What's bad with a supercharger on an old car?

MotF Bane

No Lifer
Dec 22, 2006
60,801
10
0
My '98 Pontiac Grand Prix is a GTP version, came with a factory supercharger on top of a 3.8L V6. I'm up to 120,000 miles, maintenance is good, transmission was replaced about three years ago with a rebuilt unit. My father (he's a mechanic, and has worked predominantly on GM vehicles for 20+ years) disconnected the belt from it, because it was making a ticking sound, he said it was from the rotors or vanes (I forget which) hitting each other, so it would blow up and take out the whole engine. It's still sitting up there, but he had me listen to it, I could hear a ticking thing, so I'm guessing that's for real.

Okay, so the super is dead. A replacement is $1500, but a lot cheaper than getting a whole new car, something that performs better. He's worried about a replacement, and says vague things about the car being old, it might not take the strain of how I drive, which is to say, heavy footed. I know he doesn't like how much I speed, but it's a do as I say thing, given how he drives.

Long story short, I'm wondering if that is a legitimate issue. Has the age/mileage worn the car down far enough that a new supercharger would likely cause crippling damage to something?

Cliffs:
11 years, 120k miles.
Could supercharger kill it?
 

MovingTarget

Diamond Member
Jun 22, 2003
9,002
115
106
If cared for, the 3800 is damn near bulletproof. It is the rest of the car you need to be worried about. :p At 120k miles, you should be okay provided that it runs well otherwise. You could prob get a rebuilt or salvaged supercharger for less $$.
 

TehMac

Diamond Member
Aug 18, 2006
9,976
3
71
In short: Yes.

I don't trust older cars with that kind of an engine. If it was a V8 that is designed to take the strain, I'd say there wouldn't be that much harm in it. But a 3.8L V6 puts a lot more strain on the pistons, making them go back and forth a lot faster, which is nice, obviously, but it also strains the whole "architecture" of the engine. At this point, I'd get a new car if I was into speed like you seem to be.

Also, the super probably died because superchargers/turbos get their power from the engine, so you lose a certain % of HP from charging up your supers/turbos but then gain a significant % back, hopefully. :p
 

Arkaign

Lifer
Oct 27, 2006
20,736
1,379
126
Put a replacement supercharger on it, will probably be good for a number of years yet. Also, $1,500 is utterly insane. You can snag an Eaton M90 (the stock unit) for between $150-$450, depending on source, condition, and so on.

$1,500 sounds like the cost to install a full SC kit on a stock 3800, not to replace the supercharger. The supercharger itself is not really a very complicated piece of machinery at all.
 

Pariah

Elite Member
Apr 16, 2000
7,357
20
81
No. As mentioned above, the 3800 is nearly bulletproof. The engine was designed to have a SC, and 120,000 miles is not that big a deal for it. There are a billion of these engines out there. You should be able to land a replacement supercharger for less than $1500.
 

AdamK47

Lifer
Oct 9, 1999
15,652
3,517
136
I wish it cost $1500 for a supercharger for my car. A supercharger for an LS2 is $6000+.
 

Jeff7181

Lifer
Aug 21, 2002
18,368
11
81
Originally posted by: TehMac
In short: Yes.

I don't trust older cars with that kind of an engine. If it was a V8 that is designed to take the strain, I'd say there wouldn't be that much harm in it. But a 3.8L V6 puts a lot more strain on the pistons, making them go back and forth a lot faster, which is nice, obviously, but it also strains the whole "architecture" of the engine. At this point, I'd get a new car if I was into speed like you seem to be.

Also, the super probably died because superchargers/turbos get their power from the engine, so you lose a certain % of HP from charging up your supers/turbos but then gain a significant % back, hopefully. :p

Do tell... why does a V6 put more strain on pistons than a V8? And how does the orientation and number of pistons effect piston speed?

By your logic, does a V10 or V12 put less strain on pistons than either a V8 or V6? :confused:

*EDIT* How do in-line engines fit in. Or, god help us... how do radial engines fit into this equation?
 

MotF Bane

No Lifer
Dec 22, 2006
60,801
10
0
I'll ask my father where he got the pricing on the supercharger.

