Reply from Bow Tie Overdrive

[Guest yatsen]

I've been exchanging ideas with a Corvette fanatic (who lives in the Netherlands like yours truly) on a forum regarding transmissions. Turns out he'd contacted Bow Tie Overdrives regarding a TH200-4R. I thought it might be helpful to some to post the reply he got. FYI, he's planning on installing a 440HP ZZ4 crate engine in his Corvette and he wanted to know whether he needed a level 2 or a level 3 transmission. Here goes:

Our Level Two would be fine even with the engine upgrades you’ve got planned for in the future. Our Level Two transmissions have proven to be very dependable and tough.

 

You must provide a good temperature control system, a torque converter clutch lock up wiring control circuit and a correctly set up Throttle Valve (TV) cable system. We have excellent instructions on how to do these requirements. If these things are provided, your chances of having problems are low indeed. If for some reason, you do have a problem, the only thing you could do is ship it back. We would be happy to repair it, but it would have to be returned to do so. Our return rate is less than 1/2 of one percent because we have excellent installation guidelines and pre test all of our transmission in an actual vehicle to be sure the not only work correctly but act properly before we ship them. This is the main reason we have so few problems and our transmission work so well.

 

You are correct the Th-2004R is almost a direct bolt in except the drive shaft front slip yoke will need to be changed from the current 32 spline to a 27 spline unit. We can send you one if it will be a problem. We would need some information about your current “U†joint type at the front of your drive shaft. We would need the cap diameter, the span from the top of one “U†joint cap to the other and whether the snap rings are on the inside or outside on the caps.

 

To give you an absolute example of the effect this conversion will have on your vehicle, consider the following: Say you were driving down the highway right now with your present transmission in high gear and your engine was turning 3000 rpm. If you could magically install a Th-2004R, let it go into its .67:1 overdrive gear and lock up the torque converter clutch, your engine rpm would fall to a far more reasonable, certainly more economical, 2050 rpm at the same vehicle speed! I will include the following links to our speed / rpm calculators. You may wish to place with these so you can see how dramatic the difference will really be. http://www.700r4.com/speedocalc/rpmgearscalc.html'>http://www.700r4.com/speedocalc/rpmgearscalc.html also http://www.700r4.com/speedocalc/speedocalc.html'>http://www.700r4.com/speedocalc/speedocalc.html

 

We get constant feed back from our customers. From this feedback and our own observations, it's reasonable to assume you should see an increase in fuel economy of around 40% during highway driving. This seems to be quite predictable. The reduced sound and vibration levels will be very noticeable.

 

Please find the following prices and a brief description of other items you will need to address while performing this conversion:

 

· Our Level Two Th-2004R transmission is $1020.00. These units feature a blueprint overhaul using only the finest brand name components like Torrington, Raybestos, Borg-Warner, Alto and Delco-Remy to name a few. We install a hardened stator support, hardened direct drum, a new 10 vane (or 13 vane, your choice) pump rotor with new vanes, hardened steel pump rings to prevent breakage, heavier high rpm slider springs prevent pressure fall off at high engine rpm, high performance billet servo assembly, Raybestos frictions, special diamond tool machining on the pump halves to prevent fluid cross bleeding, new bushings, seals and gaskets. Performance calibration of the valve body and spacer plate. Modifications to increase lubrication flow. Our cases feature a natural aluminum finish by a special in house process. Other companies paint their cases. We never do, because we don't have to. These units are terrific for most high performance street applications. We install new pan bolts. We take the time to install a drain plug for easy maintenance. This drain plug is 1/8" NPT which is the same size as most modern electrical temperature gauge sender units. This makes it very simple to install an electric temperature gauge to monitor your transmissions fluid temperature.

 

· Heavy Duty High Performance Torque Converter: These torque converters are great for high performance street applications. Available in 1800 to 2200 brake stall speeds. Feature a new 4130 steel pump drive hub, positive angle brazed turbine vanes, brazed pump vanes, new Torrington bearing, heavy duty sprag, aggressive stator, HD dampening spring assembly, Carbon-fiber friction material and precision balanced for smooth operation. Price is $154.00. http://www.700r4.com/catalog/catalog.php?Action=GETSUBCAT&CATID=EA2'>http://www.700r4.com/catalog/catalog.php?Action=GETSUBCAT&CATID=EA2

 

· Our exclusive U.S. patent pending Throttle Valve (T.V.) cable control system for Holley, Demon, late model Chevrolet Q-jets, Carter and Edelbrock carburetors. This unique system allows the installer of Th-700R4 and Th-2004R transmissions to quickly, easily and very precisely establish the correct physical relationship between these carburetors and the critical control system for these wonderful overdrive transmissions. This system not only allows for correct set up but also gives the installer wide control over shift timing and shift feel issues. While other companies tell you this systems set up is critically important, we supply you with a solution. Comes complete with all necessary hardware, gaskets, bolts, stud, Allen wrench, drill and the engineered components for a quick installation for only $109.95. Web site: http://www.tvmadeez.com

 

· Zero to 300 PSI gauge with six foot hose and close 90 degree fitting is $29.00. This is a basic diagnostic tool that we require be installed during the start up and test driving to confirm the pressures are the same as when the transmission left our test vehicle. http://www.700r4.com/catalog/catalog_inc/viewitem.php?ITEMID=25'>http://www.700r4.com/catalog/catalog_inc/viewitem.php?ITEMID=25

 

· Dip stick is $55.00. This is a new General Motors unit that will fit your application.

· Inspection cover (dust shield) is $25.00. This is a set of Delco-Remy parts that should work in your application well.

