Bypassing the Super charger?

[Buickguy123]

This is loaded question I know but how does one use a smaller serpentine belt to not use the SC? What size belt and where does one run it because right now the smooth side of the belt runs underneath a pulley before going up to the SC pulley and over then down to the AC unit. Anybody done this? Results. Damage? Less power I know I do not care as long as it does not do internal motor damage not using the SC. I would not buy another car with a Turbo or SC. Buick Regal LS would be fine not GS. PA no SC wanted again. My 2000 Century has 3.1 V6 185 HP works fine thanks! Thanks!

 

[Mad_Coachman]

The super charger has a separate belt.
Edit. I'll let a PA owner take this. Never mind.

 

[rsteve56]

Why do you want to bypass supercharger? What problems are you having?

 

[-Regal-]

I wouldn't have bought one because I don't want to have to buy premium fuel anymore but if I had it I would use it. Just not sure about the potential extra wear and tear for a car largely designed for less power and speed.

 

[BuickGirlFromMars]

I believe you and I had this conversation already... the supercharger is going to be doing a few things for your engine which otherwise would be slightly anemic NA with extra things bolted on, but otherwise functionally the same:
--Better cruise MPG because your car can briskly get to speeds but not flooring it, so sane driving, youre going to take advantage of your shiftpoints and ratios to get better highway mileage and a correct driver can get to that speed without putting the engine under a lot of extra load(Your supercharger can work while not in full throttle, giving your engine some fair efficiency while not dumping fuel)
--BEtter acceleration, obvious. more power. This can be helpful in evading or passing traffic.
--Noise , this is subjective but its mine so therefore objective 🙂
--Metal intake manifold , both parts. series III NA has metal but its not found in 1997-2005 park avenue would have to be swapped with extra extra work
--nice engine appearance
--robust PCV setup vs plastic cheapo nonsense on NA
--smiles per gallon
--being able to say your grandma/grandpa car can whoop someone in a race, it probably can. if not, it can really put up a fight stock
--coming with the 4t65e-HD (at least if the car would otherwise have a 4t65e, im not sure what year or model you speak of.

to bypass a supercharger you remove the belt. there you go. you could also find a way to bypass 100% of the time on the solenoid or the valve which would spin the pulleys still but not provide boost

your 2 speed fuel pump may never work out the other side, so there is an electrical device in the rear you wont utilize..fuel pump control module

 

[BuickGirlFromMars]

As someone who just replaced about 90% of their drive train pulleys with either new bearins, pulleys , or a AC Bypass pulley, I will give some gripes of my engine specifically a 1999 L67(keything being a 99, 2000+ removes a big one)
-That engine bracket. The big one blocking the belts in. THat has to be removed for a belt. So does it on a NA of the same year, but its just especially difficult on the SC since its 2 belts not just one.
-accessing some bolts on top of the supercharger, just a pain
-if i did a coupler, a coupler on this job would just have been more mess/dirt/etc to worry about(I did it all with snout on, my coupler is good)
--by extension, SC fluid is expensive and the old stuff STINKS. animal fats and 5w-30 🙁
-PCV baffle. annoying.
-vacuum system for the supercharger, the port under snout and the lines to the bypass solenoid. just more hoses and connections.
-Airbox noise baffling, i want to hear my boost, damnit
-plastic idler pulley(Maybe tensioner pulley, one of the two) was plastic and it was worn. metal would likely be worn too, but id rather have a smooth or ribbed metal pulley and bearing instead of a plastic anything pulley on a metal bearing. heat cycles, less hardness, etc. I replaced with metal pulley fortunately

So you can see.. my actual mechanical complaints are not that serious OR lenghty and i Have done some major service to my car in the last 2 years ive had it now. more complaints come from platform-wide issues that are on riviera, park avenue, and Oldsmobile Aurora as well or just GM decisions that are fleetwide and annoying, nothing specific because of SC

 

[Mad_Coachman]

I wouldn't have bought one because I don't want to have to buy premium fuel anymore but if I had it I would use it. Just not sure about the potential extra wear and tear for a car largely designed for less power and speed.

I wish I had one but they were never offered on the Lesabre. Regal GS only comes with bucket seats. I prefer split bench.

 

[LARRY70GS]

As mentioned, the S/C has it's own belt. Besides that, the engine normally bypasses the supercharger under light load. There is a bypass valve that is controlled by an actuator. The actuator is controlled by a Boost control solenoid. Under high demand, the bypass is closed forcing air through the supercharger. If you disconnect the S/C belt, there obviously will be no boost, and the car will be a dog, lacking power. I can't imagine why anyone would want to do that. In any case, there will be no damage to the motor.

 

[Buickguy123]

Why do you want to bypass supercharger? What problems are you having?

Really simple. If I can disconnect the Supercharger by taking the belt off the SC snout and driving the old beast without a running SC will NOT damage the engine then that is what I want to do. SIMPLE QUESTION? IS IT NOT 0BVIOUS THAT IF I TAKE THE SERPENTINE BELT OFF THE SC SNOUT THEN I NEED A SMALLER BELT THAT STILL NEEDS TO RUN AROUND THE WATER PUMP AND HARMONIC BALANCER AND THE AIR CONDITIONING UNIT? So, if anybody might explain what size belt I could use and how to route it because that belt now on fidelity side runs under a pulley before going UP and over the SC pulley then down to the AC unit. You see? A smaller belt needs to get around the water pump pulley and down to the AC unit correct? Would I just run the grooved pulley over that smoothie pulley or does it need to be replaced with edges. If my HP goes from 205 to 170 I do not care. Thanks! Cheers!

