 2800 stall PTC L/U. Car went 127 mph crossing at 6200 rpms. Definatley too high. Since then I've installed the PTC 9.5" N/L and can't be more happy with the spool up. It takes 1.4 seconds to go from 0 psi to 22psi nailing it from a dead stop. Going to the track in a couple of weeks to enjoy the 4% slip up top. Should gain MPH and I'll be able to turn the boost up. Dusty nailed it with these 9.5" N/L converters.

Oh also I disagree with VadersV6, there's no way in hell an AC 19930 or 16930 or any other converter they make will compare to the PTC.
 

BEATAV8

The Engine Whisperer
I haven't gone fast enough yet, but based on numbers at 90, 100, 106 MPH, I'm expecting 7.5% @ 130MPH. Will see when I get it to the track.

I'm running PTC 9.5" non lock.

 

87NAT

In Between GN's
I wish you would stop showing that freaking video! I am just getting over my "spooling envy" I developed when I first saw it.:eek: ;)
 

87NAT

In Between GN's
can you get a PTC in a lockup ???

You can get the 10" LU but not that nasty 9.5 in the video. Price is about $400-500 less for the standard 10" converter. Mine works great for the price. Contact Dusty..he will answer all your questions. Arent you running a 6776dbb right now?
 

PaCemkr86

WFO Racing
Staff member
You can get the 10" LU but not that nasty 9.5 in the video. Price is about $400-500 less for the standard 10" converter. Mine works great for the price. Contact Dusty..he will answer all your questions. Arent you running a 6776dbb right now?

correct.. I'll contact Dusty and see if he can answer some questions i have..
 

bison

Moderator
Staff member
It has nothing to do with the brand. The TC needs to be dialed in for your weight, gearing and power curve. If the AC was slipping too much, then it was obviously designed for less power, or less weight in mind. Theres rarely a time when you can buy a TC off the shelf and have it work exactly how you want. It takes ALOT of data to get a TC made just right for your car. Your dealing with a fluid turbine, not a clutch, so theres a million variables. You think the first jet engine worked just right? Every high end racer will get a TC thats close, make some passes, datalog the crap out of it, and have the TC worked on. Then the second time around, its alot closer, but usually still not perfect. Changing brand names, often times just gets you back to square 1. AC could have taken your datalogs and all your other info, and made a TC that performs exactly like this PTC one, if not better. If you went back to PTC with this data, they could improve on it as well. The only time brand names make a difference, is in terms of engineering practices which support strength and reliability. I know the AC's are damn strong. I traded an AC 16930 for a TCS 9-11 TC, and the AC is considered billet, although its a different execution. The 9-11 was a solid chunk machined out, and looked strong, but in reality wasnt half as strong as the AC. The guy I traded with was bitching about the AC saying he'd never throw this in his car, and it's not billet blah blah. Telling him it was rated for over 1000hp made no difference. He cared about the way it looked. I ended up paying him extra money to shut him up. I do know the AC made my car pull like a rocket sled compared to the stock one. But yeah, it did slip alot. AC's seem to slip more out of the box, but they can easily be reconfigured and usually for free the first time.
I disagree with most of this. I talked to AC directly last year and commented on how well the converter worked down low but i complained that it gave up a bunch up top. He did not have an answer or a solution how to improve it. Ive ran several AC's. Really old ones, new ones and TX AC. None ever coupled better than about 10% in a 120mph car. Most were in the mid teens at 125:eek: . They simply dont have the same stator machining ability and pump/stator configurations to achieve the numbers we need these days with our small inch high torque turbo engines. PTC does have this tech. Thats why their converters work so well and they sell so many. It should be mentioned that light cruise slip is much better than any other NL converter i have ever seen. None are even close. Its not as simple as fin angles. PTC's stators are in a league of their own.

The PTC in my sig is slipping approx. 3.5-5% at 132 mph. 5650rpm with a 27.5 inch tire and 3.42 rear gear. Assuming a very small amount of growth with the radial the number is what i stated. The combo propels the car like a rocket. Yes, under 5% slip in a NL converter. I dont have the exact number because the driveshaft speed sensor is not installed yet. Based on datalogs, my GPS and g-tech the slip is 3.5-5%. No AC converter will come close. Or any other converter that i have seen for under $1800:eek: .
 

GNVYUS 1

Well-Known Member
PTC has a custom stator in the 9.5" NL's and is why that converter is probably a better choice for us street/strip GN's. I tried getting them to use that stator in an import converter because it kicks so much butt while being a NL. ;)

Seeing anything around 3-4% in a NL that's not a bolt together is ridiculous for PTC's price.
 

Pronto

Believe nothing you hear and half of what you see.
What kind of slippage is seen in a 115mph car with the l/u version?
 

BEATAV8

The Engine Whisperer
I wish you would stop showing that freaking video! I am just getting over my "spooling envy" I developed when I first saw it.:eek: ;)

:biggrin:
Well the exhaust leak was holding it down a little bit.... J/K:biggrin:
 

BEATAV8

The Engine Whisperer
I made a few passes with my PTC 9.5 non lock today. Best was a 10.62 @ 127MPH. She went through the traps at a tad over 5600RPM, so the slippage was about 7.5%.

On the 2-3 she pulled down from 5960 to 5120.
 
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