I have a 37 Chevy Bus Coupe with a 355 SBC. Motor has Trick Flow Twisted Wedge heads, (67 cc, 2.02/1.64 valves) TRW forged flat tops, (10:1 or thereabouts), Comp Cams 292H - .501 lift ex & in, 244 duration @ .50, Prof. Products Hurricane high rise and Holley 650 dbl pumper with block huggers leading to 2 1/2" pipes and Magnaflow stainless mufflers. I am running a 4 link 9" Ford w/3:73 and Auburn posi unit. I guesstimate abou 420 HP and 405 ft lbs or torque. Tranny is a TCI turbo 350(not sure which one). At 60, I am running about 3,000 RPM. Now for the questions. 1) What type of torque converter will provide the snap off the line when I want to hit it without creating a lot of excess heat? I had heat problems and just now got it running cool and do NOT want to go through that exercise again (Thank God for Water Wetter!!!) 2) Will a 700R4 be a better choice if I want a good cruising tranny that I can tromp on from time to time? Thanks in advance for all the help!
I don't really have an informed answer for you but I am kind of interested in what some others may have to say, so this is just a bump up. I would think the 700 R4 would be a better choice imo.
Frankly I dont see the need for anything other than what you already are running....... IF you got that horsepower quoted in a 2800lb car[yes a 37 is that weight]and at 3000 rpm at 60[indicatse a 3:70 ratio ish... you are at optimum --mash it- RPM even in drive at 60 mph.... IT DONT GET TOO MUCH BETTER WITHOUT A TON OF SACRIFICING in several areas.... You should have the power to do anything imaginable on takeoff and not having to spend the money what you mentioned is gonna cost you..... What I mean is you are going to be able to perform very well on takeoff and at passing lane speeds as you set.... If usin a stall then you loose the cruise range /mileage... If you gear down you loos top end speed and mileage ,,,,If you gear up[700R4] then you are lugging an engine that lives best at around that 3000RPM range in drive down to under 2000RPM and it will actuall get worse mileage,plust any throttle jabs are hard on a transmission with the higher ratio gearing as well....
It's tough to give/get straight answers with all the "about this and about that" information that's provided. I'm not tryin' to be a dick here but answers can only be offered based on the info that is provided. I can tell you 2 things based on your info. I find it hard believe the "about 420 HP" number based on your build as you state. And your "about 3000 rpm" at 60 without already having an overdrive don't add up either. I'm running a 700R4 with 4.30 gears and a 31" tall tire and I'm turning 2500-2700 rpm at 65 mph. A TH350 or TH400 will add 900-1100 rpm's over that of a 700R4 or other overdrive. So I guess what I'm saying is that IF you are only turning 3000 rpm at 60 mph with a TH350, I say leave it! And that's coming from a guy that runs & races GM overdrives. I say, offer up more specific info and more accurate answers can be given.
Comp Cams website says 292H SBC - "Hydraulic-Street / Strip special, 3000 stall, headers, gears, 9.5:1 CR. Very rough idle." http://www.compcams.com/Company/CC/cam-specs/cam-search-results.aspx?sc=292h&sm=By%20Grind%20Number
Something doesn't add up here, maybe just some confusion in the wording. First off some converter basics. A T.C. has 2 basic functions 1- it is a hydraulic coupler between the engine and transmission. 2- it is a torque multiplier. Now, I'm being very basic here, but high stall converters make HEAT, no way around it, unless you have some hidden connection with some of the laws of Physics. What I don't understand is the stated connection with what sounds like ENGINE HEAT, { cured? by the water wetter }, and the converter. A correctly matched converter should actually help with a ENGINE heat issue by allowing you to not fight the cam with the brake pedal and allow the engine to pull away from a stop or begin to flash higher up on the torque curve which is much more efficient. A high stall converter will make heat, but generally for the trans temp/ fluid etc. If the trans was only cooled by the same cooler/ read- radiator as the engine, this may have caused some increased engine temps and that should have been adressed by a additional or higher capacity TRANS cooler, not water wetter.
