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#1
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Picking Torque Converter
Hi everyone,
Looking for some help picking a torque converter for my new 400 engine in my 68 GTO. Trans is a TH400 that is going out to be rebuilt this week hopefully. I am attaching the dyno sheets from the engine builder. Current rear gear ratio is 2.56. I'll take suggestions on that as well. Thanks! Sorry about the quality, if you can't read something let me know and I'll post it.
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
#2
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hard to read the hp, torque numbers, but ptc is a top quality converter company that can fix you up with your dyno info.
Un related, but you may want to add at least a half of quart of oil if you plan on doing any extended 5000 rpm+ outings. The oil pressure was dropping out pretty fast. A guess is that the pickup may be on the verge of being uncovered. It could be magnified under actual driving conditions.
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1963 Cat SD Clone (old school) streeter 1964 GTO post coupe, tripower, 4speed (build) 1965 GTO 389 tripower, 4 speed, driver 1966 GTO dragcar 1966 GTO Ragtop 1969 Tempest ET clone street/strip 1969 GTO Judge RA lll, auto 1969 GTO limelight Conv. 4speed go and show (sold) 1970 GP SSJ 1970 GTO barn find..TLB…390 horse?….yeh, 390 1972 GTO 455 HO, 4 speed, (build) 1973 Grand Safari wagon, 700hp stoplight sleeper 525ci DCI & 609ci LM V head builds |
#3
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I will take the liberty of sounding like a broken record.... call Kriss at Continental Torque Converters and relate to him your entire combination in detail... cars weight, transmission, driveline & engine, etc., then go over your dyno sheet with him with the torque numbers. Have him build a "custom" converter for your application. The stall will suit your performance needs and yet be well coupled out on the open highway, with minimum slippage.
My 2 cents. .
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'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE |
#4
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Hot sure if this matter or not but it has the ram air three 12 heads and the Pistons were dished out to get 9.5/1 comp ratio. It has all arp bolts but this is going to be a family cruiser for the most part maybe hit the track once a year. It has a edelbook performer intake with holly 750 carb but have the cast iron off the 68 with Rochester carb available . Open to all suggestion even cam change if it will help as it's still out of car an this can be easily done now thanks for any help. All dyno was done on 87 octane gas .
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
#5
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Again, I'm just curious. I keep hearing how great these Continental converters are. So, does that mean that in this day and time, they are the only guys who can build a converter that will stall correctly, without being too loose on the highway ?
I mean is that such an elusive combination, that nobody else has figured it out yet. Looks to me, if that be so, all other converter builders would soon fold up, and Continental would have a monopoly. I'd figure by now, that lots of other guys have cut open a Continetal, to see what makes 'em tick, then build one like it, with their brand name on it. |
#6
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Quote:
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#7
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Quote:
Deeper gears, if anything, but you have the torque in the bottom end to deal with it. And your stated intentions as a cruiser match what you have already. If this is the 'vert in your sig, then keep the motor/drivetrain as is, and drive them wheels off!
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"...ridge reamer and ring compressor? Do they have tools like that?" |
#8
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Continental converter,love mine, none of the hi stall sound noise when taking off like grandma from a light, but kick it in the a$$ and hang on......
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color me gone |
#9
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Continental is not so exclusive, just very popular.
Way back many years ago I bought converters from Marv Ripes at A-1 Automatic Transmissions in Southern California, Marv was a familar sight at races across the nation with a great reputation. He had one of the most formidable Stock Eliminator cars in drag racing in the hay day. Getting in touch with him was difficult (As Kriss at Contintal often is) but when you did he wanted to go over your engine dyno sheet with you, it can be a distinct advantage if available. I had him build a "custom" converter, and they also had a popular 'shelf' 10-inch converter called the "super Launcher" that acted very similar to the units Continental does today (little known fact, Kriss at Continental and Marv at A-1 had an association early on ). A-1 is still in business, however I'm not sure of Marv's participation in the company today. We have also had good luck with "custom" converters from Hughes converters out of Phoenix. You may see others post their opinions and choices. That said, I always urge people to try for a custom made converter made for your specs.... not a 'off the shelf' unit ordered thru Summit or a catalog. As we know the torque converter can be one of the best bangs for the buck ($$$) for performance. Don't cheap out A-1 Converters / note their comment: "Every 'GM TH350 & TH400' is custom built, so we need information from you." https://www.a-1perf.com/ Continental article: http://www.hotrod.com/how-to/engine/...y-continental/ .
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'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE Last edited by Steve C.; 06-08-2015 at 10:15 AM. |
#10
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Yes it is the convertible and will see almost all street maybe a quarter mile to see what it can do. Leaning toward a set of ram air 3 manifolds 2 1/2 pipes.
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
#11
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There are LOTS of companies building converters that will fit these applications and work fine.
