Amanita Posted October 1, 2018 Report Share Posted October 1, 2018 (edited) I have a '96 Grand Prix with the L82 v6. I intend to do an engine swap some time in the future when I have the time and resources to do so, but for now I'm interested in what my options for upgrades are or if it is even worth it to modify the stock engine at all. Is a goal of gaining 20-30 horsepower realistic with some bolt on parts and an aftermarket ECU? I want to hit 200 horsepower but 180-190 seems much more attainable. Edited October 1, 2018 by Amanita wording Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted October 4, 2018 Report Share Posted October 4, 2018 Theres not much you can do, ive got the same engine in my 1994 CS. One thing is going with a magnaflow cat converter and downpipe assembly coupled with a mandrel bent exhaust, if anything it`ll sound amazing. A true cold air intake system and not just a cone on the end of the factory tube, again wont do much 10 HP would be generously over estimating. Aftermarket ECU will more than likely leave you on the side of the road, there was another option for an ECU swap from an older W-body model that could be re-tuned but i dont know if anyone other than RobertSaar can do it. Save you money for a professional engine swap to a 3400 or even the L67 swap instead and enjoy the fuel economy in the meantime. Quote Link to comment Share on other sites More sharing options...
Dark Ride Posted October 4, 2018 Report Share Posted October 4, 2018 If you are thinking an engine swap in the future I would build a nice mandrel bend exhaust as suggested either 2.5 or 3 inch depending on long term plans Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 5, 2018 Report Share Posted October 5, 2018 (edited) For an easy no fuss swap, dump the L82 & pick up a healthy mid 2000's LA1 engine. There is a noticeable difference in the two engine's output. An aftermarket or reground cam will wake up the engine even moreso. Porting & polishing both the heads & the intake assembly adds to the performance. The L82's were stricken with the small dia exhaust, all LA1 engines were 2 1/2" at the downpipe. Edited October 5, 2018 by 55trucker digitaloutsider and rich_e777 2 Quote Link to comment Share on other sites More sharing options...
l67ss Posted October 5, 2018 Report Share Posted October 5, 2018 3400 throttle body wakes one up. And you might look into a 3500 topend swap. Swap to 3500 heads and intake Quote Link to comment Share on other sites More sharing options...
l67ss Posted October 5, 2018 Report Share Posted October 5, 2018 Personally I'd just do a 3800 swap. My 97 Monte was 3400 swapped when I got it. Did a few things to pep it up while I was collecting to l67 swap. Once I did my bone stock l67 swap I felt goofy for the work I put into the 3400 lol Imp558 1 Quote Link to comment Share on other sites More sharing options...
Imp558 Posted October 5, 2018 Report Share Posted October 5, 2018 L67 /4T65e HD is going to be the most cost effective too in the end. You start bone stock at 242 HP and just doing the basics in the PCM will see over 250hp without even doing a "power tune". City will be about 15-17 mpg, highway will see just under 30 mpg. All in all not bad considering you'll be able to do 0-60 MPH in 6.5 seconds with a stock engine and tranny from the wrecking yard. rich_e777 1 Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 5, 2018 Report Share Posted October 5, 2018 (edited) 1 hour ago, l67ss said: Personally I'd just do a 3800 swap. My 97 Monte was 3400 swapped when I got it. Did a few things to pep it up while I was collecting to l67 swap. Once I did my bone stock l67 swap I felt goofy for the work I put into the 3400 lol Well that's why I suggested *for an easy no fuss* upgrade one of the last LA1 engines, they were the best LA1 that GM offered for HP & torque figures, an L67 is a worthwhile upgrade but that's an entire powertrain/electronic swap, one doesn't really want to be putting 270 ft lbs thru a 4T60e. Edited October 5, 2018 by 55trucker Quote Link to comment Share on other sites More sharing options...
Imp558 Posted October 5, 2018 Report Share Posted October 5, 2018 Edit: Oops, wrong thread. I suggested doing the 4T65 at the same time. Figure a wrecked car for $350 for the drivetrain. I really think the whole swap could be done for about $500. A lot of bang for the buck. Quote Link to comment Share on other sites More sharing options...
Amanita Posted October 10, 2018 Author Report Share Posted October 10, 2018 Thanks for the replies, I think I'll keep the engine mostly stock (might still do a cold air intake) until I can do a swap then. Quote Link to comment Share on other sites More sharing options...
jman093 Posted October 14, 2018 Report Share Posted October 14, 2018 You could always do a large port swap. In 2000 3100s got the larger 3400 stuff. Larger port heads, larger port intake manifolds, and larger 56mm throttle body. I did that to my brother's L82 in his 96 GP. You'd be turning your L82 into an LG8. Amanita 1 Quote Link to comment Share on other sites More sharing options...
walterdude Posted October 16, 2018 Report Share Posted October 16, 2018 (edited) I believe the TB sizes remained the same,,, 3100 vs 3400... 52 or 54 (forget what exact size was used) for 3100 and 56 for 3400... The rest is 3400 size as far as manifolds and heads Still a MAJOR upgrade!!! Always wanted to upgrade my 99 Lumina 3100 to the newer top-end... Alas,,, as with most things I never got around to it... Oh well,,, It has been quite a few years since that car... Could be wrong on the sizes of TB altho I think I've gotten it right... Tom B... Now that I think about it,,, the reason I didn't do a top swap was I was waiting for the UIM gaskets to go... They never did... The car had 250k and NEVER had a problem with the UIM... THAT MUST be some kind of record!!! Edited October 16, 2018 by walterdude Adding Stuff!!! Quote Link to comment Share on other sites More sharing options...
Amanita Posted October 24, 2018 Author Report Share Posted October 24, 2018 (edited) I'm now wondering how difficult it would be to do a 284 swap as well. I know 5th gen Grand Prixs came with them until 1993, but since my car is a '96 it was never an option. Would this swap be as lengthy to do with this car as it is with 6th gen Grand Prixs, assuming I do it at the same time as the engine swap? Edited October 24, 2018 by Amanita Quote Link to comment Share on other sites More sharing options...
l67ss Posted October 24, 2018 Report Share Posted October 24, 2018 Will require some massaging of the dash bar Quote Link to comment Share on other sites More sharing options...
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