Edit: So the engine is fine with the strain, but what about the rest? That extra power has to go somewhere... drivetrain? Transmission?
 

JJ650

Golden Member
Apr 16, 2000
1,959
0
76
Originally posted by: Jeff7181
Originally posted by: TehMac
In short: Yes.

I don't trust older cars with that kind of an engine. If it was a V8 that is designed to take the strain, I'd say there wouldn't be that much harm in it. But a 3.8L V6 puts a lot more strain on the pistons, making them go back and forth a lot faster, which is nice, obviously, but it also strains the whole "architecture" of the engine. At this point, I'd get a new car if I was into speed like you seem to be.

Also, the super probably died because superchargers/turbos get their power from the engine, so you lose a certain % of HP from charging up your supers/turbos but then gain a significant % back, hopefully. :p

Do tell... why does a V6 put more strain on pistons than a V8? And how does the orientation and number of pistons effect piston speed?

By your logic, does a V10 or V12 put less strain on pistons than either a V8 or V6? :confused:

*EDIT* How do in-line engines fit in. Or, god help us... how do radial engines fit into this equation?



While you're at it...please tell why a turbo needs Hp to produce boost?
Superchargers do....not turbos.
 

Jeff7181

Lifer
Aug 21, 2002
18,368
11
81
Originally posted by: JJ650
Originally posted by: Jeff7181
Originally posted by: TehMac
In short: Yes.

I don't trust older cars with that kind of an engine. If it was a V8 that is designed to take the strain, I'd say there wouldn't be that much harm in it. But a 3.8L V6 puts a lot more strain on the pistons, making them go back and forth a lot faster, which is nice, obviously, but it also strains the whole "architecture" of the engine. At this point, I'd get a new car if I was into speed like you seem to be.

Also, the super probably died because superchargers/turbos get their power from the engine, so you lose a certain % of HP from charging up your supers/turbos but then gain a significant % back, hopefully. :p

Do tell... why does a V6 put more strain on pistons than a V8? And how does the orientation and number of pistons effect piston speed?

By your logic, does a V10 or V12 put less strain on pistons than either a V8 or V6? :confused:

*EDIT* How do in-line engines fit in. Or, god help us... how do radial engines fit into this equation?



While you're at it...please tell why a turbo needs Hp to produce boost?
Superchargers do....not turbos.

The misconception is that the exhaust has to be pushed through the turbo to spin the turbine... what most people don't realize is that most of the force that spins the turbine is from hot expanding gasses, not the piston pushing the exhaust gasses on the exhaust stroke.
 

jlee

Lifer
Sep 12, 2001
48,518
223
106
Originally posted by: TehMac
In short: Yes.

I don't trust older cars with that kind of an engine. If it was a V8 that is designed to take the strain, I'd say there wouldn't be that much harm in it. But a 3.8L V6 puts a lot more strain on the pistons, making them go back and forth a lot faster, which is nice, obviously, but it also strains the whole "architecture" of the engine. At this point, I'd get a new car if I was into speed like you seem to be.

Also, the super probably died because superchargers/turbos get their power from the engine, so you lose a certain % of HP from charging up your supers/turbos but then gain a significant % back, hopefully. :p

...what?
 

bruceb

Diamond Member
Aug 20, 2004
8,874
111
106
For the Grand Prix you might want to post on clubgp.com ... That forum is dedicated to the Grand Prix and their motors.
You will get reliable info there about supercharger failures and anything else you can think of on these cars.
If you do need good quality used parts, contact http://www.moradpartscompany.com/ ... He deals with parts from the
GM 3800 line and has a good selection, prices and stands behind what he sells.
 

SuperSix

Elite Member
Oct 9, 1999
9,872
2
0
Originally posted by: Jeff7181
Originally posted by: JJ650
Originally posted by: Jeff7181
Originally posted by: TehMac
In short: Yes.

I don't trust older cars with that kind of an engine. If it was a V8 that is designed to take the strain, I'd say there wouldn't be that much harm in it. But a 3.8L V6 puts a lot more strain on the pistons, making them go back and forth a lot faster, which is nice, obviously, but it also strains the whole "architecture" of the engine. At this point, I'd get a new car if I was into speed like you seem to be.