 

· Speedometer calibration gear set is $44.00. This is all new Delco parts and is everything except the speedometer cable and the gauge. We will need your tire size and rear end ratio to accomplish this. When you get the transmission installed, all you will need to do is screw the speedometer cable onto the transmission drive gears and your speedometer should be correct! If you are planning to run electronic gauges, there is no charge. These transmissions already have electronic speed sensors built in that will interface with the after market gauges.

 

· Torque converter clutch control wiring kit: This kit is used when you have a vehicle that has a General Motors Plunger style switch under the dash, activated by the brake pedal. This is a very simple kit to install since you just replace the existing brake light switch with this style and plug your wiring into it. This kit, along with the internal wiring kit that comes with all of our transmissions (can be purchased separately if you don't have our transmission) will give you automatic fourth gear converter clutch lock up and automatically unlock the torque converter clutch whenever the transmission is in any other gear. You will also have a manual control switch so you can lock up the converter during those times you need to prevent overheating. This Kit comes complete with all terminals, connectors and a terrific set of instructions. Cost is $28.00.

 

· Factory console conversion kit. This kit modifies your stock factory console shifter so it will get all seven positions needed for your new overdrive transmission. Comes with a new lens or decal for proper shift position indication. All hardware and easy to follow instruction are included. Price is $90.00.

 

· Radiator heat exchanger: This is how the factory set it up and you need to maintain this system. Our sincere advise to you car builders is make sure you have lines running to a heat exchanger built into the vehicles radiator side or bottom tank. These heat exchangers are the best way to not only get rid of excess heat quickly but also warm up the transmission properly at start up. Air cooled system don't do these tasks well in our experience. We install a 1/8" NPT drain plug in every transmission pan on every transmission we build. This is to encourage our customers to change fluid on a regular basis and also provides an easy place to install a sender unit for a transmission temperature gauge. The indicated temperature of the fluid in the pan (just after returning from the cooling system) on a good balanced radiator only heat exchanger system should read 30 to 50 degrees less then the indicated engine water temperature. Typically this will be 150 to 160 degrees F, any higher then this, you should give your cooling system some attention. We sell an inexpensive sender and gauge for only $29.00.

 

· Your present radiator lines should connect right up to the new transmission fittings. They should have the same 5/16" inverted flare fittings but may require slight "re shaping" to line up correctly to the case fittings.

 

· Our company has always felt that proper installation was the real key to success with these nifty overdrives. All of our transmissions come to you with a set of comprehensive written installation guidelines plus we have excellent technical support available via the telephone. We believe this is the main reason why our company has less than 1/2 of one percent return rate for any reason. It has been our experience that most people wish to do a job correctly; they just need to know how to do so.

 

· We have shipped many of our transmission to Europe. We work with a number of container shipping companies. The cost to ship these parts usually is around $300.00. U.S. and take about 2-3 weeks transit time.

 

We get constant feed back from our customers. From this feedback and our own observations, it's reasonable to assume you should see an increase in fuel economy of around 40% during highway driving. This seems to be quite predictable. The reduced sound and vibration levels will be very noticeable.

 

In my opinion, installing a modern overdrive transmission is the best upgrade you can do to your vehicle. It will have a greater positive overall effect on your street drive ability than any other component you could upgrade. I know this is a strong statement but the response from customers over the last 5 years that we have been doing these conversions convinces me that it's true.

 

Installing one of these modern overdrives is widely being acknowledged as a great way to not only improve the overall performance of the vehicle but also is one of the few items you can install on your car that will increase the value above its cost and also make the vehicle far more sell able.

 

We are very proud of our warranty because we feel it is the most appropriate in our market today. One year unlimited mileage on any defective parts or workmanship that starts when you and our company agree it has been installed properly and is working correctly in your vehicle. This means we will be involved with you during the installation, start up and test driving of the transmission. We will help you determine that the specific needs of this transmission are met with actual procedures that will clearly demonstrate that everything is correct. While this is added work for us, we have found our customers really appreciate our taking the time to help them with a correct installation. Our installation guidelines (supplied with every transmission) are loaded with helpful information and tips we have gained over years of specializing in this transmission. We have found, for example, these transmissions need a balanced cooling system. While most standard cooling systems are sufficient for this transmission, it must be demonstrated to be in good condition, we offer a few simple procedures to confirm this. Customers with projects that will not be completed for awhile, really appreciate having the warranty start when the project is actually on the road, even if this takes a year or more.

 

We, unlike our competition, test drive every one of our transmissions in a vehicle. We used only our in house dyno before but found this method doesn't let you check the "feel" of the transmissions shifts and other activities. We have found the only way to ensure they work the correct way is to install and test drive them in one of our two vehicles dedicated to this procedure.

 

We have all these items in stock and can ship your order very quickly. Hope this provides the information you were looking for. If something was overlooked, please feel free to ask further questions. We accept all major credit cards, money orders, cashiers checks, bank transfers or personal checks from southern CA. Our normal office hours are from 8 a.m. until 5 p.m. Monday through Friday PST.

 

Sincerely

 

Steve Holmes

 

Bow Tie Overdrive

 

E-mail address: Steve@700r4.com

 

Telephone: (760) 947-5240

 

FAX number: (760) 948-0196

 

Web site: http://www.700r4.com

[Scottie-GNZ]

They are as thorough in their written response as they are verbally.

[timh]

I used their TV made easy kit for 700r4. If every transmission company asked you to run through the pressure tests that they do, there would be very few problems/complaints with the gm700r4. Very helpful over the phone as well.