TCI makes a decent 10" unit, as does Hugh's, both are somewhat "looser" than the Continental 10" for normal driving, and show more slippage above the stall speed on drag strip runs, etc. I've also tested the very popular Hugh's 2500 BOP unit. It's not bad, but still "looser" than I like to see for these engines. Pontiac engines are actually a poor design right from the start, the heads flow no better than the run-of-the-mill small block Chevy factory head, and they sit on much larger engines. They are also full of "heavy" internals, really long rods, and much larger crankshafts than BBC's use. This makes for a pretty strong design, but weight eats up power, and works against these engines at high rpm's. Even with all that said, the Pontiac engines are EXCELLENT mid-range engines, producing power second to none in the low to mid-range. With this in mind, a "loose" converter, or one that isn't well coupled at lower rpms, and above the stall speed leaves considerable vehicle performance on the table, not to mention less efficiency eats up more fuel, and puts more heat into the transmission fluid. I've tested just about every converter out there at this point, and NONE of the "shelf" units are all that great for these engines, especially when you start getting into the 10" units. They are just too "loose" for normal driving, and don't couple all that well above the stall speed. Pontiac applications notice this more as we typically don't gear our combinations to capitalize on high rpm power, the vehicles are heavy, and weight backed up against street type axle ratios really "works" a converter pretty hard with a large CID/high torque engine in front of it. Continental knows this, and has worked with many of us for years to develop the 10" Pontiac units. They use special cores with HUGE fins to move the fluid so they can be very efficient for "normal" driving and not show a lot of "loose" characteristics or slipping excessively anyplace. Being on 10" cores they also "flash" pretty high with good traction and when hit with big power (torque), so you get the best of both Worlds, a converter that is very well coupled for "normal" driving, then shows it's colors nicely at the track with good traction. Other companies (custom units) can build converters that work well, so Continental doesn't own the entire deal here, but you simply aren't going to find anything close to them in "shelf" and low cost "generic" units from any vendor that I know of. Buying a Continental converter for one of these vehicles is much like buying a camshaft from Dave at SD. It's been tested for many years by folks who know what they are doing, and it's just flat going to work well for the application, and you aren't likely to find anything else that works nearly as well just calling some tech line or flipping thru a catalog and buying a "generic" unit.......Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#12
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Thanks for clarifying that Cliff,I just ordered a 10" continental and had a hard paying that much for a convertor that I felt could be had for less somewhere else. All it takes is money and time to make your car do what ya want! I have little of either it seems and my car reflects that. Cars seem like a big puzzle.
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#13
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#14
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Cliff I will go with Continental. Any input on stall speed? Thanks for help. Doug
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
#15
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Since price was mentioned all add this.
We've paid several companies to build us the "tightest 10" unit that you can make", and were somewhat disappointed in every one of them in one area or the other. TCI came out the winner on that deal, followed closely by Hugh's, then Coan. The tech at Hugh's actually told us that we wouldn't like the end result, that it would be "too tight" for what we were doing. Their original 10" unit was pretty "loose", we could get over 2500rp's on the brakes before it would spin the tires, it "flashed" well beyond 4000rpms when hit with full power and good traction, and slipped over 700rpms in the lights at the top end of the track. The resulting "custom" 10" unit was much better. Would go to about 2400rpm's on the brakes, flashed to right at 3200rpms, and about 300-400 rpm's slippage on tope end. Drive really nice, not overly "loose" anyplace. After all the work it was about the same cost as the Continental 10" converter, which is a little tighter everyplace with a little more flash stall at the track. The number on the "Jim Hand" 10" unit I use are 1900rpm's against the brakes, 3400 flash stall with good traction, and about 150rpm's slippage on top end. It acts and drives very much like a stock converter. One company I've heard good results from over on the "Race" section is PTC, but I have not tried one of their converters in my own car, and most like woln't. At this point I'm done testing in that area. We've been selling Continental converters now for over 10 years, and our customers have been very pleased with them. Many of you have seen this clip before, but listen to the clip this time and notice how well the car moves out when placed in gear, how tight it is coming up on the converter ont he starting line, flash stall, and how well the power is transmitted on the run without a lot of rpm's and engine rpms dropping between shifts, etc. This is what we look for in a good converter for one of these cars....Cliff https://www.youtube.com/watch?v=6zVdoLR-VzM
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#16
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Looking for some input again. I talk to Pete at continental and with my low gears he does not like the 10 inch converter unless I upgrade rear end gears into the 3.50 range. I was hoping to keep the low gears and he told me I need to find a 13 inch core he can work on , they made two different ones so I have to make sure it's the correct one, ( he said they are very tough to find?)so question is what would you do? If I can find the right 13 I can keep the drive train alone if not if I go to the 10 inch with 3.50 gears how will it be on highway? Thanks for any help but I have read enough to know how important the correct converter is. The 10 inch aren't cheap and rebuilding a 13 won't be any cheaper but I will pay to have the car run right. Thanks for all your help. Doug
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
#17
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Find a 13" core. Can't be all that hard to find, but I had heard a while back that Continental had run out of them.
Ask Pete how to ID the correct one, hopefully there is an external feature that will tell you. You'll absolutely hate the 3.50 gears for highway use, especially so after having the 2.56 gears. Glad I hung onto my 13" Continental, was using it behind a 455 with 2.56 gears and it was perfect. Need to send it in to freshen it up for my new 421 build, I will be using 2.56 gears again.
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1964 Tempest Coupe LS3/4L70E/3.42 1964 Le Mans Convertible 421 HO/TH350/2.56 2002 WS6 Convertible LS1/4L60E/3.23 |
#18
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You are absolutely correct on them running out of cores . Pete said to send him pictures of the one that was in my 68 . I think it's a 13 because there is no way you could fit anything bigger in the bell housings just need to send him some pictures and see if it's the right one, real nice guy spent 20 minute with me and wants me to be happy with the final product. That what I thought on the highway gears . This is going to be a cruiser nothing crazy nice convertible with factory air. Thanks Doug
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
#19
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Quote:
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71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile |
#20
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Correction on rearend gears 2.93 only gear they offered with the automatic with air condition with my motor if no ac it would have been 3.36 .Doug
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1979 Trans Am 307 RWHP 380RWTQ 13.8@103 1979 400 Block, 1970 Heads, Unknown Cam, Comp Cam Lifters, Edelbrock RPM Intake, Hedman Headers, Holley 750 Carb, WFO Drop Base SOLD 1968 GTO convertable project. 400 auto with air. west coast car . Not started in 15 ..update now running (around block spinning tires all the way. Have a lot of cosmetic work to do winter of 17/18 1969 GTO 400 4 Speed this a complete project. Rebuild will start in spring of 2017. SOLD |
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