got a car with a 99 3800Sc and 4t65e-HD )also 99 Grand prix. queston is: will the computer that is Now running both the 3800 and the trans, will it run a 4.9 caddy if reprogrammed? yea, I know, WHY? Curiosity LOL Just want to know if it Can be done without a Stand alone computer for the trans. thanks
so it's gotta have a 4t60 instead of the 4t65e , right ? would like to have the" Sound of a V8" without having to go down for the expense of adapter/mounts and all the other stuff for a chevy. I love the 3800SC, but the "sound" of a 6 just doesn't cut it. LOL
If I'm not mistaken, The 99 3800SC PCM only has 3 (need 4) pairs of injector outputs and the HT series caddi engines don't have places for cam/crank sensors that would work with it. Even if you could reprogram it. But If you are really considering V8, LS4. There are ways to disable the DOD(lifter/cam mod)https://www.onallcylinders.com/2017/11/30/how-to-delete-or-disable-active-fuel-management-afm-on-gm-engines/ and AFM and use an older LS series truck PCM that works with a 4L65e. With some modding to the transmission internal wiring, be made to work.
[This message has been edited by cmechmann (edited 02-16-2019).]
just looked up the "Specs" on both engines. they BOTH seem to have the Same "Torque ratings" 275-280 ft/lbs at about 3100rpm. and the 4.9 runs out of steam at about 4500 rpm. All I was" looking for" was more "seat of the pants" bottom end and the Sound of a V8, but it doesn't look like I'd really be Gaining anything with a 4.9, and I don't want tp spend $1000 just for Adapters for a SBC. I probably Would go SBC if I could find the engine/trans adapter for a decent price. (I sold a complete setup plate and all the brackets for 250 about a years ago), now that I'd like one, I'm sure they're solid gold. LOL
Lou... you can probably find a complete 4.9 donor car for under a grand. Especially in FL, with all the retirees. I would be surprised if you couldn't find a buyer for your 3800SC drivetrain.
With that said, the Caddy tranny doesn't do anything (upshift, downshift, etc.) quickly. It ultimately why I traded mine out for a 5 speed.
------------------ Raydar 88 Formula IMSA Fastback. 4.9, NVG T550
The bottom end torque of a 4.9 starts just as soon as you step on the gas. At 1700 rpm it's already at 225 pound feet. SBC Chevy is heavy with the cast iron block, the 4.9 is aluminum.
The bottom end torque of a 4.9 starts just as soon as you step on the gas. At 1700 rpm it's already at 225 pound feet. SBC Chevy is heavy with the cast iron block, the 4.9 is aluminum.
If I were going to do a Chevy V8, it would absolutely be an LS of some sort. Probably an LS4. I'm the last to "dog out" someone's choice for a swap, but there are so many better options.
yea , 4.9 wasn't my First Choice, but it's a Cheap one. I've got 2 3800SC cars. But I "grew up" in the mid 60s, corvettes, 409 chevies, hemi's,... I Miss the rumpity rump cams and "stump pulling torque". (once had a 65 cutlass with a 500 Caddy in it). to me a Stroked SBC in a Fiero would just about fill the bill. LOL
Originally posted by Lou6t4gto: ... To me a Stroked SBC in a Fiero would just about fill the bill. LOL
If I was determined to do a SBC, I would source the parts and build a 302. Something that didn't have quite as much "Getrag-shattering torque", but could wind up to 6K or so. That would have to sound amazing.
But then, I have a 4.9 bolted to a Getrag.
[This message has been edited by Raydar (edited 02-18-2019).]
got a car with a 99 3800Sc and 4t65e-HD )also 99 Grand prix. queston is: will the computer that is Now running both the 3800 and the trans, will it run a 4.9 caddy if reprogrammed?
NO.
The 3800 PCM's hardware only supports 6 cylinders (ie: 6 injector drivers), and the 3800 uses different type and pulse count crank sensors than the 4.9 uses.
Why do you think you need a 4T65-E HD trans?
------------------ More is more. Less is not enough.
4t60e's aren't falling out of the trees either, whats the last year ? 25 years ago ? LOL but then again, I suppose a 4t65e-HD would have to have a" stand alone" computer just to run IT behind a sbc ! LOL
Every 4.9 has a 4T60E attached to it from the GM plant. It is the only transmission GM used with the engine. Get a drivetrain from a Seville, the gearing is better than the DeVille drivetrains.
The 3800 PCM's hardware only supports 6 cylinders (ie: 6 injector drivers), and the 3800 uses different type and pulse count crank sensors than the 4.9 uses.
Nope. The 4T65-E uses a pressure control solenoid the 4.9 Cadillac PCM isn't capable of controlling. Also, I believe the TCC PWM solenoid control strategy in the 4T65-E trans is opposite of how it works in the 4T60-E.
4t60e's aren't falling out of the trees either, whats the last year ? 25 years ago ? LOL but then again, I suppose a 4t65e-HD would have to have a" stand alone" computer just to run IT behind a sbc ! LOL
1999 was the last model year GM used the 4T60-E transmission.
Nope. The 4T65-E uses a pressure control solenoid the 4.9 Cadillac PCM isn't capable of controlling. Also, I believe the TCC PWM solenoid control strategy in the 4T65-E trans is opposite of how it works in the 4T60-E.
Oh yeah, pressure control solenoid vs. vacuum modulator.
Time to come up with a 24x/58x wheel conversion for the 4.9 using EFI Connection hardware so it can run with 6T75s
Oh yeah, pressure control solenoid vs. vacuum modulator.
Time to come up with a 24x/58x wheel conversion for the 4.9 using EFI Connection hardware so it can run with 6T75s
That’s a lot of dough to shell out for a 200hp throw away engine. I don’t think any of the head bolts are even available any more. Hopefully they could be reused. I’m pretty sure you can purchase a micro squirt as a stand-alone TCM these days.