Converter too tight??
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
I’d guess you’re seeing a ton less RPM with the tighter converter in 3rd.? Have you run 3rd out to the same RPM you take 2nd ?
I think that is the nature of the beast as far as RPM drop on the 9.5 PTC conv. They tend to couple hard around 300feet out and require a lot of power. Where other converters would still be slipping 25-30%. I haven’t really decided if this is a good thing for moderate power setups. It gives you a nice tight converter on the big end, but it doesn’t slip and multiply torque like crazy through the 1/8th like a yank converter (or similar). I really think your converter needs more power to work correctly. If you don’t want to add the power, they are easy to sell! Get a yank SC3000 would be cool to see a direct comparison…
Stock 48 is seeing around 10% slip uptop. I see under 5% with the PTC. And we all see which nets the best ET!
I think that is the nature of the beast as far as RPM drop on the 9.5 PTC conv. They tend to couple hard around 300feet out and require a lot of power. Where other converters would still be slipping 25-30%. I haven’t really decided if this is a good thing for moderate power setups. It gives you a nice tight converter on the big end, but it doesn’t slip and multiply torque like crazy through the 1/8th like a yank converter (or similar). I really think your converter needs more power to work correctly. If you don’t want to add the power, they are easy to sell! Get a yank SC3000 would be cool to see a direct comparison…
Stock 48 is seeing around 10% slip uptop. I see under 5% with the PTC. And we all see which nets the best ET!Funny thing is, theres a guy on YB that has a sig that says "you don't make enough power for a PTC"...lol...there is some truth to that!!!
I too am out on a fence as to whether or not for a MODERATE setup a tight converter may not be ideal. It was actually something that I had concerns about going in.
Have you tried short shifting? My 17 blade PTC had very little rpm drop when I shifted it at 5800 or so. Bringing the shift point up to 6500 gave a much more pronounced drop. (dont' remember exact numbers) Thats with a glide going from 1.76 to 1.0
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Not lately....will try a 5800-6000 drop, good suggestion as the LS6 cam probably doesnt need to bet at 6400 but it seems to go there with ease!
Just got mine back and in as well. I'm working with Dusty.
Mine was a 16, now an 18.
Feels excellent on the street. Hovers around 2200 with normal driving.
Foot takes nicely to 3500. Before it was trying to spin at 3400.
I prob did not have enough power or too light a car for the prev 16 unit. I lost 800 rpm at the finish line, and the car slowed 3 mph.
Will be awhile before I can get to the track.
Mine was a 16, now an 18.
Feels excellent on the street. Hovers around 2200 with normal driving.
Foot takes nicely to 3500. Before it was trying to spin at 3400.
I prob did not have enough power or too light a car for the prev 16 unit. I lost 800 rpm at the finish line, and the car slowed 3 mph.
Will be awhile before I can get to the track.
You mean the last leg of drag weekend? I'm actually in Palm Springs visiting pops. And for sure NOT beating the heat. :-)
Things just didn't come together to even go watch in Portland.
Soon when I get home and the weather cools. Maybe try a woodburn Friday eve event.
Things just didn't come together to even go watch in Portland.
Soon when I get home and the weather cools. Maybe try a woodburn Friday eve event.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
rotary is right as usual...looking back at the logs the rpms fall back to about 5000+/-. Does this mean my engine's pk tq is 5000? Didn't think it would be that high with the smallish LS6 cam in 6.0.
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Verdad Gallardo I was told by Dusty and every other converter tech I’ve spoken to that the higher you rev the motor, the more efficiently it will couple. So in general, I’d assume the reverse would be true, no?
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
I hear ya Force...there has to be a "break-even" point or something. What if I shift at 5000 rpms...does that mean the rpms will stay at 5000 in the next gear? I doubt it, but will do some more testing.
Same setup Shifting at 6600 and turning the boost up to 25 resulted in a noticeable 900-1000 rpm drop at the shift. Trapping 153.
Few months old but a lot of good info here!
I'm curious what the second number does on these converter specs. For intsance 17-0 or 18-35.... What does the second number do? I know its reference to fin angle but how does it correlate to the way it responds.
I have a 14-35 PTC that I basically told them I wanted it to be as tight as possibly driving around.... They never told me I needed to .make 1000+rwhp but that's besides the point.
I'm getting around to restall it but with a 370 and billet s480 on 12-15psi (assuming 800whp) dam thing was dropping 1700-1800rpm shifting at 6600 and felt like it had no *****. Long story short I blew the motor and I'm doing a gen 4 SBE and plan to make a true 750-800rwhp. He is suggesting a 16-45..... I don't know but reading everything I have read so far I think it will still be too tight.
I'd really like to just sell the PTC and get a PY3400 since that thing multiplies torque so well.
On a side note I went 135mph with the budget PTC 10' converter shifting at 6400 I had a 900RPM shift drop and that thing felt amazing! If they could make this 9.5 just a touch tighter than the budget 10' they sell I would be golden!
I'm curious what the second number does on these converter specs. For intsance 17-0 or 18-35.... What does the second number do? I know its reference to fin angle but how does it correlate to the way it responds.
I have a 14-35 PTC that I basically told them I wanted it to be as tight as possibly driving around.... They never told me I needed to .make 1000+rwhp but that's besides the point.
I'm getting around to restall it but with a 370 and billet s480 on 12-15psi (assuming 800whp) dam thing was dropping 1700-1800rpm shifting at 6600 and felt like it had no *****. Long story short I blew the motor and I'm doing a gen 4 SBE and plan to make a true 750-800rwhp. He is suggesting a 16-45..... I don't know but reading everything I have read so far I think it will still be too tight.
I'd really like to just sell the PTC and get a PY3400 since that thing multiplies torque so well.
On a side note I went 135mph with the budget PTC 10' converter shifting at 6400 I had a 900RPM shift drop and that thing felt amazing! If they could make this 9.5 just a touch tighter than the budget 10' they sell I would be golden!
from what I see the race 9.5 can be made tighter than the 10" . I have a 10" ptc and I sent it back to ptc and told them to tighten it up upstairs and it works good. I can get 3200 pretty easy and it is nice and tight by 5500 rpm. mine is a 10"ths-200*degree fin angle-ported stator -spragless.
a touch tight for my 10# boost but the more I turn it up the better it works. my gut feeling is a t 15# boost it will be perfect. but I need better traction first.
a touch tight for my 10# boost but the more I turn it up the better it works. my gut feeling is a t 15# boost it will be perfect. but I need better traction first.
Thread Starter
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From: THORNTON, PA (NEAR PHILLY)
over 1700 on both 1-2 ad 2-3. car felt like a turd and this is a 370 and billet 80mm. only went 130mph at 12-14psi. hell my 5.3 cast s475 went 135+ on 14-15psi. converter was way too tight.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
My she 5.3 with JFR 215/215 112* can and box stock s475/83 @ 14psi went 135 being super fat .
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Just to demonstrate a mismatched converter....
I had the PTC converter that was the topic of this thread (spec'd for a 6.0 that blew-up) behind a 5.3. I could only muster 118 mph. Threw a cheap(er) 10" behind it, and bam - 134mph!
I had the PTC converter that was the topic of this thread (spec'd for a 6.0 that blew-up) behind a 5.3. I could only muster 118 mph. Threw a cheap(er) 10" behind it, and bam - 134mph!