LT1(383) and PY3400 problems
Thread Starter
Teching In
Joined: Nov 2002
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From: FL
LT1(383) and PY3400 problems I have a mild 383LT1 that makes 330rwh(@5700) and 380rwt (@3400). On a stock converter it pulled 1.69 60ft and 12.08 @ 113.5. Mike at YANk reccomended a PY3400. I put it in and went to the track. NOW it pulls 1.69 60ft and 12.08 at 113. Can anyone tell me whats going on here? Mike swears the converter's fine, BUT it's not doing anything!!! It doesn't brake stall past 2100, drives like a stocker, I'm a little UPSET!
Re: LT1(383) and PY3400 problems The Pro Yank 3400 is Yank's tightest feeling converter. Its larger 258mm size and extremely high stall torque ratio make the converter feel like stock. It shouldn't run like stock though. Since you were pulling a 1.69 60' time before, what kind of stock converter did you have? It certainly must have been a lot looser than the boat anchor that comes behind the stock LS1. 1.69 60' times on a stock converter is awesome. Is that on motor or on gas?
What was the weather like when you pulled 1.69 with the stock converter vs. when you pulled the same time with the Pro Yank? That could make some difference.
What was the weather like when you pulled 1.69 with the stock converter vs. when you pulled the same time with the Pro Yank? That could make some difference.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
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2023 Corvette 3LT Z51 soon to be modified.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Thread Starter
Teching In
Joined: Nov 2002
Posts: 3
Likes: 0
From: FL
Re: LT1(383) and PY3400 problems The converter I took out was a stock 1640 stall LT1 converter, all runs are NA. My stock valve heads and small cam makes ALOT of low end torque, but no HP. I knew it would drive almost like stock. I also knew the PY is built to really shine on the bottle, but I figured it would gain something running NA. The timeslips look identical, and the weather was the same. Would a ST3500 be the answer? I know it will out 60' the PY but I also thought its shift extention would be to high for my low RPM motor.
Thanks for your help
Thanks for your help
Re: LT1(383) and PY3400 problems I assume that you had no wheel spin with the PYE 3400 and were able to hammer it from the hole?
May be too much stall. If peak torque is at 3400 and a low stall stock unit is netting good 60' (never seen a 1.69 on a stock converter before) a 2800 - 3000 stall is a better a solution than a ST 3500.
A TT2800 might work better. It is a larger diameter converter and should stall around 3000 behind your motor.
May be too much stall. If peak torque is at 3400 and a low stall stock unit is netting good 60' (never seen a 1.69 on a stock converter before) a 2800 - 3000 stall is a better a solution than a ST 3500.
A TT2800 might work better. It is a larger diameter converter and should stall around 3000 behind your motor.
Thread Starter
Teching In
Joined: Nov 2002
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From: FL
Re: LT1(383) and PY3400 problems I talked to Mike at YANK and he said the cars not getting into the converter.....It flashes to 3400 but brake stalls to 2100. i asked him if it would produce identical numbers, even if the stall was too low. He claims unless you can stall it high enough the converter won't work, and it would drive & perform like a stock converter. I don't understand it. I figure a higher STR and more efficient verter would have to change something on timeslip even if its not stalling......right???
Re: LT1(383) and PY3400 problems My 355 LT4 H/I/HOT cam car at 3400#s went 12.3@108 with a 1.69. usually the car pulled 1.7s and ran 12.4-12.5 at same MPH. I was running a ST3500. I could only brake stall it to 2200ish.
I had the same 60's with 3.23s and 3.73s and nothing else changing, but the ETs dropped a good bit b/c of the Revs on the top end.
To me it sounds like you need a different TC, I would personally vote for the ST3500.
What PCM are you running? OBDI or II or aftermarket? If you are running OBDI, realize you might have a limp home problem with the high stall and brake stalling. I never had the problem unless I was brake stalling. The OBDII cars dont have this problem.
I will also add that stalling mine up vs leaving off idle produced the same 60's.
I had the same 60's with 3.23s and 3.73s and nothing else changing, but the ETs dropped a good bit b/c of the Revs on the top end.
To me it sounds like you need a different TC, I would personally vote for the ST3500.
What PCM are you running? OBDI or II or aftermarket? If you are running OBDI, realize you might have a limp home problem with the high stall and brake stalling. I never had the problem unless I was brake stalling. The OBDII cars dont have this problem.
I will also add that stalling mine up vs leaving off idle produced the same 60's.
