Performance/Maintenance Ideas for Turbo Cars

[Steve03GT]

As a preface, in 1989 I purchased 1 of ~1500, 20th Anniversary Turbo Trans Am's with a Pontiac factory-modified, Buick 3.8L GN engine which stickered at ~$30K - in 1989 mind you. I had 1 of only 39 hardtops produced, since the remainder were all T-Tops, kept it for 9 years and sold it with 165,000 miles on the clock - with the original alternator. Now don't get me wrong, I don't claim to "know it all" when it comes to turbo-powered cars, but I do have some background in the matter, having both participated in both car shows and drag strip shootouts (lo 12's @ 110 mph).
OK, I'll cut to the chase now. Since I've had the GT Cruiser, my memory (most of which is gone due to the early 70's,) is reminding me of some things I learned while owning the TTA.
Maintenance:
1.Synthetic "Oil" is a must, preferably Royal Purple, though other brands will suffice. Synthetics can/will prevent turbocharger bearings from "coking" up due to it's resistance to "boiling off", thereby, forming sludge and varnish deposits, which contribute to corrosion, decreased fuel efficiency and increased engine wear - blah, blah, blah.
2.Turbo-timers, IMHO, are a waste of money for a daily driver, unless you drive like a bat out of hell and kill the engine without a cool-down period - duhhhh.
3.To be cont'd.


Performance:
1.Find a performance sparkplug (NGK,etc.)known to perform well with a Forced Induction engine.
2.If you're an aggressive driver, I recommend changing plugs <10K miles. They degradate quickly, yet, performance losses are so slight as to be unnoticeable; however, I recently had my supercharged Vette's plugs (lo miles) changed and Zowie, what a rush - both figuratively and literally; I had forgotten that part since my TTA days.
3.To be cont'd.

Anyone else have any tips?; feel free to add to my list - dinner time.[^]

[PTGT Redman]

Don't forget to wash behind your ears, and don't use Q-tips
j/k [^]

[Steve03GT]

quote:Originally posted by PTGT Redman

Don't forget to wash behind your ears, and don't use Q-tips
j/k [^]

That's what I have a girlfriend for, along with some other areas.

[Kirby]

quote:Originally posted by Steve03GT

As a preface, in 1989 I purchased 1 of ~1500, 20th Anniversary Turbo Trans Am's with a Pontiac factory-modified, Buick 3.8L GN engine which stickered at ~$30K - in 1989 mind you. I had 1 of only 39 hardtops produced, since the remainder were all T-Tops, kept it for 9 years and sold it with 165,000 miles on the clock - with the original alternator. Now don't get me wrong, I don't claim to "know it all" when it comes to turbo-powered cars, but I do have some background in the matter, having both participated in both car shows and drag strip shootouts (lo 12's @ 110 mph).
OK, I'll cut to the chase now. Since I've had the GT Cruiser, my memory (most of which is gone due to the early 70's,) is reminding me of some things I learned while owning the TTA.
Maintenance:
1.Synthetic "Oil" is a must, preferably Royal Purple, though other brands will suffice. Synthetics can/will prevent turbocharger bearings from "coking" up due to it's resistance to "boiling off", thereby, forming sludge and varnish deposits, which contribute to corrosion, decreased fuel efficiency and increased engine wear - blah, blah, blah.
2.Turbo-timers, IMHO, are a waste of money for a daily driver, unless you drive like a bat out of hell and kill the engine without a cool-down period - duhhhh.
3.To be cont'd.


Performance:
1.Find a performance sparkplug (NGK,etc.)known to perform well with a Forced Induction engine.
2.If you're an aggressive driver, I recommend changing plugs <10K miles. They degradate quickly, yet, performance losses are so slight as to be unnoticeable; however, I recently had my supercharged Vette's plugs (lo miles) changed and Zowie, what a rush - both figuratively and literally; I had forgotten that part since my TTA days.
3.To be cont'd.

Anyone else have any tips?; feel free to add to my list - dinner time.[^]

As mentioned before, if you are changing plugs on an aluminum head every 10K use dielectric compound on the plug threads to protect the head.

Those new Iridium plugs are supposed to be a little tougher (made by NGK).

[Exhaust Depot]

steve, i run 15psi on my car. I live right off the highway. WHen I get on it to pass a car, I hold the peddle down for about 5 sec. As soon as I get home and open the hood, I can see the manifold cherry hot. So I do beleive a turbo timer is a good investment.

[dsm_mike]

The point of the turbo timer is so that you dont have to sit and wait in the car while it cools down, or come back to turn it off later. If you are patient enough to wait every time, then it is a waste of money, but it is pretty convienient for the rest of us.

[mich_132003]

Can someone explain the reason for the cool-down. I generally don't shut down immediately but how long does it take for full cool-down and why?

[PK Cruiser]

quote:Originally posted by mich_132003

Can someone explain the reason for the cool-down. I generally don't shut down immediately but how long does it take for full cool-down and why?

I'm no expert, but from what I've been told it is to get "cool" oil to the turbo...I’ve switch to synthetic oil and will be ordering a Turbo Timer (because I'm lazy) from exhaust depot this Friday...

[Dalite]

One thing that the idle period does is to keep all the heat that the oil is carrying from being transferred to the bearings in the turbo when the engine is shut off.

By circulating the oil while the engine is not under load, heat is allowed to dissipate as the oil is circulating.

Dino Oil (non-synthetic) has a tendacy to "re-refine" itself with age. Some brands are worse than others. Re-refinning is a term to describe the way the oil will try to thicken in valve covers, bearings, or other locations where it is allowed to cool on a metal surface before draining back into the oil pan. Heads are also a prime location to view the effects of re-refinning. In the turbo, the term used is to "coke up" in the bearings.

I wish I had a better explanaton than this. The end result is that idling for a minute or two adter a hard run should become a habit with a turbo. If you are going to trade in a few years, drive it like you stole it. If you are planning on keeping the car past the warranty period, allowing the system to cool for a few minutes before shutting the engine down possibly could help avoid some repair expense in the future

[Ian-PT-GT]

If you don't want to let the car cool down, Just think of this:

If the tubo bearings get choked with oil residue, the bearings will loose it's "roundness" and will let the impeller to vibrate. At 85,000 RPM it will be catastrofic! the impeller will touch the housing wich is a few millimiters from the blades, break, and trow shrapnell to the intercooler and the engine at high speeds, causing horrible damage to the entire turbo/engine combination from the turbo housing all the way to the Pistons, head, and valve train including the interccoler, throttle body and a lot of electronic sensors... repair cost = $$$$$$$$$$$

If the damage is to the turbo only, I am sure it will be about $2,000.00 at least. Our turbos are one piece, not like others that you can buy the impeller/bearing cartridge at about $300.00 or the housing or even the exhaust manifold.

Again, If you don't want to sit in the car for three minutes, just spend $100.00, $130.00 if going with good mounting instructions and all the goodies for a simple installation, to protect your 26,000.00 investment from possible $2,000.00 repair in the future. Even if you have changed the oil to synthetic.

Think of it as peace of mind.

Ian