 

[LARRY70GS]

All of the supercharged 3800 engines I have ever seen use 2 serpentine belts. One runs JUST the supercharger, the other belt runs everything else, water pump, alternator, power steering and A/C compressor. Removing the supercharger belt will in no way affect the other belt driving the accessories, or damage the engine. The engine will be down on power when you need it, and you will not enjoy driving such a car. It will not do any damage.

 

[LARRY70GS]

If you remove the supercharger belt, you do not need to put another belt on those pulleys. The Accessory belt will drive everything else. Again, this will not damage anything.

If you insist on doing this, I would also disable the Boost Bypass Actuator.

 

[-Regal-]

I think it would much more likely go from 240 horsepower to 140. Would then be driving a V6 that requires 91 octane putting out less power than a 4 banger of the era. Ridiculous idea.

 

[BuickGirlFromMars]

I think it would much more likely go from 240 horsepower to 140. Would then be driving a V6 that requires 91 octane putting out less power than a 4 banger of the era. Ridiculous idea.

At that low of a compression I don’t think 87 would knock

 

[Buickguy123]

I think it would much more likely go from 240 horsepower to 140. Would then be driving a V6 that requires 91 octane putting out less power than a 4 banger of the era. Ridiculous idea.

My PA 93 is 205 HP. The 240 HP 3800 came later. That Regal GS 240 HP SC must really move being a lot lighter than a PA. I had a 160 HP Lumina 3.1. It did not have much power but it worked.

 

[LARRY70GS]

My PA 93 is 205 HP. The 240 HP 3800 came later. That Regal GS 240 HP SC must really move being a lot lighter than a PA. I had a 160 HP Lumina 3.1. It did not have much power but it worked.

I think you should remove the belt and drive the car. I hope you will report back about your experience and give an honest assessment of the results. Tossing around HP numbers means nothing, real world results are what matters.

I would never even consider what you plan to do. If the only reason you are doing this is to save money by not using premium fuel, I think there is no reason why you can't simply use the mid grade or regular fuel, or even mix fuel grades. The reason Buick specifies 91 octane fuel or higher is because of engine knock/detonation, and the octane increase required by higher cylinder pressures caused by boost. The engine has a knock sensor that detects and reports knock to the PCM. The PCM retards ignition timing to eliminate/reduce the knock. This only becomes an issue at higher throttle openings/boost levels. If you fill up with regular and drive the car in an easy manner avoiding more than 1/2 throttle, I think that should be fine. If you have a decent scan tool, you can monitor Knock Retard (KR), and see real world results with the fuel you use, and the way you drive.

 

[BuickGirlFromMars]

what does the 93 manual call for spark plugs na/sc? If you never use boost you may want a ... hotter..? Plug, the plug difference is for the increased compression so it might foul plugs easier if the plug calls for difference in gap or heat range which is a simple swap

 

[LARRY70GS]

what does the 93 manual call for spark plugs na/sc? If you never use boost you may want a ... hotter..? Plug, the plug difference is for the increased compression so it might foul plugs easier if the plug calls for difference in gap or heat range which is a simple swap

A hotter plug makes knock more likely. The majority of time a S/C 3800 runs without boost. Air is bypassed around the supercharger. Only when power demand is high does the bypass valve close and intake air is routed through the supercharger.

 

[BuickGirlFromMars]

I

A hotter plug makes knock more likely. The majority of time a S/C 3800 runs without boost. Air is bypassed around the supercharger. Only when power demand is high does the bypass valve close and intake air is routed through the supercharger.

I know but the plug has to be able to accommodate boost conditions. A engine that will never use boost likely wouldn’t account for it. Because na has low compression and a 87 octane but sc is 91 and lower compression out of boost but higher in boost, so it’s important to check into. The plugs for 99 are different based on na or sc

 

[LARRY70GS]

No, normally aspirated 3800 engines have higher compression (9.4:1), supercharged engines have lower compression. (8.5:1). If you look up 3800 spark plugs for NA and SC engines on Rock Auto, you will frequently see they use the same plug. Supercharging doesn't change the plug need unless you are racing the car where it is in boost all the time. On a street driven car, boost is the exception, not the rule. The supercharged engine runs in bypass the overwhelming majority of the time, only in boost for short periods of time. You know how I know that? I have an analog vacuum/boost gauge.

 

[BuickGirlFromMars]

No, normally aspirated 3800 engines have higher compression (9.4:1), supercharged engines have lower compression. (8.5:1). If you look up 3800 spark plugs for NA and SC engines on Rock Auto, you will frequently see they use the same plug. Supercharging doesn't change the plug need unless you are racing the car where it is in boost all the time. On a street driven car, boost is the exception, not the rule. The supercharged engine runs in bypass the overwhelming majority of the time, only in boost for short periods of time. You know how I know that? I have an analog vacuum/boost gauge.

Doesn’t the compression get higher when in boost?
And I know it’s the exception I drive in such a way it’s the rule 😅

I know it’s lower compression normally but I’m saying what I’m saying because I understand it that boost increases compression hence the octane rating amd at least according to my car manual different plug. I use 41-01 but I’m not sure if the early L67 needs something else. I know the TSB s of the late 90s tell to use iridium or copper, not the original platinum