Why was the 3.8 Turbo motor so good?

[RobP]

My point being, it seemed to perform way better than it should have.
If there is no replacement for displacement, why don't you see the same across the board improvement on say a TPI or LT1 motor when you install a turbo? Would a 4.3 liter V6 do better with the same turbo set up? Is it engine weight? (I'm sure the GN more than made up for the loss in engine weight with body weight). Or is it simply PFM?
Anyone's thoughts on this?

[RacerX]

Well Id assume the set up was designed for the 3.8 V6, and that has a lot to do with how any engine design works. Is it done right? Was everything thought out thuroughly??? See the picture Im painting... If you take the time to work out every detail in the end whatever you do will work properly. But in the same breath Buick did miss one thing. The 89 TTA used the FWD heads for for clearance issues of certain items, and they outflowed the original Buick design, and made more power. Now where these heads available when the engine was originally designed? I dont know... hmmmmmm now maybe someone with a more scientific answer will chime in.

[ragtop88]

Well I agree they perform great but in bone stock form I would say the power is what is expected.....what is really amazing is how they react to more boost and lots of it....remember most times the SBC kits are putting out what 6-9 psi boost.....thats not even doubling the amount of pressure (hence air) your stuffing in the engine, while the TTA came with 16.5 and many of the guys running these things hard are throwing upwards of 23 psi at them......stuff 23 psi into a SBC and it'll perform like mad as well. In general terms though, i seem to notice a general trend that smaller motors live longer on larger amounts of boost.....don't have a good explanation why that is.....or if its even completely true.

[LL6]

My $.03 (inflation)

I think you know that LT1 and TPI motors were not made with boost in mind. Typically people slap on a Vortech with no internal mods. Their compression is too high, wrong cam, weak valve springs, etc. However, when you come across a purpose built one, I think you will see similar results to the TTA and GN. Also IMO there is the advantage of the factory $$$ that designed the turbo motors in the first place. My case in point, the Porsche Turbo. Absolute living proof that you can sink millions upon millions of DMs and countless years into a lowly VW and come up with a road monster.

As far as smaller motors living longer, I think my comments above apply; because they were built with boost in mind. Combine this with less reciprocating mass due to fewer cylinders and smaller components, means more reliability.

[Jeremey]

Lets not forget that all GN's are not fast. I have seen a few of the older carbed ones that were pure dogs. The best thing that happened to the turbo buicks was fuel injection.

[ragtop88]

I agree the fuel injection AND the intercooler....the hotair versions as they are referred to aren't the fastest one. Although i agree that a purpose built motor will last longer the only thing about a 3.8 turbo motor that makes it a turbo motor.....is the turbo. cast pistons, cast crank, production line forged rods (but nearly all connecting rods are forged, I say nearly because I'm sure someone will tell me that Opel or someone made some kind of cast rod for a half a year back in 1968) THe cam is turbo specific but other than that, it seems to be fairly bullet proof without being bulletproofed. Although i think with enough abuse, any motor will DIE, DIE, DIE!!!

[Jaysz28]

Its so good because it is something I will never own... :(

[RobP]

I've just been reading an article over on thirdgen about a guy who just put twin turbo's on a SBC, mongo expensive parts. The thing dyno'd at over 1000hp etc. Everyone expects this engine to run 9's or 8's in his 80ish (can't remember what year) Vette. Then they chimed in about the Turbo Supras. Those inline 6's are also pretty stout. But a highly modified V6 Grand National will run the same 9's or 8's that this 350cubic inch SBC will.
And the orignial 3.8 Litre motor was not built with turbocharging in mind. It was the general service motor for much of the GM line of the time. I had a 3.8 buick motor in my 82 Bonneville.
The 3.8 just seems to be a freak of nature.

[ July 03, 2002, 20:59: Message edited by: RobP ]

[starbuck]

Originally posted by RobP:
Would a 4.3 liter V6 do better with the same turbo set up?Ask the SyTy guys ;)

[RobP]

Is that what those guys are moving too Will? I guess useable cores are plentiful and prices may be cheaper.

[86IROC]

I'm going to toss in my .02, yes the Buick TR's and TTA's are fast little V6 powered cars. My parents have owned a few GN's and they were very good cars. But, here's my beef w/ the design on the 3.8L Buick V6 - not enough head bolts! I believe they only have 12 or 14 of them. As the boost gets higher, the risk of blowing head gaskets is greater. The SBC has 17 head bolts total, and they are very well placed. The same problem plagues the SBF 302's. EVERY engine design has an achillies heel so to speak, the inadequate clamping force of the head bolts is a weak point.

This is not to say that any motor pushed beyond it's limits wouldn't break. When it comes to all out TT SBC's, Bob Reiger ran 6.60's or 6.70's in a 380ci TT SBC powered S10 X-cab. His 57' Chevy Bel Air is powered by a similar motor as well and I watched it run 210+ MPH trap speeds at the last World's Fastest Street Car Shootout. I have heard of a Stage 2 block Dutwieler car running a few high 6 passes at 60psi on alcohol, but it didn't last long. Tom from Champion Cylinder Head Service told me that when the motor broke, it Quote: "Blew one of our new aluminum heads 10 feet in the air."

Reguardless of how much technology improves... I am firm believer in there being no replacement for displacement.

[ July 04, 2002, 09:03: Message edited by: 86IROC ]

[GMC-YA]

Is that what those guys are moving too Will? I guess useable cores are plentiful and prices may be cheaper.Nothing will interchange between the two. Turbo's suck that is why Tom is selling me the TTA!! V8's rule!! Seriously though, turbo's are great but they are hard on motors too, especially if they are ran out of tune. I dont think anything will blow faster than a lean running turbo motor. So rob sounds like steve's idea got you interesed in turbos, you thinking about a turbo 4.3 also??

[RobP]

I just sometimes think of and ponder these things. The board has been kinda dead lately and thought this discussion might liven it up.
My buddy, Bob Cosby (He writes articles for the ford magazines, and gets paid for it) got a twin turbo system for his 90's 5.0 LX from INCON for free to test. The thing was an absolute beast! He got into the extreme high 9's in the quarter with this set up. He also drove the car to work everyday, 30 plus miles from Va Beach to Norfolk Naval Base. However he was working on the car late one night and forgot to hook the vacuum lines back up on the waste gates. He told me he took it for a test spin on the old 44 in Va Beach. Got on the on ramp and hit it. He said it pulled like it never has before, right up until the head gasket blew and he killed the motor. He guessed he was running about 25psi before it died. So there are dangers of running boost I guess.
It just seems from what I'm reading on many different boards, Turbocharging is the new fad.

[WS6 VERT]

I'm reading on many different boards, Turbocharging is the new fad.
Thats because you can get the same amount of boost if not more than a supercharger, without the parasitic HP drain it takes to turn a supercharger.

[RobP]

But Superchargers sound cool! Turbos' sound like Mack trucks on the down hill run! graemlins/lol.gif

[GMC-YA]

There is nothing sweeter than the sound of a turbo sucking in air, the bigger turbo the better the sound!!!! Blow off valves sound sweet too.

[Jeremey]

I totally agree with Brian on the head bolt issue. I have a buddy with a pretty much stock GN that on 15 psi blows head gaskets like a $2 hooker. Another buddy had to have his heads and block o-ringed to achieve 25 psi in his T-Type. I always argue with some of my other buddies who think Fords huge(compared to a sbc) head bolts are better than our small but many ones. There is strength in numbers!