[GOAT8U2]

Curious what stall rpm you need to use their 9" vs 10"?

My. 10" 0 stator is tight but I'll get 3000rpm and it'll roast the tires and nets almost 3% on the dot at the end of 2nd gear at 6k rpm. But I'm 100% Street so I wanted it tighter than most.

[Dragncar]

Originally Posted by blueghoast

Have you tried a thicker fluid ?
I went to a thicker hydrualic fluid and made mine perfect.

GT

I run Red Line Synthetic type F or ATI Super F. Whatever one is the better price at the time.
I started the process of changing my TCI 8" to my PTC 9" this weekend. The fluid actually looked brand new when draining the trans. Bright as can be, clean. Smelled new.
I will stick with what is working.
I just reminded myself what it is now a pain in the @%$ to pull my transmission with the mid plate, elephant ears and 5 piece headers. Before I could pull it myself in just over a hour.
Not a chance now.
How far was yours off ? I can see where a thicker fluid would tighten it up a bit.
But I am looking for more than a little bit.

[GOAT8U2]

I was in the converter business for about 7 years, an 8" converter could actually be an 8 3/4 turbine ID. Depending on your stator, your power and shifting rpm it's easy for those little guys to slip. A 6500rpm shift is not a great window for them under high power to really couple at peak.

But on a car that shifted at 8500+ and was a 4.42 AWD these would be killer up top even at 800hp.

The 9" could be the 9 1/4" ID turbine and depending again on stator, power and shift rpm you might see a big drop in slippage.

Thick John Deere fluid can easily tighten a couple % or more depending on total slippage.

[Dragncar]

Originally Posted by GOAT8U2

I was in the converter business for about 7 years, an 8" converter could actually be an 8 3/4 turbine ID. Depending on your stator, your power and shifting rpm it's easy for those little guys to slip. A 6500rpm shift is not a great window for them under high power to really couple at peak.

But on a car that shifted at 8500+ and was a 4.42 AWD these would be killer up top even at 800hp.

The 9" could be the 9 1/4" ID turbine and depending again on stator, power and shift rpm you might see a big drop in slippage.

Thick John Deere fluid can easily tighten a couple % or more depending on total slippage.

Thanks, that was a useful post. I learned something today.
If I can get the slip down to 8% that would be nice.
Got the trans out today. Hopefully the car will be running by Friday.
I bought the 8" years ago from Butler. Kinda makes me wonder about their recommendation.
I pretty much bought the PTC because Langer recommended them. That guy would know who makes a good converter for a Pontiac.
The PTC is a steel stator unit, goes for 1200$ these days.

[blueghoast]

Originally Posted by Dragncar

I run Red Line Synthetic type F or ATI Super F. Whatever one is the better price at the time.
I started the process of changing my TCI 8" to my PTC 9" this weekend. The fluid actually looked brand new when draining the trans. Bright as can be, clean. Smelled new.
I will stick with what is working.
I just reminded myself what it is now a pain in the @%$ to pull my transmission with the mid plate, elephant ears and 5 piece headers. Before I could pull it myself in just over a hour.
Not a chance now.
How far was yours off ? I can see where a thicker fluid would tighten it up a bit.
But I am looking for more than a little bit.

You couldn't even here mine shift, sound like a snowmobile clutch.
I believe it was around 66-6800 rpm. brought it down to like 5300 I think.
I put the hole 5-gallons in and 1-qrt of f-type in for color.
I drained my pan and then added the other. Cann't beleave how good this works.

GT

[Probird]

Mine says 20.23% in the 1/8th and 6.69% in the 1/4. It’s an 8” FTI.

[Dragncar]

Originally Posted by blueghoast

You couldn't even here mine shift, sound like a snowmobile clutch.
I believe it was around 66-6800 rpm. brought it down to like 5300 I think.
I put the hole 5-gallons in and 1-qrt of f-type in for color.
I drained my pan and then added the other. Cann't beleave how good this works.

GT

I might give that I try. But, 5 gallons ? 20 quarts ?

