Over the years I have been getting things fixed up on it like AC, changed to F23, some other improvements, but overall it has been a solid car. The PO did a great swap and the car runs well after years of use.
Here is my question.
It has a low mileage Series III N/A motor , full stack IC and Gen 3 blower. Also has cam, some other goodies. Runs well., 3.0 pulley. Good power, nice driveability. Here is my dilemma. I have a brand new (no mileage) Gen V blower, nicely ported and gasket matched Series III LIM, all the correct gaskets, Northstar TB adaptor for Gen V, , basically everything needed to switch the the Gen V blower on my N/A motor
I would like to have maybe 20-30 more HP, but can totally live without it. Car already has plenty of power for such an old steering system, suspension, etc.
Since the car is running well, am I risking damaging something by changing blowers and playing around with pulley size? It currently runs a 3.0 pulley.
Part of me wants the better Gen V blower "just because:", and since I already have all the parts, including new full stack ZZP IC for Gen V, I am curious to see what difference it will make.
However, my friend Brian (mechanic who works on my car) and others who are smarter than I am keep telling me... "If it ain't broke, don't fix it"
I welcome your opinions. I know Dennis will have some
Peter: Since you mentioned me, thought that I'd chime in but realize that the foremost authority on 3800 engines is Zoomer from ZZ Peformance, not myself. Have done a few of these swaps ,have driven a 3800SC since around 2008 and do much research on this engine. Its a dated design but in terms of reliability, its one of the best engines that GM ever made. It sounds like you have a great setup there. The info out there indicates that the Eaton GenV Supercharger can only support a max of around 420 HP. After that it runs out of air. Sounds as though you will probably be at that limit. Should you wish higher power the next step would be the addition of a turbo and some serious tuning. ZZ sells a kit for this but its not cheap. Scott (Darkhorizon) was running 11's in the 1/4 mile with a turbo but on the juice he ran an amazing 9.87 @142 mph. Surely nitrous gets you to the next power level but with that stuff tuning is critical and IMO, its too easy to make a mistake and blow the engine. If you view an automobile as a system items like powertrain management, transmission, brakes, weight and reliability all need to be matched to work together. Try the Gen V supercharger and see how you like it.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I don't think I have anywhere near that type of HP but am not sure. Never had dyno test done. I guess I was just curious as to what real life benefit there could be to me doing this change, and if the change is major enough that it can risk me damaging the engine. I understand the Gen V is a more efficient blower, but if I take a 3.0 pulley from the Gen III and attach it to a Gen V, am I putting more strain on the engine? Does the Gen V have any other benefit (other than efficiency and some more HP), such as lowering intake temps? I am on the fence as to whether I should bother swapping blowers or not. I am not looking to make much more power at all. The car is 5 speed, not auto, so there is a limit on how much I can beat on it anyway before something breaks.
From what I read there should not be any problems installing a 3" pulley on the later Gen V Eaton supercharger. Estimate that should give you 15 psi of boost that is a sizable horsepower maker. If there is a concern for engine damage use the highest octane fuel that you can and scan scan and scan for KR's at all rpms. With the full stack intercooler my guess is you will be okay. I am running a 3.4" pulley on my series III engine and that provides 11 psi of boost. Zero KR problems with the short stack IC ,cooler plugs, a 180* thermostat and an improved 3" exhaust system. Have you tuned for the different MAF sensor?, The MAF is your main fueling sensor. The other fuel tables in the program are only there for back up only in the event that the MAF sensor fails. It's not like this with other programs for GM products but with Pontiac it is. My recommendation is that you should add a fuel pressure gauge, an air fuel gauge and a boost gauge so you can keep an eye on everything. IMO those are critical parameters. The fuel pressure gauge tells you if you are feeding the right pure pressure to the injectors, The Boost gauge tells you if the supercharger is working The air fuel gauge tells you if you are running rich or lean.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 05-04-2025).]
Do it! I swapped from my Gen 3 to the Gen 5 a couple of years ago. Power improved, sound improved, cooler temps and it’s a better looking blower if you take the time to grind down the casting marks and paint it nice.
Using Autolite 103 plugs @050" . They are copper. Platinum or Iridium plugs are not recommend for supercharged engines. With the higher boost that you are running you may have to go to a .045" gap. IMO the DIS ignition system on the 3800 is very good . I run low resistance 50 ohm/ft spiral core copper ignition wires. Carbon core wire has a resistance of 300 ohms per ft and I dislike it as it breaks down over time.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I figured I would post up here. Seems like the Facebook groups take over anymore. It is nice to have the forum to at least discuss the 3800. I wouldn't say I know a ton but I feel like I know quite a bit from running the 3800 in all 3 Fiero's I have since 2003. What cam do you have? The biggest question first is AFR reading and what your timing is set at and what injectors and fuel pump you are running. Going from a Gen 3 to a Gen V with the same pulley will definitely make the engine generate more air so it will need some more fuel. I'm not sure if you are E85 or Pump gas. But I would highly recommend if you do any sort of swap on the blower to scan scan scan. AFR readings at least in my opinion need to be between 11.0-11.5 at WOT. Fuel injectors for pump gas with the Gen 5 and Northstar TB and cam, etc should definitely be 60# injectors. If you have 42.5's you definitely should upgrade to be safe. I would also run an AEM high flow fuel pump. I'm not sure if you have access to HP tuners or do your own scanning or tuning but that is the heart of doing all this to be safe. If I were you the positive is more or less more work involved very minimal gains. But if you are going for most power, I mean it will make more HP just not a lot.
As far as Plugs, I run Auto Lite 103's but I would gap them closer to .045. ------------------ 88 Formula - 3800SC/4t65eHD 88 Coupe - 3800SC/4t65eHD GBCT - 3800SC/F23
[This message has been edited by Rare87GT (edited 05-15-2025).]