I have had several street strip cars andi can tell you that once you have driven a car with a higher stall than stock you will love it or hate it. Personally I like to romp on them so a bigger stall is OK with me. Sounds like with your cam and gearing, weight a 2800-3000 converter will put a grin on your face. You MUST runa large a trans cooler as you can and install a trans temp gauge. If your car creeps and lurches on the brake now, that will be really minimized with the higher stall. If you do a lot of highway driving you should ethink a lot of things. Big stalls and OD trans don't really mix all that well. Stall converters are not exact science, a lot depends on so many variables, they can be a real blast to drive though.....oh one more thing, be sure to fill the converter with trans fluid before installing it, you do NOT want to start a dry converter up, also time to replace those flex plate / converter bolts with some ARP pieces.
Call a good converter company. Dynamic, ultimate,ptc for example and have them build one to your combo and intended use. The biggest thing is to be 100% honest about your combo and intended use when ordering. You'll get the best of all worlds with a modern custom converter. It will launch like a bat outta hell and cruise on the street like a stock converter. They cost a little more but are well worth the money. Last one I bought was a 9 1/2" from dynamic. It flashed to 3800 rpm, got 3000 rpm on the foot brake with ease had an evil launch at the track but cruised the street like a stock converter. It was incredible.
Contact Hughes Performance: http://www.hughesperformance.com/ Talk to Billy, tell him what you're after, he'll set you straight. Although currently I'm running a custom built 9-1/2" converter with a 3800 stall in my 700R4. My previous 700R4 had a Hughes 2800 stall converter that I sent back to Hughes to be tweeked. Hughes makes one of the best "over the counter" converters on the market.
Appreciate all the comments. I have an 06 Z51 A6 vette(which is for sale) and it is quicker and stronger than the '37. I have not driven any other 37s, but I expected more from my set up. At cruise ins, the rodders I have spoken with have generally all agreed that the motor and rear end are set up ok, some prefer the 700 R4 but some prefer the Turbo 350. Several suggested that I change the torque converter. Both Torque converter companies I spoke with agree that the TH350 will take more abuse and with the right converter, will be a blast to drive. I have read on a couple of blogs that heat can be a problem. I am running a fairly large trans cooler( about 12 X 14). One of my cooling problems was caused by the cooler line being pinched where it ran under the radiator mount. My point was that chasing down a cooling (or perhaps better said) overheating problem can be a PITA and I don't want to go back!! I have a pusher fan and am now running about 160 - 180 with a 180 degree thermostat. It will get up to 220 if it idles for too long. Are the heat problems associated with the higher RPM stall converters experienced at cruising speed or idle? As for the questions: "I can tell you 2 things based on your info. I find it hard believe the "about 420 HP" number based on your build as you state. And your "about 3000 rpm" at 60 without already having an overdrive don't add up either."; I am basing my HP # on the Comp Camps web page. Mildly ported heads, High Rise... should be close. The RPM comes from my Tach and speed from my Speedo. They could be wrong but I don't think by much. Why is this hard to believe?
Both of my Sons are running 3000 stall convertors in their hot rods. One is a B & M Holeshot and the other is a TCI. The 3000 is not as loose as you would think and it is almost like a stock convertor on the street, except the cars don't lurch when going into gear and don't want to pull you through red lights. We had a 2600 in my Son Dan's rpu at first but it always had to be put into neutral at lights because of his fairly radical cam. I had a new B & M 3000 stall in the shop that I traded to him and it made a world of difference in the car. It also launches a lot harder and for some reason hooks better than the tighter convertor. My other Son is running a pretty well built 302 in his hot rod and when I am following him and he leaves a light I have to push my 331 stroker to keep up. The convertor just seems to get him into the right powerband right off the line. That would be my suggestion to you. Don As for the 3000 rpms at 60 mph, that seems reasonable, depending on your tire height. I am running 4.30 gears with a 29.5 rear tire and I am also turning 3000 at 60 mph.
Thanks for the practical info. I have tall rear tires as well. My car does lurch and I have to shift into neutral at lights when it is cold as it really lugs down. I read somewhere about heat issues but still don't know what issues to expect, if any. Also, what difference does the diameter of the torque converter make?
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