[Dragncar]

So I did try the PTC 9". First pass it was soft and puked a little fluid out of the dipstick. So I jacked it up, took some out and re adjusted my fluid level and made another pass. Lost 2 tenths in the 60 and 4 tenths in ET so I took it home.
Sent it back to PTC and they called me up after they cut it open and asked me what I wanted to do. They did not asked me about stuff like tire size, gears ect and all they wanted to know was my ci. Tech guy said he would have sold me a 8".
The whole thing was confusing. He said my converter looked great, was tight and said the slip had to be in the 5% range. He simply wanted to know if I wanted it tighter or looser. I thought that is why I had it sent to the experts, to help me out on where I should go. Did not get any of that. So, I had a choice to make. Weld it back up and send it back, tighten it up or loosen it up a little.
Well, it used to work great and the peak torque point of the new engine had to go up a bit I told them to loosen it up a tad.
e will see where this goes. I will try it with the Red Line F and if its seems loose try the Tractor Supply fluid.
I figured if I can still 60 foot below 1.40 and get the total slip 10% or less that should work. We will see.
Called Pro Touque and they want to go with their Bullet 9.5" Maybe I will give that a try if this does not work out.

[AG]

What was the % slip with the 9" PTC?

[PAUL K]

You'd want PTC to loosen it up.

Did you buy this converter new from PTC for your Hi-port engine?

[Dragncar]

Originally Posted by PAUL K

You'd want PTC to loosen it up.

Did you buy this converter new from PTC for your Hi-port engine?

I bought this converter from PTC "for" the High Port engine back in 2016 but ran it in the old 455 HO.
The only specs that was different in the info PTC got back then was 10.8-1 CR vs the 11.5 that it is today. And the cam was to be a Crower cam Dan spec,ed for me, 270-275 .404 lobes on a 108 vs the 265-274 .431 lobe 112 cam that in it now.
It worked great in the old 455. Had them loosen it up just a little bit and we will see how it does.

[blueghoast]

Originally Posted by blueghoast

You couldn't even here mine shift, sound like a snowmobile clutch.
I believe it was around 66-6800 rpm. brought it down to like 5300 I think.
I put the hole 5-gallons in and 1-qrt of f-type in for color.
I drained my pan and then added the other. Cann't beleave how good this works.

GT

I mean 5 qrt

[Dragncar]

Originally Posted by blueghoast

I mean 5 qrt

Did your MPH go up when the RPM went down ?
I called ATI and asked about their 50 weight type F and they told me they only add a quart or two at a time. Never do they say dump it all out and fill with 50 weight.
But that Mystic 46 worked great for you it sounds like.

[GOAT8U2]

You lost .2 in 60ft and 4 up top, that's from the loss in the 60ft.

What launch rpm on best 60ft?
What launch rpm PTC 9?
What 1/4 mph before and then on 9" PTC?

If you know where your peak torque and hp are you can configure your launch rpm and shift rpm and then find a converter that sits well inside the numbers.

One issue for our platform is around 4500rpm peak torque and 5200rpm hp so the converter needs to be loose enough for 4500 flash etc but then couple by 6000rpm and drop say 800rpm to 5200 on the shift. This isn't easy to pull off with tire size and rear gear making it harder to dial in.

If our cars were spinning to 7k + etc it would be easier for the small turbine ID converters to couple up top. They're probably gonna tweak the stator to hit the 4500 flash you might need and then sacrifice a couple % up top but you'll couple good enough up top to be high single digit, 7%+.

[Dragncar]

Originally Posted by GOAT8U2

You lost .2 in 60ft and 4 up top, that's from the loss in the 60ft.

What launch rpm on best 60ft?
What launch rpm PTC 9?
What 1/4 mph before and then on 9" PTC?

If you know where your peak torque and hp are you can configure your launch rpm and shift rpm and then find a converter that sits well inside the numbers.

One issue for our platform is around 4500rpm peak torque and 5200rpm hp so the converter needs to be loose enough for 4500 flash etc but then couple by 6000rpm and drop say 800rpm to 5200 on the shift. This isn't easy to pull off with tire size and rear gear making it harder to dial in.

If our cars were spinning to 7k + etc it would be easier for the small turbine ID converters to couple up top. They're probably gonna tweak the stator to hit the 4500 flash you might need and then sacrifice a couple % up top but you'll couple good enough up top to be high single digit, 7%+.

