Ls1tech expert help please
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
Converter plays a bigger role on the dyno than the actual transmission. The TH400 itself isn't going to make you lose but a few % over a T56. The converter could be anywhere from an additional 3-20%
TECH Junkie
Joined: Jul 2015
Posts: 3,012
Likes: 48
Hell the one we did just last week went from an auto 10 speed to a TH400 and went from making right at 1000 rwhp to 865 rwhp under identical conditions and the A10 is actually a very efficient lockup auto trans and is comparable to a manual trans. General rule of thumb that everybody should follow is that when you don't know something just don't say anything at all. I hope you don't actually believe you only lost 20 horsepower in your swap.
Correct, but with a car making those kind of power numbers the correct converter is going to be closer to 10-20% and that is usually anywhere from 100-150 rwhp loss.
Here's another "General rule of thumb", you....yes you nicd, aren't as smart as you believe that you are. As mentioned earlier, I didn't use corrected numbers, and yes, maybe the corrected numbers should have been the ones referenced. Typically, if the conditions are somewhat close, I just go with whatever it made. The point of all this is, to give a general ballpark of what to expect, going from one trans to another, using the same car, same dyno, no it wasn't the same day, but close enough, at least for me. I've seen you get railed before around here, and I can understand why.
STD is also a correction for conditions, it just corrects to a higher number and is subjectively less accurate than SAE correction. People really only use STD because it gives a higher number.
TECH Junkie
Joined: Jul 2015
Posts: 3,012
Likes: 48
Guess I had better call the morons at PTC, because they CLEARLY got my converter wrong. Lol, I'm done man, between lying dynos and the guys at PTC not knowing what they are doing (sarcasm), thank God we are blessed with your infinite wisdom.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo I like PTC, I work with those guys on the regular. They spec'd my converter in my C6 Z06 and it's about dead on. Dude, just because you don't get what is being discussed here don't cry about it. And yes your dyno results are garbage and you know it which is why you are back peddling about corrected/non-corrected numbers so it's probably for the better that you are "done". Now maybe we can help the OP with his questions, etc.
Anyone have any good reads on determining proper converter given all the variables that come into play other than "call ____ at ____" and they will set you up.
I'd rather not call the suppliers until I have an understanding of how the different variables come into play.
I'd rather not call the suppliers until I have an understanding of how the different variables come into play.
TECH Regular
Joined: Dec 2018
Posts: 456
Likes: 14
From: MIAMI
I like PTC, I work with those guys on the regular. They spec'd my converter in my C6 Z06 and it's about dead on. Dude, just because you don't get what is being discussed here don't cry about it. And yes your dyno results are garbage and you know it which is why you are back peddling about corrected/non-corrected numbers so it's probably for the better that you are "done". Now maybe we can help the OP with his questions, etc.
Dyno graphs dyno dynamics 8.5:1 compression is relatively low, that's what my old combo was because it was originally built for 91 octane since E85 wasn't really a thing back then. That power level doesn't sound out of the ordinary for the octane level through a TH400 though and a lot depends on the dyno being used, etc. Where is the dyno graph and what kind of dyno is it? Picking up 100 rwhp with another 5 psi of boost tells me it's on the right track but you could probably get away with more timing on C16, it's a pretty slow burning fuel. Read your plugs, adjust from there.
Pump gas bw s480 all the same cam huron kit fti th400 15lbs Dyno dynamics all wheel drive dyno.
Sts kit 6speed Garrett 76mm 14lbs
Race gas c20 20lbs 15 degrees th400
[QUOTE=NicD;20127272]8.5:1 compression is relatively low, that's what my old combo was because it was originally built for 91 octane since E85 wasn't really a thing back then. That power level doesn't sound out of the ordinary for the octane level through a TH400 though and a lot depends on the dyno being used, etc. Where is the dyno graph and what kind of dyno is it? Picking up 100 rwhp with another 5 psi of boost tells me it's on the right track but you could probably get away with more timing on C16, it's a pretty slow burning fuel. Read your plugs, adjust from there.[/QUOTE
it was c20 not c16 also. I originally put the wrong thing. Thank you for your help.
it was c20 not c16 also. I originally put the wrong thing. Thank you for your help.
OK so it's a dyno dynamics dyno, user configurable, no guarantee on the results being all that accurate so I wouldn't put much faith into the actual number itself and just concentrate on the improvement. I assume I'm supposed to be looking at the top graph and the bottom graph for comparison? Not really familiar with C20 but apparently it's similar to any other unleaded 100 octane? If so it's burn rate is pretty similar to any other unleaded fuel which means faster than C16 for sure so you need to keep timing in check. Really this is going to come down to putting in a fresh set of plugs and making a full pass at the track and then shutting it off at the end and pulling them out to look. That's ultimately going to tell you how close you are to optimal timing or you can keep adding timing until MPH stops going up but at some point you are going to have to read the plugs. Your MPH at the track is going to tell you if you are on the right track or if something is wrong.
do you have a data log with fuel consumption? sometimes that helps me decide whether the dyno is being stingy or generous. if you have fuel flow that matches the power output, it leads me to think the dyno is close.