DIY_EFI Digest Saturday, 13 March 1999 Volume 04 : Number 164 In this issue: Re: Real HP loss numbers Re: Real HP loss numbers Re: Convert a GM SI alternator to the CS130? Re: single injector TBI throttle body needed for 2 liter engine How easy would it be to swap a 4L60e for a 4L80e See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Clarence L.Snyder" Date: Sat, 13 Mar 1999 00:07:03 -0500 Subject: Re: Real HP loss numbers > Technically, you're correct, hp required to bring all rotating mass up > to a certain speed is actually stored, and released when you let off the > gas. But, rear wheel hp is still affected by the amount of energy you > store in the rotating assembly past the flywheel; thus, the larger the > momentum, the more energy required to bring to a certain speed, the less > energy remaining to spin the drums, thus less rear wheel hp numbers. > > Daniel No, Horsepower is the rate of doing work. Increasing the speed is doing work, slowing down is negative work, and maintaining the status quo is exactly that. It takes absolutely no power to maintain inertia - and only a little to overcome the friction in this case. ALL power stored in accelleration is recovered in decelleration once you factor out friction losses. This is why an inertia chassis dyno can so very easily if not lie, at least mislead. It is NOT measuring horsepower, it is measuring acceleration, from which you deduce Horsepower. Horsepower can ONLY be actually measured under static or quasi-static (long term repeatable) conditions, Foot Lbs/second cannot be measured at variable speeds and variable torque (load) unless you can take a snapshot in time and measure instantaneous speed and load. Even this is not accurate unless multiple snapshots are taken, and an average calculated because instantaneous torque varies with piston position, as does accelleration and speed. Only a load cell or an inertia cycle can determine real horsepower, and the inertia cycle method requires considerable computational power. ------------------------------ From: "Clarence L.Snyder" Date: Sat, 13 Mar 1999 00:10:09 -0500 Subject: Re: Real HP loss numbers If you are drag racing, all that counts is acceleration. If you are towing a trailer, or climbing a mountain, or ploughing snow, etc, accelleration is a non-issue and does not give any indication of power gain/loss. If you are running a boat or airplane, again accelleration has no significance - it is sustained output that matters. ------------------------------ From: DC Smith Date: Sat, 13 Mar 1999 00:46:14 -0600 Subject: Re: Convert a GM SI alternator to the CS130? You're in luck Detroit, The CS alternator will directly replace the SI alternator. Just hook up the idiot light wire to the CS and let it rip. It hooks up pretty much the same. Mounting may or may not be a problem, the mounting holes are a little farther apart for the CS 144, and I believe a little closer together for the CS 120. I have all 3 in the basement. If you need me to go measure them, let me know. I went from a SI 90 amp to a CS 144 120 amp on my old Regal. WATCHmeDRV@xxx.com wrote: > > On my drag car I have the old SI alternator that I want to change over to the > newer CS130 style. My old SI unit is a one wire how can I wire the new style > CS130 to work. > > Thanks > DETROIT AMERSON - -- *********************************************************************** Dan Smith 84 Regal 12.13@112 GSCA# 1459 St.Charles, Missouri mailto:dcsmith@xxx.net http://www.tetranet.net/users/morepoweral *********************************************************************** ------------------------------ From: Thomas McCabe Date: Sat, 13 Mar 1999 01:32:35 -0600 Subject: Re: single injector TBI throttle body needed for 2 liter engine Peter Fenske wrote: > > Hi Ted > > Find TBI's on a ton of 4 cyl Gms.. On my 2.0 sunbird for instance > using a 748 ecm. > > It should work ok if you don't guite mount it horizontal. > Like sidedrafts I've seen about 30 degrees. > > Dodge also had a ton of 2.2 tbis although they use higher fuel > pressure than gm. > > Gl:peter Dodge Fuel pressures are 35-40 PSI for early bosch ('84) TBI, 14 PSI for all later TBI, and 55 PSI for Turbo MPI. L8r - -- Thomas McCabe - -mccabet@xxx.net '85 D250, 340 on Propane, Auto '89 Lebaron GTC, 2.2L Turbo II, A-555 5 Speed, MPSBEC '91 Spirit R/T, 2.2L DOHC 16 Valve T3, A568 5 Speed, Anti-lock Brakes, Power Windows, Locks, Drivers Seat. '96 Dakota SLT Club Cab, Brilliant Blue, 5.2L, Auto, 3.55 SG, Gibson Cat-Back Exhaust, ARE A-234 15x7 rims w/ Dunlop GT Qualifiers 255R60-15, Molded running boards and flares, Lund bug shield, Cool Fronts, Ventvisors, and Extang Saber Tonnue cover. ------------------------------ From: Doug Bazarnic Date: Sat, 13 Mar 1999 01:25:29 -0700 Subject: How easy would it be to swap a 4L60e for a 4L80e I just broke the input hub / shaft assembly for the second time on my '95 Chevy 1/2 ton truck. It keeps blowing out the aluminum lugs that retain the snap ring for 3rd gear. I do have extra ponies under the hood, but I don't see how the extra power would be causing this problem. (It's 355 cubic inches, B&M blower, Air Flow Research Heads, large roller cam, Cola Crank, Ross Racing Pistons, Eagle Rods, etc etc) The truck only runs in the low 14's, but this tranny breakage is nuts. The truck has a total of 42,000 miles on it and I've broken an Art Carr 10" Torque Converter, and the aluminum input hub/shaft twice now. The aluminum hub is a cast piece of sh*t, and it's teeth that hold the snap ring in place leave. This last hub (which was brand new from GM and about 6 months old) lasted less than 8,000 miles. Either I'm putting too much thru this tranny, or it's a real piece of crap. Ohh, and by the way, I drive it like it was a Corvette on a road course! It weighs in at 3944 lbs. So the $100 question is: How easy would it be to swap the 4l60e vs the 4l80e. Can the stock computer talk to a 4l80e without any probs? I've got the mastertune software that lets me change what ever I want, so shift points / line pressure wouldn't be a problem, if the stock computer can do it. Also, are the wiring harness connectors the same? Thanks, Doug Bazarnic P.s. If anyone is interested in my calibrations / chip sw, lemme know, as I'd be happy to share. ------------------------------ End of DIY_EFI Digest V4 #164 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".