Also, the super probably died because superchargers/turbos get their power from the engine, so you lose a certain % of HP from charging up your supers/turbos but then gain a significant % back, hopefully. :p

Do tell... why does a V6 put more strain on pistons than a V8? And how does the orientation and number of pistons effect piston speed?

By your logic, does a V10 or V12 put less strain on pistons than either a V8 or V6? :confused:

*EDIT* How do in-line engines fit in. Or, god help us... how do radial engines fit into this equation?



While you're at it...please tell why a turbo needs Hp to produce boost?
Superchargers do....not turbos.

The misconception is that the exhaust has to be pushed through the turbo to spin the turbine... what most people don't realize is that most of the force that spins the turbine is from hot expanding gasses, not the piston pushing the exhaust gasses on the exhaust stroke.

This. You can redline a turbo motor at idle, with no load, and you won't get any negligible amount of boost pressure.

Silly people. The GM corporate 3800 is roughly the same block as the Buick 3.8l (yes, there is a difference) that is in the Turbo Buick, taking upwards of 20PSI without breaking a sweat, (or anything else) I routinely hit 23-25PSI (A bit too high), with stock heads (never been off), and there's no issues. There are stock block Buick turbos running in the low 10's, making over 700HP, I don't think the engine is what you have to worry about, (as long as it's installed correctly).

OP - You may want to see if the transmission that was replaced was a SC unit (I think they are different from an N/A FWD), and as said - $1500.00 for that is bonkers.
 

Pacfanweb

Lifer
Jan 2, 2000
13,155
59
91
Originally posted by: angry hampster
Originally posted by: TehMac
In short: Yes.

I don't trust older cars with that kind of an engine.

This is great advice if you want the wrong advice.
Correct.

Your car is already supercharged, right? So other than making a bit of a noise, the old supercharger is working fine, right?

So replacing it will simply eliminate the noise. I suppose, due to wear, it MIGHT slightly increase boost, but the amount will be negligible.

Now, putting a supercharger on an engine that is not already equipped with one, absolutely causes more wear. But as long as the engine has the correct parts/compression to take it, that wear is also insignificant.

 

MotF Bane

No Lifer
Dec 22, 2006
60,801
10
0
Originally posted by: SuperSix
OP - You may want to see if the transmission that was replaced was a SC unit (I think they are different from an N/A FWD), and as said - $1500.00 for that is bonkers.

A ... supercharged transmission, versus a non-applicable front-wheel drive transmission? I think I'm translating that wrong.

 

IcePickFreak

Platinum Member
Jul 12, 2007
2,428
9
81
The weak link in your GTP would be the transmission. I'd find another M90 to toss on it, which you can definitely find for well under $1500.
 

exdeath

Lifer
Jan 29, 2004
13,679
10
81
$1500? You cant GIVE away a M90 or M112, much less demand money for them. Seriously though, you should be able to find one for < $300.

Could also try these guys to rebuild yours: http://www.stiegemeier.com/home.html

And you're sure it's the blower? The rotors don't go bad unless they have encountered foreign debris and become damaged, or the bearings go out. Have you started the engine with the blower belt off and/or turned the blower by hand and confirmed the source of the noise? (don't drive it this way, you won't have an alternator and stuff). Sometimes it can be as simple as the internal bypass valve vacuum solenoid which causes the bypass valve to flutter instead of staying open/closed and that can make a ticking sound.

If the rotors are contacting each other you'll know it...
 

MotF Bane

No Lifer
Dec 22, 2006
60,801
10
0
@ exdeath - My father is the mechanic, not me. The car was running at an idle, he put a massive screwdriver against the super, and had me listen to it, there was a ticking sound. He said that was the super going bad. The engine now runs with the super belt off, there were two separate belts, one for normal operation, one for the super. It's still mounted on top of the motor. I can try checking for the tick and see if it is still there without the super linked in, and I might be able to put the belt back on, I know it's at home somewhere.