Early 3.8s - Page 2 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

Thread Tools Search this Thread
Old 08-08-2005, 09:24 PM   #11
Senior Member
Posts like a Northstar
Join Date: Jan 2005
Location: Richfield, MN
Posts: 781
Thanks: 0
Thanked 0 Times in 0 Posts
alec_b is on a distinguished road

Yea i'll vouch for the LG3. I've got one, 205k still goin strong. And i beat it to all hell, several times i've taken it over the redline with no adverse effects. Obviously this isn't a daily occurance, but it'* possible. The only major service ever done to my engine was the timing gear and chain. Other than that it runs perfect. Wish i could say the same for it'* tranny, i'm on my 3rd one.
alec_b is offline   Reply With Quote
Old 08-09-2005, 02:15 AM   #12
Senior Member
Posts like a Camaro
Join Date: Oct 2003
Location: Hamilton, Ontario
Posts: 1,074
Thanks: 0
Thanked 0 Times in 0 Posts
phoenix_flame220 is on a distinguished road

Originally Posted by jr's3800
I have heard of the old 3.8'* easily making 200Hp and 280 ft lbs with decent pistons and decent cam... The 3.8'* could be torquers for sure... But this goes for the conventional lifter 3.8..
Please elaborate on this 200hp and 280lb of tq
phoenix_flame220 is offline   Reply With Quote
Old 08-09-2005, 10:47 PM   #13
Senior Member
Posts like a Turbo
Join Date: Apr 2003
Posts: 342
Thanks: 0
Thanked 1 Time in 1 Post
Steve LS is on a distinguished road

I posted a topic here somewhere last year about a LG3-3 a LeSabre T-type owner was building or built I should say. I just cant remember the subject I used for the post or if I threw it up on some other post about performance

Also one about a turboed LG3-3 in a Fiero

Anyhow he had comp cams do a new cam from a blank so there is now a part number for that cam I just dont have a link The cam is most of what causes the low HP RPM. Its not the largest throttle body either but theres not much to do about that. The turbo Regal guys do not use high RPM'* either, in fact I think they shift around 4000 with the production engines, stage II engines might be different but not the production street car engines. I have a turbo Riv engine ( same as turbo Regal except manifold layout) and they do not have large tubes either. I believe this actually helps in the low RPM torque, thats what a old 3.8 needs to be built for, more torque and low RPM power curve, because that is how it was designed - its a B U I C K thing.

Heads can be ported

The rear exhaust manifold can have an obstruction near the down pipe. Its the easiest exhaust in the world to remove. If you take it out and look up in the rear manifold you will see the problem and a long shank burr in a die grinder can work wonders and its a quick job, just wear safety glasses because your kinda vulnerable down there.

The turbo guy put aluminum heads on the LG3-3 block. He also said the crank and rods were strong enough as they were, as good as the RWD turbo engine had I believe. Its probably a weaker block though.

pistons I cant remember anything about but I believe both builds used other than stock pistons.

Absoultely nothing off the later 3.8'* will fit on the early 3.8'*.

Its not the most perfected of the 3.8'* but it sure is the purtiest !

Hope this helps, its all I know and its not hands on, its from reading and asking questions, all my engines are still stock, except for the rear manifold issue and intakes/air filters.
Steve LS is offline   Reply With Quote
Old 08-20-2005, 08:23 PM   #14
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Jun 2005
Location: Streamwood, Illinois
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
sleepy231 is on a distinguished road

I've decided to go the custom route. Im going to match and mill my heads at least, since I dont have the knowledge to do a full port job.

Im going to look through boneyards and Ebay and scavenge what I can for a custom turbo setup.A guy I know has a T25 in good cond for sale, but I dont know if thats what Im looking for.

Does anyone know what has to be changed in a turbo setup? My compression is only 8.5:1 so I was thinking like starting off with around 10 PSI boost and seeing where I go from there.

I know Ill need:
Bigger Injectors
Custom Piping

And definately a beefed up transmission with preferably a posi unit.

Sorry, I dont know t hat much about custom turbo apps. Thanks for any help!
sleepy231 is offline   Reply With Quote
Old 08-20-2005, 08:36 PM   #15
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Toronto, Ontario, Canada
Posts: 5,158
Thanks: 0
Thanked 0 Times in 0 Posts
repinS is on a distinguished road

Aside from the larger injectors, a beefier, higher-flowing fuel pump may be in order.

Staffer "Merlin 91/97" had a turbo setup done on his '91, and I believe he'* running considerably less than 10psi, or intends to, anyway. I think he'* your best candidate in terms of expertise.

repinS is offline   Reply With Quote
Old 08-21-2005, 04:15 AM   #16
Senior Member
Posts like a 4 Banger
Join Date: Mar 2005
Location: Appleton, WI
Posts: 124
Thanks: 0
Thanked 0 Times in 0 Posts
2seater is on a distinguished road

The pics of Merlins install look very good, I only wish I had that much room under the hood. My installation is similar although I am not running an intercooler, and limit boost to around 8 psi. Injectors and a fuel pump will be needed. You will need to relocate the vent line on the throttle body for the PCV system to the intake ahead of the compressor. Merlins install looks like a blow through the MAF and I ran mine like that for a year and then relocated it to the intake side of the compressor, but it seems to make little difference, at least at the moderate boost levels. You will need some device to prevent boost getting to the vacuum modulator if you have one. I used a check valve from an air compressor that vents the modulator line to atmosphere when the check valve operates. I also added a check valve from a vacuum brake booster to the plumbing for the PCV valve itself as the PCV does not seal completely under boost. Oil for the turbo was drilled and tapped into the oil filter adapter from the same passage that connects to the oil pressure sender. The drain line is 3/4" and was welded to the pan. Try to keep as high as possible to get above the oil level. I also run a 160* thermostat to help reduce the detonation potential. The aftermarket A/F and timing items seem like a good idea but I am running the factory ECM with a GM Tuners chip (still in the process of refining). If you ECM is similar to mine, it can only read air flow up to 170 gr/sec, and you will exceed that somewhere around 4-5 psi of boost, although that may vary a bit. Premium fuel will be required.

The T25 turbo may be a little on the small side, a T3 would be better, but it will spool very quickly and at moderate boost levels it may work fine. You may want to get the info. off the turbo and look at compressor maps for that model to see where the expected performance will fall in it'* operating range. Precision turbo, Majestic turbo and others have the compressor maps online.
2seater is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Took an early 90's Maxima SE Tonight Bassplayincrowe General GM Chat 12 06-26-2003 04:56 PM
94 SE vs Taurus SHO (Early 90's) Dillon General GM Chat 10 02-08-2003 04:44 PM
Early 90's Bonneville features/options list PontiacXcitement General GM Chat 0 01-09-2003 02:53 PM
93 se vs. early 90's grand prix Delirious0413 General GM Chat 3 12-28-2002 11:59 PM
95 SSEi vs. Early 90's STS SSEi95 General GM Chat 1 06-13-2002 01:28 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 06:03 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.