The best 60 foots so far have happened taking off at 3800 on the 2 step with the 8" TCI. So I was still there when I tried the 9" PTC. But I have never even tried taking off at 4000 RPM or higher. new engine might like it. The old engine did not 60 foot any better at 3800. Just popped the wheels up but could not carry it out. This engine does like taking off higher. How high ? Do not know yet.
I really should have made more runs with it noting RPM drops and all that. PTC wanted more data but I got frustrated and took it home. PTC tech told me having too much fluid would not effect anything as it was in my first pass. But I think aerated fluid might have.
If I could have dynoed this thing I would have all the info for getting the converter right. Its tough on the track doing it while racing is going on. You get a couple time runs and then you are racing.
MPH dropped by 3 with the PTC.
I have it back right now so I am jacking this thing up and changing it this afternoon. See what the Red line 20 WT does. if its seems too loose next Saturday I will put the Tractor Supply thick stuff in and see what that does for Sundays race. Having a barbeque There Sunday so I hope its close so I can just race and have fun. The family does not like it when I just make test passes. They want me racing in 2 classes like normal.
The guys at Pro Torque might have a good handle on Pontiacs torque converters. The top tech guy said most companies miss with the 8" converter for Pontiacs because of our torque. TCI, PTC and ATI all said they would recommend their 8" converters. PT said they would build me a 9.5" because of that torque and they have more options inside the converter for getting it right.
If this does not work out I think I will have them build me one.
I asked PT tech guy about the Street Outlaw guys using their stuff as a bunch used too. He said they wanted like 10 converters a year without putting any money down and they got tired of it. Everyone does like free stuff I guess.

[GOAT8U2]

So the smaller converter is definitely flashing higher when they both leave at 3800rpm, that's advantage 8".

On the 9" you'd need to leave higher, it's by nature having a larger ID tighter so you might've needed 4000rpm+ if possible (I say possible because there's a chance it's too tight to get there).

Losing mph but only being down .4 is interesting.
Losing .2 in the 60ft instantly killed off .4 total so then being down 3mph but not .7 total is a possible good sign.
Once you get the 9" to leave hard and get back the .2 60ft you should see a lower rpm finish line cross and possible ET gain once the car leaves at a higher rpm but couples tighter later.

The challenge here is your 330, gotta get the car to move out but then couple and it's a balance that's tough, many factors and sometimes you need a game plan and 1 track outing to implement/test and the cars unlocked.

I'd try this, note launch rpm, rom drop on shifts
4000 on 2 step, couple passes
4200 on 2 step, couple passes

You need to have all other variables the same so write down tire pressure etc etc etc.

[Dragncar]

Originally Posted by GOAT8U2

So the smaller converter is definitely flashing higher when they both leave at 3800rpm, that's advantage 8".

On the 9" you'd need to leave higher, it's by nature having a larger ID tighter so you might've needed 4000rpm+ if possible (I say possible because there's a chance it's too tight to get there).

Losing mph but only being down .4 is interesting.
Losing .2 in the 60ft instantly killed off .4 total so then being down 3mph but not .7 total is a possible good sign.
Once you get the 9" to leave hard and get back the .2 60ft you should see a lower rpm finish line cross and possible ET gain once the car leaves at a higher rpm but couples tighter later.

The challenge here is your 330, gotta get the car to move out but then couple and it's a balance that's tough, many factors and sometimes you need a game plan and 1 track outing to implement/test and the cars unlocked.

I'd try this, note launch rpm, rom drop on shifts
4000 on 2 step, couple passes
4200 on 2 step, couple passes

You need to have all other variables the same so write down tire pressure etc etc etc.

I know the 9" would hold the car at 4400 on the brake even before I had it loosened. Never took off that high though. The 8" would go even past what the 9" would do, never took off that high either.
The old engine would get its best ETs-MPH when I got into high gear as soon as possible. Found that out on a red light pass where I got ticked and clicked it into 2ns then 3rd right away and ran it out. So I kept doing it.
This engine all I have done is shift at 6400 to 6700. Have not tried short shifting it. I will do at least a pass giving it a try and see what happens.
I have a dash cam that I will try and get on my tach.
Maybe just buy one but the cheapest playback tach is 329 $. This one.https://www.summitracing.com/parts/lng-44390
Maybe I will pick it up before the race.
Hey, thanks for all the advice on this converter stuff.

[Dragncar]

Originally Posted by AG

What was the % slip with the 9" PTC?

Never got a good run so I did not do the math. I will see if I can find the slip and check the it vs now since the converter has been changed.

[Dragncar]

Since the timing change the slip % has dropped. If I crossed the line at 6500 the slip would be around 10%. But it started to run during actual eliminations and I was not watching the tach when I crossed the line. Trying to stay just ahead of the guy in the other lane.
The first couple time runs Sat I will get a better read on converter slippage.

[AG]

Get a rollbar mount for your phone and point it at your tach and gauges to monitor the vitals.